WO2009135397A1 - Procédé, système et appareil permettant d’obtenir des informations de canal de liaison descendante - Google Patents

Procédé, système et appareil permettant d’obtenir des informations de canal de liaison descendante Download PDF

Info

Publication number
WO2009135397A1
WO2009135397A1 PCT/CN2009/071049 CN2009071049W WO2009135397A1 WO 2009135397 A1 WO2009135397 A1 WO 2009135397A1 CN 2009071049 W CN2009071049 W CN 2009071049W WO 2009135397 A1 WO2009135397 A1 WO 2009135397A1
Authority
WO
WIPO (PCT)
Prior art keywords
downlink channel
pilot signal
downlink
receiving end
receiving
Prior art date
Application number
PCT/CN2009/071049
Other languages
English (en)
Chinese (zh)
Inventor
杜颖刚
孙铭扬
Original Assignee
华为技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Publication of WO2009135397A1 publication Critical patent/WO2009135397A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202—Channel estimation
    • H04L25/0204—Channel estimation of multiple channels
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202—Channel estimation
    • H04L25/0224—Channel estimation using sounding signals
    • H04L25/0226—Channel estimation using sounding signals sounding signals per se
    • 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
    • H04L25/0224—Channel estimation using sounding signals
    • H04L25/0228—Channel estimation using sounding signals with direct estimation from sounding signals
    • 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
    • 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
    • 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
    • H04L5/0053—Allocation of signaling, i.e. of overhead other than pilot signals

Definitions

  • Embodiments of the present invention relate to the field of wireless communication technologies, and in particular, to a method, system, and apparatus for acquiring downlink channel information. Background technique
  • the transmitted signal is affected by the channel during transmission, and fading and distortion occur.
  • the receiving end In order to recover the transmitted signal, the receiving end usually needs to estimate the physical transmission channel, and eliminate the influence of the channel on the transmitted signal by the equalization method.
  • the drawback of the existing transmit-receive structure is that the effect of channel estimation and equalization is affected by noise, for example: Zero-forcing equalizer causes noise amplification at a lower signal-to-noise ratio, MMSE (Minimum Mean Square Error) The square error) equalizer can effectively suppress the influence of noise, but it is necessary to estimate the variance of the noise at the receiving end.
  • MMSE Minimum Mean Square Error
  • An effective way to solve the noise impact is to pre-process the transmitted signal at the transmitting end, that is, pre-equalize the signal for the SISO (Single Input Single Output) system, for Multiple Input Multiple Output , Multiple Input Multiple Output)
  • the system precodes the signal.
  • the transmitting end can preprocess the transmitting channel according to the characteristics of the physical transmission channel, the fading of the signal is improved, and the noise amplification of the receiving end when processing the deep fading channel is avoided, so that the complexity of signal processing at the receiving end is greatly reduced.
  • the transmitting end can perform reasonable scheduling according to the characteristics of different user channels, and reduce inter-cell interference.
  • the transmitter needs known downlink channel information for TDD (Time Division Duplex) systems because The uplink and downlink channels use the same frequency band, so the uplink and downlink channels have channel reciprocity.
  • the channel reciprocity base station can estimate the downlink channel information by measuring the uplink channel information.
  • the downlink channel information is estimated by the TDD system through the MS (Mobile Station).
  • the mobile station transmits an uplink pilot signal, for example, a sounding signal, which is a signal that is known to both the base station and the terminal mapped within the entire bandwidth.
  • the inventors have found that the following problem can be solved by estimating the downlink channel information by using the sounding signal:
  • the downlink channel information estimated by using the sounding signal is only the downlink channel information of the partial antenna pair.
  • a method for obtaining all downlink channel information in a TDD system proposed by the prior art is to transmit a sounding signal by switching a transmitting antenna, that is, using a different antenna as a transmitting antenna at intervals.
  • the base station takes longer to obtain a complete downlink channel information, and the terminal switches the antenna at an additional cost.
