WO2016015447A1 - 一种传输设备和数据帧的传输方法 - Google Patents

一种传输设备和数据帧的传输方法 Download PDF

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Publication number
WO2016015447A1
WO2016015447A1 PCT/CN2014/096007 CN2014096007W WO2016015447A1 WO 2016015447 A1 WO2016015447 A1 WO 2016015447A1 CN 2014096007 W CN2014096007 W CN 2014096007W WO 2016015447 A1 WO2016015447 A1 WO 2016015447A1
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Prior art keywords
ltf
parameter
sequence
type
indication information
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PCT/CN2014/096007
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English (en)
French (fr)
Inventor
刘乐
蓝洲
罗毅
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华为技术有限公司
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Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to EP18205190.4A priority Critical patent/EP3496507B1/en
Priority to EP23196444.6A priority patent/EP4311177A3/en
Priority to JP2017505083A priority patent/JP6454779B2/ja
Priority to CN201480080894.8A priority patent/CN106576385B/zh
Priority to KR1020177004742A priority patent/KR101995941B1/ko
Priority to EP14898532.8A priority patent/EP3163970B1/en
Priority to EP22157867.7A priority patent/EP4061091B1/en
Publication of WO2016015447A1 publication Critical patent/WO2016015447A1/zh
Priority to US15/418,462 priority patent/US10341067B2/en
Priority to US16/412,117 priority patent/US10855415B2/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2602—Signal structure
    • H04L27/26035—Maintenance of orthogonality, e.g. for signals exchanged between cells or users, or by using covering codes or sequences
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69—Spread spectrum techniques
    • H04B1/707—Spread spectrum techniques using direct sequence modulation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/0413—MIMO systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202—Channel estimation
    • H04L25/0204—Channel estimation of multiple channels
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
    • H04L25/03891—Spatial equalizers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2602—Signal structure
    • H04L27/2603—Signal structure ensuring backward compatibility with legacy system
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2602—Signal structure
    • H04L27/261—Details of reference signals
    • H04L27/2613—Structure of the reference signals
    • H04L27/26134—Pilot insertion in the transmitter chain, e.g. pilot overlapping with data, insertion in time or frequency domain
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2626—Arrangements specific to the transmitter only
    • H04L27/2627—Modulators
    • H04L27/2628—Inverse Fourier transform modulators, e.g. inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2626—Arrangements specific to the transmitter only
    • H04L27/2627—Modulators
    • H04L27/2634—Inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators in combination with other circuits for modulation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2647—Arrangements specific to the receiver only
    • H04L27/2655—Synchronisation arrangements
    • H04L27/2689—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation
    • H04L27/2695—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation with channel estimation, e.g. determination of delay spread, derivative or peak tracking
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/0001—Arrangements for dividing the transmission path
    • H04L5/0014—Three-dimensional division
    • H04L5/0023—Time-frequency-space
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W84/00—Network topologies
    • H04W84/02—Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
    • H04W84/10—Small scale networks; Flat hierarchical networks
    • H04W84/12—WLAN [Wireless Local Area Networks]

Definitions

  • the present invention relates to the field of communications, and in particular, to a transmission device and a data frame transmission method.
  • WLAN has undergone great evolution in this respect. It has evolved from the original 802.11a/b to 802.11g, 802.11n, and then to 802.11ac. As the standard evolves, the throughput that the system can provide. Increasingly, to meet the various needs of users online.
  • the 802.11ac indicates that the Very High Throughput-Long Training Field (VHT-LTF) is included in the structure of the Presentation Protocol Data Unit (PPDU).
  • VHT-LTF Very High Throughput-Long Training Field
  • PPDU Presentation Protocol Data Unit
  • CDM Domain Code Code Multiplexing
  • SU-MIMO single user-multiple input multiple output
  • MU-MIMO Multiple User-Multiple Input Multiple Output
  • the 802.11ac standard in the prior art is designed or acquired for an indoor environment.
  • OFDM Orthogonal Frequency Division Multiplexing
  • CP Cyclic Prefix
  • the invention provides a transmission device and a data frame transmission method, which saves signaling overhead and reduces the delay of data portion reception.
  • a first aspect of the present invention provides a transmission device for a wireless local area network system employing a multiple input multiple output MIMO technology, the transmission device comprising:
  • An acquiring unit configured to obtain a long training code part LTF parameter, and obtain an allocated subcarrier starting position I, where the LTF parameter includes: a frequency domain transform parameter and a time domain transform parameter required to generate an LTF sequence;
  • a frequency domain transform unit configured to perform frequency domain transform on the LTF basic sequence to obtain an LTF symbol according to the frequency domain transform parameter and the start position I acquired by the acquiring unit;
  • a time domain transforming unit configured to perform time domain transform on the LTF symbol obtained by the frequency domain transform unit to obtain the LTF sequence according to the time domain transform parameter acquired by the acquiring unit;
  • a sending unit configured to carry the LTF sequence obtained by the time domain transform unit in a first data frame, to send to a second device, so that the second device determines the LTF basic sequence according to the LTF sequence, and Channel estimation is performed according to the LTF basic sequence.
  • the frequency domain transform parameter includes: a number M of subcarriers used to distinguish the spatial stream, an element number L of the LTF basic sequence, and a number of subcarriers S ;
  • the frequency domain transform unit includes:
  • mapping module for starting from the starting position I, every a subcarrier, mapping each element in the LTF base sequence to a corresponding subcarrier to obtain a frequency domain LTF sequence; Indicates rounding down;
  • An inverse transform module configured to perform an inverse fast Fourier transform (IFFT) of the S-point of the frequency domain LTF sequence obtained by the mapping module to obtain an LTF basic symbol;
  • IFFT inverse fast Fourier transform
  • a generating module configured to combine the LTF basic symbol obtained by the inverse transform module and a cyclic prefix CP to generate the LTF symbol.
  • the frequency domain transform parameter includes: a number M of subcarriers used to distinguish the spatial stream, and an element of the LTF basic sequence. Number L and number of subcarriers S;
  • the frequency domain transform unit includes:
  • a spreading module configured to perform a spreading process on each element in the LTF basic sequence according to the M, to obtain an LTF spreading sequence;
  • the LTF spreading sequence includes M*L elements;
  • mapping module configured to map, from the starting position I, each element in the LTF spreading sequence obtained by the spreading module to a corresponding subcarrier to obtain a frequency domain LTF sequence
  • An inverse transform module configured to perform an IFFT transform of the frequency domain LTF sequence obtained by the mapping module to obtain an LTF basic symbol
  • a generating module configured to combine the LTF basic symbol obtained by the inverse transform module and the CP to generate the LTF symbol.
  • the time domain transform parameter includes: the number N of the LTF symbols included in the LTF sequence;
  • the time domain transforming unit is specifically configured to perform spreading processing on the LTF symbol according to the N to generate the LTF sequence.
  • the transmitting device is a station STA, and the second device is an access point AP;
  • the obtaining unit includes:
  • a receiving module configured to receive a second data frame that carries the indication information that is sent by the second device, where the indication information is used to indicate the LTF parameter;
  • an obtaining module configured to acquire the LTF parameter according to the indication information obtained by the receiving module and a pre-configured mapping relationship table.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the N a parameter corresponding to the type of the SS and the AP;
  • the acquiring module is specifically configured to use the N SS and the AP according to the a type, the parameter corresponding to the N SS and the type of the AP is used as the LTF parameter;
  • the acquiring module is specifically configured to be used according to the S determining the type of the AP; wherein there is a corresponding relationship between the AP and the S type; according to the type of the AP and N SS, as the parameter corresponding to the type of the AP and N SS
  • the acquiring module is specifically configured to determine the S according to the length of the CP, and determines the type of the AP based on the S; N SS according to the type of the AP and the parameters corresponding to the type of the N SS and the AP as a parameter the LTF.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the environment type of the AP, and a parameter corresponding to an environment type in which the N SS and the AP are located;
  • the indication information includes the N SS , and the transmission device acquires an environment type in which the AP is located when accessing the AP ;
  • the obtaining module according to the environment and the type of the N SS AP is located, the type of environment and parameters of the N SS corresponding to the AP and the LTF located as parameter.
  • the mapping relationship table includes a number of multiplexed spatial streams N SS and parameters corresponding to the N SS ;
  • the acquiring module is specifically configured to determine, according to the N SS , a parameter corresponding to the N SS as the LTF parameter;
  • the acquiring module is specifically configured to determine the number of subcarriers S according to the length of the CP; and determine according to the N and the S The N SS , and determining a parameter corresponding to the N SS as the LTF parameter according to the N SS .
  • the mapping relationship table includes the number of multiplexed spatial streams N SS , modulation and coding policy MCS characteristic information, and Determining, by the N SS , a parameter corresponding to the MCS characteristic information; the indication information includes the N SS and the MCS characteristic information;
  • the acquiring module is specifically configured to use, as the LTF parameter, a parameter corresponding to the N SS and the MCS characteristic information according to the N SS and the MCS characteristic information.
  • the transmission device is an AP, and the second device is an STA; or the transmission device is an STA, and the second device is an AP;
  • the obtaining unit includes: an obtaining module, configured to acquire the LTF parameter according to a pre-configured mapping relationship table;
  • the sending unit is configured to: carry the LTF sequence and the indication information in the first data frame, and send the information to the second device, so that the second device determines, according to the LTF sequence and the indication information, The LTF base sequence.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the N SS corresponding to the type of the AP and a parameter; and when the transmission device is a STA, the transmission device has been acquired when the type of the AP to access the AP;
  • the obtaining module according to the type of the AP and N SS, corresponding to the type of the N SS and the AP as a parameter the LTF parameter;
  • the transmission device is the STA
  • the second device is the AP
  • the indication information includes the N SS ;
  • the indication information includes the N SS ; or the indication information includes the N SS and the number of subcarriers S.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the environment in which the AP is located, and a parameter corresponding to an environment type in which the N SS and the AP are located; and when the transmission device is an STA, the transmission device acquires an environment type in which the AP is located when accessing the AP;
  • the obtaining module according to the type of environment parameters for the N SS and the AP is located, to the N SS and the AP corresponding to the type of the environment parameter as the LTF;
  • the indication information includes the N SS .
  • the mapping relationship table includes a number of multiplexed spatial streams N SS and parameters corresponding to the N SS ;
  • the obtaining module is specifically configured to determine, according to the N SS , a parameter corresponding to the N SS as the LTF parameter;
  • the indication information includes the N SS ; or the indication information includes the number N of the LTF symbols included in the LTF sequence.
  • the mapping relationship table includes the number of multiplexed spatial streams, N SS , MCS characteristic information, and the N SS and a parameter corresponding to the MCS characteristic information;
  • the acquiring module is specifically configured to use, as the LTF parameter, a parameter corresponding to the N SS and the MCS characteristic information according to the N SS and the MCS characteristic information;
  • the indication information includes the N SS and the MCS characteristic information.
  • the number of the multiplexed spatial streams includes: the number of users multiplexed by multiple users and/or the number of data streams multiplexed by a single user.
  • a transmission device for a wireless local area network system employing multiple input multiple output MIMO technology, including:
  • a receiving unit configured to receive a first data frame that is sent by the first device and carries a long training code part LTF sequence
  • a processing unit configured to determine an LTF basic sequence according to the received LTF sequence received by the receiving unit, and perform channel estimation according to the LTF basic sequence.
  • the method further includes:
  • An acquiring unit configured to acquire an LTF parameter and obtain an allocated subcarrier starting position I before the processing unit determines the LTF basic sequence according to the LTF sequence, where the LTF parameter includes: the first device generates Frequency domain transform parameters and time domain transform parameters required by the LTF sequence;
  • the processing unit includes:
  • a time domain inverse transform subunit configured to obtain the LTF symbol by performing inverse time domain transform on the LTF sequence according to the time domain transform parameter obtained by the acquiring unit;
  • a frequency domain inverse transform subunit configured to perform frequency domain inverse on the LTF symbol obtained by the time domain inverse transform subunit according to the obtaining, by the acquiring unit, the frequency domain transform parameter and the starting position I Transforming to obtain the LTF base sequence.
  • the time domain transform parameter includes: the number N of the LTF symbols included in the LTF sequence;
  • the time domain inverse transform subunit is specifically configured to perform despreading processing on the LTF sequence according to the N to obtain the LTF symbol.
  • the frequency domain transform parameter includes: a number M of subcarriers used to distinguish the spatial stream, and an element of the LTF basic sequence Number L and number of subcarriers S;
  • the frequency domain inverse transform subunit includes:
  • a determining module configured to determine an LTF basic symbol according to the LTF symbol; wherein the LTF symbol is composed of the LTF basic symbol and a cyclic prefix CP;
  • a transform module configured to perform fast Fourier transform FFT transform of the LTF basic symbol obtained by the determining module to obtain a frequency domain LTF sequence
  • An extracting module configured to start from the starting position I, according to the frequency domain LTF sequence obtained by the transform module Subcarriers extract the LTF base sequence; Indicates rounding down.
  • the frequency domain transform parameter includes: a number M of subcarriers used to distinguish the spatial stream, and an element of the LTF basic sequence Number L and number of subcarriers S;
  • the frequency domain inverse transform subunit includes:
  • a determining module configured to determine an LTF basic symbol according to the LTF symbol; wherein the LTF symbol is composed of the LTF basic symbol and a CP;
  • a transform module configured to perform an FFT transform of the LTF basic symbol obtained by the determining module to obtain a frequency domain LTF sequence
  • an extracting module configured to extract, according to the frequency domain LTF sequence obtained by the transform module, an LTF spreading sequence from the corresponding subcarrier from the starting position I; wherein the LTF spreading sequence includes M*L elements;
  • a despreading module configured to perform despreading processing on the LTF spreading sequence obtained by the extracting module according to the M to obtain the LTF basic sequence.
  • the first device is a site STA, and the transmission device is an access point AP;
  • the acquiring unit is further configured to: before the receiving unit receives the first data frame that carries the long training code part LTF sequence sent by the first device, acquire the LTF parameter according to the pre-configured mapping relationship table;
  • the transmission device further includes:
  • a sending unit configured to send, to the first device, a second data frame that carries indication information, where the indication information indicates the LTF parameter.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the N a parameter corresponding to the type of the SS and the AP;
  • the obtaining unit is specifically configured according to the type of the AP and N SS, corresponding to the type of the N SS and the AP as a parameter the LTF parameter;
  • the indication information includes the N SS ; or the indication information includes the N SS and the number of subcarriers S.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the environment in which the AP is located, and a parameter corresponding to the environment type of the N SS and the AP;
  • the obtaining unit is specifically configured according to the type of environment parameters of the N SS and the AP is located, to the N SS and the AP corresponding to the type of the environment parameter as the LTF;
  • the indication information includes the N SS .
  • the mapping relationship table includes the number of multiplexed spatial streams N SS and parameters corresponding to the N SS ;
  • the obtaining unit is specifically configured to determine, according to the N SS , a parameter corresponding to the N SS as the LTF parameter;
  • the indication information includes the N SS ; or the indication information includes the number N of the LTF symbols included in the LTF sequence.
  • the mapping relationship table includes the number of multiplexed spatial streams, N SS , MCS characteristic information, and the N SS and a parameter corresponding to the MCS characteristic information;
  • the acquiring unit is specifically configured to use, as the LTF parameter, a parameter corresponding to the N SS and the MCS characteristic information according to the N SS and the MCS characteristic information;
  • the indication information includes the N SS and the MCS characteristic information.
  • the first device is an AP, and the transmission device is an STA; or
  • the first device is a STA, and the transmission device is an AP;
  • the receiving unit is configured to receive, by the first device, the first data frame that carries the LTF sequence and the indication information;
  • the acquiring unit is specifically configured to acquire the LTF parameter according to the indication information received by the receiving unit and a pre-configured mapping relationship table.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the N a parameter corresponding to the type of the SS and the AP;
  • the transmission device is the AP
  • the indication information includes the N SS
  • the acquiring unit is specifically configured to: according to the type of the N SS and the AP, A parameter corresponding to the type of the N SS and the AP is used as the LTF parameter;
  • the transmission device is the STA
  • the acquiring unit is specifically configured to use the N SS and the AP according to the a type, the parameter corresponding to the N SS and the type of the AP is used as the LTF parameter;
  • the acquiring unit is specifically configured to be used according to the S determining the type of the AP; wherein there is a corresponding relationship between the AP and the S type; according to the type of the AP and N SS, as the parameter corresponding to the type of the AP and N SS
  • the acquiring unit is specifically configured to determine the S according to the length of the CP, and determines the type of the AP based on the S; N SS according to the type of the AP and the parameters corresponding to the type of the N SS and the AP as a parameter the LTF.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the environment in which the AP is located, and a parameter corresponding to an environment type in which the N SS and the AP are located;
  • the indication information includes the N SS , and when the transmission device is the STA, when the transmission device accesses the AP The type of environment in which the AP is located has been obtained;
  • the obtaining unit is configured according to the environment and the type of the N SS AP is located, the type of environment and parameters of the N SS corresponding to the AP and the LTF located as parameter.
  • the mapping relationship table includes the number of multiplexed spatial streams N SS and parameters corresponding to the N SS ;
  • the obtaining unit is specifically configured according to the N SS, with the parameters corresponding to the N SS LTF as said parameter;
  • the acquiring unit is specifically configured to determine the number of subcarriers S according to the length of the CP; and determine according to the N and the S The N SS , and determining a parameter corresponding to the N SS as the LTF parameter according to the N SS .
  • the mapping relationship table includes the number of multiplexed spatial streams N SS , modulation and coding policy MCS characteristic information, and Determining, by the N SS , a parameter corresponding to the MCS characteristic information; the indication information includes the N SS and the MCS characteristic information;
  • the acquiring unit is specifically configured to use, as the LTF parameter, a parameter corresponding to the N SS and the MCS characteristic information according to the N SS and the MCS characteristic information.
  • the number of the multiplexed spatial streams includes: the number of users multiplexed by multiple users and/or the number of data streams multiplexed by a single user.
  • a third aspect of the present invention provides a data frame transmission method for a wireless local area network system employing multiple input multiple output MIMO technology, the method comprising:
  • the first device obtains the long training code part LTF parameter, and obtains the allocated subcarrier starting position I; wherein the LTF parameter includes: a frequency domain transform parameter and a time domain transform parameter required to generate the LTF sequence;
  • the second device determines the LTF basic sequence according to the LTF sequence, and performs channel estimation according to the LTF basic sequence.
  • the frequency domain transform parameter includes: a number M of subcarriers used to distinguish the spatial stream, an element number L of the LTF basic sequence, and a number of subcarriers S ;
  • every a subcarrier mapping each element in the LTF base sequence to a corresponding subcarrier to obtain a frequency domain LTF sequence; Indicates rounding down;
  • the frequency domain transform parameter includes: a number M of subcarriers used to distinguish the spatial stream, and an element of the LTF basic sequence Number L and number of subcarriers S;
  • the LTF spreading sequence includes M*L elements
  • the time domain transform parameter includes: the number N of the LTF symbols included in the LTF sequence;
  • Performing a time domain transform on the LTF symbol according to the time domain transform parameter to obtain the LTF sequence including:
  • the LTF symbol is subjected to a spreading process according to the N to generate the LTF sequence.
  • the first device is a site STA, and the second device is an access point AP;
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the N a parameter corresponding to the type of the SS and the AP;
  • the indication information includes the N SS , and the type of the AP has been acquired by the first device when accessing the AP, the acquiring information according to the indication information and a pre-configured mapping relationship table
  • the LTF parameters including:
  • the mapping relationship table obtains the LTF parameters, including:
  • the indication information includes the N SS
  • the first device does not acquire the type of the AP when accessing the AP
  • the acquiring information according to the indication information and a pre-configured mapping relationship table
  • the LTF parameters including:
  • a parameter corresponding to the type of the N SS and the AP is used as the LTF parameter.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the environment in which the AP is located, and a parameter corresponding to the environment type of the N SS and the AP;
  • the indication information includes the N SS , and the first device acquires an environment in which the AP is located when accessing the AP Types of;
  • the acquiring the LTF parameters according to the indication information and the pre-configured mapping relationship table includes:
  • a parameter corresponding to the N SS and an environment type in which the AP is located is used as the LTF parameter according to the N SS and an environment type in which the AP is located.
  • the mapping relationship table includes the number of multiplexed spatial streams N SS and parameters corresponding to the N SS ;
  • the acquiring the LTF parameter according to the indication information and a pre-configured mapping relationship table includes:
  • the acquiring the LTF parameters according to the indication information and the pre-configured mapping relationship table includes:
  • the mapping relationship table includes the number of multiplexed spatial streams N SS , modulation and coding policy MCS characteristic information, and Determining, by the N SS , a parameter corresponding to the MCS characteristic information; the indication information includes the N SS and the MCS characteristic information;
  • the acquiring the LTF parameters according to the indication information and the pre-configured mapping relationship table includes:
  • the first device is an AP, and the second device is an STA; or
  • the first device is an STA, and the second device is an AP;
  • Transmitting the LTF sequence to the second device in the first data frame including:
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the N SS corresponding to the type of the AP and a parameter; and when the first device is a STA, the first AP of the device has been acquired when the access type of the AP;
  • the acquiring the LTF parameters according to the pre-configured mapping relationship table includes:
  • the indication information includes the N SS ;
  • the indication information includes the N SS ; or the indication information includes the N SS and the number of subcarriers S.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the environment in which the AP is located, and a parameter corresponding to an environment type of the N SS and the AP; and when the first device is an STA, the first device acquires an environment in which the AP is located when accessing the AP Types of;
  • the acquiring the LTF parameters according to the pre-configured mapping relationship forwarding table includes:
  • the indication information includes the N SS .
  • the mapping relationship table includes the number of multiplexed spatial streams N SS and parameters corresponding to the N SS ;
  • the acquiring the LTF parameters according to the pre-configured mapping relationship forwarding table includes:
  • the indication information includes the N SS ; or the indication information includes the number N of the LTF symbols included in the LTF sequence.
  • the mapping relationship table includes the number of multiplexed spatial streams, N SS , MCS characteristic information, and the N SS and a parameter corresponding to the MCS characteristic information;
  • the acquiring the LTF parameters according to the pre-configured mapping relationship forwarding table includes:
  • the indication information includes the N SS and the MCS characteristic information.
  • the number of the multiplexed spatial streams includes: the number of users multiplexed by multiple users and/or the number of data streams multiplexed by a single user.
  • a fourth aspect of the present invention provides a data frame transmission method, which is applied to a wireless local area network system using multiple input multiple output MIMO technology, including:
  • the second device receives the first data frame that is sent by the first device and carries the LTF sequence of the long training code part;
  • An LTF basic sequence is determined according to the LTF sequence, and channel estimation is performed according to the LTF basic sequence.
  • the method before the determining the LTF basic sequence according to the LTF sequence, the method further includes:
  • the LTF parameter includes: a frequency domain transform parameter and a time domain transform parameter required by the first device to generate the LTF sequence;
  • LTF sequence including:
  • the time domain transform parameter includes: the number N of the LTF symbols included in the LTF sequence;
  • Performing a time domain inverse transform on the LTF sequence according to the time domain transform parameter to obtain an LTF symbol including:
  • the frequency domain transform parameter includes: a number M of subcarriers used to distinguish the spatial stream, and an element of the LTF basic sequence Number L and number of subcarriers S;
  • LTF symbol Determining an LTF basic symbol according to the LTF symbol; wherein the LTF symbol is composed of the LTF basic symbol and a cyclic prefix CP;
  • every Subcarriers extract the LTF base sequence; Indicates rounding down.
  • the frequency domain transform parameter includes: a number M of subcarriers used to distinguish the spatial stream, and an element of the LTF basic sequence Number L and number of subcarriers S;
  • the frequency domain inverse transform is performed to obtain the LTF basic sequence, including:
  • LTF symbol Determining an LTF basic symbol according to the LTF symbol; wherein the LTF symbol is composed of the LTF basic symbol and a CP;
  • the first device is a station STA, and the second device is an access point AP;
  • the method Before the receiving, by the first device, the first data frame that carries the long training code part LTF sequence, the method further includes:
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the N a parameter corresponding to the type of the SS and the AP;
  • the acquiring the LTF parameters according to the pre-configured mapping relationship table includes:
  • the indication information includes the N SS ; or the indication information includes the N SS and the number of subcarriers S.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the environment in which the AP is located, and a parameter corresponding to the environment type of the N SS and the AP;
  • the acquiring the LTF parameters according to the pre-configured mapping relationship forwarding table includes:
  • the indication information includes the N SS .
  • the mapping relationship table includes a number of multiplexed spatial streams N SS and a parameter corresponding to the N SS ;
  • the acquiring the LTF parameters according to the pre-configured mapping relationship forwarding table includes:
  • the indication information includes the N SS ; or the indication information includes the number N of the LTF symbols included in the LTF sequence.
  • the mapping relationship table includes the number of multiplexed spatial streams, N SS , MCS characteristic information, and the N SS and a parameter corresponding to the MCS characteristic information;
  • the acquiring the LTF parameters according to the pre-configured mapping relationship forwarding table includes:
  • the indication information includes the N SS and the MCS characteristic information.
  • the first device is an AP, and the second device is an STA; or
  • the first device is an STA, and the second device is an AP;
  • the obtaining the LTF parameters includes:
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the N a parameter corresponding to the type of the SS and the AP;
  • the indication information includes the N SS ; and the acquiring the LTF parameter according to the indication information and a pre-configured mapping relationship table ,include:
  • the second device is the STA
  • the second device acquires the type of the AP when accessing the AP, the acquiring information according to the indication information and a pre-configured mapping relationship table
  • the LTF parameters including:
  • the mapping relationship table obtains the LTF parameters, including:
  • the indication information includes the N SS
  • the second device does not acquire the type of the AP when accessing the AP
  • the acquiring information according to the indication information and a pre-configured mapping relationship table
  • the LTF parameters including:
  • a parameter corresponding to the type of the N SS and the AP is used as the LTF parameter.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the environment in which the AP is located, and a parameter corresponding to an environment type in which the N SS and the AP are located;
  • the indication information includes the N SS , and when the second device is the STA, the second device is accessing the The AP has obtained the type of environment in which the AP is located;
  • the acquiring the LTF parameters according to the indication information and the pre-configured mapping relationship table includes:
  • a parameter corresponding to the N SS and an environment type in which the AP is located is used as the LTF parameter according to the N SS and an environment type in which the AP is located.
  • the mapping relationship table includes a number of multiplexed spatial streams N SS and a parameter corresponding to the N SS ;
  • the acquiring the LTF parameter according to the indication information and a pre-configured mapping relationship table includes:
  • the acquiring the LTF parameters according to the indication information and the pre-configured mapping relationship table includes:
  • the mapping relationship table includes the number of multiplexed spatial streams N SS , modulation and coding policy MCS characteristic information, and Determining, by the N SS , a parameter corresponding to the MCS characteristic information; the indication information includes the N SS and the MCS characteristic information;
  • the acquiring the LTF parameters according to the indication information and the pre-configured mapping relationship table includes:
  • the number of the multiplexed spatial streams includes: number of users multiplexed by multiple users and/or single use The number of data streams multiplexed by the user.
  • a transmission device for use in a wireless local area network system employing multiple input multiple output MIMO technology, the transmission device comprising:
  • a processor configured to obtain a long training code portion LTF parameter, and obtain an allocated subcarrier starting position I; wherein the LTF parameter includes: a frequency domain transform parameter and a time domain transform parameter required to generate an LTF sequence; Decoding the frequency domain transform parameter and the starting position I, performing frequency domain transform on the LTF basic sequence to obtain an LTF symbol; performing time domain transform on the LTF symbol according to the time domain transform parameter to obtain the LTF sequence;
  • a transmitter configured to carry the LTF sequence obtained by the processor to a second device in a first data frame, so that the second device determines the LTF basic sequence according to the LTF sequence, and according to the The LTF basic sequence is used for channel estimation.
  • the frequency domain transform parameter includes: a number M of subcarriers used to distinguish the spatial stream, an element number L of the LTF basic sequence, and a number of subcarriers S ;
  • the processor is specifically configured to:
  • every a subcarrier mapping each element in the LTF base sequence to a corresponding subcarrier to obtain a frequency domain LTF sequence; Indicates rounding down;
  • the frequency domain transform parameter includes: a number M of subcarriers used to distinguish the spatial stream, and an element of the LTF basic sequence Number L and number of subcarriers S;
  • the processor is specifically configured to:
  • the LTF spreading sequence includes M*L elements
  • the time domain transform parameter includes: the number N of the LTF symbols included in the LTF sequence;
  • the processor is specifically configured to perform spreading processing on the LTF symbol according to the N to generate the LTF sequence.
  • the transmitting device is a station STA, and the second device is an access point AP;
  • the transmission device further includes:
  • a receiver configured to receive a second data frame that carries the indication information that is sent by the second device, where the indication information is used to indicate the LTF parameter;
  • the processor is specifically configured to acquire the LTF parameter according to the indication information and a pre-configured mapping relationship table.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the N a parameter corresponding to the type of the SS and the AP;
  • the processor is specifically configured to use the N SS and the AP according to the a type, the parameter corresponding to the N SS and the type of the AP is used as the LTF parameter;
  • the processor is specifically configured to be used according to the S determining the type of the AP; wherein there is a corresponding relationship between the AP and the S type; according to the type of the AP and N SS, as the parameter corresponding to the type of the AP and N SS
  • the processor is specifically configured to determine the S according to a length of the CP, And determining, according to the S, a type of the AP; and using, according to the N SS and the type of the AP, a parameter corresponding to the type of the N SS and the AP as the LTF parameter.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the environment in which the AP is located, and a parameter corresponding to an environment type in which the N SS and the AP are located;
  • the indication information includes the N SS , and the transmission device acquires an environment type in which the AP is located when accessing the AP ;
  • the processor according to the specific environment and the type of the N SS AP is located, the type of environment and parameters of the N SS corresponding to the AP and the LTF located as parameter.
  • the mapping relationship table includes the number of multiplexed spatial streams N SS and parameters corresponding to the N SS ;
  • the processor is specifically configured to determine, according to the N SS , a parameter corresponding to the N SS as the LTF parameter;
  • the processor is specifically configured to determine, according to the length of the CP, the number of subcarriers S; determine according to the N and the S The N SS , and determining a parameter corresponding to the N SS as the LTF parameter according to the N SS .
  • the mapping relationship table includes the number of multiplexed spatial streams N SS , modulation and coding policy MCS characteristic information, and Determining, by the N SS , a parameter corresponding to the MCS characteristic information; the indication information includes the N SS and the MCS characteristic information;
  • the processor is specifically configured to use, as the LTF parameter, a parameter corresponding to the N SS and the MCS characteristic information according to the N SS and the MCS characteristic information.
  • the transmission device is an AP, and the second device is an STA; or the transmission device is an STA, and the second device is an AP;
  • the processor is specifically configured to acquire the LTF parameter according to a pre-configured mapping relationship table
  • the transmitter is specifically configured to carry the LTF sequence and the indication information in the first data frame and send the information to the second device, so that the second device determines, according to the LTF sequence and the indication information, The LTF base sequence.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the N SS corresponding to the type of the AP and a parameter; and when the transmission device is a STA, the transmission device has been acquired when the type of the AP to access the AP;
  • the processor according to the specific type of the N SS and the AP, corresponding to the type of the N SS and the AP as a parameter the LTF parameter;
  • the transmission device is the STA
  • the second device is the AP
  • the indication information includes the N SS ;
  • the indication information includes the N SS ; or the indication information includes the N SS and the number of subcarriers S.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the environment in which the AP is located, and a parameter corresponding to an environment type in which the N SS and the AP are located; and when the transmission device is an STA, the transmission device acquires an environment type in which the AP is located when accessing the AP;
  • the processor according to the specific environment and the type of the N SS AP is located, corresponding to the environment and the type of the N SS as a parameter AP which the LTF parameter;
  • the indication information includes the N SS .
  • the mapping relationship table includes the number of multiplexed spatial streams N SS and parameters corresponding to the N SS ;
  • the processor is specifically configured to determine, according to the N SS , a parameter corresponding to the N SS as the LTF parameter;
  • the indication information includes the N SS ; or the indication information includes the number N of the LTF symbols included in the LTF sequence.
  • the mapping relationship table includes the number of multiplexed spatial streams, N SS , MCS characteristic information, and the N SS and a parameter corresponding to the MCS characteristic information;
  • the processor is specifically configured to use, as the LTF parameter, a parameter corresponding to the N SS and the MCS characteristic information according to the N SS and the MCS characteristic information;
  • the indication information includes the N SS and the MCS characteristic information.
  • the number of the multiplexed spatial streams includes: the number of users multiplexed by multiple users and/or the number of data streams multiplexed by a single user.
  • a transmission device for a wireless local area network system using multiple input multiple output MIMO technology, including:
  • a receiver configured to receive a first data frame that is sent by the first device and carries a long training code portion LTF sequence
  • a processor configured to determine an LTF basic sequence according to the received LTF sequence by the receiver, and perform channel estimation according to the LTF basic sequence.
  • the processor is further configured to: before the determining the LTF basic sequence according to the LTF sequence, acquiring an LTF parameter, and acquiring an allocated subcarrier starting position I; wherein the LTF parameter comprises: the first device Generating frequency domain transform parameters and time domain transform parameters required for the LTF sequence;
  • the processor is specifically configured to:
  • the time domain transform parameter includes: the number N of the LTF symbols included in the LTF sequence;
  • the processor is specifically configured to perform despreading processing on the LTF sequence according to the N to obtain the LTF symbol.
  • the frequency domain transform parameter includes: a number M of subcarriers used to distinguish the spatial stream, and an element of the LTF basic sequence Number L and number of subcarriers S;
  • the processor is specifically configured to:
  • LTF symbol Determining an LTF basic symbol according to the LTF symbol; wherein the LTF symbol is composed of the LTF basic symbol and a cyclic prefix CP;
  • every Subcarriers extract the LTF base sequence; Indicates rounding down.
  • the frequency domain transform parameter includes: a number M of subcarriers used to distinguish the spatial stream, and an element of the LTF basic sequence Number L and number of subcarriers S;
  • the processor is specifically configured to:
  • LTF symbol Determining an LTF basic symbol according to the LTF symbol; wherein the LTF symbol is composed of the LTF basic symbol and a CP;
  • the first device is a station STA, and the transmission device is an access point AP;
  • the processor is further configured to: after the receiver receives the first data frame that carries the long training code part LTF sequence sent by the first device, acquire the LTF parameter according to the pre-configured mapping relationship table;
  • the transmission device further includes:
  • a transmitter configured to send, to the first device, a second data frame that carries indication information, where the indication information indicates the LTF parameter.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the N a parameter corresponding to the type of the SS and the AP;
  • the processor according to the specific type of the N SS and the AP, corresponding to the type of the N SS and the AP as a parameter the LTF parameter;
  • the indication information includes the N SS ; or the indication information includes the N SS and the number of subcarriers S.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the environment in which the AP is located, and a parameter corresponding to the environment type of the N SS and the AP;
  • the processor according to the specific environment and the type of the N SS AP is located, corresponding to the environment and the type of the N SS as a parameter AP which the LTF parameter;
  • the indication information includes the N SS .
  • the mapping relationship table includes a number of multiplexed spatial streams N SS and a parameter corresponding to the N SS ;
  • the processor is specifically configured to determine, according to the N SS , a parameter corresponding to the N SS as the LTF parameter;
  • the indication information includes the N SS ; or the indication information includes the number N of the LTF symbols included in the LTF sequence.
  • the mapping relationship table includes the number of multiplexed spatial streams, N SS , MCS characteristic information, and the N SS and a parameter corresponding to the MCS characteristic information;
  • the processor is specifically configured to use, as the LTF parameter, a parameter corresponding to the N SS and the MCS characteristic information according to the N SS and the MCS characteristic information;
  • the indication information includes the N SS and the MCS characteristic information.
  • the first device is an AP, and the transmission device is an STA; or
  • the first device is a STA, and the transmission device is an AP;
  • the receiver is configured to receive the first data frame that is sent by the first device and that carries the LTF sequence and the indication information;
  • the processor is configured to acquire the LTF parameter according to the indication information received by the receiver and a pre-configured mapping relationship table.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the N a parameter corresponding to the type of the SS and the AP;
  • the transmission device is the AP
  • the indication information includes the N SS
  • the processor is specifically configured to: according to the type of the N SS and the AP, A parameter corresponding to the type of the N SS and the AP is used as the LTF parameter;
  • the transmission device is the STA
  • the processor is specifically configured to use the N SS and the AP according to the a type, the parameter corresponding to the N SS and the type of the AP is used as the LTF parameter;
  • the processor is specifically configured to be used according to the S determining the type of the AP; wherein there is a corresponding relationship between the AP and the S type; according to the type of the AP and N SS, as the parameter corresponding to the type of the AP and N SS
  • the processor is specifically configured to determine the S according to a length of the CP, and determines the type of the AP based on the S; N SS according to the type of the AP and the parameters corresponding to the type of the N SS and the AP as a parameter the LTF.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the environment in which the AP is located, and a parameter corresponding to an environment type in which the N SS and the AP are located;
  • the indication information includes the N SS , and when the transmission device is the STA, when the transmission device accesses the AP The type of environment in which the AP is located has been obtained;
  • the processor according to the specific environment and the type of the N SS AP is located, the type of environment and parameters of the N SS corresponding to the AP and the LTF located as parameter.
  • the mapping relationship table includes a number of multiplexed spatial streams N SS and a parameter corresponding to the N SS ;
  • the processor is configured according to the N SS, with the parameters corresponding to the N SS LTF as said parameter;
  • the processor is specifically configured to determine, according to the length of the CP, the number of subcarriers S; determine according to the N and the S The N SS , and determining a parameter corresponding to the N SS as the LTF parameter according to the N SS .
