WO2016106936A1

WO2016106936A1 - Data transmission method, apparatus and system

Info

Publication number: WO2016106936A1
Application number: PCT/CN2015/072004
Authority: WO
Inventors: 吴作敏; 马莎
Original assignee: 华为技术有限公司
Priority date: 2014-12-31
Filing date: 2015-01-30
Publication date: 2016-07-07
Also published as: CN107113275A

Abstract

Disclosed are a data transmission method and apparatus. In an embodiment, the data transmission method comprises: receiving, on a first carrier, at least two symbols each having a first cyclic prefix (CP), the time length of the first CP being a first length; acquiring first information comprising first length information; acquiring coarse timing information on the first carrier; and according to the coarse timing information on the first carrier and the first information, performing CP removal processing on a first symbol in the at least two symbols on the first carrier according to a second length, and performing CP removal processing on the symbol other than the first symbol in the at least two symbols according to the first length, the second length being an arbitrary value smaller than the first length.

Description

Data transmission method, device and system

Technical field

Embodiments of the present invention relate to a wireless communication technology, and in particular, to a data transmission method and apparatus.

Background technique

In an existing Long Term Evolution (LTE) system, a user equipment (UE) performs data on a certain carrier of an evolved base station (Evolutional Node B, eNB or e-NodeB). Before demodulation, it is necessary to obtain time-frequency synchronization tracking (ie, fine time-frequency synchronization tracking) with the demodulation level of the eNB on the carrier. Fine time-frequency synchronization tracking is usually obtained by periodically transmitting pilot signals. However, in some specific scenarios, for example, when the eNB uses the carrier on the unlicensed spectrum for data transmission, the transmission of the periodic pilot signal cannot be guaranteed. Therefore, at the receiving end, the UE may have received the to-be-demodulated signal without completing the fine synchronization. Data, which leads to a decline in data demodulation performance.

In addition, in some specific scenarios, the eNB may use a different site or carrier to send a Physical Downlink Control CHannel (PDCCH) and a Physical Downlink Shared CHannel (PDSCH) to the UE. The PDCCH bearer scheduling and other control information specifically include a transport format, resource allocation, modulation and coding scheme information, and the like. The UE needs to demodulate the PDCCH first, and then can demodulate the PDSCH belonging to the UE itself at the corresponding resource location. The PDSCH symbol arrives at the UE receiving end may be earlier or later than the PDCCH symbol. When the PDCCH symbol is later than the PDSCH symbol, the PDSCH symbol is demodulated according to the timing of the PDCCH symbol, which may introduce inter-symbol interference, and may not correctly demodulate the data carried by the PDSCH symbol, thereby affecting the efficiency of data transmission.

Summary of the invention

Embodiments of the present invention provide a data transmission method, apparatus, and system to improve data transmission efficiency.

In a first aspect, an embodiment of the present invention provides a data transmission method, including:

Receiving, on the first carrier, at least two symbols having a first cyclic prefix CP; wherein, the length of time of the first CP is a first length;

Obtaining first information, where the first information includes first length information;

Obtaining coarse timing information on the first carrier;

De-CP processing the first one of the at least two symbols on the first carrier according to the coarse timing information on the first carrier and the first information, to the at least two The symbols other than the first one of the symbols are subjected to CP processing by the first length; wherein the second length is any value smaller than the first length.

In a first possible implementation manner of the first aspect, the first length is a length of a long cyclic prefix ECP, and the second length is a length of a normal cyclic prefix NCP.

In a second possible implementation of the first aspect, the second length is one half of the first length.

With reference to the first aspect, or any one of the first to the second possible implementation manners of the first aspect, in the third possible implementation, the obtaining the first information includes:

The first information is predefined information; or

Receiving the signaling of the first information indicates obtaining the first information.

With reference to the first aspect, or any one of the first to the third possible implementation manners of the first aspect, in the fourth possible implementation, the first information further includes a number of symbols having the first CP, and / or, the number of subframes having the first CP, and / or the starting position of the symbol having the first CP.

With reference to the first aspect, or any one of the first to fourth possible implementation manners of the first aspect, in the fifth possible implementation manner, obtaining the coarse timing information on the first carrier, including:

Obtaining timing information on the second carrier as coarse timing information of the first carrier, where the first carrier and the second carrier are carriers configured by the same base station; or, the first carrier and the first The two carriers are carriers configured for different base stations.

With reference to the fifth possible implementation manner of the first aspect, in a sixth possible implementation manner, the spectrum of the first carrier is an unlicensed spectrum, and the spectrum of the second carrier is a licensed spectrum; or

The spectrum in which the first carrier is located and the spectrum in which the second carrier is located are unlicensed spectrum; or

The spectrum in which the first carrier is located and the spectrum in which the second carrier is located are licensed spectrums of the same frequency.

With reference to any one of the possible implementations of the fifth aspect, the data frame on the first carrier carries EPDCCH/PDSCH information, where the second carrier is on the second carrier. The data frame carries the PDCCH information; the first carrier and the second carrier are carriers configured by different base stations, and the obtaining the first information includes:

Obtaining first information according to the PQI indication information included in the scheduling information of the EPDCCH/PDSCH carried in the PDCCH, where the PQI indication information is used to indicate subframe format information of a data frame on the first carrier.

With reference to any one of the possible implementation manners of the fifth aspect, the data frame on the first carrier carries EPDCCH/PDSCH information, where the second carrier is on the second carrier. The data frame carries PDCCH information; the obtaining the first information includes:

Obtaining first information according to the carrier indication information included in the scheduling information of the EPDCCH/PDSCH carried in the PDCCH, where the carrier indication information is used to indicate subframe format information of a data frame on the first carrier.

With reference to the first aspect, or any one of the foregoing first to eighth possible implementation manners, in the ninth possible implementation manner, the received at least two symbols having the first CP carry a useful signal The useful signal includes a reference signal, and the method further includes:

Estimating time-frequency synchronization information on the first carrier according to the reference signal.

With reference to the ninth possible implementation of the first aspect, in a tenth possible implementation, the method further includes:

Performing frequency domain phase compensation on the useful signal according to the estimated time-frequency synchronization information on the first carrier; or

And demodulating the symbols received after the at least two symbols according to the estimated time-frequency synchronization information on the first carrier.

With reference to the first aspect, or any one of the first to the tenth possible implementation manners of the first aspect, in the eleventh possible implementation manner, the reference signal in the useful signal includes at least one of the following information:

a common reference signal, a demodulation reference signal, a channel state information reference signal, and a reference signal;

The useful signal further includes a data signal, and the data signal of the useful signal includes the following Less information:

Physical downlink control channel, enhanced physical downlink control channel, physical downlink shared channel.

In a second aspect, an embodiment of the present invention provides a terminal, including:

a receiver, configured to receive, on the first carrier, at least two symbols having a first cyclic prefix CP, and wherein the first CP has a time length of a first length;

a processing unit, configured to obtain first information and coarse timing information on the first carrier, according to the coarse timing information on the first carrier and the first information, to the at least two symbols on the first carrier The first symbol is subjected to CP processing according to the second length, and the other symbols except the first one of the at least two symbols are subjected to CP processing according to the first length; wherein the second length is smaller than the first length Any value; the first information includes first length information.

In a first possible implementation manner of the second aspect, the first length is a length of time of the long cyclic prefix ECP, and the second length is a length of time of the normal cyclic prefix NCP.

In a second possible implementation of the second aspect, the second length is one half of the first length.

With reference to the second aspect, or the first or the second possible implementation manner of the second aspect, in a third possible implementation, the processing unit is specifically configured to: obtain the first information according to the predefined information; or

The processing unit is specifically configured to: receive signaling information of the first information to obtain the first information.

With reference to the second aspect, or any one of the first to third possible implementation manners of the second aspect, in the fourth possible implementation, the first information further includes a number of symbols having the first CP, and / or, the number of subframes having the first CP, and / or the starting position of the symbol having the first CP.

With reference to the second aspect, or any one of the possible implementations of the first to fourth aspects of the second aspect, in a fifth possible implementation, the processing unit is specifically configured to:

With reference to the fifth possible implementation manner of the second aspect, in a sixth possible implementation manner, The spectrum in which the first carrier is located is an unlicensed spectrum, and the spectrum in which the second carrier is located is a licensed spectrum; or

With reference to the fifth possible implementation manner of the second aspect, and the possible implementation manner of the sixth possible implementation manner, in the seventh possible implementation manner, the data frame on the first carrier carries the EPDCCH /PDSCH information, the data frame on the second carrier carries PDCCH information; the first carrier and the second carrier are carriers configured by different base stations;

The processing unit is specifically configured to obtain, according to the PQI indication information included in the scheduling information of the EPDCCH/PDSCH that is carried in the PDCCH, where the PQI indication information is used to indicate data on the first carrier. Subframe format information of the frame.

With reference to the fifth possible implementation manner of the second aspect, and the possible implementation manner of the sixth possible implementation manner, in the eighth possible implementation manner, the data frame on the first carrier carries the EPDCCH /PDSCH information, the data frame on the second carrier carries PDCCH information;

The processing unit is configured to obtain first information according to the carrier indication information included in the scheduling information of the EPDCCH/PDSCH that is carried in the PDCCH, where the carrier indication information is used to indicate that the first carrier is Subframe format information of the data frame.