  • Another method for obtaining all downlink channel information in the TDD system proposed by the prior art is based on CSK Channel State Information (channel state information), and the receiving end estimates downlink channel information according to the downlink pilot signal, and calculates a pair.
  • the optimal precoding matrix of the receiving end, and then the index of the optimal precoding matrix, the rank of the channel, and the CQI (Channel Quality Indicator) information are fed back to the transmitting end, and then the transmitting end pairs the signal according to the feedback information. Precoded. Summary of the invention
  • the embodiments of the present invention provide a method, a system, and a device for acquiring downlink channel information, so that the transmitting end obtains complete downlink channel information without adding additional feedback signaling overhead.
  • An embodiment of the present invention provides a method for acquiring downlink channel information, including: receiving, by a receiving end, a downlink signal that is sent by a transmitting end and carrying a downlink pilot signal; and performing demodulation on the received downlink signal to obtain a downlink pilot signal. a downlink channel element, and performing the obtained downlink channel element according to the number of receiving antennas at the receiving end Grouping, and dividing the grouped downlink channel element into a first packet downlink channel element and a second packet downlink channel element;
  • the mixed pilot signal is transmitted to the transmitting end, so that the transmitting end acquires downlink channel information.
  • the embodiment of the present invention further provides a method for acquiring downlink channel information, including: receiving, by a transmitting end, a mixed pilot signal transmitted by a receiving end; and estimating a first group according to an uplink pilot signal in the mixed pilot signal.
  • Uplink channel information estimating first packet downlink channel information according to the first packet uplink channel information and the downlink pilot signal and the orthogonal code information in the mixed pilot signal, and estimating the second packet downlink by using channel reciprocity Channel information.
  • an embodiment of the present invention further provides a system for acquiring downlink channel information, including a receiving end, where the receiving end is communicably connected to a transmitting end,
  • the receiving end is configured to receive a downlink signal that is sent by the transmitting end and carries a downlink pilot signal, and demodulate the received downlink signal to obtain a downlink channel element at the downlink signal that carries the downlink pilot signal, and And grouping the acquired downlink channel elements according to the number of receiving antennas of the receiving end, and dividing the grouped downlink channel elements into a first packet downlink channel element and a second packet downlink channel element, where the first Each of the downlink channel elements in the packet downlink channel element is multiplied by an orthogonal code and then superimposed on the uplink pilot signal to obtain a mixed pilot signal, and the mixed pilot signal is transmitted through the uplink pilot channel of the receiving end. And transmitting to the transmitting end, where the transmitting end acquires downlink channel information according to the mixed pilot signal.
  • the embodiment of the present invention further provides a receiving end, including:
  • a receiving module configured to receive a downlink signal that is sent by the transmitting end and carries a downlink pilot signal
  • a demodulation module configured to demodulate a downlink signal received by the receiving module, to obtain a downlink channel element at the downlink pilot signal
  • a grouping module configured to acquire the demodulation module according to the number of receiving antennas at the receiving end Downlink channel elements are grouped, and the grouped downlink channel elements are divided into a first packet downlink channel element and a second packet downlink channel element;
  • a superimposing module configured to multiply each of the downlink channel elements of the first packet downlink channel element divided by the grouping module by an orthogonal code and superimpose the uplink pilot signal to obtain a mixed pilot signal
  • a transmitting module configured to send, by using the uplink pilot channel of the receiving end, the mixed pilot signal acquired by the superimposing module to the transmitting end, so that the transmitting end acquires downlink channel information.
  • an embodiment of the present invention further provides a transmitting end, including:
  • a signal receiving module configured to receive a mixed pilot signal transmitted by the receiving end, and an uplink channel information estimating module, configured to estimate, according to the mixed pilot signal received by the signal receiving module, the first packet uplink channel information;
  • a downlink channel information estimation module configured to estimate first channel downlink channel information according to the first packet uplink channel information estimated by the uplink channel information estimation module, and the downlink pilot signal and the orthogonal code information in the mixed pilot signal And using the channel reciprocity to estimate the second packet downlink channel information.