  • the mapping relationship table includes the number of multiplexed spatial streams N SS , modulation and coding policy MCS characteristic information, and Determining, by the N SS , a parameter corresponding to the MCS characteristic information; the indication information includes the N SS and the MCS characteristic information;
  • the processor is specifically configured to use, as the LTF parameter, a parameter corresponding to the N SS and the MCS characteristic information according to the N SS and the MCS characteristic information.
  • the number of the multiplexed spatial streams includes: the number of users multiplexed by multiple users and/or the number of data streams multiplexed by a single user.
  • the first device performs frequency domain transformation on the LTF basic sequence according to the frequency domain transformation parameter included in the acquired LTF parameter and the obtained allocated subcarrier starting position I to obtain the LTF symbol. And performing time-domain transform on the LTF symbol according to the time domain transform parameter included in the LTF parameter to obtain an LTF sequence, and then carrying the obtained LTF sequence in the first data frame and transmitting to the second device, so that the second device determines according to the LTF sequence.
  • the LTF basic sequence and channel estimation based on the LTF basic sequence.
  • the first device reduces the number of LTF symbols included in the LTF sequence by distinguishing the spatial stream in the frequency domain and the time domain, thereby saving signaling overhead and reducing data reception time. Delay.
  • FIG. 1 is a schematic structural diagram of a PPDU provided by the prior art
  • FIG. 2 is a schematic structural diagram of a PPDU according to an embodiment of the present invention.
  • FIG. 3 is a schematic structural diagram of a transmission device according to an embodiment of the present invention.
  • FIG. 4 is a schematic structural diagram of another transmission device according to an embodiment of the present invention.
  • FIG. 5 is a schematic structural diagram of a transmission device according to another embodiment of the present invention.
  • FIG. 6 is a schematic structural diagram of another transmission device according to another embodiment of the present invention.
  • FIG. 7 is a schematic structural diagram of still another transmission device according to another embodiment of the present invention.
  • FIG. 8 is a schematic flowchart of a method for transmitting a data frame according to another embodiment of the present invention.
  • FIG. 9 is a schematic flowchart of a method for transmitting a data frame according to another embodiment of the present invention.
  • FIG. 10 is a schematic flowchart of a method for transmitting a data frame according to another embodiment of the present invention.
  • FIG. 11 is a schematic diagram of a frequency domain LTF sequence according to another embodiment of the present invention.
  • FIG. 12 is a schematic diagram of another frequency domain LTF sequence according to another embodiment of the present invention.
  • FIG. 13 is a schematic flowchart of another method for transmitting a data frame according to another embodiment of the present invention.
  • FIG. 14 is a schematic flowchart of still another method for transmitting a data frame according to another embodiment of the present invention.
  • FIG. 15 is a schematic structural diagram of a transmission device according to another embodiment of the present invention.
  • FIG. 16 is a schematic structural diagram of a transmission device according to another embodiment of the present invention.
  • FIG. 17a is a schematic structural diagram of a downlink signal sending system according to an embodiment of the present invention.
  • FIG. 17b is a schematic structural diagram of a system for uplink signal transmission according to an embodiment of the present invention.
  • FIG. 18a is a schematic structural diagram of a specific structure of an LTF transmitting module according to an embodiment of the present invention.
  • FIG. 18b is a schematic structural diagram of another LTF sending module according to an embodiment of the present disclosure.
  • 19a is a schematic structural diagram of a specific structure of an LTF receiving module according to an embodiment of the present invention.
  • FIG. 19b is a schematic structural diagram of another LTF receiving module according to an embodiment of the present invention.
  • the structure of the 802.11ac PPDU is as shown in FIG. 1.
  • the PPDU includes a Legacy-Short Training Field (L-STF) and a Legacy-Long Training Field (Legacy-Long Training Field).
  • L-LTF Legacy-SIG
  • L-SIG Legacy Signal
  • VHT-SIG-A Very High Throughput-Signal-A
  • VHT-SIG-B Very High Throughput-Signal-B
  • Data Data Part
  • the VHT-LTF is used to implement channel estimation for multiple users in a multi-stream or MU-MIMO scenario in a SU-MIMO scenario.
  • the VHT-LTF needs to include several VHT-LTF symbols, which are time-domain CDMs.
  • the way is obtained by time domain transform, which is obtained by multiplying the VHT-LTF symbols of VHT-LTF by different row sequences of P matrix (P-matrix) in the time domain.
  • VHT-LTF number N included in VHT-LTF symbols may be determined in accordance with the SS N, wherein N and N corresponding relationship between the SS may Referring to Table 1, Table 1, N is the number of streams in the SS SU-MIMO or MU scenes - The number of users in the MIMO scenario.
  • N SS number to flow under SU-MIMO scenario as an example, for example, is equal to 8 when the N SS, N values of 8, that is, when the number of streams N SS in SU-MIMO scenarios is 8,
  • the VHT-LTF needs to include eight VHT-LTF symbols.
  • the PPDU including the VHT-LTF may be as shown in the figure. 2 is shown.
  • the VHT-LTF symbol included in the VHT-LTF is composed of symbol and CP, and the 802.11ac standard in the prior art is designed or acquired for the indoor environment.
  • the length of the CP is usually 0.8us, and for the outdoor environment, There is a long multipath effect relative to the indoor environment, so a longer CP is needed to overcome the long multipath effect relative to the indoor environment.
  • a CP with a length of 3.2 us can be used.
  • the VHT-LTF is still generated by the prior art time domain CDM mode, the length of the VHT-LTF is increased due to the addition of N longer CPs, resulting in an increase in signaling overhead. Partially delayed reception.
  • the frequency domain transform and the time domain transform are used to generate multiple spaces for distinguishing multiple input multiple output (MIMO) scenes.
  • LTF Long Training Field
  • An embodiment of the present invention provides a transmission device, which is applied to a wireless local area network system using multiple input multiple output MIMO technology.
  • the transmission device includes: an obtaining unit 11, a frequency domain transform unit 12, and a time domain transform.
  • Unit 13 transmission unit 14.
  • the obtaining unit 11 is configured to obtain a long training code part LTF parameter, and obtain an allocated subcarrier starting position I.
  • the LTF parameter includes: a frequency domain transform parameter and a time domain transform parameter required to generate the LTF sequence.
  • the frequency domain transforming unit 12 is configured to perform frequency domain transform on the LTF basic sequence to obtain an LTF symbol according to the frequency domain transform parameter and the start position I acquired by the acquiring unit 11.
  • the time domain transforming unit 13 is configured to perform time domain on the LTF symbol obtained by the frequency domain transforming unit 12 according to the time domain transform parameter acquired by the acquiring unit 11 Transforming to obtain the LTF sequence.
  • the sending unit 14 is configured to carry the LTF sequence obtained by the time domain transform unit 13 in a first data frame and send the data to the second device, so that the second device determines the LTF basic sequence according to the LTF sequence. And performing channel estimation based on the LTF basic sequence.
  • the frequency domain transform parameter further includes: a number M of subcarriers used to distinguish the spatial stream, an element number L of the LTF basic sequence, and a number of subcarriers S.
  • the frequency domain transforming unit 12 includes a mapping module 121, an inverse transform module 122, and a generating module 123.
  • mapping module 121 configured to start from the starting position I, every a subcarrier, mapping each element in the LTF base sequence to a corresponding subcarrier to obtain a frequency domain LTF sequence; Indicates rounding down.
  • the inverse transform module 122 is configured to perform an inverse fast Fourier transform IFFT (SFT) of the frequency domain LTF sequence obtained by the mapping module 121 to obtain an LTF basic symbol.
  • SFT inverse fast Fourier transform IFFT
  • the generating module 123 is configured to combine the LTF basic symbol obtained by the inverse transform module 122 and the cyclic prefix CP to generate the LTF symbol.
  • the frequency domain transform parameter further includes: a number M of subcarriers used to distinguish the spatial stream, an element number L of the LTF basic sequence, and a number of subcarriers S.
  • the frequency domain transforming unit 12 includes a mapping module 121, an inverse transform module 122, a generating module 123, and a spreading module 124.
  • the spreading module 124 is configured to perform spreading processing on each element in the LTF basic sequence according to the M to obtain an LTF spreading sequence; the LTF spreading sequence includes M*L elements.
  • the mapping module 121 is configured to map each element in the LTF spreading sequence obtained by the spreading module 124 to the corresponding subcarrier from the starting position I to obtain a frequency domain LTF sequence.
  • An inverse transform module 122 configured to obtain the frequency domain LTF obtained by the mapping module 121 The sequence performs the IFFT transform of the S point to obtain the LTF basic symbol.
  • the generating module 123 is configured to combine the LTF basic symbol obtained by the inverse transform module 122 and the CP to generate the LTF symbol.
  • the time domain transform parameter further includes: the number N of the LTF symbols included in the LTF sequence.
  • the time domain transforming unit 13 is specifically configured to perform spreading processing on the LTF symbols according to the N to generate the LTF sequence.
  • the transmission device is a site STA
  • the second device is an access point AP.
  • the obtaining unit 11 includes a receiving module 111 and an obtaining module 112.
  • the receiving module 111 is configured to receive a second data frame that carries the indication information that is sent by the second device, where the indication information is used to indicate the LTF parameter.
  • the obtaining module 112 is configured to acquire the LTF parameter according to the indication information obtained by the receiving module 111 and a pre-configured mapping relationship table.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the type corresponding to the N SS and the AP. parameter.
  • the acquiring module 112 is specifically configured to use the N SS and the The type of the AP, the parameter corresponding to the N SS and the type of the AP is used as the LTF parameter.
  • the acquiring module 112 is specifically configured to be used according to the determining a type of the AP S; wherein there is a corresponding relationship between the AP and the S type; according to the type of the AP and N SS, corresponding to the type of the N SS and parameters of the AP As the LTF parameter.
  • the acquiring module 112 is specifically configured to determine the S according to the length of the CP. And determining, according to the S, the type of the AP; according to the N SS and the type of the AP, using a parameter corresponding to the type of the N SS and the AP as the LTF parameter.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the environment type in which the AP is located, and the N SS and the AP The parameter corresponding to the environment type; the indication information includes the N SS , and the transmission device has acquired the environment type in which the AP is located when accessing the AP.
  • the acquisition module 112 according to the specific environment and the type of the N SS AP is located, the type of environment and parameters of the N SS corresponding to the AP and the LTF located as parameter.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams and the parameter corresponding to the N SS .
  • the acquiring module 112 is specifically configured to determine, according to the N SS , a parameter corresponding to the N SS as the LTF parameter.
  • the acquiring module 112 is specifically configured to determine the number of subcarriers S according to the length of the CP; according to the N and the S Determining the N SS and determining a parameter corresponding to the N SS as the LTF parameter according to the N SS .
  • the mapping relationship table includes the number of multiplexed spatial streams N SS , modulation and coding policy MCS characteristic information, and the N SS and the MCS characteristic information.
  • the indication information includes the N SS and the MCS characteristic information.
  • the obtaining module 112 is specifically configured to use, as the LTF parameter, a parameter corresponding to the N SS and the MCS characteristic information according to the N SS and the MCS characteristic information.
  • the transmission device is an AP, and the second device is an STA; or the transmission device is an STA, and the second device is an AP.
  • the obtaining unit 11 includes: an obtaining module 112, configured to acquire the LTF parameter according to a pre-configured mapping relationship table.
  • the sending unit 14 is configured to carry the LTF sequence and the indication information in the first data frame and send the information to the second device, so that the second device is configured according to the LTF sequence and the indication information.
  • the LTF base sequence is determined.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the type corresponding to the N SS and the AP. a parameter; and when the transmission device is an STA, the transmission device has acquired the type of the AP when accessing the AP.
  • the obtaining module 112 configured according to the type of the AP and N SS, corresponding to the type of the parameter of the N SS and the AP as a parameter the LTF.
  • the transmitting device is the STA
  • the second device is the AP
  • the indication information includes the N SS .
  • the indication information includes the N SS ; or the indication information includes the N SS and the number of subcarriers S.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the environment type in which the AP is located, and the N SS and the AP The parameter corresponding to the environment type at the location; and when the transmission device is an STA, the transmission device has acquired the environment type in which the AP is located when accessing the AP.
  • the acquisition module 112 according to the specific environment and the type of the N SS AP is located, the type of environment and parameters of the N SS corresponding to the AP and the LTF located as parameter.
  • the indication information includes the N SS .
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams and the parameter corresponding to the N SS .
  • the obtaining module 112 is specifically configured to determine, according to the N SS , a parameter corresponding to the N SS as the LTF parameter.
  • the indication information includes the N SS ; or the indication information includes the number N of the LTF symbols included in the LTF sequence.
  • the mapping relationship table includes the number of multiplexed spatial streams, N SS , MCS characteristic information, and parameters corresponding to the N SS and the MCS characteristic information.
  • the obtaining module 112 is specifically configured to use, as the LTF parameter, a parameter corresponding to the N SS and the MCS characteristic information according to the N SS and the MCS characteristic information.
  • the indication information includes the N SS and the MCS characteristic information.
  • the number of the multiplexed spatial streams includes: a number of users multiplexed by multiple users and/or a number of data streams multiplexed by a single user.
  • the transmission device performs frequency domain transformation on the LTF basic sequence according to the obtained frequency domain transform parameter and the obtained allocated subcarrier starting position I to obtain an LTF symbol, and is included according to the LTF parameter.
  • the time domain transform parameter performs time domain transform on the LTF symbol to obtain an LTF sequence, and then the obtained LTF sequence is carried in the first data frame and sent to the second device, so that the second device determines the LTF basic sequence according to the LTF sequence, and according to the LTF
  • the basic sequence performs channel estimation.
  • the transmission device distinguishes the number of LTF symbols included in the LTF sequence by distinguishing the spatial stream in the frequency domain and the time domain, thereby saving signaling overhead and reducing the delay of receiving the data portion. .
  • the present invention provides a transmission device, which is applied to a wireless local area network system using multiple input multiple output MIMO technology.
  • the present invention includes a receiving unit 21 and a processing unit 22.
  • the receiving unit 21 is configured to receive a first data frame that is sent by the first device and carries a long training code portion LTF sequence.
  • the processing unit 22 is configured to determine an LTF basic sequence according to the received LTF sequence received by the receiving unit 21, and perform channel estimation according to the LTF basic sequence.
  • the method further includes: an obtaining unit 23.
  • the obtaining unit 23 is configured to acquire an LTF parameter and obtain an allocated subcarrier starting position before the processing unit 22 determines the LTF basic sequence according to the LTF sequence.
  • the LTF parameter includes: a frequency domain transform parameter and a time domain transform parameter required by the first device to generate the LTF sequence.
  • the processing unit 22 includes a time domain inverse transform subunit 221 and a frequency domain inverse transform subunit 222.
  • the time domain inverse transform sub-unit 221 is configured to perform time domain inverse transform on the LTF sequence to obtain an LTF symbol according to the time domain transform parameter acquired by the acquiring unit 23;
  • the frequency domain inverse transform sub-unit 222 is configured to perform, according to the acquiring, the frequency domain transform parameter and the start position I, the LTF symbol obtained by the time domain inverse transform sub-unit 221
  • the inverse frequency domain transform yields the LTF base sequence.
  • the time domain transform parameter further includes: the number N of the LTF symbols included in the LTF sequence.
  • the time domain inverse transform sub-unit 221 is specifically configured to perform despreading processing on the LTF sequence according to the N to obtain the LTF symbol.
  • the frequency domain transform parameter further includes: a number M of subcarriers used to distinguish the spatial stream, an element number L of the LTF basic sequence, and a number of subcarriers S.
  • the frequency domain inverse transform sub-unit 222 includes: a determining module 2221, a transforming module 2222, and an extracting module 2223.
  • the determining module 2221 is configured to determine an LTF basic symbol according to the LTF symbol; wherein the LTF symbol is composed of the LTF basic symbol and a cyclic prefix CP.
  • the transforming module 2222 is configured to perform fast Fourier transform FFT transform of the LTF basic symbol obtained by the determining module 2221 to obtain a frequency domain LTF sequence.
  • the extracting module 2223 is configured to start from the starting position I according to the frequency domain LTF sequence obtained by the transforming module 2222. Subcarriers extract the LTF base sequence; Indicates rounding down.
  • the frequency domain transform parameter further includes: a number M of subcarriers used to distinguish the spatial stream, an element number L of the LTF basic sequence, and a number of subcarriers S;
  • the frequency domain inverse transform sub-unit 222 includes: a determining module 2221, a transform module 2222. An extraction module 2223 and a despreading module 2224.
  • the determining module 2221 is configured to determine an LTF basic symbol according to the LTF symbol; wherein the LTF symbol is composed of the LTF basic symbol and a CP.
  • the transforming module 2222 is configured to perform FFT transform of the LTF basic symbol obtained by the determining module 2221 to obtain a frequency domain LTF sequence.
  • the extracting module 2223 is configured to extract, according to the frequency domain LTF sequence obtained by the transforming module 2222, an LTF spreading sequence from the corresponding subcarrier from the starting position I; wherein the LTF spreading sequence Contains M*L elements.
  • the despreading module 2224 is configured to perform despreading processing on the LTF spreading sequence obtained by the extracting module 2223 according to the M to obtain the LTF basic sequence.
  • the first device is a station STA
  • the transmission device is an access point AP.
  • the obtaining unit 23 is further configured to acquire the LTF parameter according to the pre-configured mapping relationship table before the receiving unit 21 receives the first data frame that carries the long training code part LTF sequence sent by the first device.
  • the transmission device further includes: a sending unit 24.
  • the sending unit 24 is configured to send, to the first device, a second data frame that carries the indication information, where the indication information indicates the LTF parameter.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the type corresponding to the N SS and the AP. parameter.
  • the acquisition unit 23 according to the type of the specific parameters for the AP and N SS, to the N SS and the AP corresponding to the type of parameter as the LTF;
  • the indication information includes the N SS ; or the indication information includes the N SS and the number of subcarriers S.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the environment type in which the AP is located, and the N SS and the AP The parameter corresponding to the environment type;
  • the indication information includes the N SS .
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams and the parameter corresponding to the N SS .
  • the obtaining unit 23 is specifically configured to determine, according to the N SS , a parameter corresponding to the N SS as the LTF parameter.
  • the indication information includes the N SS ; or the indication information includes the number N of the LTF symbols included in the LTF sequence.
  • the mapping relationship table includes the number of multiplexed spatial streams, N SS , MCS characteristic information, and parameters corresponding to the N SS and the MCS characteristic information.
  • the acquiring unit 23 is specifically configured to use, as the LTF parameter, a parameter corresponding to the N SS and the MCS characteristic information according to the N SS and the MCS characteristic information.
  • the indication information includes the N SS and the MCS characteristic information.
  • the first device is an AP, and the transmission device is an STA; or the first device is an STA, and the transmission device is an AP.
  • the receiving unit 21 is specifically configured to receive the first data frame that is sent by the first device and that carries the LTF sequence and the indication information.
  • the acquiring unit 23 is specifically configured to acquire the LTF parameter according to the indication information received by the receiving unit 21 and a pre-configured mapping relationship table.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the type corresponding to the N SS and the AP. parameter.
  • the transmission device is the AP
  • the indication information includes the N SS
  • the acquiring unit 23 is specifically configured to: according to the N SS and the type of the AP And using, as the LTF parameter, a parameter corresponding to the type of the N SS and the AP;
  • the transmission device is the STA.
  • the acquiring unit 23 is specifically configured to use the N SS and the The type of the AP, the parameter corresponding to the N SS and the type of the AP is used as the LTF parameter.
  • the acquiring unit 23 is specifically configured to be used according to the determining a type of the AP S; wherein there is a corresponding relationship between the AP and the S type; according to the type of the AP and N SS, corresponding to the type of the N SS and parameters of the AP As the LTF parameter.
  • the acquiring unit 23 is specifically configured to determine the S according to the length of the CP. And determining, according to the S, the type of the AP; according to the N SS and the type of the AP, using a parameter corresponding to the type of the N SS and the AP as the LTF parameter.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the environment type in which the AP is located, and the N SS and the AP a parameter corresponding to the environment type; the indication information includes the N SS , and when the transmission device is the STA, the transmission device acquires the AP when the AP accesses the AP Type of environment.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams and the parameter corresponding to the N SS .
  • the acquisition unit 23 specifically according to the N SS, with the parameters corresponding to the N SS as the LTF parameter.
  • the acquiring unit 23 is specifically configured to determine the number of subcarriers S according to the length of the CP; according to the N and the S Determining the N SS and determining a parameter corresponding to the N SS as the LTF parameter according to the N SS .
  • the mapping relationship table includes the number of multiplexed spatial streams N SS , modulation and coding policy MCS characteristic information, and the N SS and the MCS characteristic information.
  • the indication information includes the N SS and the MCS characteristic information.
  • the acquiring unit 23 is specifically configured to use, as the LTF parameter, a parameter corresponding to the N SS and the MCS characteristic information according to the N SS and the MCS characteristic information.
  • the number of the multiplexed spatial streams includes: a number of users multiplexed by multiple users and/or a number of data streams multiplexed by a single user.
  • the first device performs frequency domain transformation on the LTF basic sequence according to the frequency domain transform parameter included in the acquired LTF parameter and the obtained allocated subcarrier starting position I to obtain an LTF symbol, and according to the LTF
  • the time domain transform parameter included in the parameter performs time domain transform on the LTF symbol to obtain an LTF sequence
  • the obtained LTF sequence is carried in the first data frame and sent to the transmission device, so that the transmission device determines the LTF basic sequence according to the LTF sequence, and according to The LTF basic sequence performs channel estimation.
  • the first device reduces the number of LTF symbols included in the LTF sequence by distinguishing the spatial stream in the frequency domain and the time domain, thereby saving signaling overhead and reducing data reception time. Delay.
  • An embodiment of the present invention provides a data frame transmission method, which is applied to a wireless local area network system using MIMO technology. As shown in FIG. 8, the method may include:
  • the first device acquires an LTF parameter, and obtains an allocated subcarrier starting position I.
  • the LTF parameters include frequency domain transform parameters and time domain transform parameters required to generate the LTF sequence.
  • the process of obtaining the allocated subcarrier start position I may be obtained by using the first device, or may be obtained by receiving the signaling sent by the second device.
  • the first device performs frequency domain transformation on the LTF basic sequence according to the frequency domain transform parameter and I to obtain an LTF symbol.
  • the frequency domain included in the acquired LTF parameters may be used.
  • the transform parameter and the obtained allocated subcarrier start position I are subjected to frequency domain transform on the LTF basic sequence to obtain an LTF symbol.
  • the first device performs time domain transform on the LTF symbol according to the time domain transform parameter to obtain an LTF sequence.
  • the LTF symbol may be time-domain transformed according to the time domain transformation parameter included in the LTF parameter to obtain the LTF sequence.
  • the first device carries the LTF sequence in the first data frame and sends the data to the second device, so that the second device determines the LTF basic sequence according to the LTF sequence, and performs channel estimation according to the LTF basic sequence.
  • the obtained LTF sequence may be carried in the first data frame and sent to the second device, so that the second device
  • the device determines the LTF basic sequence according to the LTF sequence, and performs channel estimation according to the determined LTF basic sequence. Further, carrier frequency offset (CFO) estimation may also be performed according to the determined LTF basic sequence.
  • CFO carrier frequency offset
  • the first device may be an access point (AP) or a station (Station, STA), and when the first device is an AP, the second device is The STA is not specifically limited to the first device and the second device in the embodiment of the present invention when the first device is the STA and the second device is the AP.
  • the first device performs frequency domain transformation on the LTF basic sequence to obtain an LTF symbol according to the frequency domain transform parameter included in the acquired LTF parameter and the obtained allocated subcarrier starting position I. And performing time-domain transform on the LTF symbol according to the time domain transform parameter included in the LTF parameter to obtain an LTF sequence, and then carrying the obtained LTF sequence in the first data frame and transmitting the data to the second device, so that the second device
  • the LTF basic sequence is determined according to the LTF sequence, and channel estimation is performed according to the LTF basic sequence.
  • the first device reduces the number of LTF symbols included in the LTF sequence by distinguishing the spatial stream in the frequency domain and the time domain, thereby saving signaling overhead and reducing data reception time. Delay.
  • Another embodiment of the present invention provides a data frame transmission method, which is applied to a wireless local area network system using MIMO technology. As shown in FIG. 9, the method may include:
  • the second device receives the first data frame that is sent by the first device and carries the LTF sequence.
  • the second device determines the LTF basic sequence according to the LTF sequence, and performs channel estimation according to the LTF basic sequence.
  • the LTF basic sequence may be determined according to the LTF sequence carried in the first data frame, and the channel estimation is performed according to the LTF basic sequence, and further CFO estimation can also be performed based on the LTF basic sequence.
  • the first device performs frequency domain transformation on the LTF basic sequence to obtain an LTF symbol according to the frequency domain transform parameter included in the acquired LTF parameter and the obtained allocated subcarrier starting position I. And performing time-domain transform on the LTF symbol according to the time domain transform parameter included in the LTF parameter to obtain an LTF sequence, and then carrying the obtained LTF sequence in the first data frame and transmitting to the second device, so that the second device determines the LTF according to the LTF sequence.
  • the basic sequence and channel estimation based on the LTF basic sequence.
  • the first device reduces the number of LTF symbols included in the LTF sequence by distinguishing the spatial stream in the frequency domain and the time domain, thereby saving signaling overhead and reducing data reception time. Delay.
  • Another embodiment of the present invention provides a data frame transmission method, which is applied to a wireless local area network system using MIMO technology, and in order to facilitate understanding by those skilled in the art, in the embodiment of the present invention, the present invention is different according to application scenarios.
  • the specific implementation process is described in detail as follows:
  • the first device is an AP
  • the second device is an STA.
  • the MIMO technology used in the WLAN is specifically MU-MIMO technology, and the specific implementation is implemented.
  • the process is used for the transmission of the downlink data.
  • the AP can communicate with multiple STAs at the same time, and the spatial flow refers to the data flow sent by the AP to each user (STA).
  • the method for transmitting data frames in the application scenario is as shown in FIG. 10, and the specific method may include:
  • the AP acquires an LTF parameter, and obtains an allocated subcarrier starting position I.
  • the acquiring the LTF parameter by the AP may be: acquiring the LTF parameter according to the pre-configured mapping relationship table, where the LTF parameter may include: a frequency domain transform parameter and a time domain transform parameter required to generate the LTF sequence.
  • the frequency domain transform parameter may include: a number M of subcarriers used to distinguish the spatial stream, an element number L of the LTF basic sequence, and a number of subcarriers S
  • the time domain transform parameter may include: the LTF included in the LTF sequence The number N of symbols.
  • the obtaining process of the allocated subcarrier starting position I may be obtained by using the AP allocation.
  • the specific obtaining process is: the AP allocates a subcarrier starting position I for each spatial stream according to the actual application scenario, or the AP according to each The order of the spatial streams is assigned to each spatial stream with the same subcarrier starting position I as the spatial stream order.
  • mapping relationship table may specifically be composed of any one of the following ways:
  • the mapping relationship table includes the number of multiplexed spatial streams N SS , the type of the AP, and parameters corresponding to the types of the N SS and the AP.
  • the number of multiplexed spatial streams N SS is the number of users multiplexed by multiple users.
  • the type of the AP may be 802.11ac or 802.11ax
  • the mapping relationship table may be composed of Table 2, Table 3 or Table 3a.
  • the type 1 in the mapping relationship table shown in Table 2, Table 3, and Table 3a indicates that the type of the AP is 802.11ac
  • the type 2 indicates that the type of the AP is 802.11ax.
  • the AP ie, the transmitting end
  • the STA selects the LTF basic sequence of the same L for each user's data stream
  • the STA selects the LTF basic sequence of the same L for each user's data stream
  • the length of the data symbol is 64-FFT (64-Fast Fourier Transform), when the AP will perform frequency domain mapping for the LTF basic sequence with L equal to 56 selected for each user's data stream, the STA is based on
  • the despread LTF basic sequence is used for channel estimation, the channel estimation of all subcarriers can be obtained without interpolation, that is, the channel estimation required for the data symbols can be obtained without interpolation.
  • the length of the data symbol and the length of the data symbol of type 1 are different, and the length of the data symbol of type 2 is 256-FFT, for example, when the AP selects L for each user's data stream equal to 56.
  • the STA When the LTF basic sequence performs frequency domain mapping, when the STA performs channel estimation according to the despread LTF basic sequence, it needs 4 times interpolation to obtain channel estimation of all subcarriers, that is, 4 times interpolation is required to obtain The channel estimate required for the data symbol.
  • the mapping relationship table includes the number of multiplexed spatial streams N SS , the type of the environment in which the AP is located, and parameters corresponding to the number of users N SS and the environment type in which the AP is located.
  • the type of the AP is 802.11ax
  • the environment type of the AP may be indoor or outdoor.
  • the mapping relationship table may be listed in Table 4, Table 5, Table 5a or Table 5b.
  • the environment type 1 in the mapping relationship table shown in Table 4, Table 5, Table 5a, and Table 5b indicates that the environment type in which the AP is located is indoor, and the environment type 2 indicates that the environment type in which the AP is located is outdoor.
  • N SS is 8
  • the environment type of the AP is type 1
  • the parameter corresponding to the environment type in which the AP is located Take the mapping table shown in Table 5 as an example.
  • mapping relationship table in Table 4-5a because the APs are in different environment types, the LTF basic sequence lengths selected by the APs are different. Therefore, when the STA performs channel estimation according to the despread LTF basic sequence, the intra-area is used. The interpolation algorithm is also different.
  • the AP can select a relatively short LTF basic sequence for each user's data stream, so that when the STA performs channel estimation according to the despread LTF basic sequence, Channel estimation of all subcarriers can be obtained by interpolation of a large multiple, that is, channel interpolation required for data symbols can be obtained by interpolation of a large multiple; and for environment type 2, frequency selectivity of outdoor channels is large Therefore, the AP needs to select a relatively short LTF basic for each user's data stream.
  • mapping relationship table shown in Table 4 if the length of the data symbol is 256-FFT, for the environment type 1, when the AP selects the LTF basic sequence of L equal to 56 for each user's data stream, every When 4 subcarriers are mapped on the frequency domain subcarriers, when the STA performs channel estimation according to the despread LTF basic sequence, 4 times interpolation is required to obtain channel estimation of all subcarriers, that is, 4 times is needed.
  • Inserting can obtain the channel estimation required for the data symbols; and for environment type 2, when the AP selects the LTF basic sequence of L equal to 116 for each user's data stream, every 2 subcarriers are mapped on the frequency domain subcarriers. In this way, when the STA performs channel estimation according to the despread LTF basic sequence, it requires 2 times interpolation to obtain channel estimation of all subcarriers, that is, a channel required for data symbols can be obtained by requiring 2 times interpolation. estimate.
  • the parameters given in Table 5b are that regardless of the environment type 1 or the environment type 2, the AP can select the LTF basic sequence of the same length for each user's data stream, so that when the STA performs channel estimation according to the despread LTF basic sequence
  • a similar channel estimation interpolation algorithm can be used to obtain the channel estimation of all subcarriers, that is, a similar channel estimation interpolation algorithm can be used to obtain the channel estimation required for the data symbols.
  • the AP selects the LTF parameter for each user's data stream as S equal to 128 (equivalent to the data symbol length)
  • S is equal to 128 (equivalent to the data symbol length)
  • L is equal to 116, so that when the STA performs channel estimation based on the despread LTF basic sequence, it needs 2 times interpolation to obtain channel estimates of all subcarriers, that is, 2 times interpolation is required to obtain data.
  • the channel estimation required for the symbol; and for environment type 2, the LTF parameter selected by the AP for each user's data stream is S equal to 256, L is equal to 116 LTF basic sequence, when the AP will select the LTF basic sequence every 2 sub-subs
  • the channel estimation of all subcarriers is also required to be interpolated twice, that is, the data needs to be interpolated twice.
  • the channel estimate required for the symbol is also required to be interpolated twice, that is, the data needs to be interpolated twice.
  • the size of N should be minimized.
  • the frequency selective fading of the wireless channel is large because the environment is outdoor.
  • the AP needs to map adjacent elements in the LTF basic sequence separately. If the interval is less than or equal to 2, then the number M of subcarriers used to distinguish the spatial stream is less than or equal to 2; for the environment type 1 AP, because the environment is indoor The frequency selective fading of the wireless channel is smaller than that of the outdoor environment.
  • the AP needs to map adjacent elements in the LTF basic sequence to subcarriers with an interval of 4 or less.
  • the number M of subcarriers for distinguishing the spatial streams is less than or equal to four.
  • the mapping relationship table includes the number of multiplexed spatial streams N SS and parameters corresponding to N SS .
  • the type of the AP is 802.11ax
  • the mapping relationship table can be composed of Table 6, Table 7 or Table 7a.
  • the size of N and the length of LTF basic symbols should be minimized.
  • the mapping relationship table shown in Table 6, Table 7, and Table 7a includes two types of parameters. When the value of N SS is large, the S having a larger value may be selected to reduce N. When the value of N SS is small, the S with a smaller value can be selected to reduce the length of the LTF basic symbol while reducing the size of N.
  • the mapping relationship table may be configured as shown in Table 7b.
  • the mapping relationship table includes three types of parameters, and when the value of N SS is large, the value may be selected. S, in order to reduce the size of N; when the value of N SS is small, S can be selected to take a smaller value to reduce the length of the LTF basic symbol while reducing the size of N.
  • S in order to reduce the size of N; when the value of N SS is small, S can be selected to take a smaller value to reduce the length of the LTF basic symbol while reducing the size of N.
  • S in order to reduce the size of N; when the value of N SS is small, S can be selected to take a smaller value to reduce the length of the LTF basic symbol while reducing the size of N.
  • S in order to reduce the size of N; when the value of N SS is small, S can be selected to take a smaller value to reduce the length of the LTF basic symbol while reducing the size of N.
  • N SS when N SS is 8, S
  • the value of N SS is large, the value of N used in the present invention is compared with that of the prior art.
  • the value of S is 128, and the value of N is 3, because the N used in the prior art when N SS is 6.
  • the value of S is 64, and the value of N is 1.
  • N SS is 1, the value of N is the same, because the S of the present invention is adopted.
  • the value is small. Therefore, the length of the LTF basic symbol is also short, that is, the length of the LTF sequence generated by using the parameters of the present invention is also short, thereby saving signaling overhead.
  • the mapping relationship table includes the number of multiplexed spatial streams N SS , modulation and coding strategy (MCS) characteristic information, and parameters corresponding to N SS and MCS characteristic information.
  • the MCS characteristic information may be obtained from the wireless channel information exchanged between the AP and the STA, and the size of the MCS reflects the MCS characteristic information.
  • the type of the AP is 802.11ax
  • the mapping relationship table can be composed of Table 8, Table 9 or Table 9a.
  • the AP In order to ensure the accuracy of the STA channel estimation, it is necessary to generate the number M of subcarriers for distinguishing the spatial stream according to the size of the adopted MCS, and in order to reduce the signaling overhead, on the premise that the M meets the requirement, Try to reduce the size of N. Specifically, when the size of the MCS is between 5-9, it indicates that the STA is sensitive to the change of the signal-to-noise ratio of the wireless channel when performing channel estimation. In order to ensure the accuracy of the STA channel estimation, the AP needs to phase the LTF basic sequence.
  • the neighboring elements are respectively mapped to subcarriers with an interval of less than or equal to 2, and then, the number M of subcarriers used to distinguish the spatial streams is less than or equal to 2; when the size of the MCS is between 0 and 4
  • the STA is insensitive to the change of the SNR of the radio channel when performing channel estimation.
  • the AP needs to map the adjacent elements in the LTF basic sequence to an interval of 4 or less. On the subcarrier, then, at this time, the number M of subcarriers used to distinguish the spatial stream is less than or equal to 4.
  • the AP obtains the LTF parameters according to the pre-configured mapping relationship table, which may be: according to the number of multiplexed spatial streams N SS and the type of the AP, and the N SS and the AP The parameter corresponding to the type is used as the LTF parameter.
  • the AP queries the mapping relationship table according to the type of the N SS and the AP, and obtains parameters corresponding to the types of the N SS and the AP, and uses the parameter as the LTF parameter.
  • AP acquired according to the mapping relation LTF parameters pre-configured table may be specific: The N SS, the type of environment in which the AP, the AP with the N SS and the environment type The corresponding parameter is used as the LTF parameter.
  • the mapping relationship table query the mapping relationship table, and acquires N SS parameters corresponding to the type of AP, and as a parameter of the parameter LTF.
  • the AP obtains the LTF parameter according to the pre-configured mapping relationship table. Specifically, the parameter corresponding to the N SS is determined as the LTF parameter according to the N SS .
  • the AP queries the mapping relationship table according to the N SS , obtains a parameter corresponding to the N SS , and uses the parameter as an LTF parameter.
  • the pre-configured mapping table in the AP is the table 6 in the third mode. If the number of the spatial streams N SS multiplexed by the AP is 8, the AP queries the mapping table according to the N SS and obtains the corresponding mapping.
  • the AP obtains the LTF parameter according to the pre-configured mapping relationship table, and may specifically: use the parameter corresponding to the N SS and the MCS characteristic information as the LTF parameter according to the N SS and MCS characteristic information. .
  • the AP queries the mapping relationship table according to the N SS and MCS characteristic information, and obtains parameters corresponding to the N SS and MCS characteristic information, and uses the parameter as an LTF parameter.
  • S502 The AP performs frequency domain transformation on the LTF basic sequence according to the frequency domain transform parameter and I to obtain an LTF symbol.
