CN106506054A - For choosing the method and system of circulation delay in multiple antennas ofdm system - Google Patents

For choosing the method and system of circulation delay in multiple antennas ofdm system Download PDF

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Publication number
CN106506054A
CN106506054A CN201611067209.5A CN201611067209A CN106506054A CN 106506054 A CN106506054 A CN 106506054A CN 201611067209 A CN201611067209 A CN 201611067209A CN 106506054 A CN106506054 A CN 106506054A
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China
Prior art keywords
pilot
circulation
transmitting antenna
pilot tone
input samples
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CN201611067209.5A
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Chinese (zh)
Inventor
P·达亚尔
A·F·纳谷比
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Qualcomm Inc
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Qualcomm Inc
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Priority claimed from US12/357,935 external-priority patent/US8570939B2/en
Application filed by Qualcomm Inc filed Critical Qualcomm Inc
Publication of CN106506054A publication Critical patent/CN106506054A/en
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
    • H04B7/0667—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of delayed versions of same signal
    • H04B7/0671—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of delayed versions of same signal using different delays between antennas
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2602—Signal structure
    • H04L27/261—Details of reference signals
    • H04L27/2613—Structure of the reference signals
    • H04L27/26134—Pilot insertion in the transmitter chain, e.g. pilot overlapping with data, insertion in time or frequency domain
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/0413—MIMO systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
    • H04B7/0667—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of delayed versions of same signal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202—Channel estimation
    • H04L25/024—Channel estimation channel estimation algorithms
    • H04L25/0256—Channel estimation using minimum mean square error criteria
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2602—Signal structure
    • H04L27/261—Details of reference signals
    • H04L27/2613—Structure of the reference signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/0001—Arrangements for dividing the transmission path
    • H04L5/0014—Three-dimensional division
    • H04L5/0023—Time-frequency-space
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0048—Allocation of pilot signals, i.e. of signals known to the receiver

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  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Power Engineering (AREA)
  • Radio Transmission System (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Transmitters (AREA)

Abstract

The present invention relates to for the method and system for choosing circulation delay in multiple antennas ofdm system.Some embodiments of the disclosure are related to determine the adequate value of the circulation delay that applies at the transmitter with multiple antennas to provide the method that accurate channel gain is estimated in multiple input single output (MISO) system or multiple-input and multiple-output (MIMO) system.

Description

For choosing the method and system of circulation delay in multiple antennas ofdm system
It is PCT/US2009/035196, China on 2 25th, 2009, international application no that the application is international filing date Application No. 200980104602.9, entitled " in multiple antennas ofdm system choose circulation delay method and The divisional application of the patent application of system ".
Priority request
This application claims enjoying entitled " Method and apparatus for transmitting pilots from Multiple antennas (for from multiple antennas transmit pilot tone method and apparatus) " and on March 14th, 2008 submit to U.S. Provisional Patent Application S/N.61/036, the rights and interests of 895 priority, this application essentially by quote include completely in This.
Technical field
Some embodiments of the disclosure relate generally to radio communication, more particularly to a kind of choose for multi-antenna transmission appropriate Cyclic delay values so as to accurately estimate channel gain method.
General introduction
Some embodiments provide a kind of method for transmitting pilot tone in a wireless communication system.The method is generally comprised and is based on First circulation postpones to generate to the first pilot tone of the first transmitting antenna, and postpones big at least Cyclic Prefix based on than first circulation The second circulation of length postpones to generate to the second pilot tone of the second transmitting antenna.
Some embodiments provide a kind of method for executing channel estimation in a wireless communication system.The method is generally comprised Obtain comprising the first and second pilot tones the first input sample, wherein the first pilot tone be based on first circulation postpone generate and from First transmitting antenna sends, and the second pilot tone is to postpone to generate based on second circulation and send from the second transmitting antenna, the Two circulation delays postpone big at least circulating prefix-length than first circulation, and these first input samples are to receive day from first Line；And process these first input samples to obtain for the first channel estimation of the first transmitting antenna and for the second transmitting The second channel of antenna is estimated.
Some embodiments provide a kind of device for transmitting pilot tone in a wireless communication system.The device is generally comprised It is used for postponing to generate to the logic of the first pilot tone of the first transmitting antenna based on first circulation, and is used for being based on than first circulation The second circulation for postponing big at least circulating prefix-length postpones to generate to the logic of the second pilot tone of the second transmitting antenna.
Some embodiments provide a kind of device for executing channel estimation in a wireless communication system.The device is general Including for obtaining the logic of the first input sample comprising the first and second pilot tones, wherein the first pilot tone is based on first circulation Postpone to generate and from the transmission of the first transmitting antenna, the second pilot tone is to postpone to generate and from the second transmitting based on second circulation Antenna sends, and second circulation postpones to postpone big at least circulating prefix-length than first circulation, and these first input samples are From the first reception antenna；And for processing these first input samples to obtain the first channel for the first transmitting antenna The logic that estimation and the second channel for the second transmitting antenna are estimated.
Some embodiments provide a kind of device for transmitting pilot tone in a wireless communication system.The device is generally comprised For postponing to generate to the device of the first pilot tone of the first transmitting antenna based on first circulation, and for based on than first circulation The second circulation for postponing big at least circulating prefix-length postpones to generate to the device of the second pilot tone of the second transmitting antenna.
Some embodiments provide a kind of device for executing channel estimation in a wireless communication system.The device is general Including for obtaining the device of the first input sample comprising the first and second pilot tones, wherein the first pilot tone is based on first circulation Postpone to generate and from the transmission of the first transmitting antenna, the second pilot tone is to postpone to generate and from the second transmitting based on second circulation Antenna sends, and second circulation postpones to postpone big at least circulating prefix-length than first circulation, and these first input samples are From the first reception antenna；And for processing these first input samples to obtain the first channel for the first transmitting antenna The device that estimation and the second channel for the second transmitting antenna are estimated.
Some embodiments provide a kind of computer program for transmitting pilot tone in a wireless communication system, including which On be stored with the computer-readable medium of instruction, these instructions can be by one or more computing devices.These instructions are general Including for based on first circulation postpone generate to the first transmitting antenna the first pilot tone instruction, and be used for be based on than first The second circulation of the big at least circulating prefix-length of circulation delay postpones to generate to the instruction of the second pilot tone of the second transmitting antenna.