With reference to any one of the first to eighth possible implementations of the second aspect, in the ninth possible implementation, the received at least two symbols having the first CP carry a useful signal, where the useful The signal includes a reference signal, and the processing unit is further configured to estimate time-frequency synchronization information on the first carrier according to the reference signal.

With reference to the ninth possible implementation manner of the second aspect, in a tenth possible implementation, the processing unit is further configured to: perform, according to the estimated time-frequency synchronization information on the first carrier, the useful signal Frequency domain phase compensation; or

With reference to any one of the first to the tenth possible implementations of the second aspect, in the eleventh possible implementation, the reference signal in the useful signal includes at least one of the following information:

The useful signal further includes a data signal, and the data signal of the useful signal includes at least one of the following information:

In a third aspect, an embodiment of the present invention provides a data transmission method, including:

Transmitting, by the transmitting device, at least one symbol having a long cyclic prefix ECP from the moment of acquiring the channel usage right on the first carrier of the unlicensed spectrum to the receiving device;

The transmitting device notifies the receiving device of the second information; the second information includes a CP format of the at least one symbol.

In a first possible implementation manner of the third aspect, the sending device notifies the receiving device of the second information by means of predefined or signaling.

With reference to the third aspect, or the first possible implementation manner of the third aspect, in the second possible implementation, the second information further includes:

The number of symbols with ECP, and/or the number of subframes with ECP, and/or the starting position of the symbol with ECP.

In a fourth aspect, an embodiment of the present invention provides a sending device, including:

a transmitter, configured to send, by the time of acquiring the channel usage right on the first carrier of the unlicensed spectrum, to the receiving device, at least one symbol having a long cyclic prefix ECP;

a notification unit, configured to notify the receiving device of the second information; the second information includes a CP format of the at least one symbol.

In a first possible implementation manner of the fourth aspect, the notification unit notifies the receiving device of the second information by way of predefined or signaling.

With reference to the fourth aspect, or the first possible implementation manner of the fourth aspect, in the second possible implementation, the second information further includes:

According to an embodiment of the present invention, when the UE obtains only coarse synchronization, the first CP length to be demodulated is received. When transmitting the data, the UE refers to the timing information of the coarse synchronization, and performs the CP processing on the first symbol of the data frame by using the CP length shorter than the first CP length, and presses the other symbols except the first symbol in the data frame. The first CP length is subjected to de-CP processing, which can avoid introducing inter-symbol interference when the data frame is subjected to de-CP processing, thereby improving the performance of data processing.

DRAWINGS

FIG. 1 is a schematic flow chart of an embodiment of a data transmission method provided by the present invention

2a is an application scenario of a data transmission method provided by the present invention;

2b is another application scenario of a data transmission method provided by the present invention;

3 is a schematic flowchart diagram of another embodiment of a data transmission method according to the present invention;

4 is a schematic diagram of an embodiment of a method for processing a UE to receive a data frame;

5 is a schematic diagram of another embodiment of a method for processing a UE to receive a data frame;

FIG. 6 is another application scenario of a data transmission method provided by the present invention;

FIG. 7 is a schematic flowchart diagram of another embodiment of a data transmission method according to the present invention;

8 is a schematic diagram of another embodiment of a method for processing a UE to receive a data frame;

FIG. 9 is a schematic structural diagram of an embodiment of a terminal provided by the present invention; FIG.

FIG. 10 is a schematic structural diagram of an embodiment of a terminal provided by the present invention; FIG.

FIG. 11 is a schematic flowchart diagram of another embodiment of a data transmission method according to the present invention;

FIG. 12 is a schematic structural diagram of an embodiment of a transmitting device according to the present invention.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

The technical solution of the present invention can be applied to various communication systems, such as: Global System of Mobile Communication (GSM), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access ( WCDMA, Wideband Code Division Multiple Access Wireless), General Packet Radio Service (GPRS, General Packet) Radio Service), Long Term Evolution (LTE), Long Term Evolution-Advanced (LTE-A), Licensed Access-Assisted LTE (LAA-LTE) system, mechanical Type communication (MTC, Machine Type Communications), etc.

In the embodiment of the present invention, the user equipment UE, which may also be called a terminal, a mobile station, a mobile terminal, a mobile user equipment, etc., may be accessed via a radio access network (for example, The RAN (Radio Access Network) communicates with one or more core networks, and the user equipment may be a mobile terminal, such as a mobile phone (or "cellular" phone) and a computer with a mobile terminal, for example, may be portable, pocket-sized Mobile, built-in, computer-mounted or in-vehicle mobile devices, or mechanical communication devices (MTC UEs), etc., which exchange voice and/or data with the wireless access network.

In an embodiment of the present invention, the base station may be an evolved base station eNB, a macro base station (Macro), a micro base station (also referred to as a "small base station") (Pico), a pico base station, and an LTE system or an LAA-LTE system. Access Point (AP) or Transmission Point (TP). The invention is not limited thereto. For convenience of description, the following embodiments will be described by taking a base station and a user equipment as an example.

In the existing wireless communication field, spectrum resources are mainly divided into two types, one is licensed spectrum resources and the other is unlicensed spectrum resources. The licensed spectrum resources are delineated by the government's Radio Management Committee and have dedicated-purpose spectrum resources, such as those used by mobile operators, civil aviation, railways, and police. The quality of licensed spectrum resources is generally due to policy exclusivity. Can be guaranteed, it is relatively easy to perform scheduling control.

Unlicensed spectrum resources are also spectrum resources delineated by relevant government departments, but do not limit radio technology, operating enterprises and service life, and do not guarantee the quality of service in this band. Communication equipment using unlicensed spectrum resources only needs to meet the requirements of transmitting power, out-of-band leakage and other indicators, and can be used free of charge. Common communication systems that use application-free licensed spectrum resources for communication include civilian walkie-talkies, radio remote controls, Wi-Fi systems, Bluetooth communication systems, and the like.

In the existing LTE system, the spectrum resources used by the operators are mainly licensed spectrum resources; as the number of users of the mobile communication network increases, and the requirements of the user for the communication rate and the quality of service increase, the existing licensed spectrum resources It has been difficult to meet the needs of the operator's existing business. Considering new The license spectrum is expensive and resources are scarce. Operators are turning their attention to the unlicensed spectrum resources. It is expected that the use of unlicensed spectrum resources will be used to achieve network capacity diversion and improve service quality. Unlicensed Long Term Evolution (U-LTE), or Licensed-Assisted Access Using LTE (LAA-LTE) system, for LTE applications to unlicensed spectrum Resources.

The research on the LAA-LTE for the Assisted Access Long-Term Evolving System is mainly based on the configuration and structure in the Carrier Aggregation (CA) scenario of the existing LTE system, and is based on the communication of carriers on the licensed spectrum of the operator. The carrier on at least one unlicensed spectrum is configured and the communication on the carrier on the unlicensed spectrum is assisted by communication of carriers on the licensed spectrum. According to the design of the existing LTE system, different carriers in the carrier aggregation scenario are aligned on the subframe boundary when performing data communication.

In the LAA-LTE system, the first problem to be solved using unlicensed spectrum resources is the problem of competing resources. One method of competing for resources is to detect and send (Listen Before Talk, LBT). The basic idea of LBT is: Before each communication device sends a signal on a certain channel, it needs to detect whether the current channel is idle, that is, whether it can detect that a nearby node is occupying the channel to transmit signals. This detection process is called idle. Clear Channel Assessment (CCA); if the channel is detected to be idle for a period of time, the communication device can transmit a signal; if the channel is detected to be occupied, the communication device is currently unable to transmit a signal. Specifically, according to European regulations, the LBT mechanism is further divided into an LBT mechanism based on Frame Based Equipment (FBE) and an LBT mechanism based on Load Based Equipment (LBE). The FBE-based LBT mechanism is characterized in that the device always performs CCA detection at a fixed time. Once the channel is detected to be idle, the device transmits the signal at a fixed frame period. Therefore, the starting moment of data transmission under this mechanism is predefined. The LBE-based LBT mechanism is characterized in that the device can perform CCA detection at any time, but it is necessary to extend the time of CCA detection once it detects that the channel is occupied or the transmission reaches the maximum transmission time allowed by the system. The starting time of the next data transmission can be any time.

In the LAA-LTE system, since the eNB must first determine that the channel is idle to use the resources of the unlicensed spectrum, the signal transmission of the eNB on the carrier of the unlicensed spectrum is opportunistic transmission and discontinuous transmission, so that there is no way to guarantee the periodic pilot. Signal transmission. So from the receiving end, the UE may be Before the completion of fine synchronization with the carrier of the eNB on the unlicensed spectrum, it is necessary to receive and demodulate data transmitted from the carrier, resulting in degradation of data demodulation performance.