  • the AP may adopt the frequency domain according to the frequency domain transform parameter included in the acquired LTF parameter and the obtained allocated subcarrier start position I.
  • the LTF basic sequence is subjected to frequency domain transformation to obtain LTF symbols.
  • the AP When the AP performs frequency domain transformation on the LTF basic sequence by using the frequency domain FDM, the AP performs frequency domain transformation on the LTF basic sequence according to the frequency domain transformation parameter and I, and obtains the LTF symbol.
  • the specific steps may include the following steps S502a1 to S502a4:
  • AP starts from I, every The subcarriers are mapped to the corresponding subcarriers by mapping each element in the LTF basic sequence to obtain a frequency domain LTF sequence.
  • the LTF basic sequence is allocated by the AP.
  • the pre-configured mapping table in the AP adopts the mode one, the LTF basic sequence is directly obtained.
  • the pre-configured mapping table in the AP adopts the second mode, the third mode, and the fourth mode.
  • the AP may select the LTF basic sequence to be used from the pre-stored LTF basic sequence according to the frequency domain transformation parameter L included in the LTF parameter. For example, when the frequency domain transform parameter L included in the LTF parameter acquired by the AP is 56, the LTF basic sequence selected according to L may be:
  • LTF base sequence ⁇ 1 1 LTF left 0 LTF right -1 -1 ⁇
  • LTF left and LTF right contain 26 elements.
  • the AP may start from I according to the frequency domain transform parameters M, L, and S included in the acquired LTF parameters, and the obtained subcarrier start position I. a subcarrier, mapping each element in the LTF basic sequence to a corresponding subcarrier to obtain a frequency domain LTF sequence, where Indicates rounding down.
  • the AP is designed or acquired according to the pattern. Starting from I, every Each subcarrier maps each element in the LTF basic sequence to a corresponding subcarrier, where l is the lth element in the LTF basic sequence, and I is the starting position of the subcarrier allocated to the spatial stream, and I 0 is The starting position of the available subcarriers.
  • AP pre-configured mapping relationship table of embodiment a of Table 2 the number N SS when the type of AP as type 2, and the space AP multiplexed stream is. 8
  • the number of spatial streams differentiated in the frequency domain can be determined to be 4, correspondingly, design Or the obtained pattern is Taking the first spatial stream as an example, assuming that the starting position I0 of the available subcarrier is equal to 1, and m is equal to 0, the starting position I of the subcarrier allocated to the spatial stream is equal to 1, and the AP will each of the LTF basic sequences. Elements are designed or acquired Starting from subcarrier 1, every 4 subcarriers are mapped onto corresponding subcarriers.
  • the frequency domain mapping method of the first spatial stream may be used for mapping, and the four spatial streams are mapped to the frequency domain by the frequency domain transform parameter and I to obtain the frequency domain LTF sequence.
  • Figure 11 shows. Since the four spatial streams that the AP distinguishes in the frequency domain are respectively mapped to different subcarriers, the four spatial streams can be distinguished in the frequency domain.
  • the value of m can be any one of 0, 1, 2, and 3, and it is only necessary to ensure that the value of m corresponding to other spatial streams is different, and the corresponding m can be selected according to the scenario of the actual application. The embodiment here does not limit the value of m.
  • the AP starts from I, every After sub-carriers are mapped to the corresponding sub-carriers to obtain the frequency domain LTF sequence, the AP may perform the IFFT transform of the S-points of the frequency domain LTF sequence to obtain the LTF basic symbols.
  • S502a3 The AP combines the LTF basic symbol and the CP to generate an LTF symbol.
  • CP is the same as the element of [(L 1 -Lcp), L 1 ] in the LTF basic symbol, L 1 is the length of the LTF basic symbol, and Lcp is the length of the CP.
  • the AP When the AP performs frequency domain transform on the LTF basic sequence by using the frequency domain CDM, the AP performs frequency domain transformation on the LTF basic sequence according to the frequency domain transform parameter and I, and obtains the LTF symbol.
  • the specific steps may include the following steps S502b1 to S502b4:
  • the frequency domain transform parameter M may specifically be used to distinguish the spatial flow.
  • the AP performs spreading processing on each element in the LTF basic sequence according to M, to obtain an LTF spreading sequence.
  • the AP can determine the number of spatial streams distinguished in the frequency domain according to M. For each spatial stream, the AP repeats each element in the LTF basic sequence M times, and then multiplies the corresponding frequency domain spreading sequence to obtain the LTF. A spreading sequence, the LTF spreading sequence comprising M*L elements.
  • the domain transformation parameter M can determine that the dimension of the P matrix is 4*4 dimensions and the number of spatial streams distinguished in the frequency domain is 4.
  • the AP repeats each element in the LTF basic sequence four times and multiplies the expansion of the spatial stream.
  • the frequency sequence (the first line sequence of the P matrix) yields an LTF spreading sequence containing 4*56 elements.
  • the spread spectrum processing can be performed by referring to the spread spectrum processing method of the first spatial stream. Since the spatial streams distinguished by the AP in the frequency domain are multiplied by different row sequences of the P matrix, respectively, the four spatial streams can be distinguished in the frequency domain.
  • the spreading sequence of the first spatial stream is the ith row sequence of the P matrix, and the value of i may be any one of 1, 2, 3, and 4, and only needs to ensure different spreading sequences from other spatial streams.
  • the corresponding i can be selected according to the scenario of the actual application.
  • the value of the i is not limited in the embodiment of the present invention.
  • S502b2 The AP maps each element in the LTF spreading sequence to the corresponding subcarrier from I to obtain a frequency domain LTF sequence.
  • the AP After the AP performs spreading processing on each element in the LTF basic sequence according to M, the AP obtains an LTF spreading sequence from the I, and the AP maps each element in the LTF spreading sequence to the corresponding subcarrier from the I. Domain LTF sequence.
  • the AP is designed or acquired according to the pattern.
  • Each element in the LTF spreading sequence is mapped from the I to the corresponding subcarrier.
  • I is the starting position of the subcarrier allocated to the spatial stream
  • I 0 is the starting position of the available subcarriers.
  • the domain transformation parameter M can determine that the number of spatial streams distinguished in the frequency domain is 4, and correspondingly, the designed or acquired pattern is Taking the first spatial stream as an example, assuming that the starting position I 0 of the available subcarrier is equal to 1, the starting position I of the subcarrier allocated to the spatial stream in the frequency domain is equal to 1, and the AP will be in the LTF spreading sequence.
  • Each element of the design follows or is designed Mapping from subcarrier 1 to the corresponding subcarrier.
  • the mapping can be performed by referring to the mapping method of the first spatial stream in the frequency domain, and the four spatial streams are frequency domain mapped according to the frequency domain transform parameters and I to obtain the frequency domain LTF sequence.
  • the schematic diagram is shown in Figure 12.
  • S502b3 The AP performs an IFFT transform of the S-point in the frequency domain LTF sequence to obtain an LTF basic symbol.
  • S502b4 The AP combines the LTF basic symbol and the CP to generate an LTF symbol.
  • CP is the same as the element of [(L 1 -Lcp), L 1 ] in the LTF basic symbol, L 1 is the length of the LTF basic symbol, and Lcp is the length of the CP.
  • the AP may perform the time domain transformation on the LTF symbol according to the time domain transform parameter to obtain the LTF sequence. Specifically, the AP may include step S503:
  • the AP performs a spreading process on the LTF symbol according to N to generate an LTF sequence.
  • the AP can determine the number of spatial streams that are differentiated in the time domain according to N. For each spatial stream, the AP repeats the LTF symbols N times, and then multiplies the corresponding spreading sequence to generate an LTF sequence.
  • the number of spatial streams distinguished is 2.
  • the AP repeats the LTF symbol twice and multiplies the spreading sequence of the spatial stream (P matrix The first line of the sequence) generates an LTF sequence.
  • the spread spectrum processing can be performed by referring to the spread spectrum processing method of the first spatial stream. Since the spatial streams distinguished by the AP in the time domain are multiplied by different row sequences of the P matrix, respectively, the two spatial streams can be distinguished in the time domain.
  • the spreading sequence of the first spatial stream is the sequence of the jth row of the P matrix, and the value of j may be any one of 1, 2, and only needs to ensure that the spreading sequence is different from other spatial streams,
  • the corresponding j is selected according to the scenario of the actual application, and the value of j is not limited herein.
  • M spatial streams can be distinguished by different subcarriers in the frequency domain
  • N spatial streams are distinguished by different spreading sequences in the time domain, so M* can be distinguished by frequency domain transform and time domain transform.
  • N spatial streams are distinguished by different subcarriers in the frequency domain.
  • the length of the LTF sequence generated by the frequency domain transform and the time domain transform of the present invention is compared with the length of the LTF sequence generated by the prior art time domain transform.
  • the pre-configured mapping table in the AP adopts Table 2 in Mode 1
  • the specific comparison results are shown in Table 10:
  • the length of the LTF sequence generated by the AP using the method provided by the embodiment of the present invention is shorter than the length of the LTF sequence generated by the prior art.
  • the length of the LTF sequence generated by the AP using the method provided by the embodiment of the present invention is shorter than the length of the LTF sequence generated by the method provided by the prior art.
  • the STA Since the STA needs to parse the LTF sequence to obtain the LTF basic sequence, the STA needs to know the LTF parameter used by the AP to generate the LTF sequence. To save the signaling overhead, the AP may notify the STA of the indication information for acquiring the LTF parameter.
  • the AP sends the LTF sequence to the STA in the first data frame, which may include the following step S504:
  • the AP carries the LTF sequence and the indication information in the first data frame and sends the information to the STA.
  • the indication information may include the number of multiplexed spatial streams N SS when the composition manner of the pre-configured mapping relationship table in the AP is mode 1, or the indication information includes the number of multiplexed spatial streams N SS and subcarriers. Number S.
  • the indication information includes the number N SS of the multiplexed spatial streams.
  • the indication information includes the number of multiplexed spatial streams N SS ; or the indication information includes the number N of LTF symbols included in the LTF sequence.
  • the indication information includes the number of multiplexed spatial streams N SS and MCS characteristic information.
  • the indication information carried in the first data frame can be selected according to the actual application scenario.
  • the specific parameters included in the indication information are not limited in the embodiment of the present invention.
  • the STA receives the first data frame that is sent by the AP and carries the LTF sequence and the indication information.
  • the STA acquires the LTF parameter according to the indication information and the pre-configured mapping relationship table, and acquires the allocated subcarrier starting position I.
  • the STA may obtain the subcarrier starting position I of the spatial stream allocation according to the explicit signaling sent by the AP, or may obtain the subcarrier of the spatial stream allocation according to the implicit signaling sent by the AP.
  • the initial position I when the STA acquires the subcarrier start position I allocated by the spatial stream according to the implicit signaling sent by the AP, the allocated subcarrier starting position I obtained by the STA at this time is the default order of the received spatial stream.
  • the STA is configured according to the STA.
  • information indicating the pre-configured mapping relationship table LTF obtain specific parameters may include: STA and AP N SS according to the type of the parameter corresponding to the type and N SS LTF AP as parameters.
  • the STA queries the mapping relationship table according to the type of the N SS and the AP, and obtains parameters corresponding to the types of the N SS and the AP, and uses the parameter as the LTF parameter.
  • the STA acquires the LTF according to the indication information and the pre-configured mapping relationship table.
  • specific parameters may include: STA S determined according to the type of the AP, according to the type and N SS and the AP, the AP with the N SS and type of parameters corresponding to a parameter LTF.
  • the STA In the mapping relationship table pre-configured by the STA, the S has a corresponding relationship with the type of the AP. Therefore, the STA can determine the type of the AP by searching the mapping relationship table according to S. After the STA determines the type of the AP, the mapping relationship table is queried according to the N SS and the determined type of the AP, and the queried parameter is used as the LTF parameter.
  • the process of acquiring the LTF parameter according to the indication information and the pre-configured mapping relationship table may be specifically performed by the STA. comprising: STA S determined according to the length of the CP, according to S and determines the type of the AP, then the AP and depending on the type of N SS, with the N SS type and a parameter corresponding LTF AP as parameters.
  • the STA can obtain the length of the CP from the information exchange with the AP as Lcp when accessing the AP. It is assumed that the length of the LTF symbol is L 2 , because the CP and the LTF symbol are in [(L 2 -Lcp), The elements of L 2 ] are the same, and the elements in the LTF symbol [0, Lcp] can be autocorrelated with the elements in [(L 2 -Lcp), L 2 ], and the obtained autocorrelation peaks and presets can be obtained. The threshold values are compared.
  • the length of the LTF symbol can be determined to be L 2 ; if the obtained autocorrelation peak does not exceed the preset threshold, the assumption can be re-assumed.
  • the length of the LTF symbol is L 3 , and then the elements in the LTF symbol [0, Lcp] are autocorrelated with the elements in [(L 3 -Lcp), L 3 ], and the obtained autocorrelation peaks are The preset threshold is compared.
  • the length of the LTF symbol may be determined to be L 3 ; if the obtained autocorrelation peak does not exceed the preset threshold, then The length of the LTF symbol can be re-confirmed until the length of the LTF symbol is determined.
  • the STA determines the length of the LTF symbol, since the length of the LTF symbol is equal to the length of the symbol plus the length of the CP, and the length of the CP is known, the length of the symbol can be obtained according to the length of the determined LTF symbol (the length of the LTF symbol is reduced) The length of the CP is removed. Then, according to the corresponding relationship between the length of the symbol and the S, S can be determined.
  • the mapping relationship table can be queried according to S to determine the type of the AP.
  • the mapping relationship table is queried according to the N SS and the determined type of the AP, and the queried parameter is used as the LTF parameter.
  • the STA according to the indication information and the pre-configured LTF mapping table acquisition parameters may include: STA and AP N SS according to the type of environment in which the the AP and the N SS corresponding to the type of the environment parameter as the parameter LTF.
  • the STA queries the mapping relationship table according to the environment type in which the N SS and the AP are located, and obtains parameters corresponding to the types of the N SS and the AP, and uses the parameter as the LTF parameter.
  • the STA obtains the LTF parameter according to the indication information and the pre-configured mapping relationship table. Including: the STA determines the parameter corresponding to the N SS as the LTF parameter according to the N SS .
  • the STA queries the mapping relationship table according to the N SS , obtains a parameter corresponding to the N SS , and uses the parameter as an LTF parameter.
  • the STA acquiring the LTF parameter according to the indication information and the pre-configured mapping relationship table may include: the STA determines the sub-length according to the length of the CP. the number of carriers S, and N is determined in accordance with the SS N and S, according to a further N SS, with the parameters corresponding to the SS N LTF determined parameters.
  • the method for determining the number of subcarriers S by the STA according to the length of the CP may refer to the description of the related content in the embodiment of the present invention, and details are not described herein again.
  • the STA from N and S, lookup mapping table, the SS may be determined N, then the mapping relationship table lookup according to the determined N of the SS, the SS to obtain parameters corresponding to N, and the determined parameter corresponding to the parameter LTF.
  • the method for determining the number of subcarriers S by the STA according to the length of the CP may refer to the description of the related content in the embodiment of the present invention, and details are not described herein again.
  • the process of the STA acquiring the LTF parameters according to the indication information and the pre-configured mapping relationship table may include: N SS and MCS characteristic information, and parameters corresponding to N SS and MCS characteristic information are used as LTF parameters.
  • the STA queries the mapping relationship table according to the N SS and MCS characteristic information, and obtains parameters corresponding to the N SS and MCS characteristic information, and uses the parameter as an LTF parameter.
  • the time domain inverse transform of the LTF sequence to obtain the LTF symbol according to the time domain transform parameter may specifically include step S507:
  • the STA performs despreading processing on the LTF sequence according to N to obtain an LTF symbol.
  • the STA may determine the number of spatial streams that are differentiated in the time domain according to N. For each spatial stream, the STA multiplies the LTF sequence by a corresponding spreading sequence to obtain an LTF symbol.
  • the spreading sequence is a sequence of the jth row in the N*N-dimensional P matrix, and can be obtained from the information interaction process with the AP.
  • the domain transformation parameter N can determine that the dimension of the P matrix is 2*2 dimensions and the number of spatial streams distinguished in the time domain is 2.
  • the STA obtains the spreading sequence of the first spatial stream in the information interaction process with the AP as the first line sequence in the 2*2 dimensional P matrix. Therefore, the STA multiplies the LTF sequence.
  • the LTF symbol can be obtained by the first line sequence in the 2*2-dimensional P matrix.
  • the despreading process can be performed with reference to the despreading process of the first spatial stream. Since the spreading sequence used by the STA in the despreading process of the LTF sequence is obtained from the information interaction with the AP, that is, the spreading sequence is the same as the spreading sequence used in the spreading process of the AP end, Therefore, it can be ensured that the STA can correctly despread the LTF symbol.
  • the STA performs inverse frequency domain transform on the LTF symbol according to the frequency domain transform parameter and I, to obtain an LTF basic sequence.
  • the STA may perform the LTF symbol in the frequency domain FDM manner or the frequency domain CDM manner according to the frequency domain transform parameter and the I.
  • the inverse domain transform yields the LTF base sequence.
  • the STA can use the frequency domain FDM method to enter the LTF symbol.
  • the inverse of the line frequency domain When the STA performs frequency domain inverse transform on the LTF symbol in the frequency domain FDM manner, the STA performs inverse frequency domain transformation on the LTF symbol according to the frequency domain transform parameter and I, and obtains the LTF basic sequence.
  • the specific sequence may include steps S508a1 to S508a3:
  • the STA determines the LTF basic symbol according to the LTF symbol.
  • CP is an element in [0, Lcp] in the LTF symbol
  • LTF basic symbol can be obtained by removing the elements in the LTF symbol that are in [0, Lcp].
  • the STA performs FFT transformation of the LTF base symbol at the S point to obtain a frequency domain LTF sequence.
  • STA starts from I according to the frequency domain LTF sequence, every The subcarriers extract the LTF basic sequence.
  • the STA may perform inverse mapping processing on the frequency domain LTF sequence according to the designed or acquired pattern according to the acquired M, L, S, and I to obtain the LTF basic sequence. Description Indicates rounding down.
  • the STA follows the design or the acquired pattern. Starting from I, from the frequency domain LTF sequence every The subcarriers extract the LTF basic sequence, where l is the first element in the frequency domain LTF sequence, I is the starting position of the subcarrier allocated to the spatial stream, and I 0 is the starting position of the available subcarriers.
  • the domain transformation parameter M can determine that the number of spatial streams distinguished in the frequency domain is 4, and correspondingly, the designed or acquired pattern is Taking the first spatial stream as an example, the m corresponding to the first spatial stream can be obtained through the information exchange process with the AP. The obtained m is equal to 0, because the starting position I 0 of the available subcarrier is 1, therefore, the subcarrier starting position I assigned to the spatial stream is equal to 1, and the STA follows the design or acquired pattern. Starting from subcarrier 1, the LTF basic sequence of the spatial stream is extracted from every four subcarriers in the frequency domain LTF sequence. For the remaining three spatial streams, the inverse mapping processing can be performed by referring to the inverse mapping processing method of the first spatial stream.
  • the STA can perform the inverse frequency domain transform on the LTF symbol by using the frequency domain CDM.
  • the STA performs the frequency domain inverse transform on the LTF symbol in the manner of the frequency domain CDM, the STA performs the inverse frequency domain transformation on the LTF symbol according to the frequency domain transform parameter and I, and obtains the LTF basic sequence.
  • the specific sequence may include steps S508b1 to S508b4:
  • the frequency domain transform parameter M may be the number of consecutive subcarriers used to distinguish the spatial stream, in the process of the frequency domain inverse transform of the LTF symbol by the STA in the frequency domain CDM manner.
  • the STA determines the LTF basic symbol according to the LTF symbol.
  • step S508a1 the process of determining the LTF basic symbol by the STA according to the LTF symbol may refer to the specific description in step S508a1, and details are not described herein again.
  • the STA performs FFT transformation of the LTF base symbol at the S point to obtain a frequency domain LTF sequence.
  • S508b3 The STA extracts the LTF spreading sequence from the corresponding subcarrier according to the frequency domain LTF sequence.
  • the STA After the STA obtains the frequency domain LTF sequence, the STA performs inverse mapping processing on the frequency domain LTF sequence according to the designed or acquired pattern to obtain an LTF spreading sequence, where the LTF spreading sequence includes M*L elements.
  • the STA follows the design or the acquired pattern. Extracting the LTF spreading sequence from the corresponding subcarrier from I, where l is the lth element in the LTF sequence, I is the starting position of the subcarrier allocated to the spatial stream, and I 0 is the available subcarrier. Starting position.
  • the domain transformation parameter M can determine that the number of spatial streams distinguished in the frequency domain is 4, and correspondingly, the designed or acquired pattern is Taking the first spatial stream as an example, since the starting position I 0 of the available subcarrier is equal to 1, the starting position I of the subcarrier allocated to the spatial stream is equal to 1, and the STA follows the design or acquired pattern.
  • the LTF spreading sequence of the spatial stream is extracted from the corresponding subcarrier starting from subcarrier 1.
  • the inverse mapping processing can be performed by referring to the inverse mapping processing method of the first spatial stream.
  • the STA performs despreading processing on the LTF spreading sequence according to M to obtain an LTF basic sequence.
  • the STA can determine the number of spatial streams that are differentiated in the frequency domain according to M. For each spatial stream, the STA multiplies the LTF spreading sequence by the corresponding spreading sequence to obtain the LTF basic sequence.
  • the spreading sequence is an ith row sequence in the M*M-dimensional P matrix, and can be obtained from the information interaction process with the AP.
  • the domain transformation parameter M can determine that the dimension of the P matrix is 4*4 dimensions and the number of spatial streams distinguished in the frequency domain is 4.
  • the STA obtains the spreading sequence of the first spatial stream in the information interaction process with the AP as the first line sequence in the 4*4 dimensional P matrix. Therefore, the STA multiplies the LTF sequence.
  • the LTF basic sequence can be obtained by the first line sequence in the 4*4 dimensional P matrix.
  • the despreading process can be performed with reference to the despreading process of the first spatial stream.
  • the spreading sequence used by the STA in the despreading process of the LTF spreading sequence is obtained from the information interaction with the AP, that is, the spreading sequence used in the spreading process of the spreading sequence and the AP end. The same, therefore, can ensure that the STA can correctly de-expand the LTF base sequence.
  • the STA performs channel estimation according to the LTF basic sequence.
  • the STA After the STA de-expands the LTF basic sequence, the STA can perform channel estimation according to the LTF basic sequence. Further, the CFO estimation can be performed according to the LTF basic sequence. After the STA obtains the channel estimation and the CFO estimation of the subcarrier carrying the LTF basic sequence, the channel estimation of all subcarriers is obtained by interpolation, and then the STA detects the data on the corresponding spatial stream according to the obtained channel estimation and CFO estimation.
  • the data frame transmission method provided by the embodiment of the present invention is applicable not only to the application scenario of the MU-MIMO technology in the downlink of the wireless local area network, but also to the application scenario of the SU-MIMO technology in the downlink of the wireless local area network and the downlink application of the wireless local area network.
  • Application scenarios of MU-MIMO and SU-MIMO technologies For the application scenario of the SU-MIMO technology in the WLAN downlink, the data frame transmission method is the same as or similar to the data frame transmission method of the application scenario of the MU-MIMO technology in the WLAN downlink, and the specific steps may be provided by referring to the embodiment of the present invention.
  • the specific steps of the data frame transmission method in the application scenario of the MU-MIMO technology in the downlink of the WLAN wherein the number of multiplexed spatial streams N SS is the number of data streams multiplexed by a single user;
  • the application scenario of the MIMO and the SU-MIMO technology, the data frame transmission method is the same as or similar to the data frame transmission method of the application scenario of the MU-MIMO technology in the WLAN downlink, and the specific steps may refer to the wireless provided by the embodiment of the present invention.
  • the first device is the STA and the second device is the AP.
  • the MIMO technology used in the WLAN is specifically MU-MIMO technology, and the specific implementation process is used as an example for the uplink data transmission process.
  • multiple STAs can communicate with the AP at the same time, and the spatial flow refers to the data flow that each user (STA) sends to the AP, and the data frame transmission method in the application scenario is as shown in FIG. 13 .
  • the specific method can include:
  • the AP acquires the LTF parameter according to the pre-configured mapping relationship table.
  • the AP may also acquire the allocated subcarrier starting position I and send the I to the STA.
  • step S501 the process of obtaining the LTF parameters by the AP according to the pre-configured mapping relationship table and the process of obtaining the allocated sub-carrier starting position I may refer to the specific description in step S501, and details are not described herein again.
  • the AP sends a second data frame carrying the indication message to the STA.
  • the indication information is used to obtain an LTF parameter that generates an LTF sequence.
  • the AP may first generate an LTF sequence according to the acquired LTF parameters and I, and then carry the generated LTF sequence and the indication information in the second data frame and send the information to the STA, or carry the indication information in the second data frame.
  • the present invention does not limit the manner in which the indication information is sent here.
  • the process of the AP may first generate the LTF sequence according to the obtained LTF parameters and I may refer to the specific description of the related content of the embodiment of the present invention, and details are not described herein again.
  • the STA receives the second data frame that is sent by the AP and carries the indication information.
  • the STA acquires the LTF parameter according to the indication information and the pre-configured mapping relationship table, and acquires the allocated subcarrier starting position I.
  • the STA may obtain the subcarrier starting position I of the spatial stream allocation according to the explicit signaling sent by the AP, or may obtain the subcarrier of the spatial stream allocation according to the implicit signaling sent by the AP.
  • the initial position I when the STA acquires the subcarrier start position I allocated by the spatial stream according to the implicit signaling sent by the AP, the allocated subcarrier starting position I obtained by the STA at this time is the default order of the received spatial stream.
  • step S506 the process of obtaining the LTF parameters by the STA according to the indication information and the pre-configured mapping relationship table may refer to the specific description in step S506, and details are not described herein again.
  • the STA performs frequency domain transformation on the LTF basic sequence according to the frequency domain transform parameter and I to obtain an LTF symbol.
  • the STA may use the frequency domain FDM mode or the frequency domain CDM according to the frequency domain transform parameter included in the acquired LTF parameter and the obtained allocated subcarrier starting position I.
  • the STA When the STA performs frequency domain transform on the LTF basic sequence by using the frequency domain FDM, the STA performs frequency domain transformation on the LTF basic sequence according to the frequency domain transform parameter and I, and obtains the LTF symbol.
  • the STA may include steps S605a1 to S605a3:
  • STA starts from I, every The subcarriers are mapped to the corresponding subcarriers by mapping each element in the LTF basic sequence to obtain a frequency domain LTF sequence.
  • the LTF basic sequence is allocated by the AP, and the STA may obtain the LTF basic sequence allocated by the AP from the information interaction process with the AP.
  • STA performs the IFFT transform of the S-point in the frequency domain LTF sequence to obtain LTF Basic symbol.
  • S605a3 The STA combines the LTF basic symbol and the CP to generate an LTF symbol.
  • the STA When the STA performs the frequency domain transform on the LTF basic sequence by using the frequency domain CDM, the STA performs frequency domain transformation on the LTF basic sequence according to the frequency domain transform parameter and I, and obtains the LTF symbol.
  • the STA may include steps S605b1 to S605b4:
  • the STA performs spreading processing on each element in the LTF basic sequence according to M, to obtain an LTF spreading sequence.
  • S605b2 The STA maps each element in the LTF spreading sequence to the corresponding subcarrier from I to obtain a frequency domain LTF sequence.
  • S605b3 The STA performs an IFFT transform of the S-point in the frequency domain LTF sequence to obtain an LTF basic symbol.
  • the STA combines the LTF basic symbol and the CP to generate an LTF symbol.
  • the STA may perform the time domain transform on the LTF symbol according to the time domain transform parameter to obtain the LTF sequence.
  • the STA may include step S606:
  • the STA performs a spreading process on the LTF symbol according to N to generate an LTF sequence.
  • the process of performing the frequency domain FDM transformation on the LTF basic sequence according to the frequency domain transformation parameter and the I may refer to the specific description of steps S502a1 to S502a3 in the embodiment of the present invention.
  • the STA may refer to the specific description of the steps S502b1 to S502b4 in the embodiment of the present invention.
  • step S606 For the process of performing the time domain transformation on the LTF symbol, that is, the specific description of the step S606, refer to the detailed description of the step S503 in the embodiment of the present invention, but the execution subject of the process is STA, and details are not described herein again.
  • M spatial streams can be distinguished by different subcarriers in the frequency domain
  • N spatial streams are distinguished by different spreading sequences in the time domain, so M* can be distinguished by frequency domain transform and time domain transform.
  • N spatial streams are distinguished by different subcarriers in the frequency domain.
  • the STA carries the LTF sequence in the first data frame and sends the data to the AP.
  • the STA since the AP has acquired the LTF parameter in step S601, the STA It is not necessary to notify the AP of the indication information for acquiring the LTF parameters, and only the LTF sequence is carried in the first data frame and sent to the AP.
  • the AP receives the first data frame that is sent by the STA and carries the LTF sequence.
  • the AP After receiving the first data frame that carries the LTF sequence sent by the STA, the AP directly obtains the LTF parameter stored by the STA, and performs inverse time domain transform on the LTF sequence to obtain the LTF according to the time domain transform parameter included in the obtained LTF parameter.
  • the symbol may specifically include step S609:
  • the AP despreads the LTF sequence according to N to obtain an LTF symbol.
  • S610 The AP performs frequency domain inverse transform on the LTF symbol according to the frequency domain transform parameter and I, to obtain an LTF basic sequence.
  • the AP After the AP performs time-domain inverse transform on the LTF sequence to obtain the LTF symbol according to the time domain transform parameter, the AP acquires the allocated subcarrier start position I, and then adopts the frequency domain FDM manner according to the frequency domain transform parameter and I. Or the frequency domain CDM method performs inverse frequency domain transform on the LTF symbols to obtain the LTF basic sequence.
  • the AP can perform the inverse frequency domain transform on the LTF symbol in the frequency domain FDM mode.
  • the AP performs frequency domain inverse transform on the LTF symbol in the frequency domain FDM manner, the AP performs inverse frequency domain transformation on the LTF symbol according to the frequency domain transform parameter and I, and obtains the LTF basic sequence.
  • the specific sequence may include steps S610a1 to S610a3:
  • AP determines the LTF basic symbol according to the LTF symbol.
  • the AP can perform the inverse frequency domain transform on the LTF symbol by using the frequency domain CDM.
  • the AP performs frequency domain inverse transform on the LTF symbol by using the frequency domain CDM, the AP performs inverse frequency domain transformation on the LTF symbol according to the frequency domain transform parameter and I, and obtains the LTF basic sequence.
  • the specific steps may include steps S610b1 to S610b4:
  • the AP determines the LTF basic symbol according to the LTF symbol.
  • the S610b3 and the AP extract the LTF spreading sequence from the corresponding subcarriers from the I according to the frequency domain LTF sequence.
  • S610b4 and the AP perform despreading processing on the LTF spreading sequence according to M to obtain an LTF basic sequence.
  • the AP performs channel estimation according to the LTF basic sequence.
  • the number of multiplexed spatial streams N SS is the number of users multiplexed by multiple users.
  • the first device is the STA and the second device is the AP.
  • the MIMO technology used in the WLAN is specifically the SU-MIMO technology, and the specific implementation process is used for the uplink data transmission process.
  • there are multiple spatial streams between the AP and the STA and the spatial flow refers to the data flow between the AP and the STA.
  • the data frame transmission method in the application scenario is as shown in Figure 14. The method can include:
  • the STA acquires an LTF parameter, and obtains an allocated subcarrier starting position I.
  • the acquiring process of the sub-carrier starting position I in the frequency domain may be obtained by the STA allocation.
  • the specific obtaining process is: the STA allocates the sub-carrier starting position I or the STA for each spatial stream according to the actual application scenario.
  • Each spatial stream is assigned a subcarrier starting position I in the same order as the spatial stream according to the order of each spatial stream.
  • S702 The STA performs frequency domain transformation on the LTF basic sequence according to the frequency domain transform parameter and the I, to obtain an LTF symbol.
  • the STA may use the frequency domain according to the obtained frequency domain transform parameter included in the acquired LTF parameter and the obtained allocated subcarrier start position I.
  • FDM mode or frequency domain CDM side The LTF basic sequence is subjected to frequency domain transform to obtain LTF symbols.
  • the STA When the STA performs the frequency domain transform on the LTF basic sequence by using the frequency domain FDM, the STA performs frequency domain transformation on the LTF basic sequence according to the frequency domain transform parameter and I, and obtains the LTF symbol.
  • the STA may include steps S702a1 to S702a3:
  • STA starts from I, every The subcarriers are mapped to the corresponding subcarriers by mapping each element in the LTF basic sequence to obtain a frequency domain LTF sequence.
  • the basic sequence of the LTF is allocated by the STA.
  • the STA directly obtains the stored basic sequence of the LTF; and the pre-configured mapping table in the STA adopts the second mode, the third mode, and the fourth mode.
  • the STA may select the LTF basic sequence to be used from the pre-stored LTF basic sequence according to the frequency domain transformation parameter L included in the LTF parameter. For example, when the frequency domain transform parameter L included in the LTF parameter acquired by the STA is 56, the LTF basic sequence selected according to L may be:
  • LTF base sequence ⁇ 1 1 LTF left 0 LTF right -1 -1 ⁇
  • LTF left and LTF right contain 26 elements.
  • S702a2 The STA performs an IFFT transform of the S-point in the frequency domain LTF sequence to obtain an LTF basic symbol.
  • S702a3 The STA combines the LTF basic symbol and the CP to generate an LTF symbol.
  • the STA When the STA performs frequency domain transform on the LTF basic sequence by using the frequency domain CDM, the STA performs frequency domain transformation on the LTF basic sequence according to the frequency domain transform parameter and I, and obtains the LTF symbol.
  • the STA may include steps S702b1 to S702b4:
  • the STA performs spreading processing on each element in the LTF basic sequence according to M, to obtain an LTF spreading sequence.
  • S702b2 The STA maps each element in the LTF spreading sequence to the corresponding subcarrier from I to obtain a frequency domain LTF sequence.
  • S702b3 The STA performs an IFFT transform of the S-point in the frequency domain LTF sequence to obtain an LTF basic symbol.
  • S702b4 The STA combines the LTF basic symbol and the CP to generate an LTF symbol.
  • the STA may transform the parameter according to the time domain,
  • the LTF symbol performs a time domain transform to obtain an LTF sequence, and specifically includes step S703:
  • S703 The STA performs a spreading process on the LTF symbol according to the N to generate an LTF sequence.
  • M spatial streams can be distinguished by different subcarriers in the frequency domain
  • N spatial streams are distinguished by different spreading sequences in the time domain, so M* can be distinguished by frequency domain transform and time domain transform.
  • N spatial streams are distinguished by different subcarriers in the frequency domain.
  • the STA may notify the AP of the indication information for acquiring the LTF parameter.
  • the STA sends the LTF sequence to the AP in the first data frame, which may include the following step S704:
  • the STA carries the LTF sequence and the indication information in the first data frame and sends the information to the AP.
  • the AP receives the first data frame that is sent by the STA and carries the LTF sequence and the indication information.
  • the AP acquires the LTF parameter according to the indication information and the pre-configured mapping relationship table, and acquires the allocated subcarrier starting position I.
  • the AP may obtain the subcarrier starting position I of the spatial stream allocation according to the explicit signaling sent by the STA, or obtain the subcarrier starting position I of the spatial stream allocation according to the implicit signaling sent by the STA, when the AP sends an implicit signaling according to the STA.
  • the subcarrier starting position I of the spatial stream allocation is obtained, the allocated subcarrier starting position I acquired by the AP at this time is the default order of the received spatial streams.
  • mapping relationship table may specifically be composed of any one of the following ways:
  • the mapping relationship table includes the number of multiplexed spatial streams N SS , the type of the AP, and parameters corresponding to the types of the N SS and the AP.
  • the number of multiplexed spatial streams N SS is the number of data streams multiplexed by a single user.
  • the mapping relationship table includes the number of multiplexed spatial streams N SS , the type of the environment in which the AP is located, and parameters corresponding to the number of users N SS and the environment type in which the AP is located.
  • the mapping relationship table includes the number of multiplexed spatial streams N SS and parameters corresponding to N SS .
  • the mapping relationship table includes the number of multiplexed spatial streams N SS , MCS characteristic information, and parameters corresponding to N SS and MCS characteristic information.
  • the method for obtaining the LTF parameters according to the indication information and the pre-configured mapping relationship table may include: the AP according to the N SS and the AP, when the configuration of the pre-configured mapping relationship table in the AP is mode 1, when the indication information includes the N SS , the AP may obtain the LTF parameter according to the indication information and the pre-configured mapping relationship table.
  • Type which takes the parameters corresponding to the types of N SS and AP as LTF parameters.
  • the AP obtains the LTF parameter according to the indication information and the pre-configured mapping relationship table, and the AP may include: the AP according to the N SS and the AP.
  • the type of environment in which the N SS and the AP are in the environment type are used as the LTF parameters.
  • the AP obtains the LTF parameter according to the indication information and the pre-configured mapping relationship table. Including: the AP according to N SS , the parameter corresponding to the N SS is used as the LTF parameter.
  • the acquiring the LTF parameters by the AP according to the indication information and the pre-configured mapping relationship table may include: determining, by the AP, the length of the CP. the number of carriers S, and N is determined in accordance with the SS N and S, according to a further N SS, with the parameters corresponding to the SS N LTF determined parameters.
  • the method for determining the number of subcarriers S by the AP according to the length of the CP may refer to the method for determining the number of subcarriers S by the STA according to the length of the CP, and details are not described herein again.