  • FIG. 1 is a flowchart of a method for acquiring downlink channel information according to an embodiment of the present invention
  • FIG. 2 is a flowchart of Embodiment 1 of a method for acquiring downlink channel information according to the present invention
  • FIG. 4 is a flowchart of Embodiment 3 of a method for acquiring downlink channel information according to the present invention
  • FIG. 5 is a flowchart of Embodiment 4 of a method for acquiring downlink channel information according to the present invention
  • FIG. 7 is a structural diagram of a system for acquiring downlink channel information according to an embodiment of the present invention
  • FIG. 8 is a structural diagram of a receiving end 71 according to an embodiment of the present invention
  • FIG. 9 is a structural diagram of a transmitting end 72 according to an embodiment of the present invention. detailed description
  • the embodiment of the present invention provides a method for acquiring downlink channel information, which can ensure complete channel estimation performance, and can obtain complete downlink channel information for the transmitter without increasing the overhead of additional uplink feedback signaling. It is advantageous to pre-equalize or pre-code the signal at the transmitting end.
  • the number of transmitting antennas at the transmitting end is M
  • the number of receiving antennas at the transmitting end is N
  • the number of transmitting antennas at the receiving end is m
  • the number of receiving antennas at the receiving end is n.
  • the number of subcarriers occupied by the downlink pilot signal and the uplink pilot signal of each antenna may be equal or different.
  • the downlink pilot signal of each antenna and the subcarrier occupied by the uplink pilot signal are used. The number is equal to the description, and in the embodiment of the present invention, the number of subcarriers occupied by the downlink pilot signal and the uplink pilot signal of each antenna is assumed to be.
  • a flowchart of a method for acquiring downlink channel information includes the following steps:
  • Step S101 The receiving end receives the downlink signal that is transmitted by the transmitting end and carries the downlink pilot signal, and demodulates and groups the received downlink signal. After receiving the downlink signal sent by the transmitting end and including the downlink pilot signal, the receiving end passes the received downlink signal.
  • OFDM Orthogonal Frequency Division Multiplexing
  • Step S102 Multiply each group of downlink channel elements of the nm group downlink channel elements corresponding to the non-transmitting antenna by an orthogonal code and superimpose the uplink pilot signal to obtain a mixed pilot signal, and transmit the root signal through the receiving end.
  • the uplink pilot channel of different antennas in the antenna transmits the mixed pilot signal to the transmitting end, so that the transmitting end acquires downlink channel information.
  • the downlink channel element at the received downlink pilot signal may be compression-encoded and then superimposed and transmitted on the uplink pilot signal.
  • multiple resources may be used to carry the downlink channel elements at the downlink pilot signals, and specifically, there may be two ways: Complex frequency diversity; the other is to encode the downlink channel elements and then transmit them on multiple resources.
  • the downlink pilot signal may occupy only a part of the bandwidth, and the transmitting end hops to transmit the downlink pilot signal in all the bandwidths for a period of time; the uplink pilot signal may also occupy only a part of the bandwidth or the entire bandwidth, and the receiving end The uplink pilot signal is hopped and transmitted in the entire bandwidth at intervals.
  • the concept of antenna switching can also be used to further improve the performance of obtaining downlink channel information in the embodiment of the present invention, that is, the receiving end selects different m antennas as the transmitting antennas in n antennas at intervals, and transmits the mixed pilot signals. To achieve diversity gain.
  • Step S103 The transmitting end estimates the uplink channel information according to the mixed pilot signal transmitted by the receiving end. After receiving the mixed pilot signal transmitted through the uplink pilot channel, the transmitting end may estimate the uplink channel information by using the received mixed pilot signal.
  • Step S104 The transmitting end estimates downlink channel information according to the estimated uplink channel information, and the downlink pilot signal and the orthogonal code information in the mixed pilot signal.