In the LAA-LTE system, the carrier on the licensed spectrum is the primary carrier Pcell of the UE, so the UE can always obtain and perform fine time-frequency synchronization of the carriers on the spectrum. Since the carrier on the licensed spectrum and the carrier on the unlicensed spectrum comply with the CA mechanism when transmitting data, that is, the eNB is aligned on the subframe boundary when transmitting data on the carrier on the licensed spectrum and the carrier on the unlicensed spectrum, the UE may The fine time-frequency synchronization obtained from the carrier on the licensed spectrum is treated as coarse time-frequency synchronization on the carrier on the unlicensed spectrum. However, the coarse time-frequency synchronization information is directly used for data demodulation, and there may be cases where data cannot be correctly demodulated. Based on this, the embodiments of the present invention provide a method for ensuring data demodulation performance in the case where only coarse synchronization can be obtained.

It should be understood that the LTE system in which the base station and the user equipment mentioned in the embodiment of the present invention are located, the LTE-A system or the LAA-LTE system is a communication system having a fixed subframe format. In the communication system, it is assumed that the minimum time unit is T _s , 1T _s =1/(15000×2048) seconds; the length of one subframe is 1 millisecond, that is, one subframe length is 30720×T _s One subframe includes a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols. An OFDM symbol includes a Cyclic Prefix (CP) portion and an information segment portion, wherein the information segment portion includes all information of one OFDM symbol, the CP is a repetition of a portion of the information segment signal, and the information segment portion of an OFDM symbol is timed. The length is 2048 × T _s , which is approximately equal to 66.7 microseconds. The communication system supports two fixed subframe formats, one is a Normal Cyclic Prefix (NCP) subframe format, and one NCP subframe includes 14 OFDM symbols, and the OFDM symbol is numbered from 0 to 13, Then, the CP length of the 0th and 7th OFDM symbols is 160×Ts, and the CP lengths of the remaining 12 OFDM symbols are 144×Ts; the 0th to 6th OFDM symbols are defined as odd time slots, which will be The OFDM symbols No. 7 to No. 13 are defined as even time slots. The other is an Extended Cyclic Prefix (ECP) subframe format. One ECP subframe contains 12 OFDM symbols, where the CP length of each symbol is 512×Ts; the OFDM symbol is numbered from 0 to 11, The 0th to 5th OFDM symbols are defined as odd slots, and the 6th to 11th OFDM symbols are defined as even slots. In other embodiments of the present invention and other embodiments of the present invention, an OFDM symbol is also simply referred to as a symbol; a normal cyclic prefix NCP is also referred to as a short CP, and a corresponding subframe format is referred to as an NCP subframe format or a short CP subframe format. The long cyclic prefix ECP is also referred to as a long CP, and the corresponding subframe format is referred to as an ECP subframe format or a long CP subframe format.

It should be understood that in communication systems, time-frequency synchronization, including timing synchronization and frequency synchronization, is one of the key factors to ensure the reliability of voice communication and data connection. The communication system mentioned in the embodiment of the present invention is an OFDM system, and signal demodulation is sensitive to timing errors and frequency deviations: timing errors may cause intersymbol interference, and inaccurate frequency offset compensation may destroy orthogonality between subcarriers, thereby Inter-carrier interference and multiple access interference are generated. Therefore, before the UE and the base station establish a communication link, the time-frequency synchronization with the base station needs to be completed to reduce the impact of the time-frequency synchronization error on the demodulation performance of the UE. In the communication system mentioned in the embodiment of the present invention, the time-frequency synchronization is divided into Coarse time and frequency synchronization and Fine time and frequency synchronization. In the following behavior example, the UE needs to complete the coarse time-frequency synchronization in the initial access, and the UE can control the timing error and the frequency deviation to ensure the measurement accuracy of the radio resource management (RRM) measurement by the coarse time-frequency synchronization. Within the scope of the demand, and get frame timing information. Since the RRM measurement is not sensitive to timing errors and frequency offsets, the required coarse time-frequency synchronization cannot meet the requirements of signal demodulation. Further, the UE needs to obtain fine frequency synchronization with the base station. Specifically, the UE may perform timing estimation and frequency offset estimation by receiving a pilot signal transmitted by the base station, and reduce the time-frequency synchronization error to a range that can be tolerated by the signal demodulation, and is used for demodulation of downlink data. Further, the UE can track the time-frequency synchronization information of the base station by using periodic timing estimation and frequency offset estimation. The UE can obtain coarse timing information during the coarse time-frequency synchronization process, and can obtain fine timing information during the fine time-frequency synchronization process.

Referring to Figure 1, an embodiment of the data transmission of the present invention comprises:

Step S101: The receiving device receives, on the first carrier, at least two symbols that are sent by the transmitting device and has a first cyclic prefix CP, where the length of the first CP is a first length;

Optionally, the transmitting device may be a base station or a UE.

Optionally, the receiving device may be a UE or a base station.

In one embodiment, the first CP is an ECP, and the corresponding first length is a length of time of the ECP. In another embodiment, the first CP is an NCP, and the corresponding first length is a length of time of the NCP. In another embodiment, the first CP is an ECP, and the corresponding first length is a length of time of the ECP.

S102: The receiving device obtains first information, where the first information includes first length information.

Optionally, the manner in which the receiving device obtains the first information may include: the receiving device obtains the first information from a subframe format of the predefined symbol transmission. In another embodiment, the manner in which the receiving device obtains the first information may include: receiving, by the receiving device, indication information of a subframe format sent by the transmitting device, and obtaining first information according to the indication information; wherein the indication information may be Displayed or implicit indication signaling sent by the transmitting device.

Optionally, the first information further includes symbol number information of the first CP, and/or subframe number information of the first CP, and/or The starting position of the symbol of the first CP.

Step S103: The receiving device obtains coarse timing information on the first carrier.

In the process of specifically implementing step S103, the coarse timing information on the first carrier is timing synchronization information in coarse time-frequency synchronization. Optionally, the coarse timing information can meet the requirement of timing synchronization for RRM measurement accuracy. Optionally, the coarse timing information is frame timing information on the first carrier. Optionally, the coarse timing information is symbol timing information on the first carrier.

In an embodiment, the step includes: obtaining timing information on the second carrier as coarse timing information of the first carrier.

In the communication system mentioned in the embodiments of the present invention, the transmitting device can communicate using multiple carriers and receiving devices. When a transmitting device uses multiple carriers to communicate with a receiving device, signal transmissions on different carriers are aligned on a subframe boundary, and signals on different carriers received by the receiving device are mainly affected by signal propagation delay in time. The timing information of any one of the multiple carriers can be used as coarse timing information of other carriers in the multi-carrier. In addition, according to the requirements of the radio frequency index, when the transmitting device uses multiple carriers to communicate with the same receiving device, whether the transmitting device is one or more, frequency calibration is required to meet the frequency offset index, so any carrier in the multi-carrier The frequency offset information can be used as the coarse frequency offset information of other carriers in the multi-carrier. In the process of performing the step S103, optionally, the receiving device obtains coarse timing information on the first carrier by using the second carrier.

In one embodiment, the spectrum in which the first carrier is located is an unlicensed spectrum, and the spectrum in which the second carrier is located is a licensed spectrum. In another embodiment, the spectrum in which the first carrier is located and the spectrum in which the second carrier is located are unlicensed spectrum. In another embodiment, the spectrum in which the first carrier is located and the spectrum in which the second carrier is located are the licensed spectrum of the same frequency.

In one embodiment, the first carrier and the second carrier are carriers configured by the same base station; another In an embodiment, the first carrier and the second carrier are carriers configured by different base stations.

In one embodiment, the data frame on the first carrier carries the EPDCCH/PDSCH information, and the data frame on the second carrier carries the PDCCH information; the first carrier and the second carrier are carriers configured by different base stations, and the first information is obtained. The first information is obtained according to the PQI indication information included in the scheduling information of the EPDCCH/PDSCH carried in the PDCCH, where the PQI indication information is used to indicate subframe format information of a data frame on the first carrier. .

In another embodiment, the data frame on the first carrier carries the EPDCCH/PDSCH information, and the data frame on the second carrier carries the PDCCH information. The obtaining the first information includes: according to the EPDCCH/PDSCH carried in the PDCCH. The carrier indication information included in the scheduling information is used to obtain the first information, where the carrier indication information is used to indicate subframe format information of the data frame on the first carrier.

Step S104: The receiving device performs de-CP processing on at least two symbols on the first carrier according to the coarse timing information on the first carrier and the first information.

Specifically, the receiving device performs CP processing on the first symbol of the at least two symbols on the first carrier according to the coarse timing information and the first information on the first carrier, where The symbols other than the first one of the at least two symbols are subjected to CP processing by the first length; wherein the second length is any value smaller than the first length.

In the process of the specific implementation step S104, optionally, the receiving device determines, by using the obtained coarse timing information of the first carrier and the first information, a start time of the first symbol of the at least two symbols, A portion of the first symbol of the at least two symbols from the start time is removed as a CP, and a time length of the information segment portion of one symbol is intercepted as a valid data portion of the first symbol Used for demodulation processing. The end time after intercepting the valid data of the first symbol is taken as the start time of the second symbol, and the portion of the first length from the start time of the second symbol is removed as the CP. And the time length of the information segment portion of one symbol is intercepted as the effective data portion of the second symbol for demodulation processing. The symbols other than the first one of the at least two symbols are subjected to deCP processing in the processing manner of the second symbol and the valid data portions of the other symbols are obtained for demodulation processing.