  • the AP obtains the LTF parameter according to the indication information and the pre-configured mapping relationship table, and the AP may include: the AP according to the N SS And the MCS characteristic information, the parameters corresponding to the N SS and MCS characteristic information are used as the LTF parameters.
  • the time domain inverse transform of the LTF sequence to obtain the LTF symbol according to the time domain transform parameter may specifically include step S707:
  • the AP despreads the LTF sequence according to N to obtain an LTF symbol.
  • S708 The AP performs frequency domain inverse transform on the LTF symbol according to the frequency domain transform parameter and I, to obtain an LTF basic sequence.
  • the AP may perform the LTF symbol in a frequency domain FDM manner or a frequency domain CDM manner according to the frequency domain transform parameter and the I.
  • the inverse domain transform yields the LTF base sequence.
  • the AP can perform the inverse frequency domain transform on the LTF symbol in the frequency domain FDM mode.
  • the AP performs frequency domain inverse transform on the LTF symbol in the frequency domain FDM manner, the AP performs inverse frequency domain transformation on the LTF symbol according to the frequency domain transform parameter and I, and obtains the LTF basic sequence.
  • the specific sequence may include steps S708a1 to S708a3:
  • the AP determines the LTF basic symbol according to the LTF symbol.
  • the AP performs FFT transformation of the LTF base symbol at the S point to obtain a frequency domain LTF sequence.
  • the AP can perform the inverse frequency domain transform on the LTF symbol by using the frequency domain CDM.
  • the AP performs frequency domain inverse transform on the LTF symbol by using the frequency domain CDM
  • the AP performs inverse frequency domain transformation on the LTF symbol according to the frequency domain transform parameter and I, and obtains the LTF basic sequence.
  • the specific sequence may include steps S708b1 to S708b4:
  • the AP determines the LTF basic symbol according to the LTF symbol.
  • S708b2 The AP performs FFT transformation of the LTF base symbol at the S point to obtain a frequency domain LTF sequence.
  • S708b3 The AP extracts the LTF spreading sequence from the corresponding subcarrier according to the frequency domain LTF sequence.
  • S708b4 The AP performs despreading processing on the LTF spreading sequence according to M to obtain an LTF basic sequence.
  • the AP performs channel estimation according to the LTF basic sequence.
  • steps S701 to S709 can refer to the specific description in steps S501 to S509, and details are not described herein again.
  • the AP communicates with multiple STAs simultaneously in the application scenario, and multiple communication processes exist between each STA and the AP.
  • a spatial stream that includes the data streams of all users transmitted between the AP and the STA.
  • the same crystal oscillator is used for the spatial stream transmitted between the same STA and the AP, that is, the frequency offset of the spatial stream transmitted between the same STA and the AP is the same, and the time domain is positive.
  • the intercommunication can be maintained, so the spatial stream transmitted between the same STA and the AP can be distinguished by using the time domain CDM method; and the spatial stream transmitted between the AP and different STAs is used for the spatial stream transmitted between the AP and different STAs.
  • the orthogonality in the time domain is not easy to maintain, and the spatial stream transmitted between the AP and different STAs can be distinguished by using frequency domain FDM or frequency domain CDM as much as possible.
  • the length of the LTF sequence needs to be reduced. Therefore, it is necessary to adjust the parameters such as N, M, S, and L in the mapping table.
  • the value of the number M of subcarriers used to distinguish the spatial streams may be used. Determined to be 2, the number N of LTF symbols included in the LTF sequence is determined to be 4; if the AP communicates with four STAs at the same time, there are two spatial streams in the process of communication between each STA and the AP, according to the above rules, The value of the number M of subcarriers for distinguishing the spatial streams is determined to be 4, and the number N of LTF symbols included in the LTF sequence is determined to be 2.
  • the method for transmitting a data frame provided by the present invention, the first device performs frequency domain transformation on the LTF basic sequence according to the frequency domain transform parameter included in the acquired LTF parameter and the obtained allocated subcarrier starting position I to obtain an LTF symbol, and according to The time domain transform parameter included in the LTF parameter performs time domain transform on the LTF symbol to obtain an LTF sequence, and then the obtained LTF sequence is carried in the first data frame and sent to the second device, so that the second device determines the LTF basic sequence according to the LTF sequence. And perform channel estimation based on the LTF basic sequence.
  • the first device reduces the number of LTF symbols included in the LTF sequence by distinguishing the spatial stream in the frequency domain and the time domain, thereby saving signaling overhead and reducing data reception time. Delay.
  • the crosstalk probability between symbols in the time domain is reduced, thereby better resisting the influence of Doppler shift.
  • the transmission device includes a processor 81 and a transmitter 82.
  • the processor 81 is configured to obtain a long training code part LTF parameter, and obtain an allocated subcarrier starting position I, where the LTF parameter includes: a frequency domain transform parameter and a time domain transform parameter required to generate an LTF sequence; The frequency domain transform parameter and the I, perform frequency domain transform on the LTF basic sequence to obtain an LTF symbol; and perform time domain transform on the LTF symbol according to the time domain transform parameter to obtain the LTF sequence.
  • the transmitter 82 is configured to carry the LTF sequence obtained by the processor 81 in a first data frame and send the data to the second device, so that the second device determines the LTF basic sequence according to the LTF sequence, and Channel estimation is performed according to the LTF basic sequence.
  • the frequency domain transform parameter further includes: a number M of subcarriers used to distinguish the spatial stream, an element number L of the LTF basic sequence, and a number of subcarriers S.
  • the processor 81 is specifically configured to start from the I and every a subcarrier, mapping each element in the LTF base sequence to a corresponding subcarrier to obtain a frequency domain LTF sequence; The rounding down is performed; the frequency domain LTF sequence is subjected to an inverse fast Fourier transform IFFT transform of the S point to obtain an LTF basic symbol; and the LTF basic symbol and the cyclic prefix CP are combined to generate the LTF symbol.
  • the frequency domain transform parameter further includes: a number M of subcarriers used to distinguish the spatial stream, an element number L of the LTF basic sequence, and a number of subcarriers S.
  • the processor 81 is specifically configured to: perform spreading processing on each element in the LTF basic sequence according to the M, to obtain an LTF spreading sequence; and the LTF spreading sequence
  • the column includes M*L elements; mapping each element in the LTF spreading sequence to the corresponding subcarrier from the I to obtain a frequency domain LTF sequence; and performing the frequency domain LTF sequence at the S point
  • the IFFT transform obtains an LTF basic symbol; combining the LTF basic symbol and the CP to generate the LTF symbol.
  • the time domain transform parameter further includes: the number N of the LTF symbols included in the LTF sequence.
  • the processor 81 is specifically configured to perform a spreading process on the LTF symbol according to the N to generate the LTF sequence.
  • the transmission device is a site STA
  • the second device is an access point AP.
  • the transmission device further includes: a receiver 83.
  • the receiver 83 is configured to receive a second data frame that carries the indication information that is sent by the second device, where the indication information is used to indicate the LTF parameter.
  • the processor 81 is specifically configured to acquire the LTF parameter according to the indication information and a pre-configured mapping relationship table.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the type corresponding to the N SS and the AP. parameter.
  • the processor 81 is specifically configured to use the N SS and the The type of the AP, the parameter corresponding to the N SS and the type of the AP is used as the LTF parameter.
  • the processor 81 is specifically configured to be used according to the determining a type of the AP S; wherein there is a corresponding relationship between the AP and the S type; according to the type of the AP and N SS, corresponding to the type of the N SS and parameters of the AP As the LTF parameter.
  • the processor 81 is specifically configured to determine the S according to the length of the CP. And determining, according to the S, the type of the AP; according to the N SS and the type of the AP, using a parameter corresponding to the type of the N SS and the AP as the LTF parameter.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the environment type in which the AP is located, and the N SS and the AP The parameter corresponding to the environment type; the indication information includes the N SS , and the transmission device has acquired the environment type in which the AP is located when accessing the AP.
  • the processor 81 according to the specific environment and the type of the N SS AP is located, the type of environment and parameters of the N SS corresponding to the AP and the LTF located as parameter.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams and the parameter corresponding to the N SS .
  • the processor 81 is specifically configured to determine, according to the N SS , a parameter corresponding to the N SS as the LTF parameter.
  • the processor 81 is specifically configured to determine the number of subcarriers S according to the length of the CP; according to the N and the S Determining the N SS and determining a parameter corresponding to the N SS as the LTF parameter according to the N SS .
  • the mapping relationship table includes the number of multiplexed spatial streams N SS , modulation and coding policy MCS characteristic information, and the N SS and the MCS characteristic information.
  • the indication information includes the N SS and the MCS characteristic information.
  • the processor 81 is specifically configured to use, as the LTF parameter, a parameter corresponding to the N SS and the MCS characteristic information according to the N SS and the MCS characteristic information.
  • the transmission device is an AP, and the second device is an STA; or the transmission device is an STA, and the second device is an AP.
  • the processor 81 is specifically configured to acquire the LTF parameter according to a pre-configured mapping relationship table.
  • the transmitter 82 is configured to carry the LTF sequence and the indication information in the first data frame and send the information to the second device, so that the second device is configured according to the LTF sequence and the indication information.
  • the LTF base sequence is determined.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the type corresponding to the N SS and the AP. a parameter; and when the transmission device is an STA, the transmission device has acquired the type of the AP when accessing the AP.
  • the processor 81 according to the specific type of the N SS and the AP, the parameters corresponding to the type of the N SS and the AP as a parameter the LTF.
  • the transmitting device is the STA
  • the second device is the AP
  • the indication information includes the N SS .
  • the indication information includes the N SS ; or the indication information includes the N SS and the number of subcarriers S.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the environment type in which the AP is located, and the N SS and the AP The parameter corresponding to the environment type at the location; and when the transmission device is an STA, the transmission device has acquired the environment type in which the AP is located when accessing the AP.
  • the processor 81 according to the specific environment and the type of the N SS AP is located, the N SS and the corresponding parameter of the type of environment in which the AP as a parameter of the LTF; the The indication information includes the N SS .
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams and the parameter corresponding to the N SS .
  • the processor 81 is specifically configured to determine, according to the N SS , a parameter corresponding to the N SS as the LTF parameter; the indication information includes the N SS ; or the indication information includes the The number N of LTF symbols included in the LTF sequence.
  • the mapping relationship table includes the number of multiplexed spatial streams, N SS , MCS characteristic information, and parameters corresponding to the N SS and the MCS characteristic information.
  • the processor 81 is specifically configured to use, as the LTF parameter, a parameter corresponding to the N SS and the MCS characteristic information according to the N SS and the MCS characteristic information; the indication information includes the N SS and the MCS characteristic information.
  • the number of the multiplexed spatial streams includes: a number of users multiplexed by multiple users and/or a number of data streams multiplexed by a single user.
  • the transmission device provided by the present invention performs frequency domain transformation on the LTF basic sequence according to the frequency domain transform parameter included in the acquired LTF parameter and the obtained allocated subcarrier starting position I to obtain an LTF symbol, and according to the time included in the LTF parameter.
  • the domain transform parameter performs time domain transform on the LTF symbol to obtain an LTF sequence, and then the obtained LTF sequence is carried in the first data frame and sent to the second device, so that the second device determines the LTF basic sequence according to the LTF sequence, and according to the LTF basic sequence. Perform channel estimation.
  • the transmission device distinguishes the number of LTF symbols included in the LTF sequence by distinguishing the spatial stream in the frequency domain and the time domain, thereby saving signaling overhead and reducing the delay of receiving the data portion. .
  • the crosstalk probability between symbols in the time domain is reduced, thereby better resisting the influence of Doppler shift.
  • the receiver includes a receiver 91 and a processor 92.
  • the receiver 91 is configured to receive a first data frame that is sent by the first device and carries a long training code portion LTF sequence.
  • the processor 92 is configured to determine an LTF basic sequence according to the received LTF sequence received by the receiver 91, and perform channel estimation according to the LTF basic sequence.
  • the processor 92 is further configured to: before determining the LTF basic sequence according to the LTF sequence, acquiring an LTF parameter, and acquiring an allocated subcarrier starting position I;
  • the LTF parameter includes: a frequency domain transform parameter and a time domain transform parameter required by the first device to generate the LTF sequence.
  • the processor 92 is configured to perform inverse time domain transform on the LTF sequence to obtain an LTF symbol according to the time domain transform parameter, and perform the LTF symbol according to the frequency domain transform parameter and the I
  • the inverse frequency domain transform yields the LTF base sequence.
  • the time domain transform parameter further includes: the number N of the LTF symbols included in the LTF sequence.
  • the processor 92 is specifically configured to perform despreading processing on the LTF sequence according to the N to obtain the LTF symbol.
  • the frequency domain transform parameter further includes: a number M of subcarriers used to distinguish the spatial stream, an element number L of the LTF basic sequence, and a number of subcarriers S.
  • the processor 92 is specifically configured to: determine an LTF basic symbol according to the LTF symbol; wherein the LTF symbol is composed of the LTF basic symbol and a cyclic prefix CP; and fast performing the STF point by using the LTF basic symbol a Fourier transform FFT transform to obtain a frequency domain LTF sequence; according to the frequency domain LTF sequence, starting from the I, every Subcarriers extract the LTF base sequence; Indicates rounding down.
  • the frequency domain transform parameter further includes: a number M of subcarriers used to distinguish the spatial stream, an element number L of the LTF basic sequence, and a number of subcarriers S.
  • the processor 92 is specifically configured to: determine an LTF basic symbol according to the LTF symbol; wherein the LTF symbol is composed of the LTF basic symbol and a CP; and perform an FFT transformation of the LTF basic symbol by an S point to obtain a frequency a LTF sequence; according to the frequency domain LTF sequence, extracting an LTF spreading sequence from the corresponding subcarrier from the I; wherein the LTF spreading sequence includes M*L elements; according to the M despreading the LTF spreading sequence to obtain the LTF basic sequence.
  • the first device is a station STA
  • the transmission device is an access point AP.
  • the processor 92 is further configured to acquire the LTF parameter according to a pre-configured mapping relationship table before the receiver 91 receives the first data frame that is sent by the first device and carries the long training code portion LTF sequence.
  • the transmission device further includes: a transmitter 93.
  • the transmitter 93 is configured to send, to the first device, a second data frame that carries the indication information, where the indication information indicates the LTF parameter.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the type corresponding to the N SS and the AP. parameter.
  • the processor 92 in particular according to the type of the AP and the SS N, corresponding to the type of the parameter of the SS N and the AP as a parameter of the LTF; the indication information comprises the N SS ; or, the indication information includes the N SS and the number of subcarriers S.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the environment type in which the AP is located, and the N SS and the AP The parameter corresponding to the environment type.
  • the processor 92 according to the specific environment and the type of the N SS AP is located, the N SS and the corresponding parameter of the type of environment in which the AP as a parameter of the LTF; the The indication information includes the N SS .
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams and the parameter corresponding to the N SS .
  • the processor 92 is specifically configured to determine, according to the N SS , a parameter corresponding to the N SS as the LTF parameter; the indication information includes the N SS ; or the indication information includes the The number N of LTF symbols included in the LTF sequence.
  • the mapping relationship table includes the number of multiplexed spatial streams, N SS , MCS characteristic information, and parameters corresponding to the N SS and the MCS characteristic information.
  • the processor 92 is specifically configured to use, as the LTF parameter, a parameter corresponding to the N SS and the MCS characteristic information according to the N SS and the MCS characteristic information;
  • the indication information includes the N SS and the MCS characteristic information.
  • the first device is an AP, and the transmission device is an STA; or the first device is an STA, and the transmission device is an AP.
  • the receiver 91 is configured to receive, by the first device, the carrying The LTF sequence and the first data frame of the indication information.
  • the processor 92 is configured to acquire the LTF parameter according to the indication information received by the receiver 91 and a pre-configured mapping relationship table.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the type of the AP, and the type corresponding to the N SS and the AP. parameter.
  • the transmission device is the AP
  • the indication information includes the N SS
  • the processor 92 is specifically configured to: according to the N SS and the type of the AP A parameter corresponding to the type of the N SS and the AP is used as the LTF parameter.
  • the transmission device is the STA.
  • the processor 92 is specifically configured to use the N SS and the The type of the AP, the parameter corresponding to the N SS and the type of the AP is used as the LTF parameter.
  • the processor 92 is specifically configured to be used according to the determining a type of the AP S; wherein there is a corresponding relationship between the AP and the S type; according to the type of the AP and N SS, corresponding to the type of the N SS and parameters of the AP As the LTF parameter.
  • the processor 92 is specifically configured to determine the S according to the length of the CP. And determining, according to the S, the type of the AP; according to the N SS and the type of the AP, using a parameter corresponding to the type of the N SS and the AP as the LTF parameter.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams, the environment type in which the AP is located, and the N SS and the AP a parameter corresponding to the environment type; the indication information includes the N SS , and when the transmission device is the STA, the transmission device acquires the AP when the AP accesses the AP Type of environment.
  • the processor 92 according to the specific environment and the type of the N SS AP is located, the type of environment and parameters of the N SS corresponding to the AP and the LTF located as parameter.
  • the mapping relationship table includes the number N SS of the multiplexed spatial streams and the parameter corresponding to the N SS .
  • the processor 92 is specifically configured to use, according to the N SS , a parameter corresponding to the N SS as the LTF parameter.
  • the processor 92 is specifically configured to determine the number of subcarriers S according to the length of the CP; according to the N and the S Determining the N SS and determining a parameter corresponding to the N SS as the LTF parameter according to the N SS .
  • the mapping relationship table includes the number of multiplexed spatial streams N SS , modulation and coding policy MCS characteristic information, and the N SS and the MCS characteristic information.
  • the indication information includes the N SS and the MCS characteristic information.
  • the processor 92 is specifically configured to use, as the LTF parameter, a parameter corresponding to the N SS and the MCS characteristic information according to the N SS and the MCS characteristic information.
  • the number of the multiplexed spatial streams includes: a number of users multiplexed by multiple users and/or a number of data streams multiplexed by a single user.