Some embodiments provide a kind of computer program for executing channel estimation in a wireless communication system, bag The computer-readable medium for being stored thereon with instruction is included, these instructions can be by one or more computing devices.These instructions The instruction for first input sample of the acquisition comprising the first and second pilot tones is generally comprised, wherein the first pilot tone is based on first Circulation delay is generated and is sent from the first transmitting antenna, and the second pilot tone is to postpone to generate and from second based on second circulation Transmitting antenna sends, and second circulation postpones to postpone big at least circulating prefix-length, and these the first input samples than first circulation Originally it is from the first reception antenna；And for processing these first input samples to obtain first for the first transmitting antenna The instruction that channel estimation and the second channel for the second transmitting antenna are estimated.
Brief description
In order to be able to the mode being understood in detail used by the feature that the disclosure is set forth above, it is referred to embodiment and comes to more than Summarized is more particularly described, and some of them embodiment is illustrated in the accompanying drawings.It should be noted, however, that accompanying drawing is only illustrated Some exemplary embodiments of the disclosure, therefore be not construed as limiting its scope, because the description can other have on an equal basis with access The embodiment of effect.
Fig. 1 illustrates the example wireless communication system of some embodiments according to the disclosure.
Fig. 2 illustrates the example orthogonal frequency division multiplexing for time division duplex (TDD) according to some embodiments of the disclosure/just Hand over frequency division multiple access (OFDM/OFDMA) frame.
Fig. 3 illustrate according to the example transmitter that can be used in wireless communication system of some embodiments of the disclosure and Example Receiver.
Fig. 4 illustrates the block diagram of the design of the OFDM manipulators of some embodiments according to the disclosure.
Fig. 5 illustrates the example of the cyclic delay diversity of some embodiments according to the disclosure.
Fig. 6 illustrates the example pilot subcarricr structure for an OFDM symbol of some embodiments according to the disclosure.
Fig. 7 illustrates the block diagram of the design of the manipulator of the base station in figure 3 of some embodiments according to the disclosure.
Fig. 8 is illustrated according to some embodiments of the disclosure for for multiple input single output (MISO) or multiple-input and multiple-output (MIMO) system generates the process of pilot tone.
Fig. 8 A diagram have the ability execute Fig. 8 in diagrammatic operation exemplary components.
Fig. 9 illustrates the block diagram of the design of the channel estimator of some embodiments according to the disclosure.
Figure 10 diagrams are according to some embodiments of the disclosure for execution channel estimation in MISO or mimo system Process.
Figure 10 A diagram have the ability execute Figure 10 in diagrammatic operation exemplary components.
Describe in detail
Word " exemplary " used herein " plays a part of example, example or illustrates " representing.Here depicted as Any embodiment of " exemplary " is not necessarily to be construed as advantageous over or surpasses other embodiment.
Can be higher to provide to duplicating multi-antenna orthogonal frequency division (OFDM) transmission application cyclic delay diversity (CDD) scheme Frequency diversity and improve error rate performance.By a plurality of people just can be generated from the transmission of multiple antennas through the data of circulation delay For channel path.Can be executed using known pilot or training sequence to related to this multiple transmitting antenna in receiver side The estimation of the channel gain of connection.However, in some cases, if through all in all pilot frequency sequence match channels section views of circulation delay Path delay, then all time domain channel paths can not be completely segregated at receiver.
Example wireless communications
Technology described herein can be used for various system of broadband wireless communication, including multiple based on orthogonal multi-path Communication system with scheme.The example of such communication system includes OFDM (OFDMA) system, single-carrier frequency division multiple access (SC-FDMA) system etc..OFDMA system utilizes OFDM (OFDM), this be a kind of by whole system bandwidth partition into The modulation technique of multiple quadrature subcarriers.These subcarriers can also be referred to as frequency modulation, frequency groove etc..There is OFDM, each pair is carried Ripple just can be modulated with Dynamic data exchange.SC-FDMA systems can utilize intertexture formula FDMA (IFDMA) in cross-system bandwidth distribution Transmit on subcarrier, transmitted on the block being made up of adjacent subcarriers using locally formula FDMA (LFDMA), or utilize enhanced FDMA (EFDMA) is transmitted on multiple blocks being made up of adjacent subcarriers.In general, modulated symbol is in frequency domain under OFDM Middle transmission, and sent under SC-FDMA in the time domain.
A specific example based on the communication system of orthogonal multiplexing scheme is WiMAX system.Represent inserting of microwave The WiMAX of global interoperability manipulation is measured broadband wireless technology, and the high-throughput wideband that it is provided on over long distances connects Connect.There are two kinds of main WiMAX applications now：Fixed WiMAX and mobile WiMAX.Fixed WiMAX applications are point-to-multipoints, Which makes it possible to broadband access such as resident family and enterprise.Mobile WiMAX provides full mobility of the cellular network in broadband speeds.
IEEE 802.16 is the emerging mark for defining air interface for fixed and mobile broadband wireless access (BWA) system Quasi- tissue.These standards define at least four different physical layers (PHY) and medium education (MAC) layer.This four OFDM and OFDMA physical layers in individual physical layer are most popular in fixed and mobile BWA fields respectively.
Fig. 1 diagrams can wherein using the example of the wireless communication system 100 of embodiment of the disclosure.Radio communication system System 100 can be system of broadband wireless communication.Wireless communication system 100 can be the respective several honeycombs serviced by base station 104 Cell 102 provides communication.Base station 104 can be the fixed station communicated with user terminal 106.Alternatively can also use base station 104 Access point, B node or other certain terms are referred to as.
Fig. 1 depicts the various user terminals 106 of distributed throughout system 100.User terminal 106 can be fixed (that is, static) Or mobile.User terminal 106 can alternatively use distant station, access terminal, terminal, subscri er unit, movement station, platform, use Family equipment, subscriber station etc. are referred to as.User terminal 106 can be that such as cell phone, personal digital assistant (PDA), hand-held set The wireless devices such as standby, radio modem, laptop computer, personal computer.
Can to the transmission in wireless communication system 100 between base station 104 and user terminal 106 using various algorithms and Method.For example, it is possible to be sent and received signal between base station 104 and user terminal 106 according to OFDM/OFDMA technology.If It is this situation, then wireless communication system 100 can be referred to as OFDM/OFDMA systems.
Help carry out to be referred to as downlink (DL) from base station 104 to the communication link of the transmission of user terminal 106 108, and help carry out to be referred to as up-link (UL) from user terminal 106 to the communication link of the transmission of base station 104 110.Alternatively, downlink 108 can be referred to as forward link or forward channel, and up-link 110 can be referred to as instead To link or backward channel.