In a specific implementation step S104, according to an embodiment, the first CP is a long cyclic prefix ECP, the first length is a time length of an ECP, and the second length is a length of a normal cyclic prefix NCP. Specifically, the receiving device determines, by using the obtained coarse timing information and the first information on the first carrier, a start time of the received first symbol of the at least two symbols having the first CP, the receiving The device performs a CP process on the first symbol according to the determined start time of the first symbol and the second length, and obtains a start time of the second symbol; the receiving device is configured according to the determined The start time of the two symbols and the first length are subjected to deCP processing for symbols other than the first symbol. The receiving device can at least allow the maximum transmission delay of the channel multipath to be the second length when processing the symbol. When the time difference between the fine timing of the signal from the first carrier and the coarse timing on the first carrier is within the range of [-(L _{E -} L _N ), L _N ], the receiving device processes the symbol There is no intersymbol interference caused by the time difference. Where L _E represents the length of time of the ECP and L _N represents the length of time of the NCP.

In a specific implementation of the step, according to another embodiment, the first CP is an NCP, the first length is a length of time of the NCP, or the first CP is an ECP, and the first length is an ECP. Length of time. The second length is any length of time less than the first length. Optionally, the second length may be determined by a coverage of the first carrier. For example, the first CP is an NCP, the first length is a length of time of the NCP, and the second length is half of the first length. Determining, by using the obtained coarse timing information of the first carrier and the first information, a start time of the received first symbol of the at least two symbols having the first CP, where the receiving device is configured according to the Determining a start time of the first symbol and a length of the 1/2 NCP to de-CP process the first symbol and obtain a start time of the second symbol, the receiving device according to the determined The start time of the two symbols and the length of the NCP are subjected to deCP processing for symbols other than the first symbol. The maximum transmission delay of the channel multipath that the receiving device can at least allow when processing the symbol is 1/2×L _N . The receiving device is in the pair when the time difference between the fine timing of the signal from the first carrier and the coarse timing on the first carrier is in the range of [-1/2×L _N , 1/2×L _N ] The processing is not subject to intersymbol interference caused by the time difference. Where L _N represents the length of time of the NCP.

Optionally, when the first information further includes a start position of the symbol of the first CP, the UE may obtain, according to the information, start position information of the first symbol of the at least two symbols, thereby At least two symbols are de-CP processed.

Optionally, when the first information further includes the number of symbols having the first CP, and/or, having the first When the number of subframes of the CP is the same, the UE can obtain the number of the specific symbols of the at least two symbols according to the information, so that the at least two symbols are subjected to de-CP processing.

In this embodiment, when only the coarse timing information of the first carrier is obtained, when the received symbol transmitted by the first CP length on the first carrier is processed, the first symbol is compared with the first CP. The length of the short length is subjected to the de-CP processing, and the other symbols except the first symbol are subjected to the CP processing according to the first CP length, so as to avoid introducing inter-symbol interference when performing de-CP processing on the symbols on the first carrier. , thereby reducing the impact of timing inaccuracy and improving the performance of data processing.

In another embodiment, the data transmission method further includes:

Step S105: The at least two symbols having the first CP received by the receiving device carry a useful signal, where the useful signal includes a reference signal, and the receiving device estimates time-frequency synchronization on the first carrier according to the reference signal. information.

In a specific implementation process, optionally, the useful signal may include a reference signal and a data signal. Optionally, the reference signal in the useful signal includes at least one of the following: a Common Reference Signal (CRS), a Demodulation Reference Signal (DMRS), and a channel state information reference signal (Channel State) Information-Reference Signal (CSI-RS), a Discovery Reference Signal (DRS); optionally, the useful signal further includes a data signal, and the data signal in the useful signal includes at least one of the following information: A Physical Downlink Control CHannel (PDCCH), an Enhanced-Physical Downlink Control CHannel (ePDCCH), and a Physical Downlink Shared CHannel (PDSCH).

In a specific implementation process, optionally, the time-frequency synchronization information on the first carrier is fine time-frequency synchronization information, and the reference signal used to estimate time-frequency synchronization information on the first carrier may be CRS, and / or DMRS, and / or CSI-RS, and / or DRS.

It should be understood that when estimating fine time-frequency synchronization information, the receiving device can estimate the frequency offset by estimating the phase difference from the reference signal pairing at intervals. In combination with the system parameters of the LAA-LTE system, in order to obtain fine frequency synchronization capable of ensuring demodulation performance, the time interval of the reference signal interval used for estimating the frequency offset is not less than 3 symbols, and preferably, the reference signal for estimating the frequency offset is used. The length of the interval is 4 symbols, that is, the receiving end can jointly perform frequency offset estimation using the n _0th symbol and the reference signal on the n ₀ +3 symbols, and n ₀ is any symbol index. Optionally, in a specific implementation process, the length of the reference signal interval used to estimate the frequency offset carried in the symbol of the first CP is greater than or equal to 4 symbols.

After obtaining the time-frequency synchronization information on the first carrier, optionally, the receiving device may perform frequency domain phase compensation on the useful signal according to the time-frequency synchronization information on the first carrier. Optionally, the receiving device performs frequency domain phase compensation on the symbol carrying the useful signal of the de-CP according to the time-frequency synchronization information on the first carrier. By frequency domain phase compensation, the influence of the fine frequency synchronization of the signal from the first carrier and the time-frequency deviation of the coarse time-frequency synchronization on the first carrier on the demodulation of the useful signal can be reduced, thereby ensuring demodulation performance. .

After obtaining the time-frequency synchronization information on the first carrier, optionally, the receiving device may receive the at least two symbols on the first carrier according to the estimated time-frequency synchronization information on the first carrier. The received symbols are demodulated.

One application scenario of the present invention is a scenario used by the LAA-LTE technology. Referring to Figures 2a and 2b, a system according to an embodiment of the present invention includes a plurality of base stations eNB and a plurality of terminal UEs within its coverage; at least one terminal is configured with a carrier CC1 on a licensed spectrum and at least one unlicensed spectrum Carrier CC2. As shown in Figure 2a, the carrier on the licensed spectrum and the carrier on at least one unlicensed spectrum may be configured by the same base station. As shown in Figure 2b, the carrier on the licensed spectrum and the carrier on at least one unlicensed spectrum may also be configured by different base stations. If the carrier on the licensed spectrum and the carrier on the unlicensed spectrum are configured by different base stations, different base stations can interact through ideal backhaul transmissions or through non-ideal backhaul transmissions. The base station can transmit data to the UE using the carrier CC1 on the licensed spectrum and the carrier CC2 on the at least one unlicensed spectrum. The signal transmission by the base station on the carrier of the licensed spectrum resource and the unlicensed spectrum resource is temporally aligned on the subframe boundary. When the eNB sends data to the UE by using the carrier resources on the unlicensed spectrum, it is necessary to first determine that the carrier on the unlicensed spectrum is available for use. The UE has obtained fine time-frequency synchronization with the eNB on the carrier on the licensed spectrum before using the secondary carrier on the unlicensed spectrum. This synchronization can be used as the coarse time-frequency of the UE and the eNB on the carrier on the unlicensed spectrum. Synchronize.

It should be understood that the technical solution of the embodiments of the present invention may be applied to a LAA-LTE system that utilizes an unlicensed band, and may also be applied to other subframe boundaries or symbols that are similar and fixed. A communication system with borders and resource competition requirements.

Referring to FIG. 3, an embodiment of the data transmission method of the present invention may be applied to a LAA-LTE system, and the method includes:

Step S301: The receiving device receives, on the first carrier, the at least two symbols that are sent by the transmitting device and has the first cyclic prefix CP. The time length of the first CP is the first length, and the spectrum of the first carrier is located. To avoid the licensed spectrum;

In the process of performing step S301, optionally, the transmitting device is a base station.

Optionally, the receiving device may be a UE or a base station in the process of performing step S301.

In one embodiment, the transmitting device transmits the symbol in a subframe format of the first CP by acquiring the right to use the channel of the unlicensed spectrum. Specifically, the transmitting device may obtain the right to use the channel of the unlicensed spectrum through a competitive method; more specifically, the transmitting device may obtain the usage right through a competitive method based on the LBT criterion. Alternatively, the transmitting device may acquire the right to use the channel of the unlicensed spectrum by coordinating or scheduling with the adjacent communication device. Alternatively, the transmitting device may acquire the right to use the channel of the unlicensed spectrum through the pre-configured resource usage pattern.

In the process of the specific implementation step S301, optionally, the first CP is an ECP, and the corresponding first length is a length of time of the ECP. Alternatively, optionally, the first CP is an NCP, and the corresponding first length is a length of time of the NCP.