  • the transmitting end can estimate the downlink channel information of the n-m group by using the estimated uplink channel information, and the downlink pilot signal and the orthogonal code information in the mixed pilot signal, and can estimate the downlink of the m group by using the channel reciprocity. Channel information, thereby obtaining a complete n sets of LxMxn downlink channel information.
  • the transmitting end can obtain complete downlink channel information, so that more flexible pre-equalization processing or pre-coding processing can be performed.
  • the uplink does not need to open up valuable time-frequency resources, which saves signaling overhead and avoids the possibility of feedback signaling error.
  • the precoding matrix can be flexibly designed to avoid the accuracy degradation caused by the limited number of codes.
  • the receiving end does not need to perform precoding matrix judgment, which greatly reduces the processing complexity of the receiving end.
  • the transmitter knows the downlink channel parameters and also facilitates flexible time-frequency resource allocation for different services based on the channel information. Moreover, the destruction of pilot orthogonality caused by frequency selective fading is avoided, and the destruction of pilot orthogonality caused by different scrambling codes of uplink and downlink is avoided.
  • the transmitting end is the base station
  • the receiving end is the end.
  • the end is taken as an example for explanation.
  • FIG. 2 it is a flowchart of Embodiment 1 of the method for acquiring downlink channel information according to the present invention.
  • the uplink pilot signals of the two terminals are CDMA (Code Division Multiple Access).
  • code division multiple access) mode is multiplexed together, specifically including the following steps:
  • Step S201 The base station sends a downlink signal including a downlink pilot signal.
  • the downlink pilot signal is inserted in the frequency domain, and then OFDM modulated and then CP (Cycle Prefix) is transmitted.
  • Step S202 The terminal receives the downlink signal sent by the base station, and demodulates and groups the received downlink signal.
  • the downlink signals received by terminal i and terminal j are:
  • the number of transmitting antennas of the base station is M
  • the number of receiving antennas is N
  • the number of transmitting antennas of the terminal is m
  • the number of receiving antennas is n
  • the downlink channel matrix from the base station to the i-th terminal is an N*M matrix, where M is the number of base station transmit antennas
  • P dl (k is a ⁇ line signal, which is an M*l matrix, which is the downlink noise received by the ith terminal) is an N*l matrix, k, is a subcarrier number.
  • the downlink signal received by the jth terminal is an N*l matrix, where N is the number of base station receiving antennas;
  • the downlink channel matrix of the base station to the jth terminal is an N*M matrix, where M is the number of base station transmit antennas; and the downlink noise received by the jth terminal is an N*l matrix.
  • the values of the transmitting antenna and the receiving antenna do not affect the protection scope of the embodiment of the present invention.
  • the downlink pilot signals received by the first and second receiving antennas of the terminal i, , 2 ') are the downlink signals received by the base station to the first and second receiving antennas of the terminal i, respectively, being a 1x4 matrix
  • W dl (k') are the first and second bases of the base station to the terminal i, respectively
  • the downlink noise of the antenna is a 1x1 matrix.
  • Step S203 The terminal extracts a downlink pilot signal in the downlink signal, and superimposes the downlink pilot signal on the uplink pilot signal, acquires a mixed pilot signal, and transmits the mixed pilot signal.
  • the terminal passes the received downlink signal to the CP, and after the OFDM is demodulated, the downlink pilot signal is extracted. If the terminal uses the first antenna as the transmitting antenna, the terminal only needs to receive the downlink signal received by the second receiving antenna. After the frequency signal y 2i ( ) is multiplied by an orthogonal code, it is superimposed with the uplink pilot signal, and the superposed mixed pilot signal is OFDM-modulated together with the uplink signal, and is sent after being added with the CP.
  • the orthogonal codes corresponding to different terminals are orthogonal to each other. Therefore, the orthogonal code can be used to distinguish downlink pilot signals of different terminals.