  • the first device performs frequency domain transformation on the LTF basic sequence according to the frequency domain transform parameter included in the acquired LTF parameter and the obtained allocated subcarrier starting position I to obtain an LTF symbol, and according to the LTF parameter.
  • the included time domain transform parameter performs time domain transform on the LTF symbol to obtain an LTF sequence, and then the obtained LTF sequence is carried in the first data frame and sent to the transmission device, so that the transmission device determines the LTF basic sequence according to the LTF sequence, and according to the LTF basic The sequence performs channel estimation.
  • First device In the process of generating the LTF sequence, by dividing the spatial stream in the frequency domain and the time domain, the number of LTF symbols included in the LTF sequence is reduced, thereby saving signaling overhead and reducing the delay of data portion reception. At the same time, since the number of LTF symbols included in the LTF sequence is reduced during data frame transmission, the crosstalk probability between symbols in the time domain is reduced, thereby better resisting the influence of Doppler shift.
  • the disclosed apparatus and method may be implemented in other manners.
  • the device embodiments described above are merely illustrative.
  • the division of the modules or units is only a logical function division.
  • there may be another division manner for example, multiple units or components may be used.
  • the combination may be integrated into another device, or some features may be ignored or not performed.
  • the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.
  • FIG. 17a the system for uplink signal transmission shown in Fig. 17b.
  • the specific structure of the LTF Transmitter can be referred to FIG. 18a and FIG. 18b.
  • the specific structure of the LTF receiving module can refer to FIG. 19a and FIG. 19b.
  • the flow or working principle is as shown in FIG. 10, FIG. 13, and FIG. A detailed description of the corresponding content shown. I will not go into details here.
  • an AP or STA of a WiFi system may include a control module to acquire LTF parameters of the FDM/CDM in the CDM and the frequency domain in the time domain.
  • the LTF parameter is used to generate an LTF sequence, and the AP and the STA share the information about the LTF parameter, so that the LTF sequence is generated by the LTF parameter acquired by the sending end (AP or STA) through the control module, and the receiving end (when the transmitting end is the AP, The receiving end is the STA; when the transmitting end is the STA, the receiving end is the AP) receiving the LTF sequence through the LTF parameter obtained by the control message receiving module (Control information reception).
  • the multi-stream or multi-user channel estimation is jointly identified by using time domain and frequency domain resources.
  • the AP end is designed or obtained by a control unit (Control Unit), and the LTF sequence is generated by the LTF transmitter according to the designed or acquired LTF parameters. Part of the parameters designed or acquired are placed in the SIG-A by the Control message transmitter, and the Frame muttiptexing frame is formed according to the frame structure, together with the generated LTF sequence and the downlink data, to form a packet (packet). Frame) is sent to the STA by the radio frequency transmitting module (TX).
  • TX radio frequency transmitting module
  • the packet frame received by the radio receiving module receives the information of the SIG-A by the control message receiving module, extracts the design of the LTF sequence or acquires parameters, and then receives the module by the LTF. (LTF reception) to distinguish the LTF basic sequence corresponding to the receiving STA from the design or acquisition parameters of the LTF sequence and to perform channel estimation and CFO estimation using the LTF basic sequence (where CFO estimation is optional).
  • the above-mentioned MU-MIMO is taken as an example.
  • the LTF parameters of multiple users need to be designed or acquired by the Control Unit on the AP side, and the LTF sequence is generated by the LTF transmitter according to the designed or acquired LTF parameters.
  • Some parameters designed or obtained are placed in the SIG-A by the Control information transmitter, and enter the Frame muttiptexing module according to the frame structure, together with the downlink data, and the packet frame is sent by the TX to the STA.
  • the data received by the RX is received by the Control Information Reception to receive the information of the SIG-A, and the design or acquisition parameters of the LTF sequence are extracted therefrom, and then the LTF transmitter module generates each STA according to the design or acquisition parameters of the LTF sequence.
  • the LTF sequence, into the Frame muttiptexing module, according to the frame structure along with the uplink data, constitutes a packet frame TX is sent to the AP.
  • the LTF reception receives the LTF basic sequence of each STA according to the LTF parameters designed or acquired by the Control Unit and uses the LTF basic sequence for channel estimation and CFO estimation (where CFO estimation is optional).
  • the Control Unit and Control information transmitter responsible for designing or acquiring the LTF parameters may also be included in the STA, and the STA designs or acquires the LTF parameters according to the number of SU-MIMO streams, instead of being designed by the AP or Get notified to STA.
  • the corresponding Control information reception is included on the AP side for extracting the design or acquiring parameters of the LTF sequence from the SIG-A.
  • LTF parameters include various applications that can set different applications for generating LTF parameters, including but not limited to the number of spatial streams N SS , environment type or MCS. characteristic. Take the environment type as an example, except for indoor or outdoor, including but not limited to dense areas (such as shopping malls, stadiums or office areas), non-dense areas (such as households); or remote areas, urban areas. In short, different parameters are used for different applications as long as the LTF is generated, that is, within the scope of the embodiments of the present invention.
  • mapping relationship table may be modified according to actual conditions: for example, the AP does not need to be moved, and generally does not need to be moved in an application environment. And changing, so that only one or a part of the type of parameters can be configured on the AP, wherein the parameter includes at least a frequency domain transform parameter different from the prior art, for example, the subcarrier of the spatial stream that is included in the LTF symbol included in the LTF sequence Number M, (see Table 2, 3, 3a for parameters under Type 2, or Tables 4 and 5 for Environment Types 1 and 2, Table 5a for Environment Type 1 for parameters, see Tables 6, 7. Parameters under 7a, 7b).
  • some STAs may also configure only some of the types mentioned in this embodiment and their corresponding parameters for unknown reasons.
  • the mapping relationship table in each embodiment is only an example of the content of the mapping relationship.
  • the mapping relationship table in each embodiment may be combined when there is no conflict; on the other hand, in a specific AP or STA.
  • the specific form or state of storage is not limited.
  • an AP or an STA can store both tables 6, 7, 7a, and 7b.
  • the parameters are selected as needed.
  • the stored mapping relationship may also be a string, or an arrangement for saving storage resources according to actual needs: for example, some individual parameters that are not changed according to application conditions are set as default parameters, and no need for repeated storage, for example, a table.
  • the parameter S in 4, 5, 5a; or, the value of the parameter is indicated by a special indication value to save storage resources.
  • the specific content in the mapping relationship table in each embodiment is adopted, that is, within the scope of the present embodiment.
  • the units described as separate components may or may not be physically separated, and the components displayed as units may be one physical unit or multiple physical units, that is, may be located in one place, or may be distributed to multiple different places. . Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.
  • each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.
  • the above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.
  • the integrated unit if implemented in the form of a software functional unit and sold or used as a standalone product, may be stored in a readable storage medium. Based on such understanding, the technical solution of the present invention may contribute to the prior art or all or part of the technical solution may be embodied in the form of a software product stored in a storage medium. A number of instructions are included to cause a device (which may be a microcontroller, chip, etc.) or a processor to perform all or part of the steps of the methods described in various embodiments of the present invention.
  • the foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like. .

Abstract

本发明公开了一种传输设备和数据帧的传输方法，涉及通信领域，节省了信令开销，降低了数据部分接收的时延。具体方案为：获取单元获取LTF参数，并获取分配的子载波起始位置I；其中，LTF参数包括：生成LTF序列所需的频域变换参数以及时域变换参数；频域变换单元根据频域变换参数和起始位置I，对LTF基本序列进行频域变换得到LTF符号；时域变换单元根据时域变换参数，对LTF符号进行时域变换得到LTF序列；发送单元将LTF序列携带在第一数据帧中发送至第二设备，以便第二设备根据LTF序列确定LTF基本序列，并根据LTF基本序列进行信道估计。本发明用于数据帧的传输过程中。

Description

一种传输设备和数据帧的传输方法 技术领域
本发明涉及通信领域，尤其涉及一种传输设备和数据帧的传输方法。
背景技术
随着智能终端的广泛应用，人们对数据网络流量的需求日益增长。为了满足人们对数据网络流量的需求，需要不断提高网络系统的性能。为此，无线局域网在这方面做了很大的演进，已从最初的802.11a/b演进到802.11g、802.11n，再演进到802.11ac，随着标准的不断演进，系统可以提供的吞吐量不断增大，从而满足用户上网的各种需求。
在802.11ac系统中，802.11ac的表示协议数据单元(Presentation Protocol Data Unit，PPDU)的结构中包含的超高吞吐量长训练码部分(Very High Throughput-Long Training Field，VHT-LTF)是采用时域码分复用(Code Division Multiplexing，CDM)的方式生成得到的，其可以用于实现单用户多输入多输出(Single User-Multiple Input Multiple Output，SU-MIMO)场景下，区分多流的信道估计；或者也可以用于实现多用户多输入多输出(Multiple User-Multiple Input Multiple Output，MU-MIMO)场景下，区分多用户的信道估计。
现有技术中的802.11ac标准是针对室内环境设计或者获取的，对于室外的环境，由于存在相对于室内环境较长的多径效应，为了避免正交频分复用(Orthogonal Frequency Division Multiplexing，OFDM)符号间干扰，需要增加循环前缀(Cyclic Prefix，CP)长度，若仍采用时域CDM的方式生成VHT-LTF，VHT-LTF中包含的多个VHT-LTF符号需要的多个CP则会导致信令开销增加，数据部分延迟接收。
发明内容
本发明提供一种传输设备和数据帧的传输方法，节省了信令开销，降低了数据部分接收的时延。
为达到上述目的，本发明采用如下技术方案：
本发明的第一方面，提供一种传输设备，应用于采用多输入多输出MIMO技术的无线局域网系统，所述传输设备包括：
获取单元，用于获取长训练码部分LTF参数，并获取分配的子载波起始位置I；其中，所述LTF参数包括：生成LTF序列所需的频域变换参数以及时域变换参数；
频域变换单元，用于根据所述获取单元获取到的所述频域变换参数和所述起始位置I，对LTF基本序列进行频域变换得到LTF符号；
时域变换单元，用于根据所述获取单元获取到的所述时域变换参数，对所述频域变换单元得到的所述LTF符号进行时域变换得到所述LTF序列；
发送单元，用于将所述时域变换单元得到的所述LTF序列携带在第一数据帧中发送至第二设备，以便所述第二设备根据所述LTF序列确定所述LTF基本序列，并根据所述LTF基本序列进行信道估计。
结合第一方面，在一种可能的实现方式中，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
所述频域变换单元，包括：
映射模块，用于从所述起始位置I开始，每隔
Figure PCTCN2014096007-appb-000001
个子载波，将所述LTF基本序列中的每个元素映射到对应的子载波上得到频域LTF序列；所述
Figure PCTCN2014096007-appb-000002
表示向下取整；
逆变换模块，用于将所述映射模块得到的所述频域LTF序列进行S点的快速傅里叶逆变换IFFT变换得到LTF基本符号；
生成模块，用于将所述逆变换模块得到的所述LTF基本符号和循环前缀CP组合生成所述LTF符号。
结合第一方面和上述可能的实现方式，在另一种可能的实现方式中，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
所述频域变换单元，包括：
扩频模块，用于根据所述M将所述LTF基本序列中的每个元素进行扩频处理，获得LTF扩频序列；所述LTF扩频序列中包含M*L个元素；
映射模块，用于从所述起始位置I开始将所述扩频模块得到的所述LTF扩频序列中的每个元素映射到对应的子载波上得到频域LTF序列；
逆变换模块，用于将所述映射模块得到的所述频域LTF序列进行S点的IFFT变换得到LTF基本符号；
生成模块，用于将所述逆变换模块得到的所述LTF基本符号和CP组合生成所述LTF符号。
结合第一方面和上述可能的实现方式，在另一种可能的实现方式中，所述时域变换参数包括：所述LTF序列包含的所述LTF符号的个数N；
所述时域变换单元，具体用于根据所述N将所述LTF符号进行扩频处理，生成所述LTF序列。
结合第一方面和上述可能的实现方式，在另一种可能的实现方式中，所述传输设备为站点STA，所述第二设备为接入点AP；
所述获取单元，包括：
接收模块，用于接收所述第二设备发送的携带指示信息的第二数据帧；其中，所述指示信息用于指示所述LTF参数；
获取模块，用于根据所述接收模块得到的所述指示信息和预先配置的映射关系表获取所述LTF参数。
结合第一方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；
当所述指示信息包括所述NSS，且所述传输设备在接入所述AP时已获取到所述AP的类型时，所述获取模块，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
当所述指示信息包括所述NSS和子载波个数S，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述获取模块，具体用于根据所述S确定所述AP的类型；其中，所述S与所述AP的类型存在对应关系；根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
当所述指示信息包括所述NSS，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述获取模块，具体用于根据CP的长度确定所述S，并根据所述S确定所述AP的类型；根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
结合第一方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；所述指示信息包括所述NSS，且所述传输设备在接入所述AP时已获取到所述AP所处的环境类型；
所述获取模块，具体用于根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数。
结合第一方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
当所述指示信息包括所述NSS时，所述获取模块，具体用于根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数；
当所述指示信息包括所述LTF序列包含的所述LTF符号的个数N时，所述获取模块，具体用于根据CP的长度确定子载波个数S； 根据所述N和所述S确定所述NSS，并根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数。
结合第一方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、调制与编码策略MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；所述指示信息包括所述NSS和所述MCS特性信息；
所述获取模块，具体用于根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数。
结合第一方面和上述可能的实现方式，在另一种可能的实现方式中，
所述传输设备为AP，所述第二设备为STA；或者，所述传输设备为STA，所述第二设备为AP；
所述获取单元，包括：获取模块，用于根据预先配置的映射关系表获取所述LTF参数；
所述发送单元，具体用于将所述LTF序列和指示信息携带在所述第一数据帧中发送至所述第二设备，以便所述第二设备根据所述LTF序列和所述指示信息确定所述LTF基本序列。
结合第一方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；且当所述传输设备为STA时，所述传输设备在接入所述AP时已获取到所述AP的类型；
所述获取模块，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
若所述传输设备为所述STA，所述第二设备为所述AP，所述指示信息包括所述NSS；
若传输设备为所述AP，所述第二设备为所述STA，所述指示信息包括所述NSS；或者，所述指示信息包括所述NSS和子载波个数S。
结合第一方面和上述可能的实现方式，在另一种可能的实现方 式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；且当所述传输设备为STA时，所述传输设备在接入所述AP时已获取到所述AP所处的环境类型；
所述获取模块，具体用于根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数；
所述指示信息包括所述NSS。
结合第一方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
所述获取模块，具体用于根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数；
所述指示信息包括所述NSS；或者，所述指示信息包括所述LTF序列包含的所述LTF符号的个数N。
结合第一方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；
所述获取模块，具体用于根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数；
所述指示信息包括所述NSS和所述MCS特性信息。
结合第一方面和上述可能的实现方式，在另一种可能的实现方式中，
所述复用的空间流的个数包括：多用户复用的用户数和/或单用户复用的数据流数。
本发明的第二方面，提供一种传输设备，应用于采用多输入多输出MIMO技术的无线局域网系统，包括：
接收单元，用于接收第一设备发送的携带长训练码部分LTF序列的第一数据帧；
处理单元，用于根据所述接收单元接收到得所述LTF序列确定LTF基本序列，并根据所述LTF基本序列进行信道估计。
结合第二方面，在一种可能的实现方式中，还包括：
获取单元，用于在所述处理单元根据所述LTF序列确定LTF基本序列之前，获取LTF参数，并获取分配的子载波起始位置I；其中，所述LTF参数包括：所述第一设备生成所述LTF序列所需的频域变换参数以及时域变换参数；
所述处理单元，包括：
时域逆变换子单元，用于根据所述获取单元获取到得所述时域变换参数，对所述LTF序列进行时域逆变换得到LTF符号；
频域逆变换子单元，用于根据所述获取单元获取到得所述频域变换参数和所述起始位置I，对所述时域逆变换子单元得到的所述LTF符号进行频域逆变换得到所述LTF基本序列。
结合第二方面和上述可能的实现方式，在另一种可能的实现方式中，所述时域变换参数包括：所述LTF序列包含的所述LTF符号的个数N；
所述时域逆变换子单元，具体用于根据所述N将所述LTF序列进行解扩处理得到所述LTF符号。
结合第二方面和上述可能的实现方式，在另一种可能的实现方式中，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
所述频域逆变换子单元，包括：
确定模块，用于根据所述LTF符号确定LTF基本符号；其中，所述LTF符号由所述LTF基本符号和循环前缀CP组成；
变换模块，用于将所述确定模块得到的所述LTF基本符号进行S点的快速傅里叶变换FFT变换得到频域LTF序列；
提取模块，用于根据所述变换模块得到的所述频域LTF序列，从所述起始位置I开始，每隔
Figure PCTCN2014096007-appb-000003
个子载波提取出所述LTF基本序列；所述
Figure PCTCN2014096007-appb-000004
表示向下取整。
结合第二方面和上述可能的实现方式，在另一种可能的实现方式中，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
所述频域逆变换子单元，包括：
确定模块，用于根据所述LTF符号确定LTF基本符号；其中，所述LTF符号由所述LTF基本符号和CP组成；
变换模块，用于将所述确定模块得到的所述LTF基本符号进行S点的FFT变换得到频域LTF序列；
提取模块，用于根据所述变换模块得到的所述频域LTF序列，从所述起始位置I开始从对应的子载波上提取出LTF扩频序列；其中，所述LTF扩频序列中包含M*L个元素；
解扩模块，用于根据所述M对所述提取模块得到的所述LTF扩频序列进行解扩处理得到所述LTF基本序列。
结合第二方面和上述可能的实现方式，在另一种可能的实现方式中，所述第一设备为站点STA，所述传输设备为接入点AP；
所述获取单元，还用于在所述接收单元接收第一设备发送的携带长训练码部分LTF序列的第一数据帧之前，根据预先配置的映射关系表获取所述LTF参数；
所述传输设备，还包括：
发送单元，用于向所述第一设备发送携带指示信息的第二数据帧；其中，所述指示信息指示所述LTF参数。
结合第二方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；
所述获取单元，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
所述指示信息包括所述NSS；或者，所述指示信息包括所述NSS和子载波个数S。
结合第二方面和上述可能的实现方式，在另一种可能的实现方 式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；
所述获取单元，具体用于根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数；
所述指示信息包括所述NSS。
结合第二方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
所述获取单元，具体用于根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数；
所述指示信息包括所述NSS；或者，所述指示信息包括所述LTF序列包含的所述LTF符号的个数N。
结合第二方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；
所述获取单元，具体用于根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数；
所述指示信息包括所述NSS和所述MCS特性信息。
结合第二方面和上述可能的实现方式，在另一种可能的实现方式中，
所述第一设备为AP，所述传输设备为STA；或者，
所述第一设备为STA，所述传输设备为AP；
所述接收单元，具体用于接收所述第一设备发送的携带所述LTF序列和指示信息的所述第一数据帧；
所述获取单元，具体用于根据所述接收单元接收到得所述指示信息和预先配置的映射关系表获取所述LTF参数。
结合第二方面和上述可能的实现方式，在另一种可能的实现方 式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；
若所述第一设备为所述STA，所述传输设备为所述AP，所述指示信息包括所述NSS；所述获取单元，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
若第一设备为所述AP，所述传输设备为所述STA；
当所述指示信息包括所述NSS，且所述传输设备在接入所述AP时已获取到所述AP的类型时，所述获取单元，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
当所述指示信息包括所述NSS和子载波个数S，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述获取单元，具体用于根据所述S确定所述AP的类型；其中，所述S与所述AP的类型存在对应关系；根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
当所述指示信息包括所述NSS，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述获取单元，具体用于根据CP的长度确定所述S，并根据所述S确定所述AP的类型；根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
结合第二方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；所述指示信息包括所述NSS，且当所述传输设备为所述STA时，所述传输设备在接入所述AP时已获取到所述AP所处的环境类型；
所述获取单元，具体用于根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数。
结合第二方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
当所述指示信息包括所述NSS时，所述获取单元，具体用于根据所述NSS，将与所述NSS对应的参数作为所述LTF参数；
当所述指示信息包括所述LTF序列包含的所述LTF符号的个数N时，所述获取单元，具体用于根据CP的长度确定子载波个数S；根据所述N和所述S确定所述NSS，并根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数。
结合第二方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、调制与编码策略MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；所述指示信息包括所述NSS和所述MCS特性信息；
所述获取单元，具体用于根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数。
结合第二方面和上述可能的实现方式，在另一种可能的实现方式中，
所述复用的空间流的个数包括：多用户复用的用户数和/或单用户复用的数据流数。
本发明的第三方面，提供一种数据帧的传输方法，应用于采用多输入多输出MIMO技术的无线局域网系统，所述方法包括：
第一设备获取长训练码部分LTF参数，并获取分配的子载波起始位置I；其中，所述LTF参数包括：生成LTF序列所需的频域变换参数以及时域变换参数；
根据所述频域变换参数和所述起始位置I，对LTF基本序列进行频域变换得到LTF符号；
根据所述时域变换参数，对所述LTF符号进行时域变换得到所述LTF序列；
将所述LTF序列携带在第一数据帧中发送至第二设备，以便所 述第二设备根据所述LTF序列确定所述LTF基本序列，并根据所述LTF基本序列进行信道估计。
结合第三方面，在一种可能的实现方式中，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
所述根据所述频域变换参数和所述起始位置I，对LTF基本序列进行频域变换得到LTF符号，包括：
从所述起始位置I开始，每隔
Figure PCTCN2014096007-appb-000005
个子载波，将所述LTF基本序列中的每个元素映射到对应的子载波上得到频域LTF序列；所述
Figure PCTCN2014096007-appb-000006
表示向下取整；
将所述频域LTF序列进行S点的快速傅里叶逆变换IFFT变换得到LTF基本符号；
将所述LTF基本符号和循环前缀CP组合生成所述LTF符号。
结合第三方面和上述可能的实现方式，在另一种可能的实现方式中，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
所述根据所述频域变换参数和所述起始位置I，对LTF基本序列进行频域变换得到LTF符号，包括：
根据所述M将所述LTF基本序列中的每个元素进行扩频处理，获得LTF扩频序列；所述LTF扩频序列中包含M*L个元素；
从所述起始位置I开始将所述LTF扩频序列中的每个元素映射到对应的子载波上得到频域LTF序列；
将所述频域LTF序列进行S点的IFFT变换得到LTF基本符号；
将所述LTF基本符号和CP组合生成所述LTF符号。
结合第三方面和上述可能的实现方式，在另一种可能的实现方式中，所述时域变换参数包括：所述LTF序列包含的所述LTF符号的个数N；
所述根据所述时域变换参数，对所述LTF符号进行时域变换得到所述LTF序列，包括：
根据所述N将所述LTF符号进行扩频处理，生成所述LTF序列。
结合第三方面和上述可能的实现方式，在另一种可能的实现方式中，所述第一设备为站点STA，所述第二设备为接入点AP；
所述获取长训练码部分LTF参数，包括：
接收所述第二设备发送的携带指示信息的第二数据帧；其中，所述指示信息用于指示所述LTF参数；
根据所述指示信息和预先配置的映射关系表获取所述LTF参数。
结合第三方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；
当所述指示信息包括所述NSS，且所述第一设备在接入所述AP时已获取到所述AP的类型时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
当所述指示信息包括所述NSS和子载波个数S，且所述第一设备在接入所述AP时未获取到所述AP的类型时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
根据所述S确定所述AP的类型；其中，所述S与所述AP的类型存在对应关系；
根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
当所述指示信息包括所述NSS，且所述第一设备在接入所述AP时未获取到所述AP的类型时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
根据CP的长度确定所述S，并根据所述S确定所述AP的类型；
根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
结合第三方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；所述指示信息包括所述NSS，且所述第一设备在接入所述AP时已获取到所述AP所处的环境类型；
所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数。
结合第三方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
当所述指示信息包括所述NSS时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数；
当所述指示信息包括所述LTF序列包含的所述LTF符号的个数N时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
根据CP的长度确定子载波个数S；
根据所述N和所述S确定所述NSS，并根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数。
结合第三方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、调制与编码策略MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；所述指示信息包括所述NSS和所述MCS特性信息；
所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数。
结合第三方面和上述可能的实现方式，在另一种可能的实现方式中，
所述第一设备为AP，所述第二设备为STA；或者，
所述第一设备为STA，所述第二设备为AP；
所述获取长训练码部分LTF参数，包括：
根据预先配置的映射关系表获取所述LTF参数；
所述将所述LTF序列携带在第一数据帧中发送至第二设备，包括：
将所述LTF序列和指示信息携带在所述第一数据帧中发送至所述第二设备，以便所述第二设备根据所述LTF序列和所述指示信息确定所述LTF基本序列。
结合第三方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；且当所述第一设备为STA时，所述第一设备在接入所述AP时已获取到所述AP的类型；
所述根据预先配置的映射关系表获取LTF参数，包括：
根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
若所述第一设备为所述STA，所述第二设备为所述AP，所述指示信息包括所述NSS；
若第一设备为所述AP，所述第二设备为所述STA，所述指示信息包括所述NSS；或者，所述指示信息包括所述NSS和子载波个数S。
结合第三方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；且当所述第一设备为STA时，所述第一设备在接入所述AP时已获取到所述AP所处的环境类型；
所述根据预先配置的映射关系转发表获取LTF参数，包括：
根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数；
所述指示信息包括所述NSS。
结合第三方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
所述根据预先配置的映射关系转发表获取LTF参数，包括：
根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数；
所述指示信息包括所述NSS；或者，所述指示信息包括所述LTF序列包含的所述LTF符号的个数N。
结合第三方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；
所述根据预先配置的映射关系转发表获取LTF参数，包括：
根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数；
所述指示信息包括所述NSS和所述MCS特性信息。
结合第三方面和上述可能的实现方式，在另一种可能的实现方式中，
所述复用的空间流的个数包括：多用户复用的用户数和/或单用户复用的数据流数。
本发明的第四方面，提供一种数据帧的传输方法，应用于采用多输入多输出MIMO技术的无线局域网系统，包括：
第二设备接收第一设备发送的携带长训练码部分LTF序列的第一数据帧；
根据所述LTF序列确定LTF基本序列，并根据所述LTF基本序列进行信道估计。
结合第四方面，在一种可能的实现方式中，在所述根据所述LTF序列确定LTF基本序列之前，还包括：
获取LTF参数，并获取分配的子载波起始位置I；其中，所述LTF参数包括：所述第一设备生成所述LTF序列所需的频域变换参数以及时域变换参数；
所述根据所述LTF序列确定LTF基本序列，包括：
根据所述时域变换参数，对所述LTF序列进行时域逆变换得到LTF符号；
根据所述频域变换参数和所述起始位置I，对所述LTF符号进行频域逆变换得到所述LTF基本序列。
结合第四方面和上述可能的实现方式，在另一种可能的实现方式中，所述时域变换参数包括：所述LTF序列包含的所述LTF符号的个数N；
所述根据所述时域变换参数，对所述LTF序列进行时域逆变换得到LTF符号，包括：
根据所述N将所述LTF序列进行解扩处理得到所述LTF符号。
结合第四方面和上述可能的实现方式，在另一种可能的实现方式中，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
所述根据所述频域变换参数和所述起始位置I，对所述LTF符号进行频域逆变换得到所述LTF基本序列，包括：
根据所述LTF符号确定LTF基本符号；其中，所述LTF符号由所述LTF基本符号和循环前缀CP组成；
将所述LTF基本符号进行S点的快速傅里叶变换FFT变换得到频域LTF序列；
根据所述频域LTF序列，从所述起始位置I开始，每隔
Figure PCTCN2014096007-appb-000007
个子载波提取出所述LTF基本序列；所述
Figure PCTCN2014096007-appb-000008
表示向下取整。
结合第四方面和上述可能的实现方式，在另一种可能的实现方式中，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
所述根据所述频域变换参数和所述起始位置I，对所述LTF符 号进行频域逆变换得到所述LTF基本序列，包括：
根据所述LTF符号确定LTF基本符号；其中，所述LTF符号由所述LTF基本符号和CP组成；
将所述LTF基本符号进行S点的FFT变换得到频域LTF序列；
根据所述频域LTF序列，从所述起始位置I开始从对应的子载波上提取出LTF扩频序列；其中，所述LTF扩频序列中包含M*L个元素；
根据所述M对所述LTF扩频序列进行解扩处理得到所述LTF基本序列。
结合第四方面和上述可能的实现方式，在另一种可能的实现方式中，所述第一设备为站点STA，所述第二设备为接入点AP；
在所述接收第一设备发送的携带长训练码部分LTF序列的第一数据帧之前，还包括：
根据预先配置的映射关系表获取所述LTF参数；
向所述第一设备发送携带指示信息的第二数据帧；其中，所述指示信息指示所述LTF参数。
结合第四方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；
所述根据预先配置的映射关系表获取所述LTF参数，包括：
根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
所述指示信息包括所述NSS；或者，所述指示信息包括所述NSS和子载波个数S。
结合第四方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；
所述根据预先配置的映射关系转发表获取LTF参数，包括：
根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数；
所述指示信息包括所述NSS。
结合第四方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
所述根据预先配置的映射关系转发表获取LTF参数，包括：
根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数；
所述指示信息包括所述NSS；或者，所述指示信息包括所述LTF序列包含的所述LTF符号的个数N。
结合第四方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；
所述根据预先配置的映射关系转发表获取LTF参数，包括：
根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数；
所述指示信息包括所述NSS和所述MCS特性信息。
结合第四方面和上述可能的实现方式，在另一种可能的实现方式中，
所述第一设备为AP，所述第二设备为STA；或者，
所述第一设备为STA，所述第二设备为AP；
所述接收第一设备发送的携带长训练码部分LTF序列的第一数据帧，包括：
接收所述第一设备发送的携带所述LTF序列和指示信息的所述第一数据帧；
所述获取LTF参数，包括：
根据所述指示信息和预先配置的映射关系表获取所述LTF参数。
结合第四方面和上述可能的实现方式，在另一种可能的实现方 式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；
若所述第一设备为所述STA，所述第二设备为所述AP，所述指示信息包括所述NSS；所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
若第一设备为所述AP，所述第二设备为所述STA；
当所述指示信息包括所述NSS，且所述第二设备在接入所述AP时已获取到所述AP的类型时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
当所述指示信息包括所述NSS和子载波个数S，且所述第二设备在接入所述AP时未获取到所述AP的类型时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
根据所述S确定所述AP的类型；其中，所述S与所述AP的类型存在对应关系；
根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
当所述指示信息包括所述NSS，且所述第二设备在接入所述AP时未获取到所述AP的类型时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
根据CP的长度确定所述S，并根据所述S确定所述AP的类型；
根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
结合第四方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参 数；所述指示信息包括所述NSS，且当所述第二设备为所述STA时，所述第二设备在接入所述AP时已获取到所述AP所处的环境类型；
所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数。
结合第四方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