It should be understood that although the time at which the transmitting device acquires the right to use the channel of the unlicensed spectrum may be any time, the signal transmission of the multi-carrier is temporally aligned on the subframe boundary. Considering that the LAA-LTE system can transmit signals by symbols, the starting moment of signal transmission of the transmitting device on the channel of the unlicensed spectrum may be the starting moment of any one subframe, or the subframe format with the first CP. The starting moment of any symbol.

In the process of the specific implementation step S301, optionally, when the time when the transmitting device acquires the usage right of the channel of the unlicensed spectrum is the starting moment of any one of the subframes, the transmitting device sends the symbol with the first CP. The duration consists of at least one full subframe. Further, the symbol with the first CP sent by the transmitting device is sent in a subframe.

In the process of specifically implementing step S301, optionally, when the transmitting device acquires the unlicensed spectrum When the time of use of the channel is the start time of any one of the symbols of the subframe format of the first CP, it is assumed that the start time is transmittable from the start time of the first subframe after the start time The number of symbols having the first CP is N. If N is not less than M, the duration of the symbol with the first CP sent by the transmitting device includes at least N symbols; if N is less than M, the duration of the symbol with the first CP sent by the transmitting device is at least Contains N symbols and the next complete subframe. Wherein the value of N may be a positive integer of 1 to 14. The M is the number of symbols required to obtain the fine time-frequency synchronization of the LAA-LTE system, and the value of M may be a positive integer of 4 to 14, and preferably, the value of M is 4.

S302: The receiving device obtains first information, where the first information includes first length information.

In an embodiment, the manner in which the receiving device obtains the first CP information may include: the receiving device obtains the first CP information from a subframe format of the predefined symbol transmission. In another embodiment, the manner in which the receiving device obtains the first CP information may include: receiving, by the receiving device, indication information of a subframe format sent by the transmitting device, and obtaining first CP information according to the indication information; wherein the indication information It may be displayed or implicit indication signaling sent by the base station.

Optionally, the first CP information further includes symbol number information of the first CP, and/or subframe number information of the first CP, and/or, in the process of performing step S302. The starting moment of the symbol with the first CP.

Step S303: The receiving device obtains timing information on the second carrier.

It should be understood that in a LAA-LTE communication system, a transmitting device can communicate using multiple carriers and receiving devices. When a transmitting device uses multiple carriers to communicate with a receiving device, signal transmissions on different carriers are aligned on a subframe boundary, and signals on different carriers received by the receiving device are mainly affected by signal propagation delay in time. The timing information of any one of the multiple carriers can be used as coarse timing information of other carriers in the multi-carrier. In addition, according to the requirements of the radio frequency index, when the transmitting device uses multiple carriers to communicate with the same receiving device, whether the transmitting device is one or more, frequency calibration is required to meet the frequency offset index, so any carrier in the multi-carrier The frequency offset information can be used as the coarse frequency offset information of other carriers in the multi-carrier. Therefore, the timing information on the second carrier obtained by the receiving device can be used as coarse timing information on the first carrier.

In one embodiment, the spectrum in which the first carrier is located is an unlicensed spectrum, and the spectrum in which the second carrier is located is a licensed spectrum. In another embodiment, the spectrum of the first carrier and the spectrum of the second carrier are both To avoid licensing spectrum.

In an embodiment, the first carrier and the second carrier are carriers configured by the same base station; in another embodiment, the first carrier and the second carrier are carriers configured by different base stations.

Step 304: The receiving device performs de-CP processing on the at least two symbols on the first carrier according to the first information and timing information on the second carrier.

Specifically, performing de-CP processing on the first one of the at least two symbols on the first carrier by using a second length, and using the first length of the symbols other than the first one of the at least two symbols Performing a de-CP process; wherein the second length is any value less than the first length.

Based on the foregoing technical solution, the receiving device can at least allow the maximum transmission delay of the channel multipath to be the second length when the symbol is processed, that is, the second length is related to the coverage of the first carrier. When the time difference between the signal from the first carrier and the signal of the second carrier received by the receiving device is within a certain time range, the receiving device does not suffer from the time difference when processing the symbol. Intersymbol interference. The time difference is the timing of the signal of the first carrier minus the timing of the signal of the second carrier, and the time range of the time difference is [-(L ₁ -L ₂ ), L ₂ ], and L ₁ is the first length. L ₂ is the second length.

Optionally, the first CP is a long cyclic prefix ECP, the first length is a length of time of the ECP, and the second length is a length of a normal cyclic prefix NCP. Specifically, the receiving device determines, by using the obtained first information and timing information on the second carrier, a start time of the received first symbol of the at least two symbols having the first CP, Receiving, by the receiving device, de-CP processing the first symbol according to the determined start time of the first symbol and the second length, and obtaining a start time of the second symbol; the receiving device is determined according to the determining The start time of the second symbol and the first length are subjected to deCP processing for symbols other than the first symbol. The receiving device can at least allow the maximum transmission delay of the channel multipath to be the second length when processing the symbol. When the time difference between the signal from the first carrier and the signal of the second carrier received by the receiving device is within the range of [-(L _{E -} L _N ), L _N ], the receiving device performs the symbol The processing is not subject to intersymbol interference caused by the time difference. Where L _E represents the length of time of the ECP and L _N represents the length of time of the NCP.

In the process of the specific implementation step S304, optionally, the first CP is an NCP, the first length is a time length of the NCP, or the first CP is an ECP, and the first length is an ECP time. length. The second length is any length of time less than the first length. Optionally, the second length may be determined by a coverage of the first carrier. For example, the first CP is an NCP, the first length is a length of time of the NCP, and the second length is half of the first length. Determining, by using the obtained timing information of the second carrier and the first information, a start time of the received first symbol of the at least two symbols of the first CP, where the receiving device is configured according to the Determining the first symbol by the start time of the first symbol and the length of the 1/2 NCP, and performing a de-CP processing on the first symbol to obtain a start time of the second symbol, the receiving device according to the determined The start time of the second symbol and the length of the NCP are subjected to deCP processing for symbols other than the first symbol. The maximum transmission delay of the channel multipath that the receiving device can at least allow when processing the symbol is 1/2×L _N . When the time difference between the signal from the first carrier and the signal of the second carrier received by the receiving device is in the range of [-1/2×L _N , 1/2×L _N ], the receiving device is in the opposite The symbols are processed without intersymbol interference caused by the time difference. Where L _N represents the length of time of the NCP.

Optionally, the method further includes:

Step S305: The at least two symbols having the first CP received by the receiving device carry a useful signal, where the useful signal includes a reference signal, and the receiving device estimates the time on the first carrier according to the reference signal. Frequency synchronization information.

In the process of performing step S305, optionally, the time-frequency synchronization information on the first carrier is fine time-frequency synchronization information, and is used to estimate the reference signal of the time-frequency synchronization information on the first carrier. It can be a CRS, and/or a DMRS, and/or a CSI-RS, and/or a DRS.

After obtaining the time-frequency synchronization information on the first carrier, optionally, the receiving device performs frequency domain phase compensation on the useful signal according to the time-frequency synchronization information on the first carrier. Optionally, the receiving device performs frequency domain phase compensation on the symbol carrying the useful signal of the de-CP according to the time-frequency synchronization information on the first carrier. By frequency domain phase compensation, the influence of the time-frequency deviation of the signal from the first carrier and the signal of the second carrier received by the receiving device on the demodulation of the useful signal can be reduced, thereby ensuring demodulation performance.

After obtaining the time-frequency synchronization information on the first carrier, optionally, the receiving device receives the at least two symbols on the first carrier according to the estimated time-frequency synchronization information on the first carrier. The symbols are demodulated.

Referring to FIG. 4, the present invention provides a schematic diagram of processing of a UE receiving a data frame. The UE receives an OFDM symbol on a carrier Pcell of a licensed spectrum and a carrier Scell of an unlicensed spectrum, where a symbol on the Pcell is a symbol with a short CP, on the Scell. The symbol is a symbol with a long CP. The UE can obtain the time-frequency synchronization on the Pcell by using the reference signal periodically transmitted on the Pcell, and the UE performs the CP-removal processing on the OFDM symbol received on the Pcell according to the obtained time-frequency synchronization information. The timing information in the time-frequency synchronization on the Pcell obtained by the UE may be used as coarse timing information on the Scell. For the OFDM symbol received on the Scell, the UE uses the coarse timing information on the Scell to determine the symbol start time, the first symbol on the Scell is processed by the short CP, and the symbol following the first symbol is processed by the long CP. Regardless of whether the signal on the Scell is advanced or delayed relative to the signal on the Pcell, it can be ensured that the effective data portion information of each OFDM symbol intercepted does not introduce intersymbol interference. The time difference between the signal that the UE can tolerate the received signal on the Scell minus the signal on the Pcell is [short CP-long CP, Short CP].