Cellular cell 102 can be divided into multiple sectors 112.Sector 112 is that the physics in cellular cell 102 is covered Area.Base station 104 in wireless communication system 100 can utilize and concentrate on power flow in the particular sector 112 of cellular cell 102 Antenna.So antenna can be referred to as beam antenna.
Fig. 2 illustrates the example frame structure 200 for being used for time division duplex (TDD) pattern in IEEE 802.16.Transmission time line can To be divided in units of frame.Each frame can be lasted across predetermined, such as 5 milliseconds (ms), and can be divided into descending Link subframe and uplink sub-frames.In general, downlink and uplink sub-frames can cover any segment of frame.Under Line link and uplink sub-frames can be separated by transmitting transmission gap (TTG) and reception transmission gap (RTG).
Several physical sub-channels can be defined.Each physical sub-channels can include can adjoin, can also cross-system band The sets of subcarriers of wide distribution.Several logical sub-channels can also be defined and physics can be mapped to based on known Channel.Logical sub-channel can simplify the distribution of resource.
As shown in Figure 2, downlink subframe can include preamble, frame control head portion (FCH), downlink map (DL-MAP), uplink map (UL-MAP) and downlink (DL) paroxysm.Preamble can be carried can be by subscriber Stand for making frame detection and synchronous known transmission.FCH can be carried for receiving DL-MAP, UL-MAP and downlink The parameter of paroxysm.DL-MAP can carry DL-MAP message, and the message can include all kinds accessed for downlink Control information (for example, resource allocation or appointment) information element (IE).UL-MAP can carry UL-MAP message, the message The IE of the various types of control information for up-link access can be included.Downlink paroxysm can be carried to positive bedding and clothing The data of the subscriber station of business.Uplink sub-frames can include up-link paroxysm, the latter can carry scheduled carry out up The data transmitted by the subscriber station of link transmission.
Pilot transmission techniques described herein both can be used for multiple-input and multiple-output (MIMO) transmission be can be used for Multiple input single output (MISO) is transmitted.These technology can be also used for the pilot transmission on downlink and up-link. For the sake of clarity, in terms of describing some of these technology below for the pilot transmission on downlink in MIMO situations.
Fig. 3 is shown as the frame of the base station 104 of one of one of base station in Fig. 1 and subscriber station and the design of subscriber station 106 Figure.Base station 104 is equipped with multiple (M) antenna 334a to 334m.Subscriber station 106 is equipped with multiple (R) antenna 352a and arrives 352r.
At base station 104, transmitting (TX) data processor 320 can receive the data from data source 312, based on one Or more modulation and encoding scheme process (for example, the coding and code element map) data, and provide data symbols.As this institute Use, data symbols correspond to the code element of data, and pilot frequency code element corresponds to the code element of pilot tone, and code element can be real number Or complex values.Data symbols and pilot frequency code element can be derived from the modulated symbol of the modulation schemes such as PSK or QAM.Pilot tone Can include for base station and data known to subscriber station priori by both.TX MIMO processors 330 can process these data and lead M output code flow filament is simultaneously supplied to M manipulator (MOD) 332a to 332m by frequency code unit.Each manipulator 332 can process which Output code flow filament (for example, for realize OFDM) is obtaining output sample stream.(example can further be nursed one's health by each manipulator 332 Such as, simulation, filtering, amplification and up-conversion are converted to) its output sample stream generate down link signal.From manipulator The M down link signal of 332a to 332m can be launched via antenna 334a to 334m respectively.
At subscriber station 106, R antenna 352a to 352r can receive this M downlink letter from base station 104 Number, and the signal for receiving can be supplied to associated demodulator (DEMOD) 354 by each antenna 352.Each demodulator 354 Can nurse one's health (for example, filtering, amplify, down coversion and digitized) its signal for receiving to be obtaining input sample and can be with Further process these input samples (for example, for realize OFDM) code element is received to obtain.Each demodulator 354 will can be received MIMO detectors 360 are supplied to data symbols and pilot frequency code element will be received and be supplied to channel processor 394.Channel processor 394 can based on receive pilot frequency code element estimate from base station 104 to the mimo channel of subscriber station 120 response and mimo channel estimated Meter is supplied to MIMO detectors 360.MIMO detectors 360 can be estimated to execute the MIMO to receiving code element based on this mimo channel The code element for detecting is detected and provides, the latter is the estimation to the data symbols for being transmitted.Receiving (RX) data processor 370 can To process (for example, symbol de-maps and decoding) code element for detecting and the data for decoding be supplied to data trap 372.
Subscriber station 106 can be evaluated channel conditions and generate the feedback information that can include various types of information.Feedback Information and the data from data source 378 can process (for example, coding and code element map) by TX data processors 380, by TX 382 spatial manipulation of MIMO processor is simultaneously further processed by manipulator 354a to 354r to generate R uplink signal, this A little signals can be launched via antenna 352a to 352r.At base station 104, carry out this R up-link letter of subscriber station 106 Number can by antenna 334a to 334m receive, by demodulator 332a to 332m process, by 336 spatial manipulation of MIMO detectors and (for example, symbol de-maps and decoding) is further processed by RX data processors 338 to recover the feedback of the transmission of subscriber station 106 Information and data.Controller/processor 340 can control the data transfer to subscriber station 106 based on the feedback information.
Controller/processor 340 and 390 can distinguish direct base station 104 and the operation at subscriber station 106.Memorizer 342 The data and program code that for base station 104 and subscriber station 106 use are stored with 392 respectively can.Scheduler 344 can be based on and connect Receipts come scheduling subscriber stations 106 and/or other subscriber stations from the feedback information of all subscriber stations carries out downlink and/or uplink Data transfer on road.
IEEE 802.16 utilizes Orthodoxy Frequency Division Multiplex (OFDM) to downlink and up-link.OFDM is by system Bandwidth division is into multiple (NFFTIndividual) quadrature subcarrier, they are also referred to as frequency modulation, frequency groove etc..Each subcarrier can use number According to or pilot modulated.The number of subcarrier can depend on the frequency interval between system bandwidth and adjacent subcarriers.For example, NFFT128,256,512,1024 or 2048 can be equal to.This N altogetherFFTIndividual subcarrier only its subset may be available for data and lead Defeated use is kept pouring in, and remaining subcarrier can serve as the protection subcarrier that permission system meets spectral mask requirement.Retouch following In stating, data subcarriers are the subcarriers for data, and pilot subcarrier is the subcarrier for pilot tone.OFDM symbol can be with Transmission in each OFDM symbol cycle (or abbreviation code-element period).Each OFDM symbol can include the number for sending data According to subcarrier, in order to sending the pilot subcarrier of pilot tone, and/or be not used for the protection subcarrier of data or pilot tone.