当所述指示信息包括所述NSS时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
根据所述NSS，将与所述NSS对应的参数作为所述LTF参数；
当所述指示信息包括所述LTF序列包含的所述LTF符号的个数N时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
根据CP的长度确定子载波个数S；
根据所述N和所述S确定所述NSS，并根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数。
结合第四方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、调制与编码策略MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；所述指示信息包括所述NSS和所述MCS特性信息；
所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数。
结合第四方面和上述可能的实现方式，在另一种可能的实现方式中，
所述复用的空间流的个数包括：多用户复用的用户数和/或单用 户复用的数据流数。
本发明的第五方面，提供一种传输设备，应用于采用多输入多输出MIMO技术的无线局域网系统，所述传输设备包括：
处理器，用于获取长训练码部分LTF参数，并获取分配的子载波起始位置I；其中，所述LTF参数包括：生成LTF序列所需的频域变换参数以及时域变换参数；根据所述频域变换参数和所述起始位置I，对LTF基本序列进行频域变换得到LTF符号；根据所述时域变换参数，对所述LTF符号进行时域变换得到所述LTF序列；
发送器，用于将所述处理器得到的所述LTF序列携带在第一数据帧中发送至第二设备，以便所述第二设备根据所述LTF序列确定所述LTF基本序列，并根据所述LTF基本序列进行信道估计。
结合第五方面，在一种可能的实现方式中，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
所述处理器，具体用于：
从所述起始位置I开始，每隔
Figure PCTCN2014096007-appb-000009
个子载波，将所述LTF基本序列中的每个元素映射到对应的子载波上得到频域LTF序列；所述
Figure PCTCN2014096007-appb-000010
表示向下取整；
将所述频域LTF序列进行S点的快速傅里叶逆变换IFFT变换得到LTF基本符号；
将所述LTF基本符号和循环前缀CP组合生成所述LTF符号。
结合第五方面和上述可能的实现方式，在另一种可能的实现方式中，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
所述处理器，具体用于：
根据所述M将所述LTF基本序列中的每个元素进行扩频处理，获得LTF扩频序列；所述LTF扩频序列中包含M*L个元素；
从所述起始位置I开始将所述LTF扩频序列中的每个元素映射到对应的子载波上得到频域LTF序列；
将所述频域LTF序列进行S点的IFFT变换得到LTF基本符号；
将所述LTF基本符号和CP组合生成所述LTF符号。
结合第五方面和上述可能的实现方式，在另一种可能的实现方式中，所述时域变换参数包括：所述LTF序列包含的所述LTF符号的个数N；
所述处理器，具体用于根据所述N将所述LTF符号进行扩频处理，生成所述LTF序列。
结合第五方面和上述可能的实现方式，在另一种可能的实现方式中，所述传输设备为站点STA，所述第二设备为接入点AP；
所述传输设备，还包括：
接收器，用于接收所述第二设备发送的携带指示信息的第二数据帧；其中，所述指示信息用于指示所述LTF参数；
所述处理器，具体用于根据所述指示信息和预先配置的映射关系表获取所述LTF参数。
结合第五方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；
当所述指示信息包括所述NSS，且所述传输设备在接入所述AP时已获取到所述AP的类型时，所述处理器，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
当所述指示信息包括所述NSS和子载波个数S，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述处理器，具体用于根据所述S确定所述AP的类型；其中，所述S与所述AP的类型存在对应关系；根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
当所述指示信息包括所述NSS，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述处理器，具体用于根据CP的长度确定所述S，并根据所述S确定所述AP的类型；根据所述NSS和 所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
结合第五方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；所述指示信息包括所述NSS，且所述传输设备在接入所述AP时已获取到所述AP所处的环境类型；
所述处理器，具体用于根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数。
结合第五方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
当所述指示信息包括所述NSS时，所述处理器，具体用于根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数；
当所述指示信息包括所述LTF序列包含的所述LTF符号的个数N时，所述处理器，具体用于根据CP的长度确定子载波个数S；根据所述N和所述S确定所述NSS，并根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数。
结合第五方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、调制与编码策略MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；所述指示信息包括所述NSS和所述MCS特性信息；
所述处理器，具体用于根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数。
结合第五方面和上述可能的实现方式，在另一种可能的实现方式中，
所述传输设备为AP，所述第二设备为STA；或者，所述传输设备为STA，所述第二设备为AP；
所述处理器，具体用于根据预先配置的映射关系表获取所述LTF参数；
所述发送器，具体用于将所述LTF序列和指示信息携带在所述第一数据帧中发送至所述第二设备，以便所述第二设备根据所述LTF序列和所述指示信息确定所述LTF基本序列。
结合第五方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；且当所述传输设备为STA时，所述传输设备在接入所述AP时已获取到所述AP的类型；
所述处理器，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
若所述传输设备为所述STA，所述第二设备为所述AP，所述指示信息包括所述NSS；
若传输设备为所述AP，所述第二设备为所述STA，所述指示信息包括所述NSS；或者，所述指示信息包括所述NSS和子载波个数S。
结合第五方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；且当所述传输设备为STA时，所述传输设备在接入所述AP时已获取到所述AP所处的环境类型；
所述处理器，具体用于根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数；
所述指示信息包括所述NSS。
结合第五方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
所述处理器，具体用于根据所述NSS，将与所述NSS对应的参数确 定为所述LTF参数；
所述指示信息包括所述NSS；或者，所述指示信息包括所述LTF序列包含的所述LTF符号的个数N。
结合第五方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；
所述处理器，具体用于根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数；
所述指示信息包括所述NSS和所述MCS特性信息。
结合第五方面和上述可能的实现方式，在另一种可能的实现方式中，
所述复用的空间流的个数包括：多用户复用的用户数和/或单用户复用的数据流数。
本发明的第六方面，提供一种传输设备，应用于采用多输入多输出MIMO技术的无线局域网系统，包括：
接收器，用于接收第一设备发送的携带长训练码部分LTF序列的第一数据帧；
处理器，用于根据所述接收器接收到得所述LTF序列确定LTF基本序列，并根据所述LTF基本序列进行信道估计。
结合第六方面，在一种可能的实现方式中，
所述处理器，还用于在所述根据所述LTF序列确定LTF基本序列之前，获取LTF参数，并获取分配的子载波起始位置I；其中，所述LTF参数包括：所述第一设备生成所述LTF序列所需的频域变换参数以及时域变换参数；
所述处理器，具体用于：
根据所述时域变换参数，对所述LTF序列进行时域逆变换得到LTF符号；
根据所述频域变换参数和所述起始位置I，对所述LTF符号进行频域逆变换得到所述LTF基本序列。
结合第六方面和上述可能的实现方式，在另一种可能的实现方式中，所述时域变换参数包括：所述LTF序列包含的所述LTF符号的个数N；
所述处理器，具体用于根据所述N将所述LTF序列进行解扩处理得到所述LTF符号。
结合第六方面和上述可能的实现方式，在另一种可能的实现方式中，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
所述处理器，具体用于：
根据所述LTF符号确定LTF基本符号；其中，所述LTF符号由所述LTF基本符号和循环前缀CP组成；
将所述LTF基本符号进行S点的快速傅里叶变换FFT变换得到频域LTF序列；
根据所述频域LTF序列，从所述起始位置I开始，每隔
Figure PCTCN2014096007-appb-000011
个子载波提取出所述LTF基本序列；所述
Figure PCTCN2014096007-appb-000012
表示向下取整。
结合第六方面和上述可能的实现方式，在另一种可能的实现方式中，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
所述处理器，具体用于：
根据所述LTF符号确定LTF基本符号；其中，所述LTF符号由所述LTF基本符号和CP组成；
将所述LTF基本符号进行S点的FFT变换得到频域LTF序列；
根据所述频域LTF序列，从所述起始位置I开始从对应的子载波上提取出LTF扩频序列；其中，所述LTF扩频序列中包含M*L个元素；
根据所述M对所述LTF扩频序列进行解扩处理得到所述LTF基本序列。
结合第六方面和上述可能的实现方式，在另一种可能的实现方式中，所述第一设备为站点STA，所述传输设备为接入点AP；
所述处理器，还用于在所述接收器接收第一设备发送的携带长训练码部分LTF序列的第一数据帧之前，根据预先配置的映射关系表获取所述LTF参数；
所述传输设备，还包括：
发送器，用于向所述第一设备发送携带指示信息的第二数据帧；其中，所述指示信息指示所述LTF参数。
结合第六方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；
所述处理器，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
所述指示信息包括所述NSS；或者，所述指示信息包括所述NSS和子载波个数S。
结合第六方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；
所述处理器，具体用于根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数；
所述指示信息包括所述NSS。
结合第六方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
所述处理器，具体用于根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数；
所述指示信息包括所述NSS；或者，所述指示信息包括所述LTF序列包含的所述LTF符号的个数N。
结合第六方面和上述可能的实现方式，在另一种可能的实现方 式中，所述映射关系表中包含复用的空间流的个数NSS、MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；
所述处理器，具体用于根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数；
所述指示信息包括所述NSS和所述MCS特性信息。
结合第六方面和上述可能的实现方式，在另一种可能的实现方式中，
所述第一设备为AP，所述传输设备为STA；或者，
所述第一设备为STA，所述传输设备为AP；
所述接收器，具体用于接收所述第一设备发送的携带所述LTF序列和指示信息的所述第一数据帧；
所述处理器，具体用于根据所述接收器接收到得所述指示信息和预先配置的映射关系表获取所述LTF参数。
结合第六方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；
若所述第一设备为所述STA，所述传输设备为所述AP，所述指示信息包括所述NSS；所述处理器，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
若第一设备为所述AP，所述传输设备为所述STA；
当所述指示信息包括所述NSS，且所述传输设备在接入所述AP时已获取到所述AP的类型时，所述处理器，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
当所述指示信息包括所述NSS和子载波个数S，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述处理器，具体用于根据所述S确定所述AP的类型；其中，所述S与所述AP的类型存在对应关系；根据所述NSS和所述AP的类型，将与所述NSS和所述 AP的类型对应的参数作为所述LTF参数；
当所述指示信息包括所述NSS，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述处理器，具体用于根据CP的长度确定所述S，并根据所述S确定所述AP的类型；根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
结合第六方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；所述指示信息包括所述NSS，且当所述传输设备为所述STA时，所述传输设备在接入所述AP时已获取到所述AP所处的环境类型；
所述处理器，具体用于根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数。
结合第六方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
当所述指示信息包括所述NSS时，所述处理器，具体用于根据所述NSS，将与所述NSS对应的参数作为所述LTF参数；
当所述指示信息包括所述LTF序列包含的所述LTF符号的个数N时，所述处理器，具体用于根据CP的长度确定子载波个数S；根据所述N和所述S确定所述NSS，并根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数。
结合第六方面和上述可能的实现方式，在另一种可能的实现方式中，所述映射关系表中包含复用的空间流的个数NSS、调制与编码策略MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；所述指示信息包括所述NSS和所述MCS特性信息；
所述处理器，具体用于根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数。
结合第六方面和上述可能的实现方式，在另一种可能的实现方式中，
所述复用的空间流的个数包括：多用户复用的用户数和/或单用户复用的数据流数。
本发明提供的传输设备及数据帧的传输方法，第一设备根据获取的LTF参数中包含的频域变换参数和获取的分配的子载波起始位置I对LTF基本序列进行频域变换得到LTF符号，并根据LTF参数中包含的时域变换参数对LTF符号进行时域变换得到LTF序列，然后将得到的LTF序列携带在第一数据帧中发送至第二设备，以便第二设备根据LTF序列确定LTF基本序列，并根据LTF基本序列进行信道估计。第一设备在生成LTF序列的过程中，通过在频域上和时域上区分空间流，使得LTF序列包含的LTF符号的个数减少，从而节省了信令开销，降低了数据部分接收的时延。
附图说明
为了更清楚地说明本发明或现有技术中的技术方案，下面将对本发明实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动性的前提下，还可以根据这些附图获得其他的附图。
图1为现有技术提供的一种PPDU的结构示意图；
图2为本发明实施例提供的一种PPDU结构示意图；
图3为本发明一实施例提供的一种传输设备的组成示意图；
图4为本发明一实施例提供的另一种传输设备的组成示意图；
图5为本发明另一实施例提供的一种传输设备的组成示意图；
图6为本发明另一实施例提供的另一种传输设备的组成示意图；
图7为本发明另一实施例提供的又一种传输设备的组成示意图；
图8为本发明另一实施例提供的一种数据帧的传输方法流程示意图；
图9为本发明另一实施例提供的一种数据帧的传输方法流程示意图；
图10为本发明另一实施例提供的一种数据帧的传输方法流程示意图；
图11为本发明另一实施例提供的一种频域LTF序列的示意图；
图12为本发明另一实施例提供的另一种频域LTF序列的示意图；
图13为本发明另一实施例提供的另一种数据帧的传输方法流程示意图；
图14为本发明另一实施例提供的又一种数据帧的传输方法流程示意图；
图15为本发明另一实施例提供的一种传输设备的组成示意图；
图16为本发明另一实施例提供的一种传输设备的组成示意图；
图17a为本发明实施例提供的一种下行信号发送系统组成示意图；
图17b为本发明实施例提供的一种上行信号发送的系统组成示意图；
图18a为本发明实施例提供的一种LTF发送模块的具体结构组成示意图；
图18b为本发明实施例提供的另一种LTF发送模块的具体结构组成示意图；
图19a为本发明实施例提供的一种LTF接收模块的具体结构组成示意图；
图19b为本发明实施例提供的另一种LTF接收模块的具体结构组成示意图。
具体实施方式
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
在802.11ac系统中，802.11ac的PPDU的结构如图1所示，该PPDU包括传统短训练码部分(Legacy-Short Training Field，L-STF)、传统长训练码部分(Legacy-Long Training Field，L-LTF)、传统信号部分(Legacy Signal，L-SIG)、超高吞吐量的信号部分A(Very High Throughput-Signal-A，VHT-SIG-A)、超高吞吐量段训练码部分(Very High Throughput-Short Training Field，VHT-STF)、VHT-LTF、超高吞吐量信号部分B(Very High Throughput-Signal-B，VHT-SIG-B)和数据部分(Data)。其中，VHT-LTF用于实现区分SU-MIMO场景下多流或者MU-MIMO场景下多用户的信道估计。为了区分SU-MIMO场景下的多流或者MU-MIMO场景下的多用户，在现有技术中，VHT-LTF需要包含若干个VHT-LTF符号，该若干个VHT-LTF符号是采用时域CDM的方式进行时域变换得到，具体的是由VHT-LTF的VHT-LTF符号在时域上乘以P矩阵(P-matrix)的不同行序列得到的。VHT-LTF中包含的VHT-LTF符号的个数N可以根据NSS确定，其中，N与NSS的对应关系可以参照表1，表1中NSS为SU-MIMO场景下的流数或者MU-MIMO场景下的用户数。
表1
NSS N
7，8 8
5，6 6
3，4 4
2 2
1 1
以NSS为SU-MIMO场景下的流数为例，例如，当NSS等于8时，N的取值为8，也就是说，当SU-MIMO场景下的流数NSS为8时，为了区分该场景下的8个数据流，则在采用时域CDM方式生成 VHT-LTF时，该VHT-LTF需要包含8个VHT-LTF符号，具体的，包含该VHT-LTF的PPDU可以如图2所示。
VHT-LTF中包含的VHT-LTF符号由symbol和CP组成，且现有技术中的802.11ac标准是针对室内内环境设计或者获取的，CP的长度通常取0.8us，而对于室外的环境，由于存在相对于室内环境较长的多径效应，因此需采用较长的CP来克服相对室内环境较长的多径效应，例如，可以使用长度为3.2us的CP。当使用较长的CP时，若仍采用现有技术的时域CDM方式生成VHT-LTF，则会因N个较长的CP相加使得VHT-LTF的长度增加，导致信令开销增加，数据部分延迟接收。
在本发明实施例中，为了节省信令开销，降低数据部分接收的时延，采用频域变换以及时域变换的方式生成用于区分多输入多输出(Multiple Input Multiple Output，MIMO)场景多空间流的信道估计的长训练码部分(Long Training Field，LTF)序列，其中，多空间流指的是SU-MIMO场景下用户的多个数据流和/或MU-MIMO场景下多个用户的数据流。
为了便于本领域技术人员的理解，本发明提供的技术方案具体的实施过程具体可以参考本发明提供的以下实施例。
本发明一实施例提供一种传输设备，应用于采用多输入多输出MIMO技术的无线局域网系统，如图3所示，所述传输设备包括：获取单元11、频域变换单元12、时域变换单元13、发送单元14。
获取单元11，用于获取长训练码部分LTF参数，并获取分配的子载波起始位置I；其中，所述LTF参数包括：生成LTF序列所需的频域变换参数以及时域变换参数。
频域变换单元12，用于根据所述获取单元11获取到的所述频域变换参数和所述起始位置I，对LTF基本序列进行频域变换得到LTF符号。
时域变换单元13，用于根据所述获取单元11获取到的所述时域变换参数，对所述频域变换单元12得到的所述LTF符号进行时域 变换得到所述LTF序列。
发送单元14，用于将所述时域变换单元13得到的所述LTF序列携带在第一数据帧中发送至第二设备，以便所述第二设备根据所述LTF序列确定所述LTF基本序列，并根据所述LTF基本序列进行信道估计。
在本发明实施例中，进一步可选的，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S。
如图4所示，所述频域变换单元12，包括：映射模块121、逆变换模块122、生成模块123。
映射模块121，用于从所述起始位置I开始，每隔
Figure PCTCN2014096007-appb-000013
个子载波，将所述LTF基本序列中的每个元素映射到对应的子载波上得到频域LTF序列；所述
Figure PCTCN2014096007-appb-000014
表示向下取整。
逆变换模块122，用于将所述映射模块121得到的所述频域LTF序列进行S点的快速傅里叶逆变换IFFT变换得到LTF基本符号。
生成模块123，用于将所述逆变换模块122得到的所述LTF基本符号和循环前缀CP组合生成所述LTF符号。
在本发明实施例中，进一步可选的，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S。
所述频域变换单元12，包括：映射模块121、逆变换模块122、生成模块123、扩频模块124。
扩频模块124，用于根据所述M将所述LTF基本序列中的每个元素进行扩频处理，获得LTF扩频序列；所述LTF扩频序列中包含M*L个元素。
映射模块121，用于从所述起始位置I开始将所述扩频模块124得到的所述LTF扩频序列中的每个元素映射到对应的子载波上得到频域LTF序列。
逆变换模块122，用于将所述映射模块121得到的所述频域LTF 序列进行S点的IFFT变换得到LTF基本符号。
生成模块123，用于将所述逆变换模块122得到的所述LTF基本符号和CP组合生成所述LTF符号。
在本发明实施例中，进一步可选的，所述时域变换参数包括：所述LTF序列包含的所述LTF符号的个数N。
所述时域变换单元13，具体用于根据所述N将所述LTF符号进行扩频处理，生成所述LTF序列。
在本发明实施例中，进一步可选的，所述传输设备为站点STA，所述第二设备为接入点AP。
所述获取单元11，包括：接收模块111、获取模块112。
接收模块111，用于接收所述第二设备发送的携带指示信息的第二数据帧；其中，所述指示信息用于指示所述LTF参数。
获取模块112，用于根据所述接收模块111得到的所述指示信息和预先配置的映射关系表获取所述LTF参数。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数。
当所述指示信息包括所述NSS，且所述传输设备在接入所述AP时已获取到所述AP的类型时，所述获取模块112，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
当所述指示信息包括所述NSS和子载波个数S，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述获取模块112，具体用于根据所述S确定所述AP的类型；其中，所述S与所述AP的类型存在对应关系；根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
当所述指示信息包括所述NSS，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述获取模块112，具体用于根据CP的长度确定所述S，并根据所述S确定所述AP的类型；根据所 述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；所述指示信息包括所述NSS，且所述传输设备在接入所述AP时已获取到所述AP所处的环境类型。
所述获取模块112，具体用于根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数。
当所述指示信息包括所述NSS时，所述获取模块112，具体用于根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数。
当所述指示信息包括所述LTF序列包含的所述LTF符号的个数N时，所述获取模块112，具体用于根据CP的长度确定子载波个数S；根据所述N和所述S确定所述NSS，并根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、调制与编码策略MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；所述指示信息包括所述NSS和所述MCS特性信息。
所述获取模块112，具体用于根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数。
在本发明实施例中，进一步可选的，所述传输设备为AP，所述第二设备为STA；或者，所述传输设备为STA，所述第二设备为AP。
所述获取单元11，包括：获取模块112，用于根据预先配置的映射关系表获取所述LTF参数。
所述发送单元14，具体用于将所述LTF序列和指示信息携带在所述第一数据帧中发送至所述第二设备，以便所述第二设备根据所述LTF序列和所述指示信息确定所述LTF基本序列。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；且当所述传输设备为STA时，所述传输设备在接入所述AP时已获取到所述AP的类型。
所述获取模块112，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
若所述传输设备为所述STA，所述第二设备为所述AP，所述指示信息包括所述NSS。
若传输设备为所述AP，所述第二设备为所述STA，所述指示信息包括所述NSS；或者，所述指示信息包括所述NSS和子载波个数S。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；且当所述传输设备为STA时，所述传输设备在接入所述AP时已获取到所述AP所处的环境类型。
所述获取模块112，具体用于根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数。所述指示信息包括所述NSS。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数。
所述获取模块112，具体用于根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数。
所述指示信息包括所述NSS；或者，所述指示信息包括所述LTF序列包含的所述LTF符号的个数N。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数。
所述获取模块112，具体用于根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数。
所述指示信息包括所述NSS和所述MCS特性信息。
在本发明实施例中，进一步可选的，所述复用的空间流的个数包括：多用户复用的用户数和/或单用户复用的数据流数。
需要说明的是，本发明实施例提供的传输设备中各功能模块的具体工作过程可以参考方法实施例中对应过程的具体描述，本发明实施例在此不再详细赘述。
本发明实施例提供的传输设备，根据获取的LTF参数中包含的频域变换参数和获取的分配的子载波起始位置I对LTF基本序列进行频域变换得到LTF符号，并根据LTF参数中包含的时域变换参数对LTF符号进行时域变换得到LTF序列，然后将得到的LTF序列携带在第一数据帧中发送至第二设备，以便第二设备根据LTF序列确定LTF基本序列，并根据LTF基本序列进行信道估计。传输设备在生成LTF序列的过程中，通过在频域上和时域上区分空间流，使得LTF序列包含的LTF符号的个数减少，从而节省了信令开销，降低了数据部分接收的时延。
本发明另一实施例提供一种传输设备，应用于采用多输入多输出MIMO技术的无线局域网系统，如图5所示，包括：接收单元21、处理单元22。
接收单元21，用于接收第一设备发送的携带长训练码部分LTF序列的第一数据帧。
处理单元22，用于根据所述接收单元21接收到得所述LTF序列确定LTF基本序列，并根据所述LTF基本序列进行信道估计。
在本发明实施例中，进一步可选的，如图6所示，还包括：获取单元23。
获取单元23，用于在所述处理单元22根据所述LTF序列确定LTF基本序列之前，获取LTF参数，并获取分配的子载波起始位置 I；其中，所述LTF参数包括：所述第一设备生成所述LTF序列所需的频域变换参数以及时域变换参数。
所述处理单元22，包括：时域逆变换子单元221、频域逆变换子单元222。
时域逆变换子单元221，用于根据所述获取单元23获取到得所述时域变换参数，对所述LTF序列进行时域逆变换得到LTF符号；
频域逆变换子单元222，用于根据所述获取单元23获取到得所述频域变换参数和所述起始位置I，对所述时域逆变换子单元221得到的所述LTF符号进行频域逆变换得到所述LTF基本序列。
在本发明实施例中，进一步可选的，所述时域变换参数包括：所述LTF序列包含的所述LTF符号的个数N。
所述时域逆变换子单元221，具体用于根据所述N将所述LTF序列进行解扩处理得到所述LTF符号。
在本发明实施例中，进一步可选的，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S。
如图7所示，所述频域逆变换子单元222，包括：确定模块2221、变换模块2222、提取模块2223。
确定模块2221，用于根据所述LTF符号确定LTF基本符号；其中，所述LTF符号由所述LTF基本符号和循环前缀CP组成。
变换模块2222，用于将所述确定模块2221得到的所述LTF基本符号进行S点的快速傅里叶变换FFT变换得到频域LTF序列。
提取模块2223，用于根据所述变换模块2222得到的所述频域LTF序列，从所述起始位置I开始，每隔
Figure PCTCN2014096007-appb-000015
个子载波提取出所述LTF基本序列；所述
Figure PCTCN2014096007-appb-000016
表示向下取整。
在本发明实施例中，进一步可选的，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
所述频域逆变换子单元222，包括：确定模块2221、变换模块 2222、提取模块2223、解扩模块2224。
确定模块2221，用于根据所述LTF符号确定LTF基本符号；其中，所述LTF符号由所述LTF基本符号和CP组成。
变换模块2222，用于将所述确定模块2221得到的所述LTF基本符号进行S点的FFT变换得到频域LTF序列。
提取模块2223，用于根据所述变换模块2222得到的所述频域LTF序列，从所述起始位置I开始从对应的子载波上提取出LTF扩频序列；其中，所述LTF扩频序列中包含M*L个元素。
解扩模块2224，用于根据所述M对所述提取模块2223得到的所述LTF扩频序列进行解扩处理得到所述LTF基本序列。
在本发明实施例中，进一步可选的，所述第一设备为站点STA，所述传输设备为接入点AP。
所述获取单元23，还用于在所述接收单元21接收第一设备发送的携带长训练码部分LTF序列的第一数据帧之前，根据预先配置的映射关系表获取所述LTF参数。
所述传输设备，还包括：发送单元24。
发送单元24，用于向所述第一设备发送携带指示信息的第二数据帧；其中，所述指示信息指示所述LTF参数。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数。
所述获取单元23，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
所述指示信息包括所述NSS；或者，所述指示信息包括所述NSS和子载波个数S。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；
所述获取单元23，具体用于根据所述NSS和所述AP所处的环境 类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数。所述指示信息包括所述NSS。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数。
所述获取单元23，具体用于根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数。
所述指示信息包括所述NSS；或者，所述指示信息包括所述LTF序列包含的所述LTF符号的个数N。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数。
所述获取单元23，具体用于根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数。
所述指示信息包括所述NSS和所述MCS特性信息。
在本发明实施例中，进一步可选的，所述第一设备为AP，所述传输设备为STA；或者，所述第一设备为STA，所述传输设备为AP。
所述接收单元21，具体用于接收所述第一设备发送的携带所述LTF序列和指示信息的所述第一数据帧。
所述获取单元23，具体用于根据所述接收单元21接收到得所述指示信息和预先配置的映射关系表获取所述LTF参数。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数。
若所述第一设备为所述STA，所述传输设备为所述AP，所述指示信息包括所述NSS；所述获取单元23，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
若第一设备为所述AP，所述传输设备为所述STA。
当所述指示信息包括所述NSS，且所述传输设备在接入所述AP 时已获取到所述AP的类型时，所述获取单元23，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
当所述指示信息包括所述NSS和子载波个数S，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述获取单元23，具体用于根据所述S确定所述AP的类型；其中，所述S与所述AP的类型存在对应关系；根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
当所述指示信息包括所述NSS，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述获取单元23，具体用于根据CP的长度确定所述S，并根据所述S确定所述AP的类型；根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；所述指示信息包括所述NSS，且当所述传输设备为所述STA时，所述传输设备在接入所述AP时已获取到所述AP所处的环境类型。
所述获取单元23，具体用于根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数。
当所述指示信息包括所述NSS时，所述获取单元23，具体用于根据所述NSS，将与所述NSS对应的参数作为所述LTF参数。
当所述指示信息包括所述LTF序列包含的所述LTF符号的个数N时，所述获取单元23，具体用于根据CP的长度确定子载波个数S；根据所述N和所述S确定所述NSS，并根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、调制与编码策略MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；所述指示信息包括所述NSS和所述MCS特性信息。
所述获取单元23，具体用于根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数。
在本发明实施例中，进一步可选的，所述复用的空间流的个数包括：多用户复用的用户数和/或单用户复用的数据流数。
需要说明的是，本发明实施例提供的传输设备中各功能模块的具体工作过程可以参考方法实施例中对应过程的具体描述，本发明实施例在此不再详细赘述。
本发明实施例提供的传输设备，第一设备根据获取的LTF参数中包含的频域变换参数和获取的分配的子载波起始位置I对LTF基本序列进行频域变换得到LTF符号，并根据LTF参数中包含的时域变换参数对LTF符号进行时域变换得到LTF序列，然后将得到的LTF序列携带在第一数据帧中发送至传输设备，以便传输设备根据LTF序列确定LTF基本序列，并根据LTF基本序列进行信道估计。第一设备在生成LTF序列的过程中，通过在频域上和时域上区分空间流，使得LTF序列包含的LTF符号的个数减少，从而节省了信令开销，降低了数据部分接收的时延。
本发明一实施例提供一种数据帧的传输方法，应用于采用MIMO技术的无线局域网系统，如图8所示，该方法可以包括：
S301、第一设备获取LTF参数，并获取分配的子载波起始位置I。
其中，LTF参数包括生成LTF序列所需的频域变换参数以及时域变换参数。
需要说明的是，分配的子载波起始位置I的获取过程可以是通过第一设备分配获取的，也可以是通过接收第二设备发送的信令获取的。
S302、第一设备根据频域变换参数和I，对LTF基本序列进行频域变换得到LTF符号。
其中，在第一设备获取到包括生成LTF序列所需的频域变换参数以及时域变换参数的LTF参数和分配的子载波起始位置I之后，可以根据获取到的LTF参数中包括的频域变换参数和获取到的分配的子载波起始位置I，对LTF基本序列进行频域变换得到LTF符号。
S303、第一设备根据时域变换参数，对LTF符号进行时域变换得到LTF序列。
其中，在第一设备根据频域变换参数和I对LTF基本序列进行频域变换得到LTF符号后，可以根据LTF参数中包括的时域变换参数，对LTF符号进行时域变换得到LTF序列。
S304、第一设备将LTF序列携带在第一数据帧中发送至第二设备，以便第二设备根据LTF序列确定LTF基本序列，并根据LTF基本序列进行信道估计。
其中，在第一设备根据LTF参数中包含的时域变换参数对LTF符号进行时域变换得到LTF序列后，可以将得到的LTF序列携带在第一数据帧中发送至第二设备，以便第二设备根据LTF序列确定LTF基本序列，并根据确定出的LTF基本序列进行信道估计。进一步的，还可以根据确定出的LTF基本序列进行载波频率偏移(Carrier Frequency Offset，CFO)估计。
需要说明的是，在本发明实施例中，第一设备可以为接入点(Access Point，AP)，也可以为站点(Station，STA)，且当第一设备为AP时，第二设备为STA，当第一设备为STA时，第二设备为AP，本发明实施例在此对第一设备以及第二设备不做具体限制。
本发明实施例提供的数据帧的传输方法，第一设备根据获取的LTF参数中包含的频域变换参数和获取的分配的子载波起始位置I对LTF基本序列进行频域变换得到LTF符号，并根据LTF参数中包含的时域变换参数对LTF符号进行时域变换得到LTF序列，然后将得到的LTF序列携带在第一数据帧中发送至第二设备，以便第二设 备根据LTF序列确定LTF基本序列，并根据LTF基本序列进行信道估计。第一设备在生成LTF序列的过程中，通过在频域上和时域上区分空间流，使得LTF序列包含的LTF符号的个数减少，从而节省了信令开销，降低了数据部分接收的时延。
本发明另一实施例提供一种数据帧的传输方法，应用于采用MIMO技术的无线局域网系统，如图9所示，该方法可以包括：
S401、第二设备接收第一设备发送的携带LTF序列的第一数据帧。
S402、第二设备根据LTF序列确定LTF基本序列，并根据LTF基本序列进行信道估计。
其中，在第二设备接收到第一设备发送的携带LTF序列的第一数据帧后，可以根据第一数据帧中携带的LTF序列确定LTF基本序列，并根据LTF基本序列进行信道估计，进一步的，还可以根据LTF基本序列进行CFO估计。
本发明实施例提供的数据帧的传输方法，第一设备根据获取的LTF参数中包含的频域变换参数和获取的分配的子载波起始位置I对LTF基本序列进行频域变换得到LTF符号，并根据LTF参数中包含的时域变换参数对LTF符号进行时域变换得到LTF序列，然后将得到的LTF序列携带在第一数据帧中发送至第二设备，以便第二设备根据LTF序列确定LTF基本序列，并根据LTF基本序列进行信道估计。第一设备在生成LTF序列的过程中，通过在频域上和时域上区分空间流，使得LTF序列包含的LTF符号的个数减少，从而节省了信令开销，降低了数据部分接收的时延。
本发明另一实施例提供一种数据帧的传输方法，应用于采用MIMO技术的无线局域网系统，且为了便于本领域技术人员的理解，在本发明实施例中，根据应用场景的不同，对本发明的具体实施过程进行详细描述，具体如下：
在第一种应用场景中，以第一设备为AP，第二设备为STA，无线局域网采用的MIMO技术具体为MU-MIMO技术，且具体的实施 过程用于下行数据的传输过程中为例进行介绍，在该应用场景下AP可以同时与多个STA进行通信，且空间流指的是AP发送至每个用户(STA)的数据流，在该应用场景下的数据帧的传输方法，如图10所示，具体的该方法可以包括：
S501、AP获取LTF参数，并获取分配的子载波起始位置I。
其中，AP获取LTF参数具体的可以是根据预先配置的映射关系表获取LTF参数，LTF参数可以包括：生成LTF序列所需的频域变换参数以及时域变换参数。其中，该频域变换参数可以包括：用于区分空间流的子载波的个数M、LTF基本序列的元素个数L、子载波个数S，时域变换参数可以包括：LTF序列包含的LTF符号的个数N。
其中，分配的子载波起始位置I的获取过程可以是通过AP分配获取的，具体的获取过程为：AP根据实际应用场景为每个空间流分配子载波起始位置I，或者AP根据每个空间流的顺序为每个空间流分配与空间流顺序相同的子载波起始位置I。
该映射关系表具体的可以由以下方式中的任一种方式组成：
方式一：映射关系表中包含复用的空间流的个数NSS、AP的类型、以及与NSS和AP的类型对应的参数。
其中，复用的空间流的个数NSS为多用户复用的用户数。
例如，AP的类型可以是802.11ac或802.11ax，该映射关系表的组成方式可以为表2，表3或表3a所示。其中，该如表2，表3和表3a所示的映射关系表中的类型1表示AP的类型为802.11ac，类型2表示AP的类型为802.11ax。以如表2所示的映射关系表为例，当NSS为8，且AP的类型为类型1时，S＝64，N＝8，M＝1，L＝56为与NSS和AP的类型对应的参数。以如表3所示的映射关系表为例，当NSS为8，且AP的类型为类型2时，S＝512(相当于类型1的数据符号长度的8倍)，N＝1，M＝8，L＝56为与NSS和AP的类型对应的参数。以如表3a所示的映射关系表为例，当NSS为8，且AP的类型为类型2时，S＝128(相当于类型1的数据符号长度的2倍)，N＝4， M＝2，L＝56为与NSS和AP的类型对应的参数。
虽然对于类型1和类型2，AP(即，发送端)为每个用户的数据流选择相同L的LTF基本序列，但是，由于类型1和类型2的数据符号的长度不同，因此，在STA(即，接收端)根据解扩出的LTF基本序列进行信道估计时，采用的内插算法也不同。对于类型1，数据符号的长度为64-FFT(64-快速傅里叶变换)，当AP将为每个用户的数据流选择的L等于56的LTF基本序列进行频域映射时，STA在根据解扩出的LTF基本序列进行信道估计时，不需要内插便可以得到所有子载波的信道估计，即不需要内插便可以得到数据符号所需的信道估计。而对于类型2，数据符号的长度和类型1的数据符号的长度不相同，以类型2的数据符号的长度为256-FFT为例，当AP将为每个用户的数据流选择的L等于56的LTF基本序列进行频域映射时，STA在根据解扩出的LTF基本序列进行信道估计时，需要4倍内插才可以得到所有子载波的信道估计，即需要4倍的内插才可以得到数据符号所需的信道估计。
表2
NSS 类型1 类型2
7，8 S＝64，N＝8，M＝1，L＝56 S＝256，N＝2，M＝4，L＝56
5，6 S＝64，N＝6，M＝1，L＝56 S＝256，N＝2，M＝3，L＝56
3，4 S＝64，N＝4，M＝1，L＝56 S＝256，N＝1，M＝4，L＝56
2 S＝64，N＝2，M＝1，L＝56 S＝256，N＝1，M＝2，L＝56
1 S＝64，N＝1，M＝1，L＝56 S＝256，N＝1，M＝1，L＝56
表3
NSS 类型1 类型2
7，8 S＝64，N＝8，M＝1，L＝56 S＝512，N＝1，M＝8，L＝56
5，6 S＝64，N＝6，M＝1，L＝56 S＝512，N＝1，M＝6，L＝56
3，4 S＝64，N＝4，M＝1，L＝56 S＝512，N＝1，M＝4，L＝56
2 S＝64，N＝2，M＝1，L＝56 S＝512，N＝1，M＝2，L＝56
1 S＝64，N＝1，M＝1，L＝56 S＝512，N＝1，M＝1，L＝56
表3a
NSS 类型1 类型2
7，8 S＝64，N＝8，M＝1，L＝56 S＝128，N＝4，M＝2，L＝56
5，6 S＝64，N＝6，M＝1，L＝56 S＝128，N＝3，M＝2，L＝56
3，4 S＝64，N＝4，M＝1，L＝56 S＝128，N＝2，M＝2，L＝56
2 S＝64，N＝2，M＝1，L＝56 S＝128，N＝1，M＝2，L＝56
1 S＝64，N＝1，M＝1，L＝56 S＝128，N＝1，M＝1，L＝56
方式二：映射关系表中包含复用的空间流的个数NSS、AP所处的环境类型、以及与用户数NSS和AP所处的环境类型对应的参数。
例如，AP的类型均为802.11ax，且AP所处的环境类型可以为室内或室外，该映射关系表的组成方式可以为表4，表5，表5a或表5b所示。其中，该如表4，表5，表5a和表5b所示的映射关系表中的环境类型1表示AP所处的环境类型为室内，环境类型2表示AP所处的环境类型为室外。以如表4所示的映射关系表为例，当NSS为8，且AP所处的环境类型为类型1时，S＝256，N＝2，M＝4，L＝56为与NSS和AP所处的环境类型对应的参数。以如表5所示的映射关系表为例，当NSS为8，且AP所处的环境类型为类型2时，S＝512，N＝4，M＝2，L＝224为与NSS和AP所处的环境类型对应的参数。以如表5a所示的映射关系表为例，当NSS为8，且AP所处的环境类型为类型2时，S＝128，N＝8，M＝1，L＝116为与NSS和AP所处的环境类型对应的参数。
对于表4-5a的映射关系表，由于AP所处的环境类型不同，因此，AP选择的LTF基本序列长度不同，这样，在STA根据解扩出的LTF基本序列进行信道估计时，采用的内插算法也不同。对于环境类型1，由于室内信道的频率选择性小，因此，AP可以为每个用户的数据流选择相对短的LTF基本序列，这样，在STA根据解扩出的LTF基本序列进行信道估计时，需通过较大倍数的内插才能得到所有子载波的信道估计，即需通过较大倍数的内插才能得到数据符号所需的信道估计；而对于环境类型2，由于室外信道的频率选择性大，因此，AP需要为每个用户的数据流选择相对短的LTF基本 序列，这样，在STA根据解扩出的LTF基本序列进行信道估计时，通过较小倍数的内插便可以得到所有子载波的信道估计，即通过较小倍数的内插便可以得到数据符号所需的信道估计。以如表4所示的映射关系表为例，若数据符号的长度为256-FFT，对于环境类型1，当AP将为每个用户的数据流选择的L等于56的LTF基本序列，每隔4个子载波映射在频域子载波上时，这样，在STA根据解扩出的LTF基本序列进行信道估计时，需要4倍的内插才能得到所有子载波的信道估计，即需要4倍的内插才能得到数据符号所需的信道估计；而对于环境类型2，当AP将为每个用户的数据流选择的L等于116的LTF基本序列，每隔2个子载波映射在频域子载波上时，这样，在STA根据解扩出的LTF基本序列进行信道估计时，需要2倍的内插便可以得到所有子载波的信道估计，即需要2倍的内插便可以得到数据符号所需的信道估计。
表5b给出的参数是无论环境类型1还是环境类型2，AP都可以为每个用户的数据流选择相同长度的LTF基本序列，这样，在STA根据解扩出的LTF基本序列进行信道估计时，都可以采用类似的信道估计内插算法得到所有子载波的信道估计，即都可以采用类似的信道估计内插算法得到数据符号所需的信道估计。以如表5b所示的映射关系表为例，如果数据符号的长度为256-FFT，对于环境类型1，AP为每个用户的数据流选择的LTF参数为S等于128(相当于数据符号长度的一半)，L等于116的LTF基本序列，这样，在STA根据解扩出的LTF基本序列进行信道估计时，需要2倍内插得到所有子载波的信道估计，即需要2倍内插得到数据符号所需的信道估计；而对于环境类型2，AP为每个用户的数据流选择的LTF参数为S等于256，L等于116的LTF基本序列，当AP将选择的LTF基本序列每隔2个子载波映射到频域子载波上时，这样，在STA根据解扩出的LTF基本序列进行信道估计时，同样需要2倍内插得到所有子载波的信道估计，即同样需要2倍内插得到数据符号所需的信道估计。
表4
Figure PCTCN2014096007-appb-000017
表5
Figure PCTCN2014096007-appb-000018
表5a
Figure PCTCN2014096007-appb-000019
表5b
NSS 环境类型1 环境类型2
7，8 S＝128，N＝8，M＝1，L＝116 S＝256，N＝4，M＝2，L＝116
5，6 S＝128，N＝6，M＝1，L＝116 S＝256，N＝3，M＝2，L＝116
4 S＝128，N＝4，M＝1，L＝116 S＝256，N＝2，M＝2，L＝116
3 S＝128，N＝3，M＝1，L＝116 S＝256，N＝2，M＝2，L＝116
2 S＝128，N＝2，M＝1，L＝116 S＝256，N＝1，M＝2，L＝116
1 S＝128，N＝1，M＝1，L＝116 S＝256，N＝1，M＝1，L＝116
其中，为了确保STA信道估计的准确性，需要根据AP所处环境的不同生成用于区分空间流的子载波的个数M，且为了减小信令开销，在确保M满足需求的前提下，应尽量减小N的大小。具体的：对于处于环境类型2的AP，由于所处的环境为室外，无线信道的频率选择性衰落大，为了保证STA信道估计的准确性，AP需要将LTF基本序列中相邻的元素分别映射到的间隔小于等于2的子载波上，那么此时，用于区分空间流的子载波的个数M的取值便小于等于2；对于对于环境类型1的AP，由于所处的环境为室内，无线信道的频率选择性衰落相比室外环境小，同样，为了保证STA信道估计的准确性，AP需要将LTF基本序列中相邻的元素分别映射到的间隔小于等于4的子载波上，那么此时，用于区分空间流的子载波的个数M的取值便小于等于4。
方式三：映射关系表中包含复用的空间流的个数NSS、以及与NSS对应的参数。
例如，AP的类型均为802.11ax，该映射关系表的组成方式可以为表6，表7或表7a所示。其中，为了节省信令开销，应尽量减小N的大小以及LTF基本符号的长度。具体的，该如表6，表7和表7a所示的映射关系表包含的参数中包括两种S，当NSS取值较大时，可以选择取值较大的S，以便减小N的大小；当NSS取值较小时，可以选择取值较小的S，以便在减小N的大小的同时，减小LTF基本符号的长度。以如表6所示的映射关系表为例，当NSS为8，S＝256， N＝2，M＝4，L＝56为与NSS和AP所处的环境类型对应的参数，此时，可以看出S的取值为256，N的取值为2，由于现有技术当NSS为8时N的取值为8，因此，当NSS取值较大时，本发明相比现有技术采用的N的取值有所减小，即采用本发明的参数生成的LTF序列比采用现有技术的参数生成的LTF序列的长度短，从而节省了信令开销；当NSS为1时，S＝64，N＝1，M＝1，L＝56为与NSS对应的参数，此时，可以看出S的取值为64，N的取值为1，与现有技术当NSS为1时N的取值相同，由于本发明采用的S的取值较小，因此，LTF基本符号的长度也较短，即采用本发明的参数生成的LTF序列的长度也较短，从而节省了信令开销。
为了进一步节省信令开销，该映射关系表的组成方式可以为表7b所示，该映射关系表包含的参数中包括三种S，当NSS取值较大时，可以选择取值较大的S，以便减小N的大小；当NSS取值较小时，可以选择取值较小的S，以便在减小N的大小的同时，减小LTF基本符号的长度。如表7b所示的映射关系表，当NSS为8时，S＝256，N＝2，M＝4，L＝56为与NSS对应的参数，此时可以看出S的取值为256，N的取值为2，由于现有技术当NSS为8时N的取值为8，因此，当NSS取值较大时，本发明相比现有技术采用的N的取值有所减小，即采用本发明的参数生成的LTF序列比采用现有技术的参数生成的LTF序列的长度短，从而节省了信令开销；当NSS为6时，S＝128，N＝3，M＝2，L＝56为与NSS对应的参数，此时，可以看出S的取值为128，N的取值为3，由于现有技术当NSS为6时采用的N的取值为6，因此，当NSS取值较大时，本发明相比现有技术采用的N的取值有所减小，同时本发明采用的S对应的LTF基本符号的长度(本发明采用的S对应的LTF基本符号的长度为6.4us)与现有技术采用的S对应的LTF基本符号的长度(现有技术采用的S对应的LTF基本符号的长度为3.2us)相差不大，即采用本发明的参数生成的LTF序列比采用现有技术的参数生成的LTF序列的长度短，从而节省了信令开销；当NSS为1时，S＝64，N＝1，M＝1，L＝56为与NSS对应的参数，可以 看出S的取值为64，N的取值为1，与现有技术当NSS为1时N的取值相同，由于本发明采用的S的取值较小，因此，LTF基本符号的长度也较短，即采用本发明的参数生成的LTF序列的长度也较短，从而节省了信令开销。