  • the orthogonal codes corresponding to different terminals may be orthogonal to each other: the cyclic shift of the cross code, the length of the cyclic shift is greater than the maximum delay spread of the channel; or the orthogonality of the other terminals except the terminal.
  • the code and the orthogonal code corresponding to the terminal are different spreading codes.
  • the specific orthogonal code may be a Walsh code, a CAZAC code, or the like.
  • Step S204 The base station demodulates the received mixed pilot signal, and estimates uplink channel information according to the obtained uplink pilot signal.
  • the mixed pilot signal received by the base station is:
  • YBs(k) H uU (k) Y 2l (k C ull (k) + P ull (k)) + W ull (k) + H u
  • WAk) H Community, k)-W M , Ak'YC,., Ak) + W behalf, Ak) (6) ( k ) in equation ( 4 ) is a plurality of user uplink pilot signals received by the base station
  • the signal superimposed with the downlink pilot signal is a 2*1 matrix
  • ' ⁇ ) is the uplink channel of the i-th terminal to the base station, which is a 2*1 matrix
  • P "" is the uplink pilot of the i-th terminal
  • the signal is a 1*1 matrix.
  • C "" is the ith terminal used to distinguish orthogonal codes of different users.
  • , ' for the i-th terminal to the base station's uplink channel noise.
  • the channel is a 2*1 matrix
  • P «' ( fc ) is the uplink pilot signal of the jth terminal, which is a 1*1 matrix
  • C " k " is the jth terminal used to distinguish orthogonal codes of different users.
  • W resonate ⁇ k) is the uplink channel noise of the jth terminal to the base station.
  • the design of the downlink pilot signal and the uplink pilot signal should meet the following conditions:
  • the convolution of the uplink pilot signal in the time domain is an impulse function in the range of L "', that is, the autocorrelation function of the uplink pilot signal in the time domain is: .: (?)
  • the convolution of the downlink pilot signal in the time domain is an impulse function in the range, that is, the autocorrelation function of the downlink pilot signal in the time domain is: c)
  • the convolution of the downlink pilot and the uplink pilot in the time domain is zero in the 1 + range, ie:
  • the uplink and downlink pilot signal design that satisfies the above conditions enables the base station to not interfere with each other in the process of estimating the uplink and downlink channel information.
  • the above conditions can be met by the following operations:
  • the downlink pilot signal and the uplink pilot signal are orthogonal to each other. Specifically, it can be:
  • the uplink pilot signal is a cyclic shift of the downlink pilot signal, and the length of the cyclic shift is greater than the maximum delay spread of the channel;
  • the downlink pilot signal and the uplink pilot signal are respectively spread by different orthogonal codes and then superposed to obtain a mixed pilot signal;
  • the downlink pilot signal is spread by an orthogonal code and then superimposed on the uplink pilot signal to obtain a mixed pilot signal.
  • the uplink and downlink pilot signals do not satisfy the above three conditions, as long as the spreading factor is large enough and the average of the uplink pilot signals is zero, the influence of the uplink pilot signals on the downlink channel estimation is considered to be almost can be omitted;
  • the uplink pilot signals of different receiving ends are orthogonal to each other. Specifically, it can be:
  • the uplink pilot signal of the other receiving end except the terminal is a cyclic shift of the pilot signal on the receiving end, and the length of the cyclic shift is greater than the maximum delay spread of the channel.
  • the uplink pilot signals of different receiving ends are spread by different orthogonal codes respectively.
  • the estimation of the uplink channel information may specifically be:
  • the conjugate of the uplink pilot signal in the frequency domain is:
  • Z ul Ak Y BS (k)-P* ul (k)
  • the estimation of the uplink channel is not affected by the pilot aliasing.
  • the base station to the first terminal can be estimated according to the prior art.
  • Receive downlink channel information of the antenna Receive downlink channel information of the antenna.
  • Step S205 estimating downlink channel information according to the estimated uplink channel information and the downlink pilot signal and the orthogonal code information in the mixed pilot signal. Specifically, the conjugate of the downlink pilot signal in the frequency domain is obtained, and the downlink channel information of the second receiving antenna from the base station to the terminal is obtained.