Fig. 4 is illustrated and can be included among manipulator 332a to 332m in figure 3 and manipulator 354a to 354r The block diagram of the design of the OFDM manipulators 400 in each.In OFDM manipulators 400, code element-sub-carrier mapped device 410 connects Receive output symbol and map that to this N altogetherFFTIndividual subcarrier.In each OFDM symbol cycle, unit 412 uses NFFTPoint from Scattered inverse fourier transform (IDFT) will be corresponding to this N altogetherFFTThe N of individual subcarrierFFTIndividual output symbol transforms to time domain and provides Comprising NFFTThe useful part of individual time domain samples.Each sample is the complex values that will be transmitted in a chip period.And-string (P/ S) transducer 414 is by this N in the useful partFFTIndividual sample serialization.Cyclic Prefix maker 416 replicates the useful part Last NCPIndividual sample by this NCPIndividual sample is attached to before the useful part to be formed comprising NFFT+NCPIndividual sample OFDM symbol.Thus each OFDM symbol includes NFFTThe useful part of individual sample and there is NCPThe Cyclic Prefix of individual sample.Circulation Prefix be used for resisting due to wireless channel in delay spread institute caused by inter symbol interference (ISI) and inter-carrier interference (ICI).
Fig. 3 is returned to, on the uplink, mimo channel is by this M transmitting antenna and subscriber station 106 of base station 104 This R reception antenna at place is formed.The mimo channel be by M R single-input single-outputs (SISO) channel or i.e. each can The transmitting and reception antenna of energy is constituted to a SISO channel.The channel response of each SISO channel can be rushed by time domain channel Swash response or the response of corresponding frequency-domain channel frequency any one among both characterizing.Channel frequency response is channel impulse The discrete Fourier transform (DFT) (DFT) of response.
The channel impulse response of each SISO channel can be characterized by L time domain channel taps, and wherein L is in typical case Compare NFFTMuch smaller.That is, if applying impulse at transmitting antenna, got with regard to the impulse excitation at reception antenna In the response that L time domain samples of sample rate will be enough to characterize the SISO channels.Channel tap required by channel impulse response Number (L) depends on the delay spread of system, and the latter is to reach the letter with abundant energy at reception antenna earliest and the latest Time difference between number example.
Each SISO channel corresponding to the SISO channels transmitting antenna and reception antenna between potentially include one or More a plurality of propagation path, wherein these propagation paths are determined by wireless environment.Can be with specific multiple increasing per paths Benefit and specific delay are associated.For every SISO channel, the complex gain of this L channel tap is by all roads of SISO channels The complex gain in footpath determines.Every therefore SISO channels have with path d0Arrive dL-1Channel section view, wherein per paths dl's Complex gain can be zero or nonzero value.
Cyclic delay diversity (CDD) can be used for frequency diversity of creating in MIMO transmission, and this can improve error rate Performance.There is cyclic delay diversity, the OFDM symbol to each transmitting antenna can be different by circulation delay as described below Amount.The M different signal through circulation delay can be launched from this M transmitting antenna.However, cyclic delay diversity is one Mimo channel estimation may be negatively affected in a little situations.Particularly, if in through the Signal Matching channel section view of circulation delay Path delay, then perhaps all paths can not possibly be separated.For example, for given reception antenna, perhaps can not can determine that Complex gain corresponding to 2 sample delays is derived from (i) from the transmitting antenna 0 without circulation delay and via there is 2 sample delays The down link signal that receives of path, or (ii) is having the transmitting antenna 1 of 1 sample loops delay by oneself and via there is 1 sample The down link signal that the path of this delay receives, or (iii) come have by oneself 2 sample loops delay transmitting antenna 2 and pass through The down link signal received by the path not postponed.
If channel section view has path d0Arrive dL-1And if the M down link signal tool from this M transmitting antenna There is t0Arrive tM-1Circulation delay, then in (dl+tm)mod TSIn the case of different to all values for indexing l and m, each L channel tap of SISO channels unambiguously can be determined, wherein l=0 ..., L-1, m=0 ..., M-1, TSIt is useful Partial lasts and is equal to NFFTIndividual sample, and " mod " sign modulo operation.The condition is reused to full rate and is also suitable.
For some embodiments, the circulation of each transmitting antenna (except that transmitting antenna with 0 circulation delay) Postpone tmCan be selected to equal to or more than the largest anticipated delay spread in the system.Circulating prefix-length NCPCan be with selected It is selected to make it equal to or more than the largest anticipated delay spread in the system, so that L≤NCP.Therefore, for some are implemented Example, the circulation delay for each transmitting antenna can be selected as follows：
Wherein NC,0>=0, and forThere is NC,i≥NCP.
Fig. 5 illustrates formula (1) in NC,0=0 and for i=1 ..., M-1 has NC,i=NCPWhen an example scenario under Cyclic delay diversity, wherein M=4 transmitting antenna.Transmitting antenna 0 has the circulation delay for 0, and for the transmitting antenna, Useful part is by 0 sample of cyclic shift/delay.It is N that transmitting antenna 1 hasCPCirculation delay, and for the transmitting antenna, Useful part is by cyclic shift NCPIndividual sample.It is 2 N that transmitting antenna 2 hasCPCirculation delay, and for the transmitting antenna, Useful part is by 2 N of cyclic shiftCPIndividual sample.It is 3 N that transmitting antenna 3 hasCPCirculation delay, and for the transmitting day Line, useful part is by 3 N of cyclic shiftCPIndividual sample.
According to formula (1), the circulation delay for this M transmitting antenna can be selected as：
tm+1-tm≥NCP, m=0 ..., M-2, (2)
While tM-1≤NFFT-NCP.
This design in formula (2) guarantees dl+tmAll values to l and m are different.Thus to launching from all M The unambiguous channel estimation (which is referred to as complete channel estimation) of all L paths of antenna will become possibility.If being used for this M The circulation delay of individual transmitting antenna is standardized or known a priori, then without the need for explicitly sending signaling for these circulation delays.
Can transmit from this M transmitting antenna by the way of helping subscriber station 106 to carry out complete channel estimation base station 104 Pilot frequency code element.Pilot frequency code element can be in S subcarrier k0Arrive kS-1Upper transmission, wherein general S≤NFFT.This S pilot subcarrier Can determine as described below.