表6
NSS 参数
7，8 S＝256，N＝2，M＝4，L＝56
5，6 S＝256，N＝2，M＝3，L＝56
3，4 S＝256，N＝1，M＝4，L＝56
2 S＝64，N＝2，M＝1，L＝56
1 S＝64，N＝1，M＝1，L＝56
表7
NSS 参数
7，8 S＝512，N＝2，M＝4，L＝116
5，6 S＝512，N＝2，M＝3，L＝116
3，4 S＝512，N＝1，M＝4，L＝116
2 S＝64，N＝2，M＝1，L＝56
1 S＝64，N＝1，M＝1，L＝56
表7a
NSS 参数
7，8 S＝128，N＝4，M＝2，L＝56
5，6 S＝128，N＝3，M＝2，L＝56
3，4 S＝128，N＝1，M＝2，L＝56
2 S＝64，N＝2，M＝1，L＝56
1 S＝64，N＝1，M＝1，L＝56
表7b
NSS 参数
7，8 S＝256，N＝2，M＝4，L＝56
5，6 S＝128，N＝3，M＝2，L＝56
4 S＝256，N＝1，M＝4，L＝56
3 S＝64，N＝3，M＝1，L＝56
2 S＝128，N＝1，M＝2，L＝56
1 S＝64，N＝1，M＝1，L＝56
方式四：映射关系表中包含复用的空间流的个数NSS、调制与编码策略(modulation and coding strategy，MCS)特性信息、以及与NSS和MCS特性信息对应的参数。
其中，MCS特性信息可以从AP与STA间交互的无线信道信息中获取，MCS的大小反映了MCS特性信息。
例如，AP的类型均为802.11ax，该映射关系表的组成方式可以为表8，表9或表9a所示。
表8
Figure PCTCN2014096007-appb-000020
表9
Figure PCTCN2014096007-appb-000021
表9a
Figure PCTCN2014096007-appb-000022
其中，为了确保STA信道估计的准确性，需要根据采用的MCS的大小生成用于区分空间流的子载波的个数M，且为了减小信令开销，在确保M满足需求的前提下，应尽量减小N的大小。具体的：当MCS的大小在5-9之间时，说明STA在进行信道估计时对无线信道信噪比的变化较敏感，为了保证STA信道估计的准确性，AP需要将LTF基本序列中相邻的元素分别映射到的间隔小于等于2的子载波上，那么此时，用于区分空间流的子载波的个数M的取值便小于等于2；当MCS的大小在0-4之间，说明STA在进行信道估计时对无线信道信噪比的变化不敏感，同样，为了保证STA信道估计的准确性，AP需要将LTF基本序列中相邻的元素分别映射到的间隔小于等于4的子载波上，那么此时，用于区分空间流的子载波的个数M的取值便小于等于4。
当映射关系表的组成方式为方式一时，AP根据预先配置的映射关系表获取LTF参数具体的可以是：根据复用的空间流的个数NSS和AP的类型，将与NSS和AP的类型对应的参数作为LTF参数。
其中，AP根据NSS和AP的类型，查询该映射关系表，获取与NSS和AP的类型对应的参数，并将该参数作为LTF参数。例如，AP中预先配置的映射关系表为方式一中的表2，若AP的类型为类型2，且AP复用的空间流的个数NSS为8，AP根据NSS以及AP的类型，查询该映射关系表，可以获取到对应的参数为：S＝256，N＝2，M＝4，L＝56，即LTF参数为：S＝256，N＝2，M＝4，L＝56。
当映射关系表的组成方式为方式二时，AP根据预先配置的映射 关系表获取LTF参数具体的可以是：根据NSS、AP所处的环境类型，将与NSS和AP所处的环境类型对应的参数作为LTF参数。
其中，AP根据NSS和AP所处的环境类型，查询该映射关系表，获取与NSS和AP的类型对应的参数，并将该参数作为LTF参数。例如，AP中预先配置的映射关系表为方式二中的表4，若AP所处的环境类型为室外，且AP复用的空间流的个数NSS为8时，AP根据NSS以及AP所处的环境类型，查询该映射关系表，可以获取到对应的参数为：S＝256，N＝4，M＝2，L＝116，即LTF参数为：S＝256，N＝4，M＝2，L＝116。
当映射关系表的组成方式为方式三时，AP根据预先配置的映射关系表获取LTF参数具体的可以是：根据NSS，将与该NSS对应的参数确定为LTF参数。
其中，AP根据NSS，查询该映射关系表，获取与NSS对应的参数，并将该参数作为LTF参数。例如，AP中预先配置的映射关系表为方式三中的表6，若AP复用的空间流的个数NSS为8时，AP根据NSS，查询该映射关系表，可以获取到对应的参数为：S＝256，N＝2，M＝4，L＝56，即LTF参数为：S＝256，N＝2，M＝4，L＝56。
当映射关系表的组成方式为方式四时，AP根据预先配置的映射关系表获取LTF参数具体的可以是：根据NSS和MCS特性信息，将与NSS和MCS特性信息对应的参数作为LTF参数。
其中，AP根据NSS和MCS特性信息，查询该映射关系表，获取与NSS和MCS特性信息对应的参数，并将该参数作为LTF参数。例如，AP中预先配置的映射关系表为方式四中的表7，若AP复用的空间流的个数NSS为8，且MCS的特性信息为3时，AP根据NSS以及MCS的特性信息，查询该映射关系表，可以获取到对应的参数为：S＝256，N＝2，M＝4，L＝56，即LTF参数为：S＝256，N＝2，M＝4，L＝56。
S502、AP根据频域变换参数和I，对LTF基本序列进行频域变换得到LTF符号。
其中，在AP获取到LTF参数和分配的子载波起始位置I之后，AP可以根据获取到的LTF参数中包含的频域变换参数和获取到的分配的子载波起始位置I，采用频域频分复用(Frequency Division Multiplexing，FDM)的方式或频域CDM的方式对LTF基本序列进行频域变换得到LTF符号。
当AP采用频域FDM的方式对LTF基本序列进行频域变换时，AP根据频域变换参数和I，对LTF基本序列进行频域变换得到LTF符号具体的可以包括以下步骤S502a1至S502a4：
S502a1、AP从I开始，每隔
Figure PCTCN2014096007-appb-000023
个子载波，将LTF基本序列中的每个元素映射到对应的子载波上得到频域LTF序列。
其中，LTF基本序列是AP分配的，当AP中预先配置的映射关系表采用方式一时，直接获取存储的LTF基本序列；当AP中预先配置的映射关系表采用方式二、方式三以及方式四中的任一种方式时，在AP获取到LTF参数后，AP可以根据LTF参数中包含的频域变换参数L，从预先存储的LTF基本序列中选择需要使用的LTF基本序列。例如，AP获取到的LTF参数中包含的频域变换参数L为56时，根据L选择的LTF基本序列可以为：
LTF基本序列＝{1 1 LTFleft 0 LTFright -1 -1}
其中，LTFleft和LTFright包含的元素个数均为26。
其中，在AP获取到LTF参数后，AP可以根据获取的LTF参数中包含的频域变换参数M、L、S和获取的分配的子载波起始位置I，从I开始，每隔
Figure PCTCN2014096007-appb-000024
个子载波，将LTF基本序列中的每个元素映射到对应的子载波上得到频域LTF序列，其中，所述
Figure PCTCN2014096007-appb-000025
表示向下取整。
在一种可能的实现方式中，AP根据设计或者获取的图样
Figure PCTCN2014096007-appb-000026
从I开始，每隔
Figure PCTCN2014096007-appb-000027
个子载波，将LTF基本序列中的每个元素映射到对应的子载波上，其中，l为LTF基本序列中的第l个元素，I为分配给空间流的子载波起始位置，I0为可用子载波的起始位置。例如，AP中预先配置的映射关系表为方式一中的表2，若AP的类型为类型2，且AP复用的空 间流的个数NSS为8，AP根据NSS以及AP的类型，查询该映射关系表，可以获取到LTF参数为：S＝256、N＝2、M＝4、L＝56。当AP获取的LTF参数为S＝256、M＝4、L＝56时，根据LTF参数中包含的频域变换参数M可以确定频域上区分的空间流的个数为4，相应的，设计或者获取的图样为
Figure PCTCN2014096007-appb-000028
以第1个空间流为例，假设可用子载波的起始位置I0等于1，m等于0，则分配给该空间流的子载波起始位置I等于1，AP将LTF基本序列中的每个元素按照设计或者获取的图样
Figure PCTCN2014096007-appb-000029
从子载波1开始，每隔4个子载波映射到对应的子载波上。对于其余3个空间流，可以参照第1个空间流的频域映射方法进行映射，4个空间流根据频域变换参数和I将LTF基本序列进行频域映射后得到频域LTF序列的示意图如图11所示。由于AP在频域上区分的4个空间流分别映射到不同的子载波上，因此，便可以在频域上区分这4个空间流。其中，m的取值可以为0、1、2、3中的任一个，只需确保与其它空间流对应的m的取值不同即可，可以根据实际应用的场景选择相应的m，本发明实施例在此对m的取值不做限制。
S502a2、AP将频域LTF序列进行S点的IFFT变换得到LTF基本符号。
其中，在AP从I开始，每隔
Figure PCTCN2014096007-appb-000030
个子载波，将LTF基本序列中的每个元素映射到对应的子载波上得到频域LTF序列后，AP可以将频域LTF序列进行S点的IFFT变换得LTF基本符号。
S502a3、AP将LTF基本符号和CP组合生成LTF符号。
其中，CP与LTF基本符号中处于[(L1-Lcp)，L1]的元素相同，L1为LTF基本符号的长度，Lcp为CP的长度。
当AP采用频域CDM的方式对LTF基本序列进行频域变换时，AP根据频域变换参数和I，对LTF基本序列进行频域变换得到LTF符号具体的可以包括以下步骤S502b1至S502b4：
其中，在AP采用频域CDM的方式对LTF基本序列进行频域变换的过程中，频域变换参数M具体的可以为用于区分空间流的连续 子载波的个数。
S502b1、AP根据M将LTF基本序列中的每个元素进行扩频处理，获得LTF扩频序列。
其中，AP根据M可以确定频域上区分的空间流的个数，对于每个空间流，AP将LTF基本序列中的每个元素重复M次，然后乘以对应的频域扩频序列获得LTF扩频序列，该LTF扩频序列包含M*L个元素。
在一种可能的实现方式中，该扩频序列可以为M*M维P矩阵的第i行序列{p(i，1)，...，p(i，M)}i＝1，...M，其中，i为P矩阵的第i行。例如，为了便于本领域技术人员的理解，仍以步骤S502a1中的例子中获取的LTF参数(S＝256，N＝2，M＝4，L＝56)为例，根据LTF参数中包含的频域变换参数M可以确定P矩阵的维数为4*4维以及频域上区分的空间流的个数为4。以第1个空间流为例，假设第1个空间流的扩频序列为P矩阵的第1行序列，AP将LTF基本序列中的每个元素重复4次后，乘以该空间流的扩频序列(P矩阵的第1行序列)得到包含4*56个元素的LTF扩频序列。对于其余3个空间流，可以参照第1个空间流的扩频处理方法进行扩频处理。由于AP在频域上区分的空间流在进行扩频处理时，分别乘以P矩阵的不同行序列，因此，便可以在频域上区分这4个空间流。其中，第1个空间流的扩频序列为P矩阵的第i行序列，i的取值可以为1、2、3、4中的任一个，只需确保与其它空间流的扩频序列不同即可，可以根据实际应用的场景选择相应的i，本发明实施例在此对i的取值不做限制。
S502b2、AP从I开始将LTF扩频序列中的每个元素映射到对应的子载波上得到频域LTF序列。
其中，在AP根据M，将LTF基本序列中的每个元素进行扩频处理获得LTF扩频序列后，AP从I开始将LTF扩频序列中的每个元素映射到对应的子载波上得到频域LTF序列。
在一种可能的实现方式中，AP根据设计或者获取的图样
Figure PCTCN2014096007-appb-000031
从I开始将 LTF扩频序列中的每个元素映射到对应的子载波上。其中，l为LTF扩频序列中的第l个元素，I为分配给空间流的子载波起始位置，I0为可用子载波的起始位置。例如，为了便于本领域技术人员的理解，仍以步骤S502a1中的例子中获取的LTF参数(S＝256，N＝2，M＝4，L＝56)为例，根据LTF参数中包含的频域变换参数M可以确定频域上区分的空间流的个数为4，相应的，设计或者获取的图样为
Figure PCTCN2014096007-appb-000032
以第1个空间流为例，假设可用的子载波的起始位置I0等于1，则在频域上分配给该空间流的子载波起始位置I等于1，AP将LTF扩频序列中的每个元素按照设计或者获取的图样
Figure PCTCN2014096007-appb-000033
从子载波1开始映射到对应的子载波上。对于其余3个空间流，可以参照第1个空间流在频域上的映射方法进行映射，4个空间流根据频域变换参数和I将LTF扩频序列进行频域映射后得到频域LTF序列的示意图如图12所示。
S502b3、AP将频域LTF序列进行S点的IFFT变换得到LTF基本符号。
S502b4、AP将LTF基本符号和CP组合生成LTF符号。
其中，CP与LTF基本符号中处于[(L1-Lcp)，L1]的元素相同，L1为LTF基本符号的长度，Lcp为CP的长度。
在AP获得到LTF符号后，AP可以根据时域变换参数，对LTF符号进行时域变换得到LTF序列，具体的可以包括步骤S503：
S503、AP根据N将LTF符号进行扩频处理，生成LTF序列。
其中，AP根据N可以确定时域上区分的空间流的个数，对于每个空间流，AP将LTF符号重复N次，然后乘以对应的扩频序列生成LTF序列。
在一种可能的实现方式中，该扩频序列可以为N*N维P矩阵的第j行序列{p(j，1)，...，p(j，N)}j＝1，...，N，其中，j为P矩阵的第j行。例如，为了便于本领域技术人员的理解，仍以步骤S502a1中的例子中获取 的LTF参数(S＝256，N＝2，M＝4，L＝56)为例，根据LTF参数中包含的时域变换参数N可以确定P矩阵的维数为2*2维以及时域上区分的空间流的个数为2。以第1个空间流为例，假设第1个空间流的扩频序列为P矩阵的第1行序列，AP将LTF符号重复2次后，乘以该空间流的扩频序列(P矩阵的第1行序列)生成LTF序列。对于其余3个空间流，可以参照第1个空间流的扩频处理方法进行扩频处理。由于AP在时域上区分的空间流在进行扩频处理时，分别乘以P矩阵的不同行序列，因此，便可以在时域上区分这2个空间流。其中，第1个空间流的扩频序列为P矩阵的第j行序列，j的取值可以为1、2中的任一个，只需确保与其它空间流的扩频序列不同即可，可以根据实际应用的场景选择相应的j，本发明实施例在此对j的取值不做限制。
综上，由于在频域上可以通过不同的子载波区分M个空间流，在时域上通过不同的扩频序列区分N个空间流，因此，通过频域变换以及时域变换可以区分M*N个空间流。
以无线局域网的带宽为20MHz，且CP等于3.2us为例，对采用本发明的频域变换以及时域变换生成的LTF序列的长度与采用现有技术的时域变换生成的LTF序列的长度进行比较，当AP中预先配置的映射关系表采用方式一中的表2时，具体的比较结果如表10所示：
表10
Figure PCTCN2014096007-appb-000034
从表10可以看出，当复用的空间流的个数NSS大于2时，AP采用本发明实施例提供的方法生成的LTF序列的长度比采用现有技术生成的LTF序列的长度短。
当AP中预先配置的映射关系表采用方式一中的表2时，具体的比较结果如表11所示：
表11
Figure PCTCN2014096007-appb-000035
从表11可以看出，当复用的空间流的个数NSS大于4时，AP采用本发明实施例提供的方法生成的LTF序列的长度比采用现有技术生成的LTF序列的长度短。
当AP中预先配置的映射关系表采用方式三中的表6时，具体的比较结果如表12所示：
表12
Figure PCTCN2014096007-appb-000036
从表12可以看出，AP采用本发明实施例提供的方法生成的LTF序列的长度比采用现有技术提供的方法生成的LTF序列的长度短。
当AP中预先配置的映射关系表采用方式三中的表7a时，具体的比较结果如表13所示：
表13
Figure PCTCN2014096007-appb-000037
从表13可以看出，当复用的空间流的个数NSS大于2时，AP采用本发明实施例提供的方法生成的LTF序列的长度比采用现有技术提供的方法生成的LTF序列的长度短。
当AP中预先配置的映射关系表采用方式三中的表7b时，具体的比较结果如表14所示：
表14
Figure PCTCN2014096007-appb-000038
从表14可以看出，当复用的空间流的个数NSS大于1时，AP采用本发明实施例提供的方法生成的LTF序列的长度比采用现有技术提供的方法生成的LTF序列的长度短。
由于STA需要对LTF序列进行解析获得LTF基本序列，因此，STA需要获知AP生成LTF序列所采用的LTF参数，为了节省信令开销，AP可以将用于获取LTF参数的指示信息通知给STA，因此，AP将LTF序列携带在第一数据帧中发送至STA，具体的可以包括以下步骤S504：
S504、AP将LTF序列和指示信息携带在第一数据帧中发送至STA。
其中，当AP中预先配置的映射关系表的组成方式为方式一时，指示信息可以包括复用的空间流的个数NSS；或者，指示信息包括复用的空间流的个数NSS和子载波个数S。
当AP中预先配置的映射关系表的组成方式为方式二时，指示信息包括复用的空间流的个数NSS。
当AP中预先配置的映射关系表的组成方式为方式三时，指示信息包括复用的空间流的个数NSS；或者指示信息包括LTF序列包含的LTF符号的个数N。
当AP中预先配置的映射关系表的组成方式为方式四时，指示信息包括复用的空间流的个数NSS和MCS特性信息。
需要说明的是，第一数据帧中携带的指示信息可以根据实际的应用场景选择相应的参数，本发明实施例在此对指示信息包含的具体参数不做限制。
S505、STA接收AP发送的携带LTF序列和指示信息的第一数据帧。
S506、STA根据指示信息和预先配置的映射关系表获取LTF参数，并获取分配的子载波起始位置I。
其中，STA可以根据AP发送的显式信令(explict signaling)获取空间流分配的子载波起始位置I，也可以根据AP发送的隐式信令(implicit signaling)获取空间流分配的子载波起始位置I，当STA根据AP发送的implicit signaling获取空间流分配的子载波起始位置I时，此时STA获取的分配的子载波起始位置I为接收的空间流默认的顺序。
当STA中预先配置的映射关系表的组成方式为方式一时，在第一种可能的实现方式中，当指示信息包括NSS，且STA在接入AP时已获取到AP的类型时，STA根据指示信息和预先配置的映射关系表获取LTF参数具体的可以包括：STA根据NSS和AP的类型，将与NSS和AP的类型对应的参数作为LTF参数。
其中，STA根据NSS和AP的类型，查询该映射关系表，获取与NSS和AP的类型对应的参数，并将该参数作为LTF参数。
在第二种可能的实现方式中，当指示信息包括NSS和子载波个数S，且STA在接入AP时未获取到AP的类型时，STA根据指示信息和预先配置的映射关系表获取LTF参数具体可以包括：STA根据S确定AP的类型，并根据NSS和AP的类型，将与NSS和AP的类型对 应的参数作为LTF参数。
其中，在STA预先配置的映射关系表中，由于S与AP的类型存在对应关系，因此，STA根据S，查找映射关系表便可以确定出AP的类型。在STA确定出AP的类型后，根据NSS和确定出的AP的类型，查询该映射关系表，并将查询到的参数作为LTF参数。
在第三种可能的实现方式中，当指示信息包括NSS，且STA在接入AP时未获取到AP的类型时，STA根据指示信息和预先配置的映射关系表获取LTF参数的过程具体可以包括：STA根据CP的长度确定S，并根据S确定AP的类型，然后根据NSS和AP的类型，将与NSS和AP的类型对应的参数作为LTF参数。
其中，STA在接入AP时可以从与AP间的信息交互中获取到CP的长度为Lcp，现假设LTF符号的长度为L2，由于CP与LTF符号中处于[(L2-Lcp)，L2]的元素相同，可以将LTF符号处于[0，Lcp]内的元素与处于[(L2-Lcp)，L2]的元素做自相关运算，将得到的自相关峰值与预设的门限值进行比较，若得到的自相关峰值超过预设的门限值，则可以确定LTF符号的长度为L2；若得到的自相关峰值没有超过预设的门限值，则可以重新假设LTF符号的长度为L3，然后将LTF符号处于[0，Lcp]内的元素与处于[(L3-Lcp)，L3]内的元素做自相关运算，再将得到的自相关峰值与预设的门限值进行比较，若得到的自相关峰值超过预设的门限值，则可以确定LTF符号的长度为L3；若得到的自相关峰值没有超过预设的门限值，则可以重新假设LTF符号的长度，直到确定出LTF符号的长度。在STA确定LTF符号的长度后，由于LTF符号的长度等于symbol的长度加上CP的长度，且CP的长度已知，从而可以根据确定的LTF符号的长度得到symbol的长度(LTF符号的长度减去CP的长度)，然后根据symbol的长度与S的对应关系，可以确定出S，此时便可以根据S查询该映射关系表，确定AP的类型。在STA确定出AP的类型后，根据NSS和确定出的AP的类型，查询该映射关系表，并将查询到的参数作为LTF参数。
当STA中预先配置的映射关系表的组成方式为方式二时，当指示信息包括NSS，且STA在接入AP时已获取到AP所处的环境类型时，STA根据指示信息和预先配置的映射关系表获取LTF参数可以包括：STA根据NSS和AP所处的环境类型，将与NSS和AP所处的环境类型对应的参数作为LTF参数。
其中，STA根据NSS和AP所处的环境类型，查询该映射关系表，获取与NSS和AP的类型对应的参数，并将该参数作为LTF参数。
当STA中预先配置的映射关系表的组成方式为方式三时，在第一种可能的实现方式中，当指示信息包括NSS时，STA根据指示信息和预先配置的映射关系表获取LTF参数可以包括：STA根据NSS，将与NSS对应的参数确定为LTF参数。
其中，STA根据NSS，查询该映射关系表，获取与NSS对应的参数，并将该参数作为LTF参数。
在第二种可能的实现方式中，当指示信息包括LTF序列包含的LTF符号的个数N时，STA根据指示信息和预先配置的映射关系表获取LTF参数可以包括：STA根据CP的长度确定子载波个数S，然后根据N和S确定NSS，进一步根据NSS，将与NSS对应的参数确定为LTF参数。
需要说明的是，STA根据CP的长度确定子载波个数S的方法可以参照本发明实施例相关内容的描述，本处不再赘述。
其中，STA根据N和S，查找映射关系表，可以确定NSS，然后根据确定出的NSS查找映射关系表，得到与NSS对应的参数，并将该对应的参数确定为LTF参数。
需要说明的是，STA根据CP的长度确定子载波个数S的方法可以参照本发明实施例相关内容的描述，本处不再赘述。
当STA中预先配置的映射关系表的组成方式为方式四时，当指示信息包括NSS和MCS特性信息时，STA根据指示信息和预先配置的映射关系表获取LTF参数的过程可以包括：STA根据NSS、MCS特性信息，将与NSS和MCS特性信息对应的参数作为LTF参数。
其中，STA根据NSS和MCS特性信息，查询该映射关系表，获取与NSS和MCS特性信息对应的参数，并将该参数作为LTF参数。
在STA获取到LTF参数以及分配的子载波起始位置I后，根据时域变换参数，对LTF序列进行时域逆变换得到LTF符号具体可以包括步骤S507：
S507、STA根据N将LTF序列进行解扩处理得到LTF符号。
其中，STA根据N可以确定时域上区分的空间流的个数，对于每个空间流，STA对LTF序列乘以对应的扩频序列得到LTF符号。该扩频序列为N*N维P矩阵中的第j行序列，且可以从与AP的信息交互过程中获取到。例如，为了便于本领域技术人员的理解，仍以步骤S502a1中的例子中获取的LTF参数(S＝256，N＝2，M＝4，L＝56)为例，根据LTF参数中包含的时域变换参数N可以确定P矩阵的维数为2*2维以及时域上区分的空间流的个数为2。以第1个空间流为例，STA在与AP的信息交互过程中获取到第1个空间流的扩频序列为2*2维P矩阵中的第1行序列，因此，STA对LTF序列乘以2*2维P矩阵中的第1行序列，便可以得到LTF符号。对于第2个空间流，可以参照第1个空间流的解扩处理过程进行解扩处理。由于STA在对LTF序列解扩过程中使用的扩频序列是从与AP的信息交互中获取的，也就是说，该扩频序列与AP端进行扩频处理过程中使用的扩频序列相同，因此，可以确保STA能正确解扩出LTF符号。
S508、STA根据频域变换参数和I，对LTF符号进行频域逆变换得到LTF基本序列。
其中，在STA根据时域变换参数，对LTF序列进行时域逆变换得到LTF符号后，STA可以根据频域变换参数和I，采用频域FDM的方式或频域CDM的方式对LTF符号进行频域逆变换得到LTF基本序列。
当AP采用频域FDM的方式对LTF基本序列进行频域变换得到LTF符号时，此时STA便可以采用频域FDM的方式对LTF符号进 行频域逆变换。当STA采用频域FDM的方式对LTF符号进行频域逆变换时，STA根据频域变换参数和I，对LTF符号进行频域逆变换得到LTF基本序列具体的可以包括步骤S508a1至S508a3：
S508a1、STA根据LTF符号确定LTF基本符号。
其中，CP为LTF符号中处于[0，Lcp]内的元素，将LTF符号中处于[0，Lcp]内的元素去除后便可以得到LTF基本符号。
S508a2、STA将LTF基本符号进行S点的FFT变换得到频域LTF序列。
S508a3、STA根据频域LTF序列，从I开始，每隔
Figure PCTCN2014096007-appb-000039
个子载波提取出LTF基本序列。
其中，在STA得到频域LTF序列后，STA可以根据获取的M、L、S和I，从I开始按照设计或者获取的图样对频域LTF序列进行反映射处理得到LTF基本序列，其中，所述
Figure PCTCN2014096007-appb-000040
表示向下取整。
在一种可能的实现方式中，STA按照设计或者获取的图样
Figure PCTCN2014096007-appb-000041
从I开始，从频域LTF序列中每隔
Figure PCTCN2014096007-appb-000042
个子载波提取出LTF基本序列，其中，l为频域LTF序列中的第l个元素，I为分配给空间流的子载波起始位置，I0为可用子载波的起始位置。例如，为了便于本领域技术人员的理解，仍以步骤S502a1中的例子中获取的LTF参数(S＝256，N＝2，M＝4，L＝56)为例，根据LTF参数中包含的频域变换参数M可以确定频域上区分的空间流的个数为4，相应的，设计或者获取的图样为
Figure PCTCN2014096007-appb-000043
以第1个空间流为例，与第1个空间流对应的m可以通过与AP的信息交互过程中获取到，此时获取的m等于0，由于可用的子载波的起始位置I0为1，因此，分配给该空间流的子载波起始位置I等于1，STA按照设计或者获取的图样
Figure PCTCN2014096007-appb-000044
从子载波1开始，从频域LTF序列中每隔4个子载波提取出该空间流的LTF基本序列。对于其余3个空间流，可以参照第1个空间流的反映射处理方法进行反映射处理。
当AP采用频域CDM的方式对LTF基本序列进行频域变换得到LTF符号时，此时STA便可以采用频域CDM的方式对LTF符号进行频域逆变换。当STA采用频域CDM的方式对LTF符号进行频域逆变换时，STA根据频域变换参数和I，对LTF符号进行频域逆变换得到LTF基本序列具体的可以包括步骤S508b1至S508b4：
其中，在STA采用频域CDM的方式对LTF符号进行频域逆变换的过程中，频域变换参数M具体的可以为用于区分空间流的连续子载波的个数。
S508b1、STA根据LTF符号确定LTF基本符号。
需要说明的是，STA根据LTF符号确定LTF基本符号的过程可以参照步骤S508a1中的具体描述，本处不再赘述。
S508b2、STA将LTF基本符号进行S点的FFT变换得到频域LTF序列。
S508b3、STA根据频域LTF序列，从I开始从对应的子载波上提取出LTF扩频序列。
其中，在STA得到频域LTF序列后，STA从I开始按照设计或者获取的图样对频域LTF序列进行反映射处理得到LTF扩频序列，该LTF扩频序列中包含M*L个元素。
在一种可能的实现方式中，STA按照设计或者获取的图样
Figure PCTCN2014096007-appb-000045
从I开始从对应的子载波上提取出LTF扩频序列，其中，l为LTF序列中的第l个元素，I为分配给空间流的子载波起始位置，I0为可用子载波的起始位置。例如，为了便于本领域技术人员的理解，仍以步骤S502a1中的例子中获取的LTF参数(S＝256，N＝2，M＝4，L＝56)为例，根据LTF参数中包含的频域变换参数M可以确定频域上区分的空间流的个数为4，相应的，设计或者获取的图样为
Figure PCTCN2014096007-appb-000046
以第1个空间流为例，由于可用的子载波的起始位置I0等于1，则分配给该空间流的子载波起始位置I等于1，STA按照设计或者获取的图样
Figure PCTCN2014096007-appb-000047
从子载波1开始从对应的子载波上提取出该空间流的LTF扩频序列。对于其余3个空间流，可以参照第1个空间流的反映射处理方法进行反映射处理。
S508b4、STA根据M对LTF扩频序列进行解扩处理得到LTF基本序列。
其中，STA根据M可以确定频域上区分的空间流的个数，对于每个空间流，STA对LTF扩频序列乘以对应的扩频序列得到LTF基本序列。该扩频序列为M*M维P矩阵中的第i行序列，且可以从与AP的信息交互过程中获取到。例如，为了便于本领域技术人员的理解，仍以步骤S502a1中的例子中获取的LTF参数(S＝256，N＝2，M＝4，L＝56)为例，根据LTF参数中包含的时域变换参数M可以确定P矩阵的维数为4*4维以及频域上区分的空间流的个数为4。以第1个空间流为例，STA在与AP的信息交互过程中获取到第1个空间流的扩频序列为4*4维P矩阵中的第1行序列，因此，STA对LTF序列乘以4*4维P矩阵中的第1行序列，便可以得到LTF基本序列。对于其它3个空间流，可以参照第1个空间流的解扩处理过程进行解扩处理。由于STA在对LTF扩频序列解扩过程中使用的扩频序列是从与AP的信息交互中获取的，也就是说，该扩频序列与AP端进行扩频处理过程中使用的扩频序列相同，因此，可以确保STA能正确解扩出LTF基本序列。
S509、STA根据LTF基本序列进行信道估计。
其中，在STA解扩出LTF基本序列后，STA便可以根据LTF基本序列进行信道估计，进一步的，还可以根据LTF基本序列进行CFO估计。在STA得到承载该LTF基本序列的子载波的信道估计和CFO估计后，通过内插得到所有子载波的信道估计，然后STA再根据得到的信道估计和CFO估计检测对应的空间流上的数据。
需要说明的是，本发明实施例提供的数据帧的传输方法不仅适用于无线局域网下行采用MU-MIMO技术的应用场景，也适用于无线局域网下行采用SU-MIMO技术的应用场景以及无线局域网下行 采用MU-MIMO和SU-MIMO技术的应用场景。针对无线局域网下行采用SU-MIMO技术的应用场景，数据帧的传输方法与无线局域网下行采用MU-MIMO技术的应用场景的数据帧的传输方法相同或类似，其具体步骤可以参照本发明实施例提供的无线局域网下行采用MU-MIMO技术的应用场景下的数据帧的传输方法的具体步骤，其中复用的空间流的个数NSS为单用户复用的数据流数；针对无线局域网下行采用MU-MIMO和SU-MIMO技术的应用场景，数据帧的传输方法与无线局域网下行采用MU-MIMO技术的应用场景的数据帧的传输方法相同或类似，其具体步骤可以参照本发明实施例提供的无线局域网下行采用MU-MIMO技术的应用场景下的数据帧的传输方法的具体步骤，其中复用的空间流的个数NSS为多用户复用的用户数和单用户复用的数据流数，本处不再赘述。
在第二种应用场景下，以第一设备为STA，第二设备为AP，无线局域网采用的MIMO技术具体为MU-MIMO技术，且具体的实施过程用于上行数据的传输过程中为例介绍，在该应用场景下多个STA可以同时与AP间进行通信，且空间流指的是每个用户(STA)发送至AP的数据流，在该应用场景下的数据帧的传输方法如图13所示，具体的该方法可以包括：
S601、AP根据预先配置的映射关系表获取LTF参数。
其中，AP还可以获取分配的子载波起始位置I，并将I发送至STA。
需要说明的是，AP根据预先配置的映射关系表获取LTF参数的过程以及获取分配的子载波起始位置I的过程可以参照步骤S501中的具体描述，本处不再赘述。
S602、AP向STA发送携带指示消息的第二数据帧。
其中，指示信息用于获取生成LTF序列的LTF参数。
需要说明的是，AP可以先根据获取的LTF参数以及I生成LTF序列，然后将生成的LTF序列以及指示信息携带在第二数据帧中发送给STA，也可以将指示信息携带在第二数据帧中的数据部分发送 给STA，本发明在此对指示信息的发送方式不做限制。
需要说明的是，AP可以先根据获取的LTF参数和I生成LTF序列的过程可以参照本发明实施例相关内容的具体描述，本处不再赘述。
S603、STA接收AP发送的携带指示信息的第二数据帧。
S604、STA根据指示信息和预先配置的映射关系表获取LTF参数，并获取分配的子载波起始位置I。
其中，STA可以根据AP发送的明示的信令(explict signaling)获取空间流分配的子载波起始位置I，也可以根据AP发送的暗示的信令(implicit signaling)获取空间流分配的子载波起始位置I，当STA根据AP发送的implicit signaling获取空间流分配的子载波起始位置I时，此时STA获取的分配的子载波起始位置I为接收的空间流默认的顺序。
需要说明的是，STA根据指示信息和预先配置的映射关系表获取LTF参数的过程可以参照步骤S506中的具体描述，本处不再赘述。
S605、STA根据频域变换参数和I，对LTF基本序列进行频域变换得到LTF符号。
其中，在STA获取到LTF参数和I之后，STA可以根据获取到的LTF参数中包含的频域变换参数和获取到的分配的子载波起始位置I，采用频域FDM的方式或频域CDM的方式对LTF基本序列进行频域变换得到LTF符号。
当STA采用频域FDM的方式对LTF基本序列进行频域变换时，STA根据频域变换参数和I，对LTF基本序列进行频域变换得到LTF符号具体的可以包括步骤S605a1至S605a3：
S605a1、STA从I开始，每隔
Figure PCTCN2014096007-appb-000048
个子载波，将LTF基本序列中的每个元素映射到对应的子载波上得到频域LTF序列。
其中，LTF基本序列是由AP进行分配的，STA可以从与AP的信息交互过程中获取到AP分配的LTF基本序列。
S605a2、STA将频域LTF序列进行S点的IFFT变换得到LTF 基本符号。
S605a3、STA将LTF基本符号和CP组合生成LTF符号。
当STA采用频域CDM的方式对LTF基本序列进行频域变换时，STA根据频域变换参数和I，对LTF基本序列进行频域变换得到LTF符号具体的可以包括步骤S605b1至S605b4：
S605b1、STA根据M将LTF基本序列中的每个元素进行扩频处理，获得LTF扩频序列。
S605b2、STA从I开始将LTF扩频序列中的每个元素映射到对应的子载波上得到频域LTF序列。
S605b3、STA将频域LTF序列进行S点的IFFT变换得到LTF基本符号。
S605b4、STA将LTF基本符号和CP组合生成LTF符号。
在STA获得到LTF符号后，STA可以根据时域变换参数，对LTF符号进行时域变换得到LTF序列，具体的可以包括步骤S606：
S606、STA根据N将LTF符号进行扩频处理，生成LTF序列。
需要说明的是，STA根据频域变换参数和I，对LTF基本序列进行频域FDM变换的过程，也就是步骤S605a1至S605a3的具体描述，可以参照本发明实施例中步骤S502a1至S502a3的具体描述，STA根据频域变换参数和I，对LTF基本序列进行频域CDM变换的过程，也就是步骤S605b1至S605b4的具体描述，可以参照本发明实施例中步骤S502b1至S502b4的具体描述，STA根据时域变换参数，对LTF符号进行时域变换的过程，也就是步骤S606的具体描述，可以参照本发明实施例中步骤S503的具体描述，只是该过程的执行主体为STA，本处不再赘述。
综上，由于在频域上可以通过不同的子载波区分M个空间流，在时域上通过不同的扩频序列区分N个空间流，因此，通过频域变换以及时域变换可以区分M*N个空间流。
S607、STA将LTF序列携带在第一数据帧中发送至AP。
其中，由于AP在步骤S601中已获取了LTF参数，因此，STA 不需要将用于获取LTF参数的指示信息通知给AP，只需将LTF序列携带在第一数据帧中发送给AP即可。
S608、AP接收STA发送的携带LTF序列的第一数据帧。
在AP接收到STA发送的携带LTF序列的第一数据帧后，直接获取自身存储的LTF参数，并根据获取到的LTF参数中包含的时域变换参数，对LTF序列进行时域逆变换得到LTF符号，具体可以包括步骤S609：
S609、AP根据N将LTF序列进行解扩处理得到LTF符号。
S610、AP根据频域变换参数和I，对LTF符号进行频域逆变换得到LTF基本序列。
其中，在AP根据时域变换参数，对LTF序列进行时域逆变换得到LTF符号后，AP获取分配的子载波起始位置I，紧接着根据频域变换参数和I，采用频域FDM的方式或频域CDM的方式对LTF符号进行频域逆变换得到LTF基本序列。
当STA采用频域FDM的方式对LTF基本序列进行频域变换得到LTF符号时，此时AP便可以采用频域FDM的方式对LTF符号进行频域逆变换。当AP采用频域FDM的方式对LTF符号进行频域逆变换时，AP根据频域变换参数和I，对LTF符号进行频域逆变换得到LTF基本序列具体的可以包括步骤S610a1至S610a3：
S610a1、AP根据LTF符号确定LTF基本符号。
S610a2、AP将LTF基本符号进行S点的FFT变换得到频域LTF序列。
S610a3、AP根据频域LTF序列，从I开始，每隔
Figure PCTCN2014096007-appb-000049
个子载波提取出LTF基本序列。
当STA采用频域CDM的方式对LTF基本序列进行频域变换得到LTF符号时，此时AP便可以采用频域CDM的方式对LTF符号进行频域逆变换。当AP采用频域CDM的方式对LTF符号进行频域逆变换时，AP根据频域变换参数和I，对LTF符号进行频域逆变换得到LTF基本序列具体的可以包括步骤S610b1至S610b4：
S610b1、AP根据LTF符号确定LTF基本符号。
S610b2、AP将LTF基本符号进行S点的FFT变换得到频域LTF序列。
S610b3、AP根据频域LTF序列，从I开始从对应的子载波上提取出LTF扩频序列。
S610b4、AP根据M对LTF扩频序列进行解扩处理得到LTF基本序列。
S611、AP根据LTF基本序列进行信道估计。
需要说明的是，步骤S609至S611的具体描述可以参照步骤S507至S509的具体描述，只是执行该过程的执行主体为AP，本处不再赘述。
需要说明的是，在本发明实施例中，复用的空间流的个数NSS为多用户复用的用户数。
在第三种应用场景中，以第一设备为STA，第二设备为AP，无线局域网采用的MIMO技术具体为SU-MIMO技术，且具体的实施过程用于上行数据的传输过程中为例进行介绍，在该应用场景下AP与STA间存在多个空间流，且空间流指的是AP与STA间的数据流，在该应用场景下的数据帧的传输方法如图14所示，具体的该方法可以包括：
S701、STA获取LTF参数，并获取分配的子载波起始位置I。
其中，频域上分配的子载波起始位置I的获取过程可以是通过STA分配获取的，具体的获取过程为：STA根据实际应用场景为每个空间流分配子载波起始位置I，或者STA根据每个空间流的顺序为每个空间流分配与空间流顺序相同的子载波起始位置I。
S702、STA根据频域变换参数和I，对LTF基本序列进行频域变换得到LTF符号。
其中，在STA获取到LTF参数和分配的子载波起始位置I之后，STA可以根据获取到的LTF参数中包含的频域变换参数和获取到的分配的子载波起始位置I，采用频域FDM的方式或频域CDM的方 式对LTF基本序列进行频域变换得到LTF符号。
当STA采用频域FDM的方式对LTF基本序列进行频域变换时，STA根据频域变换参数和I，对LTF基本序列进行频域变换得到LTF符号具体的可以包括步骤S702a1至S702a3：
S702a1、STA从I开始，每隔
Figure PCTCN2014096007-appb-000050
个子载波，将LTF基本序列中的每个元素映射到对应的子载波上得到频域LTF序列。
其中，LTF基本序列是STA分配的，当STA中预先配置的映射关系表采用方式一时，STA直接获取存储的LTF基本序列；当STA中预先配置的映射关系表采用方式二、方式三以及方式四中的任一种方式时，在STA获取到LTF参数后，STA可以根据LTF参数中包含的频域变换参数L，从预先存储的LTF基本序列中选择需要使用的LTF基本序列。例如，STA获取到的LTF参数中包含的频域变换参数L为56时，根据L选择的LTF基本序列可以为：
LTF基本序列＝{1 1 LTFleft 0 LTFright -1 -1}
其中，LTFleft和LTFright包含的元素个数均为26。
S702a2、STA将频域LTF序列进行S点的IFFT变换得到LTF基本符号。
S702a3、STA将LTF基本符号和CP组合生成LTF符号。
当STA采用频域CDM的方式对LTF基本序列进行频域变换时，STA根据频域变换参数和I，对LTF基本序列进行频域变换得到LTF符号具体的可以包括步骤S702b1至S702b4：
S702b1、STA根据M将LTF基本序列中的每个元素进行扩频处理，获得LTF扩频序列。
S702b2、STA从I开始将LTF扩频序列中的每个元素映射到对应的子载波上得到频域LTF序列。
S702b3、STA将频域LTF序列进行S点的IFFT变换得到LTF基本符号。
S702b4、STA将LTF基本符号和CP组合生成LTF符号。
在STA获得到LTF符号后，STA可以根据时域变换参数，对 LTF符号进行时域变换得到LTF序列，具体的可以包括步骤S703：
S703、STA根据N将LTF符号进行扩频处理，生成LTF序列。
综上，由于在频域上可以通过不同的子载波区分M个空间流，在时域上通过不同的扩频序列区分N个空间流，因此，通过频域变换以及时域变换可以区分M*N个空间流。
由于AP需要对LTF序列进行解析获得LTF基本序列，因此，AP需要获知STA生成LTF序列所采用的LTF参数，为了节省信令开销，STA可以将用于获取LTF参数的指示信息通知给AP，因此，STA将LTF序列携带在第一数据帧中发送至AP，具体的可以包括以下步骤S704：
S704、STA将LTF序列和指示信息携带在第一数据帧中发送至AP。
S705、AP接收STA发送的携带LTF序列和指示信息的第一数据帧。
S706、AP根据指示信息和预先配置的映射关系表获取LTF参数，并获取分配的子载波起始位置I。
其中，AP可以根据STA发送的explict signaling获取空间流分配的子载波起始位置I，也可以根据STA发送的implicit signaling获取空间流分配的子载波起始位置I，当AP根据STA发送的implicit signaling获取空间流分配的子载波起始位置I时，此时AP获取的分配的子载波起始位置I为接收的空间流默认的顺序。
该映射关系表具体的可以由以下方式中的任一种方式组成：
方式一：映射关系表中包含复用的空间流的个数NSS、AP的类型、以及与NSS和AP的类型对应的参数。
其中，复用的空间流的个数NSS为单用户复用的数据流数。
方式二：映射关系表中包含复用的空间流的个数NSS、AP所处的环境类型、以及与用户数NSS和AP所处的环境类型对应的参数。
方式三：映射关系表中包含复用的空间流的个数NSS、以及与NSS对应的参数。
方式四：映射关系表中包含复用的空间流的个数NSS、MCS特性信息、以及与NSS和MCS特性信息对应的参数。
其中，当AP中预先配置的映射关系表的组成方式为方式一时，当指示信息包括NSS时，AP根据指示信息和预先配置的映射关系表获取LTF参数可以包括：AP根据NSS和AP的类型，将与NSS和AP的类型对应的参数作为LTF参数。
当AP中预先配置的映射关系表的组成方式为方式二时，当指示信息包括NSS时，AP根据指示信息和预先配置的映射关系表获取LTF参数具体的可以包括：AP根据NSS和AP所处的环境类型，将与NSS和AP所处的环境类型对应的参数作为LTF参数。
当AP中预先配置的映射关系表的组成方式为方式三时，在第一种可能的实现方式中，当指示信息包括NSS时，AP根据指示信息和预先配置的映射关系表获取LTF参数可以包括：AP根据NSS，将与NSS对应的参数作为LTF参数。
在第二种可能的实现方式中，当指示信息包括LTF序列包含的LTF符号的个数N时，AP根据指示信息和预先配置的映射关系表获取LTF参数可以包括：AP根据CP的长度确定子载波个数S，然后根据N和S确定NSS，进一步根据NSS，将与NSS对应的参数确定为LTF参数。
需要说明的是，AP根据CP的长度确定子载波个数S的方法可以参照STA根据CP的长度确定子载波个数S的方法，本处不再赘述。
当AP中预先配置的映射关系表的组成方式为方式四时，当指示信息包括NSS和MCS特性信息时，AP根据指示信息和预先配置的映射关系表获取LTF参数可以包括：AP根据NSS和MCS特性信息，将与NSS和MCS特性信息对应的参数作为LTF参数。
在AP获取到LTF参数以及分配的子载波起始位置I后，根据时域变换参数，对LTF序列进行时域逆变换得到LTF符号具体可以包括步骤S707：
S707、AP根据N将LTF序列进行解扩处理得到LTF符号。
S708、AP根据频域变换参数和I，对LTF符号进行频域逆变换得到LTF基本序列。
其中，在AP根据时域变换参数，对LTF序列进行时域逆变换得到LTF符号后，AP可以根据频域变换参数和I，采用频域FDM的方式或频域CDM的方式对LTF符号进行频域逆变换得到LTF基本序列。
当STA采用频域FDM的方式对LTF基本序列进行频域变换得到LTF符号时，此时AP便可以采用频域FDM的方式对LTF符号进行频域逆变换。当AP采用频域FDM的方式对LTF符号进行频域逆变换时，AP根据频域变换参数和I，对LTF符号进行频域逆变换得到LTF基本序列具体的可以包括步骤S708a1至S708a3：
S708a1、AP根据LTF符号确定LTF基本符号。
S708a2、AP将LTF基本符号进行S点的FFT变换得到频域LTF序列。
S708a3、AP根据频域LTF序列，从I开始，每隔
Figure PCTCN2014096007-appb-000051
个子载波提取出LTF基本序列。
当STA采用频域CDM的方式对LTF基本序列进行频域变换得到LTF符号时，此时AP便可以采用频域CDM的方式对LTF符号进行频域逆变换。当AP采用频域CDM的方式对LTF符号进行频域逆变换时，AP根据频域变换参数和I，对LTF符号进行频域逆变换得到LTF基本序列具体的可以包括步骤S708b1至S708b4：
S708b1、AP根据LTF符号确定LTF基本符号。
S708b2、AP将LTF基本符号进行S点的FFT变换得到频域LTF序列。
S708b3、AP根据频域LTF序列，从I开始从对应的子载波上提取出LTF扩频序列。
S708b4、AP根据M对LTF扩频序列进行解扩处理得到LTF基本序列。
S709、AP根据LTF基本序列进行信道估计。
需要说明的是，步骤S701至S709中的具体描述可以参照步骤S501至S509中的具体描述，本处不再赘述。
优选的，当无线局域网采用的MIMO技术为MU-MIMO以及SU-MIMO技术时，在该应用场景下AP与多个STA同时进行通信，且每个STA与AP间进行通信的过程中存在多个空间流，该空间流包括了AP与STA间传输的所有用户的数据流。针对AP与同一STA间传输的空间流，由于同一STA与AP间传输的空间流使用相同的晶振器，也就是说，同一STA与AP间传输的空间流的频偏相同，时域上的正交性可以保持，所以可以使用时域CDM的方式对同一STA与AP间传输的空间流进行区分；而针对AP与不同STA间传输的空间流，由于AP与不同STA间传输的空间流的频偏不同，时域上的正交性不容易保持，可以尽可能得使用频域FDM或者频域CDM的方式对AP与不同STA间传输的空间流进行区分。在保证时域CDM正交性的前提下，为了节省信令开销，需要减少LTF序列的长度，因此，需要合理得调整映射关系表中N、M、S和L等参数。例如，若AP同时与两个STA进行通信，每个STA与AP间进行通信的过程中存在四个空间流，根据上述规则，可以将用于区分空间流的子载波的个数M的取值确定为2，LTF序列包含的LTF符号的个数N确定为4；若AP同时与四个STA进行通信，每个STA与AP间进行通信的过程中存在两个空间流，根据上述规则，可以将用于区分空间流的子载波的个数M的取值确定为4，LTF序列包含的LTF符号的个数N确定为2。
本发明提供的数据帧的传输方法，第一设备根据获取的LTF参数中包含的频域变换参数和获取的分配的子载波起始位置I对LTF基本序列进行频域变换得到LTF符号，并根据LTF参数中包含的时域变换参数对LTF符号进行时域变换得到LTF序列，然后将得到的LTF序列携带在第一数据帧中发送至第二设备，以便第二设备根据LTF序列确定LTF基本序列，并根据LTF基本序列进行信道估计。 第一设备在生成LTF序列的过程中，通过在频域上和时域上区分空间流，使得LTF序列包含的LTF符号的个数减少，从而节省了信令开销，降低了数据部分接收的时延。同时，由于在数据帧发送过程中，LTF序列包含的LTF符号个数减少，使得时域上符号间的串扰概率降低，从而更好得抵抗了多普勒频移的影响。
本发明另一实施例提供一种传输设备，应用于采用多输入多输出MIMO技术的无线局域网系统，如图15所示，所述传输设备包括：处理器81、发送器82。
处理器81，用于获取长训练码部分LTF参数，并获取分配的子载波起始位置I；其中，所述LTF参数包括：生成LTF序列所需的频域变换参数以及时域变换参数；根据所述频域变换参数和所述I，对LTF基本序列进行频域变换得到LTF符号；根据所述时域变换参数，对所述LTF符号进行时域变换得到所述LTF序列。
发送器82，用于将所述处理器81得到的所述LTF序列携带在第一数据帧中发送至第二设备，以便所述第二设备根据所述LTF序列确定所述LTF基本序列，并根据所述LTF基本序列进行信道估计。
在本发明实施例中，进一步可选的，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S。
所述处理器81，具体用于：从所述I开始，每隔
Figure PCTCN2014096007-appb-000052
个子载波，将所述LTF基本序列中的每个元素映射到对应的子载波上得到频域LTF序列；所述
Figure PCTCN2014096007-appb-000053
表示向下取整；将所述频域LTF序列进行S点的快速傅里叶逆变换IFFT变换得到LTF基本符号；将所述LTF基本符号和循环前缀CP组合生成所述LTF符号。
在本发明实施例中，进一步可选的，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S。
所述处理器81，具体用于：根据所述M将所述LTF基本序列中的每个元素进行扩频处理，获得LTF扩频序列；所述LTF扩频序 列中包含M*L个元素；从所述I开始将所述LTF扩频序列中的每个元素映射到对应的子载波上得到频域LTF序列；将所述频域LTF序列进行S点的IFFT变换得到LTF基本符号；将所述LTF基本符号和CP组合生成所述LTF符号。
在本发明实施例中，进一步可选的，所述时域变换参数包括：所述LTF序列包含的所述LTF符号的个数N。
所述处理器81，具体用于根据所述N将所述LTF符号进行扩频处理，生成所述LTF序列。
在本发明实施例中，进一步可选的，所述传输设备为站点STA，所述第二设备为接入点AP。
所述传输设备，还包括：接收器83。
接收器83，用于接收所述第二设备发送的携带指示信息的第二数据帧；其中，所述指示信息用于指示所述LTF参数。
所述处理器81，具体用于根据所述指示信息和预先配置的映射关系表获取所述LTF参数。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数。
当所述指示信息包括所述NSS，且所述传输设备在接入所述AP时已获取到所述AP的类型时，所述处理器81，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
当所述指示信息包括所述NSS和子载波个数S，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述处理器81，具体用于根据所述S确定所述AP的类型；其中，所述S与所述AP的类型存在对应关系；根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
当所述指示信息包括所述NSS，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述处理器81，具体用于根据CP 的长度确定所述S，并根据所述S确定所述AP的类型；根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；所述指示信息包括所述NSS，且所述传输设备在接入所述AP时已获取到所述AP所处的环境类型。
所述处理器81，具体用于根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数。
当所述指示信息包括所述NSS时，所述处理器81，具体用于根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数。
当所述指示信息包括所述LTF序列包含的所述LTF符号的个数N时，所述处理器81，具体用于根据CP的长度确定子载波个数S；根据所述N和所述S确定所述NSS，并根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、调制与编码策略MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；所述指示信息包括所述NSS和所述MCS特性信息。
所述处理器81，具体用于根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数。
在本发明实施例中，进一步可选的，所述传输设备为AP，所述第二设备为STA；或者，所述传输设备为STA，所述第二设备为AP。
所述处理器81，具体用于根据预先配置的映射关系表获取所述LTF参数。
所述发送器82，具体用于将所述LTF序列和指示信息携带在所述第一数据帧中发送至所述第二设备，以便所述第二设备根据所述LTF序列和所述指示信息确定所述LTF基本序列。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；且当所述传输设备为STA时，所述传输设备在接入所述AP时已获取到所述AP的类型。
所述处理器81，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
若所述传输设备为所述STA，所述第二设备为所述AP，所述指示信息包括所述NSS。