Referring to FIG. 5, a schematic diagram of a process for a UE to receive a data frame is provided. The UE receives an OFDM symbol on a carrier Pcell and a carrier Scell on an unlicensed spectrum, respectively, where the symbol on the Pcell is a symbol with a short CP, and the Scell The symbol above is a symbol with a long CP. The UE can obtain the time-frequency synchronization on the Pcell by using the reference signal periodically transmitted on the Pcell, and the UE performs the CP-removal processing on the OFDM symbol received on the Pcell according to the obtained time-frequency synchronization information. The timing information in the time-frequency synchronization on the Pcell obtained by the UE may be used as coarse timing information on the Scell. For the OFDM symbol received on the Scell, the UE uses the coarse timing information on the Scell to determine the symbol start time, the first symbol on the Scell is processed by the partial CP, and the symbol following the first symbol is processed by the short CP. For example, the partial CP here is 1/2 short CP. Regardless of whether the signal on the Scell is advanced or delayed relative to the signal on the Pcell, it can be ensured that the effective data portion information of each OFDM symbol intercepted does not introduce intersymbol interference. The signal time difference range in which the UE can tolerate the signal on the received Scell minus the signal on the Pcell is [-1/2 short CP, 1/2 short CP].

One application scenario of the present invention is a scenario used by Coordinated Multiple Point Transmission/Reception (CoMP) technology. Referring to FIG. 6, a system of another embodiment of the present invention includes at least two eNBs and UEs. In a CoMP non-co-located scenario, the UE can be served by two eNBs at the same time, that is, one of the serving cell eNBs sends a synchronization signal and a physical downlink control channel (Physical Downlink Control CHannel, PDCCH) to the UE, and the other The coordinated cell eNB sends a Physical Downlink Shared Channel (PDSCH) to the UE. That is, the functions of scheduling and resource allocation are all performed by one eNB, and the data transmission is performed by another eNB. The two eNBs can use the same frequency carrier. It is also possible to use carriers of different frequencies. The PDCCH and PDSCH signals received by the UE are from APs having different geographical locations. Due to the geographical location of the UE and the distance between the two APs, considering the influence of the signal propagation delay, the PDCCH and the PDSCH symbols received by the UE have a certain time difference, and the PDSCH symbol arrives at the UE receiving end may be earlier or later than the PDCCH. symbol.

In the prior art, when the PDCCH symbol is later than the PDSCH symbol, the PDSCH symbol is demodulated according to the timing of the PDCCH symbol, which may introduce inter-symbol interference, and may not correctly demodulate the data carried by the PDSCH symbol, thereby affecting the efficiency of data transmission.

Referring to FIG. 7, another embodiment of the data transmission method of the present invention may be applied to a system using CoMP or cross-carrier scheduling technology, the method comprising:

S701: The UE simultaneously receives the data frame that is sent by the first base station in the ECP subframe format on the first carrier and the data frame that is sent by the second base station on the second carrier.

The data frame on the first carrier carries the EPDCCH/PDSCH symbol of the UE, the data frame on the second carrier carries the PDCCH symbol of the UE, and the PDCCH symbol carries the scheduling information of the EPDCCH/PDSCH; The scheduling information of the EPDCCH/PDSCH includes subframe format information on the first carrier;

S702: The timing information on the second carrier obtained by the UE, and obtaining the scheduling information of the EPDCCH/PDSCH carried in the PDCCH symbol by demodulating a PDCCH on a data frame of the second carrier;

In an embodiment, the first base station and the second base station are different base stations, and the first carrier and the second carrier are carriers of the same frequency. In another embodiment, the first base station and the second base station are the same base station, and the first carrier and the second carrier are carriers of different frequency bands. In another embodiment, the first base station and the second base station are different base stations, and the first carrier and the second carrier are carriers of different frequency bands.

It should be understood that in an LTE/LTE-A communication system, a transmitting device can communicate using multiple carriers and receiving devices. When a transmitting device uses multiple carriers to communicate with a receiving device, signal transmissions on different carriers are aligned on a subframe boundary, and signals on different carriers received by the receiving device are mainly affected by signal propagation delay in time. The timing information of any one of the multiple carriers can be used as coarse timing information of other carriers in the multi-carrier. In addition, according to the requirements of the radio frequency index, when the transmitting device uses multiple carriers to communicate with the same receiving device, whether the transmitting device is one or more, frequency calibration is required to meet the frequency offset index, so any carrier in the multi-carrier The frequency offset information can be used as the coarse frequency offset information of other carriers in the multi-carrier. Therefore, the timing information on the second carrier obtained by the receiving device can be used as coarse timing information on the first carrier.

It should be understood that, in the prior art, when the first carrier and the second carrier are carriers of the same frequency configured by different base stations, that is, the PDCCH symbols and EPDCCH/PDSCH symbols received by the UE are transmitted from different base stations. When the effective data of the same frequency is used, the second base station that transmits the PDCCH symbol is the serving base station of the UE, and the first base station that transmits the EPDCCH/PDSCH symbol is the coordinated base station of the UE (also called For data transmission base stations). The transmission mode (TM) of the valid data received by the UE in this scenario is TM10, and the working mode of the UE is qcl-Operation Type B. When the UE is configured with the TM10 by the serving base station, it can be configured with up to four parameter sets by high-level signaling, and each parameter set includes a CRS antenna port (crs-PortsCount-r11) and a CRS frequency domain offset position (crs-FreqShift- R11), MBSFN subframe configuration (mbsfn-SubframeConfigList-r11), zero-power CSI-RS configuration (csi-RS-ConfigZPId-r11), PDSCH start position (pdsch-Start-r11), non-zero power of quasi-common station Parameters such as CSI-RS configuration (qcl-CSI-RS-ConfigNZPId-r11). It should be understood that TM10 can have two working modes: qcl-Operation Type A and qcl-Operation Type B. A UE transmitting in TM10 mode can be configured by high-level parameters as one of qcl-Operation Type A and qcl-Operation Type B. Kind. In the Type A mode of operation, the UE can assume that antenna ports 0-3, 7-22 are in delay spread, Doppler spread, Doppler shift, and average delay. (average delay) and other channel characteristics are consistent; in the TypeB mode of operation, the UE can assume that the quasi co-located antenna ports 15-22 and antenna ports 7-14 are spread over time, Doppler The channel characteristics such as extension, Doppler shift, and average delay are consistent. The antenna port 0-3 is an antenna port of the CRS, the antenna port 7-14 is an antenna port of the DMRS, and the antenna port 15-22 is an antenna port of the CSI-RS. If the UE is configured with the Type B working mode, the UE needs to demodulate the 2 included in the scheduling information of the EPDCCH/PDSCH carried in the PDCCH transmitted by the serving base station in the Downlink Control Information Format (DCI format) 2D. The PSCH (PDSCH RE Mapping and Quasi-Co-Location indicator) indication information is used to determine which of the parameter sets 7-14 and the pre-configured maximum of the four parameter sets are quasi-co-located, thereby determining the PDSCH. The RE mapping information of the RE and the quasi-co-site information of the antenna port and the CSI-RS antenna port of the DMRS and the CRS antenna port are determined. Therefore, in one embodiment, the PQI indication information included in the scheduling information of the EPDCCH/PDSCH carried in the PDCCH of the UE may be used to indicate subframe format information of a data frame on the first carrier. When the PQI indication information indicates that the PDCCH information and the EPDCCH/PDSCH information are valid data transmitted by different base stations, optionally, the PQI indication information simultaneously indicates a sub-frame of the data frame on the first carrier. The frame format is an ECP subframe format, and the UE learns the EPDCCH on the first carrier by using the acquired ECP subframe format information and the uplink pre-configured signaling indicating the start position of the EPDCCH/PDSCH symbol. The starting position of the /PDSCH symbol.

It should be understood that, in the prior art, the scheduling information of the EPDCCH/PDSCH carried in the PDCCH of the UE includes carrier indicator information, which is used to indicate whether the first carrier and the second carrier are the same. Frequency carrier. When the first carrier and the second carrier are carriers of different frequency bands, that is, the PDCCH symbol and the EPDCCH/PDSCH symbol received by the UE are from different frequency bands, the UE can learn the EPDCCH/PDSCH symbol by using the signaling of the high layer configuration. starting point. Therefore, in another embodiment, the carrier indication information included in the scheduling information of the EPDCCH/PDSCH carried in the PDCCH of the UE may be used to indicate subframe format information of a data frame on the first carrier. When the carrier indication information indicates that the first carrier and the second carrier are carriers of different frequencies, optionally, the carrier indication information simultaneously indicates that a subframe format of the data frame on the first carrier is an ECP sub- In the frame format, the UE learns the start position of the EPDCCH/PDSCH symbol on the first carrier by using the acquired ECP subframe format information and the uplink pre-configured signaling indicating the start position of the EPDCCH/PDSCH symbol.

In a specific implementation process, optionally, the UE may estimate timing information on the second carrier by using a CRS on the second carrier. Optionally, the UE may use the CRS on the second carrier to demodulate the PDCCH symbol on the second carrier and obtain scheduling information of the EPDCCH/PDSCH carried in the PDCCH symbol.

In a specific implementation process, it should be understood that since the data frames on the first carrier and the second carrier are simultaneously sent, the timing information on the second carrier may be regarded as coarse timing information on the first carrier.

S703: The UE performs de-CP processing on the data frame on the first carrier according to the timing information on the second carrier and the subframe format information on the first carrier.