Can defineThe set of individual coefficient is as follows：
Wherein for m=0 ..., M-1, there is l=0 ..., NC,m- 1, and NC,m≥NCP, q=l M+m=0 ..., Q-1, And bqIt is q-th coefficient in the set.Due to L≤NCP, may have less than NCPIndividual channel tap.Can using take threshold come by Non-existent channel tap zero suppression.
Can be that this S pilot subcarrier defines S × Q matrix Bs, as follows：
WhereinBe matrix B the i-th row q row in element, wherein i=0 ..., S-1 and q=0 ..., Q-1.
The sufficient condition that complete channel is estimated is that the order of matrix B is equal to L M.B is wanted in this derivationqDifferent necessary bar Part, it means that dl+tmTo TSShould be different in the case of delivery.
The system is operated together with being reused with full rate, and each cellular cell can be in all N altogetherFFTIndividual secondary load Ripple (except protection subcarrier) is upper to be transmitted.For full rate is reused, pilot frequency code element can be in each subcarrier that can be used for transmitting Upper transmission, or i.e. S=NFFT, and matrix B can be S × S vandermondes (Vandermonde) matrix V with following form：
For full rate is reused, bqThis essential condition different be enough to allow for complete channel estimation.Even if Some subcarriers are preserved for protecting, but every other subcarrier is all used and has such subcarrier individual more than Q, thus Matrix V will be full rank.
The system can be operated together with fractional frequency reuse, and each cellular cell can be in N altogetherFFTIndividual subcarrier Subset on transmit.For example, in the case where the fractional frequency reuse factor is 3, each cellular cell can be in N altogetherFFTIndividual pair Transmit on about 1/3rd of carrier wave.For fractional frequency reuse, pilot frequency code element can be in N altogetherFFTIn the subset of individual subcarrier Send, matrix B can be the submatrix of generalized circular matrix, and want bqThis essential condition different is perhaps insufficient. However, this S pilot subcarrier k0Arrive kS-1Might be chosen such that the essential condition is abundant for realizing that all channel is estimated 's.
For some embodiments, this S pilot subcarrier can be separated by p subcarrier, and wherein p is can not be by NFFTEliminate Prime number.These pilot subcarriers can be chosen as follows：
ki=i p, i=0 ..., S-1, (6)
Wherein kiIt is the index of i-th pilot subcarrier,AndSign seeks base limit (floor) fortune Son.
Fig. 6 illustrates the example pilot subcarricr structure for an OFDM symbol corresponding to the design shown in formula (6). In this example, p=3 and each pilot subcarrier is separated by three subcarriers.Pilot frequency code element can be sent out on subcarrier 0,3,6 etc. Send.Identical pilot subcarrier collection can be used to each among this M transmitting antenna, as shown in Figure 6.There are these The OFDM symbol of pilot subcarrier can be used for the preamble shown in Fig. 2 or other certain OFDM symbols.
For the design shown in formula (6), matrix B is arranged by q=0 ..., Q-1 with front Q in the middle of S × S generalized circular matrix ElementConstitute and Q arranges the element of S row with being all different than theseAny unit of each among element As element is constituted.Thus complete channel is estimated to become possibility under the following conditions：
1.p·(dl+tm)mod NFFTTo all values of l and m should be different, and
2. line number S in matrix B should be equal to or more than the columns Q in matrix B, or i.e. S >=Q.
If p is not divisible NFFTPrime number and NFFT/ p >=Q, so that it may meet two above condition, no matter Cyclic Prefix How length L is all such.However, NCPMaximum (NCP,max) subcarrier sum (N may be subject toFFT), transmitting antenna number (M) and pilot subcarrier interval (p) restriction as follows：
For example, for M=2, NFFT=1024 and p=3 situation, NCP,max=170.For the example can select to circulate Prefix length is 128.As another example, for M=2, NFFT=1024 and p=3 situation, NCP,max=85.For this shows It is 64 that example can select circulating prefix-length.As another example, for M=2, NFFT=1024 and p=5 situation, NCP,max =102.It is 64 for the example can select circulating prefix-length.
Pilot subcarrier interval can be based on the circulation delay length and subcarrier sum that applies on M transmitting antenna NFFTAs follows to select：
Fig. 7 illustrates the block diagram of the design of manipulator 332a to 332m at base station 104 in Fig. 3.For simplicity, Fig. 7 is only It is shown as the process that this M transmitting antenna generates pilot tone.In the manipulator 332a for transmitting antenna 0, code element-subcarrier reflects Emitter 710a is reflected by map pilot symbols to pilot subcarrier (for example, as shown in formula (6) determine) and by zero symbol It is incident upon remaining subcarrier.IDFT units 712a is to this NFFTIndividual pilot tone and zero symbol execute NFFTPoint IDFT simultaneously provides NFFTIndividual time domain Sample.P/S transducers 714a is by this NFFTIndividual sample serialization.For some embodiments, circulation delay unit 716a is by this NFFT Individual sample is 0 cyclic shift N of transmitting antennaC,0Individual sample.Cyclic Prefix maker 718a pended cyclic prefix and provide including to The OFDM symbol of the first pilot tone of transmitting antenna 0.
Manipulator 332b can similarly generate the OFDM symbol including the second pilot tone to transmitting antenna 1.However, circulation Delay cell 716b is by this NFFTIndividual sample is 1 cyclic shift N of transmitting antennaC,0+NC,1≥NCPIndividual sample.Each remaining modulation Device 332 can similarly generate the OFDM symbol including the pilot tone to its transmitting antenna, but can be by this NFFTIndividual sample is to send out Penetrate antenna m cyclic shiftsIndividual sample, wherein m=0,1 ..., M-1.
Fig. 8 is shown for the design for MISO or the process 800 of mimo system generation pilot tone.Process 800 can be by base 104 execution stand for the pilot transmission on downlink, is executed by subscriber station 106 and is passed for the pilot tone in up-link Defeated, or certain entity is executed by other.
810, the circulation delay that can be postponed such as zero sample based on first circulation is launched to first to generate First pilot tone of antenna.820, length at least circulating prefix-length N bigger than (m-1) circulation delay length can be based onCP's M circulation delays are generating to m-th pilot frequency sequence of m-th transmitting antenna, wherein m ＞ 1.For some embodiments, it is used for The circulation delay of each transmitting antenna such as by being given formula (1) Suo Shi, wherein NC,0=0 and for There is NC,m=m NCPCan be generated based on suitable circulation delay to more pilot tones of more transmitting antennas.