若传输设备为所述AP，所述第二设备为所述STA，所述指示信息包括所述NSS；或者，所述指示信息包括所述NSS和子载波个数S。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；且当所述传输设备为STA时，所述传输设备在接入所述AP时已获取到所述AP所处的环境类型。
所述处理器81，具体用于根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数；所述指示信息包括所述NSS。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数。
所述处理器81，具体用于根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数；所述指示信息包括所述NSS；或者，所述指示信息包括所述LTF序列包含的所述LTF符号的个数N。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数。
所述处理器81，具体用于根据所述NSS和所述MCS特性信息， 将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数；所述指示信息包括所述NSS和所述MCS特性信息。
在本发明实施例中，进一步可选的，所述复用的空间流的个数包括：多用户复用的用户数和/或单用户复用的数据流数。
需要说明的是，本发明实施例提供的传输设备中各功能模块的具体工作过程可以参考方法实施例中对应过程的具体描述，本发明实施例在此不再详细赘述。
本发明提供的传输设备，根据获取的LTF参数中包含的频域变换参数和获取的分配的子载波起始位置I对LTF基本序列进行频域变换得到LTF符号，并根据LTF参数中包含的时域变换参数对LTF符号进行时域变换得到LTF序列，然后将得到的LTF序列携带在第一数据帧中发送至第二设备，以便第二设备根据LTF序列确定LTF基本序列，并根据LTF基本序列进行信道估计。传输设备在生成LTF序列的过程中，通过在频域上和时域上区分空间流，使得LTF序列包含的LTF符号的个数减少，从而节省了信令开销，降低了数据部分接收的时延。同时，由于在数据帧发送过程中，LTF序列包含的LTF符号个数减少，使得时域上符号间的串扰概率降低，从而更好得抵抗了多普勒频移的影响。
本发明另一实施例提供一种传输设备，应用于采用多输入多输出MIMO技术的无线局域网系统，如图16所示，包括：接收器91、处理器92。
接收器91，用于接收第一设备发送的携带长训练码部分LTF序列的第一数据帧。
处理器92，用于根据所述接收器91接收到得所述LTF序列确定LTF基本序列，并根据所述LTF基本序列进行信道估计。
在本发明实施例中，进一步可选的，所述处理器92，还用于在所述根据所述LTF序列确定LTF基本序列之前，获取LTF参数，并获取分配的子载波起始位置I；其中，所述LTF参数包括：所述第一设备生成所述LTF序列所需的频域变换参数以及时域变换参数。
所述处理器92，具体用于：根据所述时域变换参数，对所述LTF序列进行时域逆变换得到LTF符号；根据所述频域变换参数和所述I，对所述LTF符号进行频域逆变换得到所述LTF基本序列。
在本发明实施例中，进一步可选的，所述时域变换参数包括：所述LTF序列包含的所述LTF符号的个数N。
所述处理器92，具体用于根据所述N将所述LTF序列进行解扩处理得到所述LTF符号。
在本发明实施例中，进一步可选的，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S。
所述处理器92，具体用于：根据所述LTF符号确定LTF基本符号；其中，所述LTF符号由所述LTF基本符号和循环前缀CP组成；将所述LTF基本符号进行S点的快速傅里叶变换FFT变换得到频域LTF序列；根据所述频域LTF序列，从所述I开始，每隔
Figure PCTCN2014096007-appb-000054
个子载波提取出所述LTF基本序列；所述
Figure PCTCN2014096007-appb-000055
表示向下取整。
在本发明实施例中，进一步可选的，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S。
所述处理器92，具体用于：根据所述LTF符号确定LTF基本符号；其中，所述LTF符号由所述LTF基本符号和CP组成；将所述LTF基本符号进行S点的FFT变换得到频域LTF序列；根据所述频域LTF序列，从所述I开始从对应的子载波上提取出LTF扩频序列；其中，所述LTF扩频序列中包含M*L个元素；根据所述M对所述LTF扩频序列进行解扩处理得到所述LTF基本序列。
在本发明实施例中，进一步可选的，所述第一设备为站点STA，所述传输设备为接入点AP。
所述处理器92，还用于在所述接收器91接收第一设备发送的携带长训练码部分LTF序列的第一数据帧之前，根据预先配置的映射关系表获取所述LTF参数。
所述传输设备，还包括：发送器93。
发送器93，用于向所述第一设备发送携带指示信息的第二数据帧；其中，所述指示信息指示所述LTF参数。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数。
所述处理器92，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；所述指示信息包括所述NSS；或者，所述指示信息包括所述NSS和子载波个数S。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数。
所述处理器92，具体用于根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数；所述指示信息包括所述NSS。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数。
所述处理器92，具体用于根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数；所述指示信息包括所述NSS；或者，所述指示信息包括所述LTF序列包含的所述LTF符号的个数N。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数。
所述处理器92，具体用于根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数；
所述指示信息包括所述NSS和所述MCS特性信息。
在本发明实施例中，进一步可选的，所述第一设备为AP，所述传输设备为STA；或者，所述第一设备为STA，所述传输设备为AP。
所述接收器91，具体用于接收所述第一设备发送的携带所述 LTF序列和指示信息的所述第一数据帧。
所述处理器92，具体用于根据所述接收器91接收到得所述指示信息和预先配置的映射关系表获取所述LTF参数。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数。
若所述第一设备为所述STA，所述传输设备为所述AP，所述指示信息包括所述NSS；所述处理器92，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
若第一设备为所述AP，所述传输设备为所述STA。
当所述指示信息包括所述NSS，且所述传输设备在接入所述AP时已获取到所述AP的类型时，所述处理器92，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
当所述指示信息包括所述NSS和子载波个数S，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述处理器92，具体用于根据所述S确定所述AP的类型；其中，所述S与所述AP的类型存在对应关系；根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
当所述指示信息包括所述NSS，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述处理器92，具体用于根据CP的长度确定所述S，并根据所述S确定所述AP的类型；根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；所述指示信息包括所述NSS，且当所述传输设备为所述STA时，所述传输设备在接入所述AP时 已获取到所述AP所处的环境类型。
所述处理器92，具体用于根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数。
当所述指示信息包括所述NSS时，所述处理器92，具体用于根据所述NSS，将与所述NSS对应的参数作为所述LTF参数。
当所述指示信息包括所述LTF序列包含的所述LTF符号的个数N时，所述处理器92，具体用于根据CP的长度确定子载波个数S；根据所述N和所述S确定所述NSS，并根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数。
在本发明实施例中，进一步可选的，所述映射关系表中包含复用的空间流的个数NSS、调制与编码策略MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；所述指示信息包括所述NSS和所述MCS特性信息。
所述处理器92，具体用于根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数。
在本发明实施例中，进一步可选的，所述复用的空间流的个数包括：多用户复用的用户数和/或单用户复用的数据流数。
需要说明的是，本发明实施例提供的传输设备中各功能模块的具体工作过程可以参考方法实施例中对应过程的具体描述，本发明实施例在此不再详细赘述。
本发明提供的传输设备，第一设备根据获取的LTF参数中包含的频域变换参数和获取的分配的子载波起始位置I对LTF基本序列进行频域变换得到LTF符号，并根据LTF参数中包含的时域变换参数对LTF符号进行时域变换得到LTF序列，然后将得到的LTF序列携带在第一数据帧中发送至传输设备，以便传输设备根据LTF序列确定LTF基本序列，并根据LTF基本序列进行信道估计。第一设备 在生成LTF序列的过程中，通过在频域上和时域上区分空间流，使得LTF序列包含的LTF符号的个数减少，从而节省了信令开销，降低了数据部分接收的时延。同时，由于在数据帧发送过程中，LTF序列包含的LTF符号个数减少，使得时域上符号间的串扰概率降低，从而更好得抵抗了多普勒频移的影响。
通过以上的实施方式的描述，所属领域的技术人员可以清楚地了解到，各实施方式中的公式可以进行不同程度的变形而不影响其功能，例如向下取整可以变换为(向上取整-1)，在各实施方式中不再赘述。
通过以上的实施方式的描述，所属领域的技术人员可以清楚地了解到，为描述的方便和简洁，仅以上述各功能模块的划分进行举例说明，实际应用中，可以根据需要而将上述功能分配由不同的功能模块完成，即将装置的内部结构划分成不同的功能模块，以完成以上描述的全部或者部分功能。
在本申请所提供的几个实施例中，应该理解到，所揭露的装置和方法，可以通过其它的方式实现。例如，以上所描述的装置实施例仅仅是示意性的，例如，所述模块或单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个装置，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口，装置或单元的间接耦合或通信连接，可以是电性，机械或其它的形式。
例如，参考图17a所示的下行信号发送系统，图17b所示的上行信号发送的系统。其中LTF发送模块(LTF Transmitter)的具体结构可以参考图18a、18b，LTF接收模块(LTF Recption)的具体结构可以参考图19a、19b；其流程或者工作原理如前述图10、图13、图14所示的对应内容的具体描述。此处不赘述。
参考图17a和17b，在WiFi系统的AP或者STA，可以包括一个控制模块来获取在时域上CDM和频域上FDM/CDM的LTF参数， 该LTF参数用于生成LTF序列，由AP和STA共享LTF参数的相关信息，使在发送端(AP或STA)通过控制模块获取的LTF参数产生LTF序列，接收端(当发送端为AP时，接收端为STA；当发送端为STA时，接收端为AP)通过控制消息接收模块(Control information reception)获取的LTF参数接收LTF序列。利用时域和频域资源共同识别出多流或者多用户的信道估计。
参考图17a，对于下行SU-MIMO或者MU-MIMO，AP端由控制模块(Control Unit)来设计或者获取LTF参数，按照设计或者获取的LTF参数由LTF发送模块(LTF transmitter)产生LTF序列，同时设计或者获取的部分参数由控制消息发送模块(Control information transmitter)放在SIG-A内，进入帧成型模块(Frame muttiptexing)按照帧结构，连同产生的LTF序列和下行的数据，组成包帧(packet frame)由射频发射模块(TX)发送给STA。在STA侧，射频接收模块(RX)接收下来的packet frame，由控制消息接收模块(Control information reception)去接收SIG-A的信息，从中提取LTF序列的设计或者获取参数，接下来由LTF接收模块(LTF reception)来根据LTF序列的设计或者获取参数区分出对应于接收STA的LTF基本序列以及利用LTF基本序列做信道估计以及CFO估计(其中，进行CFO估计为可选的)。
参考图17b，以上行MU-MIMO为例，需要在AP侧统一由控制模块(Control Unit)来设计或者获取多个用户的LTF参数，按照设计或者获取的LTF参数由LTF transmitter产生LTF序列，同时设计或者获取的部分参数由Control information transmitter放在SIG-A内，进入Frame muttiptexing模块按照帧结构，连同下行数据，组成packet frame由TX发送给STA。在STA侧，RX接收下来的数据，由Control information reception去接收SIG-A的信息，从中提取LTF序列的设计或者获取参数，接下来由LTF transmitter模块来根据LTF序列的设计或者获取参数产生各个STA的LTF序列，进Frame muttiptexing模块按照帧结构连同上行的数据，组成packet frame由 TX发送给AP。在AP，LTF reception按照Control Unit设计或者获取的LTF参数接收各个STA的LTF基本序列以及利用LTF基本序列做信道估计以及CFO估计(其中，进行CFO估计为可选的)。
另外，对于上行SU-MIMO，负责设计或者获取LTF参数的Control Unit和Control information transmitter也可以包含于STA中，由STA按照SU-MIMO的流数来设计或者获取LTF参数，而不是由AP设计或者获取告知STA。相应的Control information reception就包含于AP侧，用于从SIG-A中提取LTF序列的设计或者获取参数。
本领域技术人员可以理解，本文各实施方式提到的类型，包含各种可以设置不同的用于生成LTF的参数的应用的情况，包括但不限于空间流的个数NSS、环境类型或者MCS特性。仅以环境类型为例，除提到的室内或者室外，其包括但不限于密集区域(如商场、球场或者办公区域等)、非密集区域(如家庭)；或者，边远地区，城市地区。简言之，只要生成LTF时针对不同的应用的情况采用了不同的参数，即在本发明实施方式范围内。
本领域技术人员可以理解，在具体的AP或者STA中，可以根据实际情况对前述提到的映射关系表进行各种可能的变形：例如基于AP一般不需要移动，一旦在一个应用环境下一般不再改变，所以可以在AP上仅配置一种或者部分类型下的参数，其中参数中至少包括不同于现有技术的频域变换参数，例如LTF序列包含的LTF符号内区分空间流的子载波的个数M，(参见表2，3，3a中类型2下的参数，或者表4、5下的环境类型1和2的参数、表5a的环境类型1下的参数，参见表6、7、7a、7b下的参数)。又例如，某些STA也可能基于不可知的原因，只配置本实施方式提到的部分类型及其相应的参数。
各实施方式中的映射关系表仅是对其中的映射关系内容的举例，一方面，各实施方式中的映射关系表可以在不矛盾冲突时进行组合；另一方面，在具体的AP或者STA中存储的具体形式或者状态不做限定。例如AP或者STA可以同时存储有表6、7、7a、7b下 的参数，根据需要进行选用。又例如，存储的映射关系也有可能是字符串，或者根据实际需要进行节约存储资源的安排：例如将某些不根据应用情况改变的个别参数设为默认参数，不需要重复的存储，例如，表4、5、5a中的参数S；或者，将参数的值用特殊的指示值进行指示以节约存储资源，例如表4中，对于L用指示值1指示L＝56，用指示值2指示L＝112，用指示值3指示L＝224，只需要3个针对L的指示值。只要生成LTF时采用了如各实施方式中映射关系表中的具体内容，即在本实施方式的范围内。
所述作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的部件可以是一个物理单元或多个物理单元，即可以位于一个地方，或者也可以分布到多个不同地方。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。
另外，在本发明各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个单元中。上述集成的单元既可以采用硬件的形式实现，也可以采用软件功能单元的形式实现。
所述集成的单元如果以软件功能单元的形式实现并作为独立的产品销售或使用时，可以存储在一个可读取存储介质中。基于这样的理解，本发明的技术方案本质上或者说对现有技术做出贡献的部分或者该技术方案的全部或部分可以以软件产品的形式体现出来，该软件产品存储在一个存储介质中，包括若干指令用以使得一个设备(可以是单片机，芯片等)或处理器(processor)执行本发明各个实施例所述方法的全部或部分步骤。而前述的存储介质包括：U盘、移动硬盘、只读存储器(ROM，Read-Only Memory)、随机存取存储器(RAM，Random Access Memory)、磁碟或者光盘等各种可以存储程序代码的介质。
以上所述，仅为本发明的具体实施方式，但本发明的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本发明揭露的技 术范围内，可轻易想到变化或替换，都应涵盖在本发明的保护范围之内。因此，本发明的保护范围应所述以权利要求的保护范围为准。

Claims (62)

  1. 一种传输设备，其特征在于，应用于采用多输入多输出MIMO技术的无线局域网系统，所述传输设备包括：
    获取单元，用于获取长训练码部分LTF参数，并获取分配的子载波起始位置I；其中，所述LTF参数包括：生成LTF序列所需的频域变换参数以及时域变换参数；
    频域变换单元，用于根据所述获取单元获取到的所述频域变换参数和所述起始位置I，对LTF基本序列进行频域变换得到LTF符号；
    时域变换单元，用于根据所述获取单元获取到的所述时域变换参数，对所述频域变换单元得到的所述LTF符号进行时域变换得到所述LTF序列；
    发送单元，用于将所述时域变换单元得到的所述LTF序列携带在第一数据帧中发送至第二设备，以便所述第二设备根据所述LTF序列确定所述LTF基本序列，并根据所述LTF基本序列进行信道估计。
  2. 根据权利要求1所述的传输设备，其特征在于，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
    所述频域变换单元，包括：
    映射模块，用于从所述起始位置I开始，每隔
    Figure PCTCN2014096007-appb-100001
    个子载波，将所述LTF基本序列中的每个元素映射到对应的子载波上得到频域LTF序列；所述
    Figure PCTCN2014096007-appb-100002
    表示向下取整；
    逆变换模块，用于将所述映射模块得到的所述频域LTF序列进行S点的快速傅里叶逆变换IFFT变换得到LTF基本符号；
    生成模块，用于将所述逆变换模块得到的所述LTF基本符号和循环前缀CP组合生成所述LTF符号。
  3. 根据权利要求1所述的传输设备，其特征在于，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
    所述频域变换单元，包括：
    扩频模块，用于根据所述M将所述LTF基本序列中的每个元素进行扩频处理，获得LTF扩频序列；所述LTF扩频序列中包含M*L个元素；
    映射模块，用于从所述起始位置I开始将所述扩频模块得到的所述LTF扩频序列中的每个元素映射到对应的子载波上得到频域LTF序列；
    逆变换模块，用于将所述映射模块得到的所述频域LTF序列进行S点的IFFT变换得到LTF基本符号；
    生成模块，用于将所述逆变换模块得到的所述LTF基本符号和CP组合生成所述LTF符号。
  4. 根据权利要求1-3中任一项所述的传输设备，其特征在于，所述时域变换参数包括：所述LTF序列包含的所述LTF符号的个数N；
    所述时域变换单元，具体用于根据所述N将所述LTF符号进行扩频处理，生成所述LTF序列。
  5. 根据权利要求1-4中任一项所述的传输设备，其特征在于，所述传输设备为站点STA，所述第二设备为接入点AP；
    所述获取单元，包括：
    接收模块，用于接收所述第二设备发送的携带指示信息的第二数据帧；其中，所述指示信息用于指示所述LTF参数；
    获取模块，用于根据所述接收模块得到的所述指示信息和预先配置的映射关系表获取所述LTF参数。
  6. 根据权利要求5所述的传输设备，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；
    当所述指示信息包括所述NSS，且所述传输设备在接入所述AP时已获取到所述AP的类型时，所述获取模块，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
    当所述指示信息包括所述NSS和子载波个数S，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述获取模块，具体用于根据所述S确定所述AP的类型；其中，所述S与所述AP的类型存在对应关系；根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
    当所述指示信息包括所述NSS，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述获取模块，具体用于根据CP的长度确定所述S，并根据所述S确定所述AP的类型；根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
  7. 根据权利要求5所述的传输设备，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；所述指示信息包括所述NSS，且所述传输设备在接入所述AP时已获取到所述AP所处的环境类型；
    所述获取模块，具体用于根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数。
  8. 根据权利要求5所述的传输设备，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
    当所述指示信息包括所述NSS时，所述获取模块，具体用于根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数；
    当所述指示信息包括所述LTF序列包含的所述LTF符号的个数N时，所述获取模块，具体用于根据CP的长度确定子载波个数S；根据所述N和所述S确定所述NSS，并根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数。
  9. 根据权利要求5所述的传输设备，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、调制与编码策略MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；所述指示信息包括 所述NSS和所述MCS特性信息；
    所述获取模块，具体用于根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数。
  10. 根据权利要求1-4中任一项所述的传输设备，其特征在于，
    所述传输设备为AP，所述第二设备为STA；或者，所述传输设备为STA，所述第二设备为AP；
    所述获取单元，包括：获取模块，用于根据预先配置的映射关系表获取所述LTF参数；
    所述发送单元，具体用于将所述LTF序列和指示信息携带在所述第一数据帧中发送至所述第二设备，以便所述第二设备根据所述LTF序列和所述指示信息确定所述LTF基本序列。
  11. 根据权利要求10所述的传输设备，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；且当所述传输设备为STA时，所述传输设备在接入所述AP时已获取到所述AP的类型；
    所述获取模块，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
    若所述传输设备为所述STA，所述第二设备为所述AP，所述指示信息包括所述NSS；
    若传输设备为所述AP，所述第二设备为所述STA，所述指示信息包括所述NSS；或者，所述指示信息包括所述NSS和子载波个数S。
  12. 根据权利要求10所述的传输设备，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；且当所述传输设备为STA时，所述传输设备在接入所述AP时已获取到所述AP所处的环境类型；
    所述获取模块，具体用于根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数；
    所述指示信息包括所述NSS。
  13. 根据权利要求10所述的传输设备，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
    所述获取模块，具体用于根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数；
    所述指示信息包括所述NSS；或者，所述指示信息包括所述LTF序列包含的所述LTF符号的个数N。
  14. 根据权利要求10所述的传输设备，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；
    所述获取模块，具体用于根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数；
    所述指示信息包括所述NSS和所述MCS特性信息。
  15. 根据权利要求6-9、11-14中任一项所述的传输设备，其特征在于，
    所述复用的空间流的个数包括：多用户复用的用户数和/或单用户复用的数据流数。
  16. 一种传输设备，其特征在于，应用于采用多输入多输出MIMO技术的无线局域网系统，包括：
    接收单元，用于接收第一设备发送的携带长训练码部分LTF序列的第一数据帧；
    处理单元，用于根据所述接收单元接收到得所述LTF序列确定LTF基本序列，并根据所述LTF基本序列进行信道估计。
  17. 根据权利要求16所述的传输设备，其特征在于，还包括：
    获取单元，用于在所述处理单元根据所述LTF序列确定LTF基本序列之前，获取LTF参数，并获取分配的子载波起始位置I；其中，所述LTF参数包括：所述第一设备生成所述LTF序列所需的频域变换参数以及时域变换参数；
    所述处理单元，包括：
    时域逆变换子单元，用于根据所述获取单元获取到得所述时域变换参数，对所述LTF序列进行时域逆变换得到LTF符号；
    频域逆变换子单元，用于根据所述获取单元获取到得所述频域变换参数和所述起始位置I，对所述时域逆变换子单元得到的所述LTF符号进行频域逆变换得到所述LTF基本序列。
  18. 根据权利要求17所述的传输设备，其特征在于，所述时域变换参数包括：所述LTF序列包含的所述LTF符号的个数N；
    所述时域逆变换子单元，具体用于根据所述N将所述LTF序列进行解扩处理得到所述LTF符号。
  19. 根据权利要求17或18所述的传输设备，其特征在于，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
    所述频域逆变换子单元，包括：
    确定模块，用于根据所述LTF符号确定LTF基本符号；其中，所述LTF符号由所述LTF基本符号和循环前缀CP组成；
    变换模块，用于将所述确定模块得到的所述LTF基本符号进行S点的快速傅里叶变换FFT变换得到频域LTF序列；
    提取模块，用于根据所述变换模块得到的所述频域LTF序列，从所述起始位置I开始，每隔
    Figure PCTCN2014096007-appb-100003
    个子载波提取出所述LTF基本序列；所述
    Figure PCTCN2014096007-appb-100004
    表示向下取整。
  20. 根据权利要求17或18所述的传输设备，其特征在于，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
    所述频域逆变换子单元，包括：
    确定模块，用于根据所述LTF符号确定LTF基本符号；其中，所述LTF符号由所述LTF基本符号和CP组成；
    变换模块，用于将所述确定模块得到的所述LTF基本符号进行S点的FFT变换得到频域LTF序列；
    提取模块，用于根据所述变换模块得到的所述频域LTF序列， 从所述起始位置I开始从对应的子载波上提取出LTF扩频序列；其中，所述LTF扩频序列中包含M*L个元素；
    解扩模块，用于根据所述M对所述提取模块得到的所述LTF扩频序列进行解扩处理得到所述LTF基本序列。
  21. 根据权利要求17-20中任一项所述的传输设备，其特征在于，所述第一设备为站点STA，所述传输设备为接入点AP；
    所述获取单元，还用于在所述接收单元接收第一设备发送的携带长训练码部分LTF序列的第一数据帧之前，根据预先配置的映射关系表获取所述LTF参数；
    所述传输设备，还包括：
    发送单元，用于向所述第一设备发送携带指示信息的第二数据帧；其中，所述指示信息指示所述LTF参数。
  22. 根据权利要求21所述的传输设备，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；
    所述获取单元，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
    所述指示信息包括所述NSS；或者，所述指示信息包括所述NSS和子载波个数S。
  23. 根据权利要求21所述的传输设备，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；
    所述获取单元，具体用于根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数；
    所述指示信息包括所述NSS。
  24. 根据权利要求21所述的传输设备，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
    所述获取单元，具体用于根据所述NSS，将与所述NSS对应的参数 确定为所述LTF参数；
    所述指示信息包括所述NSS；或者，所述指示信息包括所述LTF序列包含的所述LTF符号的个数N。
  25. 根据权利要求21所述的传输设备，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；
    所述获取单元，具体用于根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数；
    所述指示信息包括所述NSS和所述MCS特性信息。
  26. 根据权利要求17-20中任一项所述的传输设备，其特征在于，
    所述第一设备为AP，所述传输设备为STA；或者，
    所述第一设备为STA，所述传输设备为AP；
    所述接收单元，具体用于接收所述第一设备发送的携带所述LTF序列和指示信息的所述第一数据帧；
    所述获取单元，具体用于根据所述接收单元接收到得所述指示信息和预先配置的映射关系表获取所述LTF参数。
  27. 根据权利要求26所述的传输设备，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；
    若所述第一设备为所述STA，所述传输设备为所述AP，所述指示信息包括所述NSS；所述获取单元，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
    若第一设备为所述AP，所述传输设备为所述STA；
    当所述指示信息包括所述NSS，且所述传输设备在接入所述AP时已获取到所述AP的类型时，所述获取单元，具体用于根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
    当所述指示信息包括所述NSS和子载波个数S，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述获取单元，具体用 于根据所述S确定所述AP的类型；其中，所述S与所述AP的类型存在对应关系；根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
    当所述指示信息包括所述NSS，且所述传输设备在接入所述AP时未获取到所述AP的类型时，所述获取单元，具体用于根据CP的长度确定所述S，并根据所述S确定所述AP的类型；根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
  28. 根据权利要求26所述的传输设备，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；所述指示信息包括所述NSS，且当所述传输设备为所述STA时，所述传输设备在接入所述AP时已获取到所述AP所处的环境类型；
    所述获取单元，具体用于根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数。
  29. 根据权利要求26所述的传输设备，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
    当所述指示信息包括所述NSS时，所述获取单元，具体用于根据所述NSS，将与所述NSS对应的参数作为所述LTF参数；
    当所述指示信息包括所述LTF序列包含的所述LTF符号的个数N时，所述获取单元，具体用于根据CP的长度确定子载波个数S；根据所述N和所述S确定所述NSS，并根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数。
  30. 根据权利要求26所述的传输设备，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、调制与编码策略MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；所述指示信息包括所述NSS和所述MCS特性信息；
    所述获取单元，具体用于根据所述NSS和所述MCS特性信息，将 与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数。
  31. 根据权利要求22-25、27-30中任一项所述的传输设备，其特征在于，
    所述复用的空间流的个数包括：多用户复用的用户数和/或单用户复用的数据流数。
  32. 一种数据帧的传输方法，其特征在于，应用于采用多输入多输出MIMO技术的无线局域网系统，所述方法包括：
    第一设备获取长训练码部分LTF参数，并获取分配的子载波起始位置I；其中，所述LTF参数包括：生成LTF序列所需的频域变换参数以及时域变换参数；
    根据所述频域变换参数和所述起始位置I，对LTF基本序列进行频域变换得到LTF符号；
    根据所述时域变换参数，对所述LTF符号进行时域变换得到所述LTF序列；
    将所述LTF序列携带在第一数据帧中发送至第二设备，以便所述第二设备根据所述LTF序列确定所述LTF基本序列，并根据所述LTF基本序列进行信道估计。
  33. 根据权利要求32所述的方法，其特征在于，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
    所述根据所述频域变换参数和所述起始位置I，对LTF基本序列进行频域变换得到LTF符号，包括：
    从所述起始位置I开始，每隔
    Figure PCTCN2014096007-appb-100005
    个子载波，将所述LTF基本序列中的每个元素映射到对应的子载波上得到频域LTF序列；所述
    Figure PCTCN2014096007-appb-100006
    表示向下取整；
    将所述频域LTF序列进行S点的快速傅里叶逆变换IFFT变换得到LTF基本符号；
    将所述LTF基本符号和循环前缀CP组合生成所述LTF符号。
  34. 根据权利要求32所述的方法，其特征在于，所述频域变换 参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
    所述根据所述频域变换参数和所述起始位置I，对LTF基本序列进行频域变换得到LTF符号，包括：
    根据所述M将所述LTF基本序列中的每个元素进行扩频处理，获得LTF扩频序列；所述LTF扩频序列中包含M*L个元素；
    从所述起始位置I开始将所述LTF扩频序列中的每个元素映射到对应的子载波上得到频域LTF序列；
    将所述频域LTF序列进行S点的IFFT变换得到LTF基本符号；
    将所述LTF基本符号和CP组合生成所述LTF符号。
  35. 根据权利要求32-34中任一项所述的方法，其特征在于，所述时域变换参数包括：所述LTF序列包含的所述LTF符号的个数N；
    所述根据所述时域变换参数，对所述LTF符号进行时域变换得到所述LTF序列，包括：
    根据所述N将所述LTF符号进行扩频处理，生成所述LTF序列。
  36. 根据权利要求32-35中任一项所述的方法，其特征在于，所述第一设备为站点STA，所述第二设备为接入点AP；
    所述获取长训练码部分LTF参数，包括：
    接收所述第二设备发送的携带指示信息的第二数据帧；其中，所述指示信息用于指示所述LTF参数；
    根据所述指示信息和预先配置的映射关系表获取所述LTF参数。
  37. 根据权利要求36所述的方法，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；
    当所述指示信息包括所述NSS，且所述第一设备在接入所述AP时已获取到所述AP的类型时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
    根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
    当所述指示信息包括所述NSS和子载波个数S，且所述第一设备在接入所述AP时未获取到所述AP的类型时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
    根据所述S确定所述AP的类型；其中，所述S与所述AP的类型存在对应关系；
    根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
    当所述指示信息包括所述NSS，且所述第一设备在接入所述AP时未获取到所述AP的类型时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
    根据CP的长度确定所述S，并根据所述S确定所述AP的类型；
    根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数。
  38. 根据权利要求36所述的方法，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；所述指示信息包括所述NSS，且所述第一设备在接入所述AP时已获取到所述AP所处的环境类型；
    所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
    根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数。
  39. 根据权利要求36所述的方法，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
    当所述指示信息包括所述NSS时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
    根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数；
    当所述指示信息包括所述LTF序列包含的所述LTF符号的个数N时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF 参数，包括：
    根据CP的长度确定子载波个数S；
    根据所述N和所述S确定所述NSS，并根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数。
  40. 根据权利要求36所述的方法，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、调制与编码策略MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；所述指示信息包括所述NSS和所述MCS特性信息；
    所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
    根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数。
  41. 根据权利要求32-35中任一项所述的方法，其特征在于，
    所述第一设备为AP，所述第二设备为STA；或者，
    所述第一设备为STA，所述第二设备为AP；
    所述获取长训练码部分LTF参数，包括：
    根据预先配置的映射关系表获取所述LTF参数；
    所述将所述LTF序列携带在第一数据帧中发送至第二设备，包括：
    将所述LTF序列和指示信息携带在所述第一数据帧中发送至所述第二设备，以便所述第二设备根据所述LTF序列和所述指示信息确定所述LTF基本序列。
  42. 根据权利要求41所述的方法，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；且当所述第一设备为STA时，所述第一设备在接入所述AP时已获取到所述AP的类型；
    所述根据预先配置的映射关系表获取LTF参数，包括：
    根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
    若所述第一设备为所述STA，所述第二设备为所述AP，所述指示信息包括所述NSS；
    若第一设备为所述AP，所述第二设备为所述STA，所述指示信息包括所述NSS；或者，所述指示信息包括所述NSS和子载波个数S。
  43. 根据权利要求41所述的方法，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；且当所述第一设备为STA时，所述第一设备在接入所述AP时已获取到所述AP所处的环境类型；
    所述根据预先配置的映射关系转发表获取LTF参数，包括：
    根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数；
    所述指示信息包括所述NSS。
  44. 根据权利要求41所述的方法，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
    所述根据预先配置的映射关系转发表获取LTF参数，包括：
    根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数；
    所述指示信息包括所述NSS；或者，所述指示信息包括所述LTF序列包含的所述LTF符号的个数N。
  45. 根据权利要求41所述的方法，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；
    所述根据预先配置的映射关系转发表获取LTF参数，包括：
    根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数；
    所述指示信息包括所述NSS和所述MCS特性信息。
  46. 根据权利要求37-40、42-45中任一项所述的方法，其特征在于，
    所述复用的空间流的个数包括：多用户复用的用户数和/或单用 户复用的数据流数。
  47. 一种数据帧的传输方法，其特征在于，应用于采用多输入多输出MIMO技术的无线局域网系统，包括：
    第二设备接收第一设备发送的携带长训练码部分LTF序列的第一数据帧；
    根据所述LTF序列确定LTF基本序列，并根据所述LTF基本序列进行信道估计。
  48. 根据权利要求47所述的方法，其特征在于，在所述根据所述LTF序列确定LTF基本序列之前，还包括：
    获取LTF参数，并获取分配的子载波起始位置I；其中，所述LTF参数包括：所述第一设备生成所述LTF序列所需的频域变换参数以及时域变换参数；
    所述根据所述LTF序列确定LTF基本序列，包括：
    根据所述时域变换参数，对所述LTF序列进行时域逆变换得到LTF符号；
    根据所述频域变换参数和所述起始位置I，对所述LTF符号进行频域逆变换得到所述LTF基本序列。
  49. 根据权利要求48所述的方法，其特征在于，所述时域变换参数包括：所述LTF序列包含的所述LTF符号的个数N；
    所述根据所述时域变换参数，对所述LTF序列进行时域逆变换得到LTF符号，包括：
    根据所述N将所述LTF序列进行解扩处理得到所述LTF符号。
  50. 根据权利要求48或49所述的方法，其特征在于，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
    所述根据所述频域变换参数和所述起始位置I，对所述LTF符号进行频域逆变换得到所述LTF基本序列，包括：
    根据所述LTF符号确定LTF基本符号；其中，所述LTF符号由所述LTF基本符号和循环前缀CP组成；
    将所述LTF基本符号进行S点的快速傅里叶变换FFT变换得到频域LTF序列；
    根据所述频域LTF序列，从所述起始位置I开始，每隔
    Figure PCTCN2014096007-appb-100007
    个子载波提取出所述LTF基本序列；所述
    Figure PCTCN2014096007-appb-100008
    表示向下取整。
  51. 根据权利要求48或49所述的方法，其特征在于，所述频域变换参数包括：用于区分空间流的子载波的个数M、所述LTF基本序列的元素个数L和子载波个数S；
    所述根据所述频域变换参数和所述起始位置I，对所述LTF符号进行频域逆变换得到所述LTF基本序列，包括：
    根据所述LTF符号确定LTF基本符号；其中，所述LTF符号由所述LTF基本符号和CP组成；
    将所述LTF基本符号进行S点的FFT变换得到频域LTF序列；
    根据所述频域LTF序列，从所述起始位置I开始从对应的子载波上提取出LTF扩频序列；其中，所述LTF扩频序列中包含M*L个元素；
    根据所述M对所述LTF扩频序列进行解扩处理得到所述LTF基本序列。
  52. 根据权利要求48-51中任一项所述的方法，其特征在于，所述第一设备为站点STA，所述第二设备为接入点AP；
    在所述接收第一设备发送的携带长训练码部分LTF序列的第一数据帧之前，还包括：
    根据预先配置的映射关系表获取所述LTF参数；
    向所述第一设备发送携带指示信息的第二数据帧；其中，所述指示信息指示所述LTF参数。
  53. 根据权利要求52所述的方法，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；
    所述根据预先配置的映射关系表获取所述LTF参数，包括：
    根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对 应的参数作为所述LTF参数；
    所述指示信息包括所述NSS；或者，所述指示信息包括所述NSS和子载波个数S。
  54. 根据权利要求52所述的方法，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；
    所述根据预先配置的映射关系转发表获取LTF参数，包括：
    根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数；
    所述指示信息包括所述NSS。
  55. 根据权利要求52所述的方法，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
    所述根据预先配置的映射关系转发表获取LTF参数，包括：
    根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数；
    所述指示信息包括所述NSS；或者，所述指示信息包括所述LTF序列包含的所述LTF符号的个数N。
  56. 根据权利要求52所述的方法，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；
    所述根据预先配置的映射关系转发表获取LTF参数，包括：
    根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数；
    所述指示信息包括所述NSS和所述MCS特性信息。
  57. 根据权利要求48-51中任一项所述的方法，其特征在于，
    所述第一设备为AP，所述第二设备为STA；或者，
    所述第一设备为STA，所述第二设备为AP；
    所述接收第一设备发送的携带长训练码部分LTF序列的第一数据帧，包括：
    接收所述第一设备发送的携带所述LTF序列和指示信息的所述 第一数据帧；
    所述获取LTF参数，包括：
    根据所述指示信息和预先配置的映射关系表获取所述LTF参数。
  58. 根据权利要求57所述的方法，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、所述AP的类型、以及与所述NSS和所述AP的类型对应的参数；
    若所述第一设备为所述STA，所述第二设备为所述AP，所述指示信息包括所述NSS；所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
    根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
    若第一设备为所述AP，所述第二设备为所述STA；
    当所述指示信息包括所述NSS，且所述第二设备在接入所述AP时已获取到所述AP的类型时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
    根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
    当所述指示信息包括所述NSS和子载波个数S，且所述第二设备在接入所述AP时未获取到所述AP的类型时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
    根据所述S确定所述AP的类型；其中，所述S与所述AP的类型存在对应关系；
    根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对应的参数作为所述LTF参数；
    当所述指示信息包括所述NSS，且所述第二设备在接入所述AP时未获取到所述AP的类型时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
    根据CP的长度确定所述S，并根据所述S确定所述AP的类型；
    根据所述NSS和所述AP的类型，将与所述NSS和所述AP的类型对 应的参数作为所述LTF参数。
  59. 根据权利要求57所述的方法，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、所述AP所处的环境类型、以及与所述NSS和所述AP所处的环境类型对应的参数；所述指示信息包括所述NSS，且当所述第二设备为所述STA时，所述第二设备在接入所述AP时已获取到所述AP所处的环境类型；
    所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
    根据所述NSS和所述AP所处的环境类型，将与所述NSS和所述AP所处的环境类型对应的参数作为所述LTF参数。
  60. 根据权利要求57所述的方法，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、以及与所述NSS对应的参数；
    当所述指示信息包括所述NSS时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
    根据所述NSS，将与所述NSS对应的参数作为所述LTF参数；
    当所述指示信息包括所述LTF序列包含的所述LTF符号的个数N时，所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
    根据CP的长度确定子载波个数S；
    根据所述N和所述S确定所述NSS，并根据所述NSS，将与所述NSS对应的参数确定为所述LTF参数。
  61. 根据权利要求57所述的方法，其特征在于，所述映射关系表中包含复用的空间流的个数NSS、调制与编码策略MCS特性信息、以及与所述NSS和所述MCS特性信息对应的参数；所述指示信息包括所述NSS和所述MCS特性信息；
    所述根据所述指示信息和预先配置的映射关系表获取所述LTF参数，包括：
    根据所述NSS和所述MCS特性信息，将与所述NSS和所述MCS特性信息对应的参数作为所述LTF参数。
  62. 根据权利要求53-56、58-61中任一项所述的方法，其特征在于，
    所述复用的空间流的个数包括：多用户复用的用户数和/或单用户复用的数据流数。
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