Specifically, the UE performs de-CP processing on the first symbol in the EPDCCH/PDSCH symbol in the data frame on the first carrier according to the timing information on the second carrier, where The symbols other than the first one of the EPDCCH/PDSCH symbols in the data frame are subjected to CP processing according to the ECP length, wherein the second length is any length smaller than the ECP length.

In the process of implementing the method S703, the UE obtains, by using the obtained subframe format information on the first carrier, the data frame on the first carrier is a subframe format of the ECP; The subframe format information on the first carrier and the uplink pre-configured signaling indicating the start position of the EPDCCH/PDSCH symbol learn the EPDCCH/PDSCH on the first carrier. The starting position of the symbol. Decoding, by the second length, the first symbol in the EPDCCH/PDSCH symbol on the first carrier, according to the timing information on the second carrier, performing de-CP processing on the EPDCCH/PDSCH symbol Other symbols than the first symbol are subjected to CP processing in accordance with the ECP length, wherein the second length is any length less than the ECP length. Optionally, the second length may be the length of the NCP, so that the UE can receive the first carrier and the second carrier when the UE performs the effective symbol interception on the symbol on the data frame on the first carrier. When the signal time difference range is [NCP-ECP, NCP], intersymbol interference is not introduced.

In another embodiment, the data transmission method further includes:

S704: The UE estimates time-frequency synchronization information on the first carrier according to a reference signal in an EPDCCH/PDSCH symbol on the first carrier, and the UE obtains a time-frequency on the first carrier according to the estimation. The synchronization information performs frequency domain phase compensation on the EPDCCH/PDSCH symbols.

In the process of implementing S704, optionally, the UE estimates time-frequency synchronization information of the first carrier according to a pilot signal carried in an EPDCCH/PDSCH symbol on the first carrier. The pilot signal used to estimate the time-frequency synchronization information of the first carrier may be a CRS on the first carrier, and/or a CSI-RS, and/or a DMRS. Further optionally, the frequency offset of the first carrier may be estimated by using the CRS on the first carrier, and the timing of the first carrier may be estimated by using the CSI-RS on the first carrier. The time-frequency synchronization information on the first carrier may be used to perform frequency domain phase compensation on the EPDCCH/PDSCH symbol. Optionally, the time-frequency synchronization information on the first carrier may be used to perform demodulation processing on the subsequently received symbols on the first carrier.

Referring to FIG. 8, a schematic diagram of a process for a UE to receive a data frame is provided. The UE receives an OFDM symbol on a carrier of a serving cell and a carrier of a coordinated cell, where a symbol on a serving cell is a symbol with a short CP, on a coordinated cell. The symbol is a symbol with a long CP. The UE can obtain the time-frequency synchronization on the serving cell by using the reference signal periodically transmitted on the serving cell, and the UE performs the CP processing on the OFDM symbol received on the serving cell according to the obtained time-frequency synchronization information. The timing information in the time-frequency synchronization on the serving cell obtained by the UE may be used as coarse timing information on the coordinated cell. For the OFDM symbol received on the coordinated cell, the UE determines the symbol start time using the coarse timing information on the coordinated cell, performs the short CP processing on the first symbol on the coordinated cell, and processes the symbol following the first symbol by the long CP. . Regardless of the signal on the cooperating cell relative to the message on the serving cell Whether the number is early or delayed, it can be ensured that the effective data portion information of each OFDM symbol intercepted does not introduce intersymbol interference. The time difference range in which the UE can tolerate the signal on the received coordinated cell minus the signal on the serving cell is [short CP-long CP, short CP].

Corresponding to the foregoing method, an embodiment of the present invention provides a terminal. Referring to FIG. 9, the terminal includes:

The receiver 901 is configured to receive, on the first carrier, at least two symbols having a first cyclic prefix CP, where the length of the first CP is a first length;

The processing unit 902 is configured to obtain first information and coarse timing information on the first carrier, and according to the coarse timing information on the first carrier and the first information, the at least two symbols on the first carrier The first symbol is de-CP processed according to the second length, and the other symbols except the first one of the at least two symbols are subjected to CP processing according to the first length; wherein the second length is smaller than the first Any value of length, the first information including first length information.

In one embodiment, the first length is a length of time of the long cyclic prefix ECP, and the second length is a length of time of the normal cyclic prefix NCP.

In another embodiment, the second length is one half of the first length; the first length is a length of time of the NCP; or the first length is a length of time of the ECP.

In an embodiment, the processing unit is specifically configured to: obtain the first information according to the predefined information. In another embodiment, the processing unit is specifically configured to: receive signaling information of the first information to obtain the first information.

In one embodiment, the first information further includes a number of symbols having the first CP, and/or a number of subframes having the first CP, and/or a starting position of the symbol having the first CP.

In another embodiment, the processing unit 902 is specifically configured to:

Specifically, the spectrum in which the first carrier is located is an unlicensed spectrum, and the spectrum in which the second carrier is located is a licensed spectrum; or the spectrum in which the first carrier is located and the spectrum in which the second carrier is located are all unlicensed spectrum Or, the spectrum in which the first carrier is located and the spectrum in which the second carrier is located are licensed spectrums of the same frequency.

In one embodiment, the data frame on the first carrier carries EPDCCH/PDSCH information, The data frame on the second carrier carries the PDCCH information; the first carrier and the second carrier are carriers configured by different base stations; and the processing unit 902 is specifically configured to: according to the EPDCCH/PDSCH carried in the PDCCH The PQI indication information included in the scheduling information is used to obtain first information, where the PQI indication information is used to indicate subframe format information of a data frame on the first carrier.

In another embodiment, the data frame on the first carrier carries the EPDCCH/PDSCH information, and the data frame on the second carrier carries the PDCCH information. The processing unit 902 is specifically configured to be used according to the PDCCH carried in the PDCCH. The carrier indication information included in the scheduling information of the EPDCCH/PDSCH obtains the first information, where the carrier indication information is used to indicate the subframe format information of the data frame on the first carrier.

In another embodiment, the received at least two symbols having the first CP carry a useful signal, the useful signal includes a reference signal, and the processing unit is further configured to: estimate the first according to the reference signal Time-frequency synchronization information on a carrier.

In another embodiment, the processing unit is further configured to: perform frequency domain phase compensation on the useful signal according to the estimated time-frequency synchronization information on the first carrier; or, according to the estimated first carrier The time-frequency synchronization information demodulates the symbols received after the at least two symbols.

Specifically, the reference signal in the useful signal includes at least one of the following information:

The common reference signal, the demodulation reference signal, the channel state information reference signal, and the reference signal are found. The useful signal further includes a data signal, and the data signal of the useful signal includes at least one of the following information:

Of course, in different cases, the processing unit can be divided into different units. In one embodiment, the processing unit includes:

An information obtaining unit, configured to obtain first information and coarse timing information on the first carrier;

De-CP processing unit, performing de-CP processing on the first one of the at least two symbols on the first carrier according to the coarse timing information on the first carrier and the first information, And deselecting the symbols other than the first one of the at least two symbols by a first length; wherein the second length is an arbitrary value smaller than the first length.

The information obtaining unit is specifically configured to obtain the first information according to the predefined information; or, the signaling that receives the first information indicates that the first information is obtained.

In another embodiment, the information obtaining unit is specifically configured to: obtain timing information on the second carrier as coarse timing information of the first carrier, where the first carrier and the second carrier are configured by the same base station. a carrier; or the first carrier and the second carrier are carriers configured by different base stations.

Referring to FIG. 10, another embodiment of a terminal 1000 provided by the present invention includes a receiver 1010, a modem 1020, at least one processor 1040, a memory 1050, and at least one communication bus. Memory 1050 can include read only memory and random access memory and provides instructions and data to processor 1040. For example: random access memory, flash memory, read only memory, programmable read only memory, nonvolatile memory, non-volatile random access memory (NVRAM) or registers. The processor 1040 can be a Central Processing Unit (CPU). The processor 1040 performs various functions by calling a program or instruction stored in the memory 1050.

The mobile terminal 1000 optionally includes a user interface 1030, including a display (eg, a touch screen, LCD, CRT, Holographic or Projector, etc.), a keyboard or a pointing device (eg, a mouse, a trackball) , touch panel or touch screen, etc.).

The receiver 1010 is configured to receive, on the first carrier, at least two symbols having a first cyclic prefix CP, where the length of the first CP is a first length.

For example, the receiver can be an antenna of the mobile terminal.

The modem 1020 is configured to obtain first information and coarse timing information on the first carrier, according to the coarse timing information on the first carrier and the first information, to the at least two symbols on the first carrier The first symbol is subjected to CP processing according to the second length, and the other symbols except the first one of the at least two symbols are subjected to CP processing according to the first length; wherein the second length is smaller than the first length Any value of the first information includes first length information.

Referring to FIG. 11, another embodiment of a data transmission method provided by the present invention includes:

S1101: The sending device sends at least one symbol having a long cyclic prefix ECP to the receiving device from a moment of acquiring the channel usage right on the first carrier of the unlicensed spectrum;

S1102: The sending device notifies the receiving device of the second information; the second information includes a CP format of the at least one symbol.