810, the first sample sequence including the first pilot tone can be generated and be recycled delay first circulation delay.Bag Include the first pilot tone and with first circulation postpone the first OFDM symbol can based on the first sample sequence through circulation delay come Generate.820, the m sample sequences including m pilot tones can be generated and postpone m circulation delays with being recycled, wherein m ＞ 1.M OFDM symbols including m pilot tones and with m circulation delays can be based on the m sample sequences through circulation delay To generate, wherein m ＞ 1.For the first OFDM symbol, pilot frequency code element can be mapped to the subcarrier for being separated by p, and wherein p can be with It is not divisible NFFTPrime number.For m OFDM symbols, pilot frequency code element can be mapped to the subcarrier for being separated by p, wherein m ＞ 1.Identical pilot subcarrier collection can be utilized in all of OFDM symbol.Pilot subcarrier number (S) can be equal to or big In M NCP.Pilot subcarrier interval (p) can be selected as shown in formula (8).
Subscriber station 106 can be derived to this M R SISO letter in the mimo channel between base station 104 and subscriber station 106 The channel estimation of each among road.For each reception antenna, subscriber station 106 can obtain the S from S pilot subcarrier Individual receive pilot frequency code element, and pilot modulated can be removed observed with obtaining S to this S pilot subcarrier.Each reception The S observation of antenna j can be expressed as：
yj=B hj+ n, (9)
Wherein yjIt is S × 1 observation vector to this S pilot subcarrier on reception antenna j, B is defined in formula (4) S × Q matrixes, hjIt is Q × 1 channel gains vector with regard to this M transmitting antenna, and n is S × 1 noise vector.
Vectorial hjIncludingIndividual element hj,0Arrive hj,Q-1.Front NC,0≥NCPIndividual element hj,0ArriveBe with regard to The channel gain of transmitting antenna 0, following NC,1≥NCPIndividual elementArriveIt is the channel with regard to transmitting antenna 1 Gain, the rest may be inferred, and last NC,M-1≥NCPIndividual elementArrive hj,Q-1It is the channel increasing with regard to transmitting antenna M-1 Benefit.hjEstimation can be based on various technology from yjObtain.In a design, hjEstimation can be based on such as lowest mean square Error (MMSE) technology etc is from yjObtain, as follows：
WhereinAndIt is hjEstimation.
Can same treatment be executed to each reception antenna to obtain between this M transmitting antenna and the reception antenna M channel estimation of M SISO channel.
Fig. 9 illustrates the block diagram of the design of channel estimator 900.In channel estimator 900, R unit 910a to 910r Obtain the S corresponding to this S pilot subcarrier respectively from R reception antenna 0 to R-1 and receive pilot frequency code element.Each unit 910 Remove and receive the pilot modulated on pilot frequency code element and S observation is provided from this S of its reception antenna.Pilot modulated is removed can To be multiplied by the complex conjugate of transmitted pilot frequency code element to reach by each is received pilot frequency code element.R channel estimator 912a S observation from unit 910a to 910r is received respectively to 912r.Shown in each channel estimator 912 such as formula (10) Etc derived to the h with regard to its reception antenna j like thatjEstimation, and provideR demultiplexer (Demux) 914a to 914r Receive from channel estimator 912a to 912r respectively914 points of use of each demultiplexerIn channel gain and provide for this M M channel estimation of individual transmitting antenna.
Figure 10 is shown for the design for MISO or the process 1000 of mimo system execution channel estimation.Process 1000 can To be executed for Downlink channel estimation by subscriber station 106, executed for uplink channel estimation by base station 104, or By other, certain entity is executed.Can be launched from M transmitting antenna through the pilot frequency sequence of circulation delay at 1010, M, wherein M pilot frequency sequences are than (m-1) circulation delay length at least systemic circulation prefix length N based on lengthCPM circulation delay (m =1 ..., M) carry out circulation delay.
1020, can process for all R reception antennas and receive sample to obtain for the M transmitting antenna being utilized Estimation channel gain.In general, receive sample and can obtain from any number of reception antenna and be processed to as each Reception antenna is obtained for the channel estimation of any number transmitting antenna.1020, can process that to receive sample right to obtain The observation of pilot subcarrier, for example, obtained corresponding to these pilot subcarriers to receiving sample execution OFDM demodulation by (1) Receive pilot frequency code element and (ii) receive pilot frequency code element from these and remove pilot modulated to obtain to these pilot subcarriers Observe making this process.Can process these observation (for example, based on the MMSE technology as shown in formula (10)) come obtain for The channel estimation of all transmitting antennas being utilized.
The various operations of method described above can by with accompanying drawing diagrammatic device add corresponding each of functional block Plant hardware and/or component software and/or module to execute.For example, in Fig. 8, the diagrammatic frame 810-820 of institute corresponds to institute in Fig. 8 A The device for showing adds functional block 810A-820A.Similarly, in Figure 10 the diagrammatic frame 1010-1020 of institute corresponding to being illustrated in Figure 10 A Device add functional block 1010A-1020A.More generally, in figure, there are diagrammatic method corresponding contrast means to add function The occasion of accompanying drawing, operation box add functional block corresponding to the device with similar numbering.
General processor, numeral letter can be used in conjunction with the various illustrative logical blocks of disclosure description, module and circuit Number processor (DSP), special IC (ASIC), field programmable gate array (FPGA) or other PLDs (PLD), discrete door or transistor logic, discrete nextport hardware component NextPort or its be designed to carry out appointing for function described herein What combines to realize or execute.General processor can be microprocessor, but in alternative, processor can be any city Processor, controller, microcontroller or the state machine that sells.Processor is also implemented as the combination of computing device, for example The combining of DSP and microprocessor, one or more microprocessors that multi-microprocessor is cooperated with DSP core or any its His such configuration.
The step of method described in conjunction with the disclosure or algorithm, can be embodied directly in hardware, in by the software of computing device Implement in module or in combination of the two.Software module may reside within any type of storage known in the art and be situated between In matter.Some examples for the storage medium that can be used include random access memory (RAM), read only memory (ROM), dodge Deposit, eprom memory, eeprom memory, depositor, hard disk, removable disk, CD-ROM etc..Software module can include single Bar instruction, perhaps a plurality of instruction, and can be distributed on some different code segments, be distributed among different programs and It is distributed across multiple storage mediums.Storage medium may be coupled to processor so that the processor can be read from/to the storage medium And write information.In alternative, storage medium can be integrated into processor.
Method disclosed herein is included for reaching one or more steps or the action of described method.This A little method and steps and/or action can be with the scopes without departing from claim interchangeable with one another.In other words, unless specified step Or the concrete order of action, otherwise the order and/or use of concrete steps and/or action can change without departing from right will The scope that asks.
Described function can be realized in hardware, software, firmware or its any combinations.If realized in software, Then each function can be as one or more bars instruction storage on a computer-readable medium.Storage medium can be calculated Any usable medium that machine is accessed.Non-limiting as an example, such computer-readable medium can include RAM, ROM, EEPROM, CD-ROM or other optical disc storages, disk storage or other magnetic storage apparatus or can be used to carry or store refer to Order or the conjunction of data structure form need program code and any other medium that can be accessed by a computer.As used herein Dish and disk include compact disk (CD), laser disk, CD, digital versatile disc (DVD), soft dish andDisk, wherein dish are usually With the mode reproduce data of magnetic, and disk laser reproduce data optically.
Software or instruction can also be transmitted over a transmission medium.For example, if software is using coaxial cable, optical fiber electricity Cable, twisted-pair feeder, digital subscriber line (DSL) or such as infrared, radio and microwave etc wireless technology from web site, Server or other remote sources are transmitted, then the coaxial cable, fiber optic cables, twisted-pair feeder, DSL or such as infrared, wireless The wireless technology of electricity and microwave etc is just included among the definition of transmission medium.
In addition, it is to be appreciated that the module and/or other appropriate devices for executing methods and techniques described herein can To be downloaded by user and/or base station under usable condition and/or otherwise be obtained.For example, equipment so can be by coupling It is bonded to server to help to transfer for executing the device of approach described herein.Alternatively, described herein various Method can be come via storage device (for example, physical storage medium of RAM, ROM, compact disk (CD) or soft dish etc etc.) There is provided, so that once being coupled to or being supplied to user terminal and/or base station by the storage device, the equipment can just obtain various Method.Furthermore, it is possible to utilize for any other the suitable technology to equipment offer methods and techniques described herein.
It should be understood that claim is not limited to accurate configuration illustrated above and component.Can be above In the layout, operation and details of described method and device, various modification can be adapted, change and deformation will without departing from right The scope that asks.

Claims (15)

1. the method that one kind transmits pilot tone in wireless communication system (100), including：
Postpone to generate first pilot tone of (810) to the first transmitting antenna (334a-334m) based on first circulation；And
Postpone to generate (820) to second based on the second circulation for postponing big at least circulating prefix-length than the first circulation Penetrate the second pilot tone of antenna (334a-334m)；
Wherein described (810) first pilot tone of generation includes generating to be included first pilot tone and postpones with the first circulation The first OFDM symbol, and wherein described (820) second pilot tone of generation include generate include second pilot tone and have The second OFDM symbol that the second circulation postpones；
Wherein the first OFDM symbol of the generation includes that by map pilot symbols to the subcarrier for being separated by p wherein p is based on every The number of subcarriers of OFDM symbol and based on the circulation delay length that applies on M transmitting antenna selecting；And
Wherein the second OFDM symbol of the generation is included map pilot symbols to the subcarrier for being separated by p.
2. the method for claim 1, it is characterised in that further include：
(820) are generated to the based on the 3rd circulation delay of big at least described circulating prefix-length is postponed than the second circulation 3rd pilot tone of three transmitting antennas (334a-334m)；And/or preferably
Wherein to the circulation delay of each transmitting antenna (334a-334m) it is
Wherein m=0,1 ..., M-1,
Wherein NC,0>=0, NC,i≥NCP,NCPIt is the circulating prefix-length, and NC,iIt is i-th sample, m is transmitting Antenna index, and tm is the circulation delay for transmitting antenna (334a-334m) m, m=0,1 ..., M-1.
3. the method for claim 1, it is characterised in that it is zero that the first circulation postpones, and the second circulation Postpone to be equal to or more than the circulating prefix-length；And/or preferably
Wherein described first and second circulation delay is not sent by signaling；And/or preferably
Wherein described (810) first pilot tone of generation includes：
Generating includes the first sample sequence of first pilot tone；And
The first sample sequence loops are postponed the first circulation to postpone；And wherein described (820) second pilot tone of generation Including generating the second sample sequence for including second pilot tone and following described in the second sample sequence circulation delay second Ring postpones.
4. the method for claim 1, it is characterised in that
S ≥ Σ i = 0 M - 1 N C , i ,
Wherein S is the number of the subcarrier with pilot frequency code element, and M is the number of transmitting antenna (334a-334m), and It is the length of the circulation delay for transmitting antenna (334a-334m) m, wherein m=0 ..., M-1；And/or preferably
Wherein：
p ≤ N F F T Σ i = 0 M - 1 N C , i ,
Wherein M is the number of transmitting antenna (334a-334m), andIt is following for transmitting antenna (334a-334m) m The length that ring postpones, wherein m=0 ..., M-1.
5. the method that one kind executes channel estimation in wireless communication system (100), including：
Obtaining includes the first input sample of the first and second pilot tones, and these first input samples wherein described are connect from first Receive antenna (352a-352r)；And
Process these first input samples described in (1020) to obtain first for the first transmitting antenna (334a-334m) Channel estimation and the second channel for the second transmitting antenna (334a-334m) are estimated；
These first input samples described in wherein described process (1020) include：
Process these first input samples described in (1020) to obtain the observation to pilot subcarrier；And
Process (1020) these observations described to obtain first and second channel estimation；And
Wherein described pilot subcarrier is separated by p, and wherein p is the number of subcarriers based on every OFDM symbol and is based at M The circulation delay length that applies on antenna is penetrated selecting, and
Wherein pilot frequency code element is mapped to the pilot subcarrier for being separated by p.
6. method as claimed in claim 5, it is characterised in that further include：
Obtaining includes the second input sample of first and second pilot tone, and these second input samples described are connect from second Receive antenna；And
Process these second input samples described in (1020) to obtain the 3rd for the first transmitting antenna (334a-334m) Channel estimation and the 4th channel estimation for the second transmitting antenna (334a-334m).
7. method as claimed in claim 5, it is characterised in that these first input samples described in process (1020) are obtaining Must observe including：
OFDM demodulation is executed to these first input samples described to lead corresponding to receiving for these pilot subcarriers to obtain Frequency code unit；And
Pilot frequency code element is received from described these, and to remove (910a-910r) pilot modulated described to these pilot subcarriers to obtain Observation；And/or preferably
Wherein described process (1020) these observations are included based on these observations described in least mean-square error (MMSE) technical finesse To obtain first and second channel estimation.