In an embodiment, the sending device notifies the receiving device by means of predefined or signaling The second information.

In another implementation, the second information further includes:

Referring to FIG. 12, an embodiment of a sending device provided by the present invention includes:

The transmitter 1201 is configured to send, by the time of acquiring the channel usage right on the first carrier of the unlicensed spectrum, to the receiving device, at least one symbol having a long cyclic prefix ECP;

The notification unit 1202 is configured to notify the receiving device of the second information, where the second information includes a CP format of the at least one symbol.

In an embodiment, the notifying unit 1202 notifies the receiving device of the second information by means of predefined or signaling.

In another embodiment, the second information further includes:

Optionally, the sending device may be a base station.

One of ordinary skill in the art can understand that all or part of the process of implementing the foregoing embodiments can be completed by a computer program to instruct related hardware, and the program can be stored in a computer readable storage medium. When executed, the flow of an embodiment of the methods as described above may be included. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed. In addition, 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. It can be electrical, mechanical or other form.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, 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.

In summary, the above description is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

A data transmission method, comprising:

Receiving, on the first carrier, at least two symbols having a first cyclic prefix CP; wherein, the length of time of the first CP is a first length;

Obtaining first information, where the first information includes first length information;

Obtaining coarse timing information on the first carrier;

De-CP processing the first one of the at least two symbols on the first carrier according to the coarse timing information on the first carrier and the first information, to the at least two The symbols other than the first one of the symbols are subjected to CP processing by the first length; wherein the second length is any value smaller than the first length.
The method according to claim 1, wherein the first length is a length of time of a long cyclic prefix ECP, and the second length is a length of time of a normal cyclic prefix NCP.
The method of claim 1 wherein said second length is one half of said first length.
The method according to any one of claims 1-3, wherein obtaining the first information comprises:

The first information is predefined information; or

Receiving the signaling of the first information indicates obtaining the first information.
The method according to any one of claims 1-4, wherein the first information further comprises a number of symbols having a first CP, and/or a number of subframes having a first CP, and/or , the starting position of the symbol of the first CP.
The method according to any one of claims 1-5, wherein obtaining coarse timing information on the first carrier comprises:

Obtaining timing information on the second carrier as coarse timing information of the first carrier, where the first carrier and the second carrier are carriers configured by the same base station; or, the first carrier and the first The two carriers are carriers configured for different base stations.
The method according to claim 6, wherein the spectrum in which the first carrier is located is an unlicensed spectrum, and the spectrum in which the second carrier is located is a licensed spectrum; or

The spectrum in which the first carrier is located and the spectrum in which the second carrier is located are unlicensed spectrum; or

The spectrum in which the first carrier is located and the spectrum in which the second carrier is located are licensed spectrums of the same frequency.
The method according to any one of claims 6-7, wherein the data frame on the first carrier carries EPDCCH/PDSCH information, and the data frame on the second carrier carries PDCCH information; And the second carrier is a carrier configured by a different base station, where the obtaining the first information includes:

Obtaining first information according to the PQI indication information included in the scheduling information of the EPDCCH/PDSCH carried in the PDCCH, where the PQI indication information is used to indicate subframe format information of a data frame on the first carrier.
The method according to any one of claims 6-7, wherein the data frame on the first carrier carries EPDCCH/PDSCH information, and the data frame on the second carrier carries PDCCH information; Information includes:

Obtaining first information according to the carrier indication information included in the scheduling information of the EPDCCH/PDSCH carried in the PDCCH, where the carrier indication information is used to indicate subframe format information of a data frame on the first carrier.
The method according to any one of claims 1-9, wherein the received at least two symbols having the first CP carry a useful signal, and the useful signal includes a reference signal, the method further comprising:

Estimating time-frequency synchronization information on the first carrier according to the reference signal.
The method of claim 10, wherein the method further comprises:

Performing frequency domain phase compensation on the useful signal according to the estimated time-frequency synchronization information on the first carrier; or

And demodulating the symbols received after the at least two symbols according to the estimated time-frequency synchronization information on the first carrier.
A method according to any of claims 1-11, wherein the reference signal in the useful signal comprises at least one of the following:

a common reference signal, a demodulation reference signal, a channel state information reference signal, and a reference signal;

The useful signal further includes a data signal, and the data signal of the useful signal includes at least one of the following information:

Physical downlink control channel, enhanced physical downlink control channel, physical downlink shared channel.
A terminal, comprising:

a receiver, configured to receive, on the first carrier, at least two symbols having a first cyclic prefix CP, and wherein the first CP has a time length of a first length;

a processing unit, configured to obtain first information and coarse timing information on the first carrier, according to the coarse timing information on the first carrier and the first information, to the at least two symbols on the first carrier The first symbol is subjected to CP processing according to the second length, and the other symbols except the first one of the at least two symbols are subjected to CP processing according to the first length; wherein the second length is smaller than the first length Any value; the first information includes first length information.
The terminal according to claim 13, wherein the first length is a length of time of a long cyclic prefix ECP, and the second length is a length of time of a normal cyclic prefix NCP.
The terminal of claim 13 wherein said second length is one half of said first length.
The terminal according to any one of claims 13-15, wherein the processing unit is specifically configured to: obtain first information according to predefined information; or

The processing unit is specifically configured to: receive signaling information of the first information to obtain the first information.
The terminal according to any one of claims 13-16, wherein the first information further comprises a number of symbols having a first CP, and/or a number of subframes having a first CP, and/or , the starting position of the symbol of the first CP.
The terminal according to any one of claims 13-17, wherein the processing unit is specifically configured to:

Obtaining timing information on the second carrier as coarse timing information of the first carrier, where the first carrier and the second carrier are carriers configured by the same base station; or, the first carrier and the first The two carriers are carriers configured for different base stations.
The terminal according to claim 18, wherein the spectrum in which the first carrier is located is an unlicensed spectrum, and the spectrum in which the second carrier is located is a licensed spectrum; or

The spectrum in which the first carrier is located and the spectrum in which the second carrier is located are unlicensed spectrum; or

The spectrum in which the first carrier is located and the spectrum in which the second carrier is located are licensed spectrums of the same frequency.
The terminal according to claim 18 or 19, wherein the data frame on the first carrier carries EPDCCH/PDSCH information, and the data frame on the second carrier carries a PDCCH signal. The first carrier and the second carrier are carriers configured by different base stations;

The processing unit is specifically configured to obtain, according to the PQI indication information included in the scheduling information of the EPDCCH/PDSCH that is carried in the PDCCH, where the PQI indication information is used to indicate data on the first carrier. Subframe format information of the frame.
The terminal according to claim 18 or 19, wherein the data frame on the first carrier carries EPDCCH/PDSCH information, and the data frame on the second carrier carries PDCCH information;

The processing unit is configured to obtain first information according to the carrier indication information included in the scheduling information of the EPDCCH/PDSCH that is carried in the PDCCH, where the carrier indication information is used to indicate that the first carrier is Subframe format information of the data frame.
The terminal according to any one of claims 13 to 21, wherein the received at least two symbols having the first CP carry a useful signal, the useful signal includes a reference signal, and the processing unit is further configured to: Estimating time-frequency synchronization information on the first carrier according to the reference signal.
The terminal according to claim 22, wherein the processing unit is further configured to perform frequency domain phase compensation on the useful signal according to the estimated time-frequency synchronization information on the first carrier; or

And demodulating the symbols received after the at least two symbols according to the estimated time-frequency synchronization information on the first carrier.
The terminal according to claims 13-23, wherein the reference signal in the useful signal comprises at least one of the following information:

a common reference signal, a demodulation reference signal, a channel state information reference signal, and a reference signal;

The useful signal further includes a data signal, and the data signal of the useful signal includes at least one of the following information:

Physical downlink control channel, enhanced physical downlink control channel, physical downlink shared channel.
A data transmission method, comprising:

Transmitting, by the transmitting device, at least one symbol having a long cyclic prefix ECP from the moment of acquiring the channel usage right on the first carrier of the unlicensed spectrum to the receiving device;

The transmitting device notifies the receiving device of the second information; the second information includes a CP format of the at least one symbol.
The method of claim 25 wherein said transmitting device is scheduled Notifying the receiving device of the second information by means of signaling or signaling.
The method according to claim 25 or 26, wherein the second information further comprises:

The number of symbols with ECP, and/or the number of subframes with ECP, and/or the starting position of the symbol with ECP.
A transmitting device, comprising:

a transmitter, configured to send, by the time of acquiring the channel usage right on the first carrier of the unlicensed spectrum, to the receiving device, at least one symbol having a long cyclic prefix ECP;

a notification unit, configured to notify the receiving device of the second information; the second information includes a CP format of the at least one symbol.
The transmitting device according to claim 28, wherein the notification unit notifies the receiving device of the second information by means of predefined or signaling.
The transmitting device according to claim 28 or 29, wherein the second information further comprises:

The number of symbols with ECP, and/or the number of subframes with ECP, and/or the starting position of the symbol with ECP.