8. method as claimed in claim 6, it is characterised in that these the second input sample bags described in process (1020) Include：
Process these second input samples described in (1020) to obtain the observation to pilot subcarrier；And
Process (1020) these observations described to obtain third and fourth channel estimation；And/or preferably
These second input samples described in wherein described process (1020) are included with obtaining observation：
OFDM demodulation is executed to these second input samples described to lead corresponding to receiving for these pilot subcarriers to obtain Frequency code unit；And
Pilot frequency code element is received from described these, and to remove (910a-910r) pilot modulated described to these pilot subcarriers to obtain Observation；And/or preferably
Wherein described process (1020) these observations are included based on these observations described in least mean-square error (MMSE) technical finesse To obtain third and fourth channel estimation.
9. one kind is used for the equipment (104) of transmission pilot tone in wireless communication system (100), including：
For postponing to generate to the device (810A) of the first pilot tone of the first transmitting antenna (334a-334m) based on first circulation； And
For postponing to generate to second based on the second circulation for postponing big at least circulating prefix-length than the first circulation Penetrate the device (820A) of the second pilot tone of antenna (334a-334m)；
The wherein described device for generating the first pilot tone includes including first pilot tone and with described for generating The device of the first OFDM symbol of one circulation delay, and the wherein described device for generating the second pilot tone includes for generating The logic of the second OFDM symbol postponed including second pilot tone and with the second circulation；
The wherein described device for generating first OFDM symbol is included for carrying map pilot symbols to the secondary of p is separated by The device of ripple, wherein p are the number of subcarriers based on every OFDM symbol and are prolonged based on the circulation that applies on M transmitting antenna Late length is selecting；And
Wherein described for generate the second OFDM symbol device include for by map pilot symbols to the subcarrier for being separated by p Device.
10. as claimed in claim 9 to equipment (104), it is characterised in that to further include：
For being generated to the based on the 3rd circulation delay of big at least described circulating prefix-length is postponed than the second circulation The device of the 3rd pilot tone of three transmitting antennas (334a-334m)；And/or preferably
Wherein to the circulation delay of each transmitting antenna (334a-334m) it is
Wherein m=0,1 ..., M-1,
Wherein NC,0>=0, NC,i≥NCP,NCPIt is the circulating prefix-length, and NC,iIt is ith sample, m is transmitting Antenna (334a-334m) is indexed, and tm is the circulation delay for transmitting antenna (334a-334m) m, m=0, and 1 ..., M- 1；And/or preferably
Wherein described first circulation postpones to be zero, and the second circulation postpones to be equal to or more than the circulating prefix-length； And/or preferably
Wherein described first and second circulation delay is not sent by signaling；And/or preferably
The wherein described logic for generating the first pilot tone includes：
For generating the device of the first sample sequence for including first pilot tone；And
For the first sample sequence loops are postponed the device that the first circulation postpones；And
The wherein described device for generating the second pilot tone includes the second sample sequence for including second pilot tone for generation Device and for by described in the second sample sequence circulation delay second circulation postpone device.
11. equipment (104) as claimed in claim 9, it is characterised in that for both first and second OFDM symbols Speech, pilot frequency code element is to be mapped to identical sets of subcarriers.
12. equipment (104) as claimed in claim 9, it is characterised in that：
S ≥ Σ i = 0 M - 1 N C , i ,
Wherein S is the number of the subcarrier with pilot frequency code element, and M is the number of transmitting antenna (334a-334m), and It is the length of the circulation delay for transmitting antenna (334a-334m) m, wherein m=0 ..., M-1；And/or preferably
Wherein：
p ≤ N F F T Σ i = 0 M - 1 N C , i ,
Wherein M is the number of transmitting antenna (334a-334m), andIt is following for transmitting antenna (334a-334m) m The length that ring postpones, wherein m=0 ..., M-1.
A kind of 13. equipment (106) for executing channel estimation in wireless communication system (100), including：
For obtaining the device of the first input sample for including first and second pilot tone, these the first input samples wherein described Originally it is from the first reception antenna；And
For processing these first input samples described to obtain the first letter for the first transmitting antenna (334a-334m) The device (1020A) that road estimation and the second channel for the second transmitting antenna (334a-334m) are estimated；
The wherein described device (1020A) for processing these first input samples includes：
For processing these first input samples described to obtain the device (1020A) of the observation to pilot subcarrier；And
For processing these observations described to obtain the device (1020A) of first and second channel estimation；And
Wherein described pilot subcarrier is separated by p, and wherein p is the number of subcarriers based on every OFDM symbol and is based at M The circulation delay length that applies on antenna is penetrated selecting, and
Wherein described pilot frequency code element is mapped to the pilot subcarrier for being separated by p.
14. equipment (106) as claimed in claim 13, it is characterised in that further include：
For obtaining the device of the second input sample for including first and second pilot tone, these second input samples described are From the second reception antenna (352a-352r)；And
For processing these second input samples described to obtain the 3rd letter for the first transmitting antenna (334a-334m) Road estimation and the device (1020A) of the 4th channel estimation for the second transmitting antenna (334a-334m)；And/or preferably Ground
Wherein described included with the device (1020A) for obtaining observation for processing these first input samples described：
For executing OFDM demodulation to obtain the receipts corresponding to these pilot subcarriers to these first input samples described Device to pilot frequency code element；And
Remove pilot modulated to obtain the observation to these pilot subcarriers for receiving pilot frequency code element from described these Device；And/or preferably
The wherein described device (1020A) for processing these observations is included for based on least mean-square error (MMSE) technical office Described these of reason are observed obtaining the device of first and second channel estimation；And/or preferably
The wherein described device (1020A) for processing these second input samples includes：
For processing these second input samples described to obtain the device (1020A) of the observation to pilot subcarrier；And
For processing these observations described to obtain the device (1020A) of third and fourth channel estimation；And/or preferably
Wherein described included with the device (1020A) for obtaining observation for processing these second input samples described：
For executing OFDM demodulation to obtain the receipts corresponding to these pilot subcarriers to these second input samples described Device to pilot frequency code element；And
Remove pilot modulated to obtain the observation to these pilot subcarriers for receiving pilot frequency code element from described these Device；And/or preferably
The wherein described device (1020A) for processing these observations is included for based on least mean-square error (MMSE) technical office Described these of reason are observed obtaining the device of third and fourth channel estimation.
A kind of 15. computer programs, including being stored thereon with the computer-readable medium of instruction, the instruction can be by one Or multiple computing devices and the instruction include：
For realizing in claim 1 to 8 instruction the step of any one.
CN201611067209.5A 2008-03-14 2009-02-25 For choosing the method and system of circulation delay in multiple antennas ofdm system Pending CN106506054A (en)

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