  • ⁇ is a 2 4 matrix. Since the uplink and downlink pilot signals of the respective terminals satisfy the above conditions, the estimation of the downlink channel is not affected by the pilot aliasing, so the equation (12) can be compressed into:
  • the estimated downlink channel information of the i-th terminal is:
  • equation (14) other processing methods such as MMSE equalization can also be used for derivation.
  • the noise when estimating the uplink pilot signal and the downlink channel information, the noise not only has uplink channel noise but also downlink channel noise, so the MMSE channel can be used when the terminal receives the downlink pilot signal.
  • the estimation method first estimates the downlink channel information at the downlink pilot signal, suppresses the downlink channel noise, and then estimates The downlink channel information at the downlink pilot signal is superimposed on the uplink pilot signal to improve the estimation performance of the uplink pilot signal and the downlink channel information.
  • the downlink channel information at the downlink pilot signal estimated by the MMSE channel estimation method is:
  • the base station can obtain complete downlink channel information, so that more flexible pre-equalization processing or pre-coding processing can be performed.
  • the uplink does not need to open up valuable time-frequency resources, which saves signaling overhead and avoids the possibility of feedback signaling error.
  • the precoding matrix can be flexibly designed to avoid the accuracy degradation caused by the limited number of codebooks.
  • the receiving end does not need to perform precoding matrix judgment, which greatly reduces the processing complexity of the receiving end.
  • Embodiment 2 reduces the damage of pilot orthogonality due to frequency selective fading, and specifically includes the following steps:
  • Step S301 the base station generates a downlink pilot signal, and performs FFT (Fast Fourier).
  • Step S302 the terminal performs OFDM demodulation on the received downlink pilot signal, and obtains LxMxn downlink channel elements.
  • the terminal performs OFDM demodulation on the received downlink pilot signal, acquires LxMxn downlink channel elements, and then groups the received LxMxn downlink channel elements into n groups of LxM downlink channel elements, one for each group. Downstream channel information between antenna pairs.
  • Step S303 The terminal multiplies each group of the n-m group downlink channel elements by one orthogonal to obtain a mixed pilot signal, and transmits the signal to the base station.
  • the uplink pilot signal can be used to estimate downlink channel information of the m group of downlink channel elements.
  • Step S304 the base station demodulates the received mixed pilot signal, and estimates uplink channel information according to the obtained uplink pilot signal. After receiving the mixed pilot signal, the base station performs FFT, de-subcarrier mapping, and IFFT operation on the received mixed pilot signal, which is equivalent to first using the uplink pilot signal in the mixed pilot signal in the time domain to the uplink channel information. Make an estimate.
  • Step S305 the base station estimates, by using the estimated uplink channel information, the downlink pilot signal and the orthogonal code information in the mixed pilot signal, the n-m group downlink channel information, and then uses the channel reciprocity estimation to obtain the m group.
  • the downlink channel information is obtained, thereby obtaining a complete n sets of LxMxn downlink channel information.
  • the base station performs FFT transformation on the generated downlink pilot signal, performs sub-carrier mapping, and then transmits the IFFT to the terminal, and after receiving the uplink pilot signal fed back by the terminal, the base station estimates the uplink channel information. And estimating the downlink channel information by using the estimated uplink channel information. Therefore, the base station can obtain complete downlink channel information, thereby enabling more flexible pre-equalization processing or pre-coding processing. Moreover, when the base station acquires the downlink channel information, the uplink does not need to open up valuable time-frequency resources, which saves signaling overhead and avoids the possibility of feedback signaling error. At the same time, the receiving end does not need to perform precoding matrix judgment, which greatly reduces the processing complexity of the receiving end.
  • FIG. 4 it is a flowchart of Embodiment 3 of a method for obtaining downlink channel information according to the present invention, which specifically includes the following steps:
  • Step S401 The base station generates a downlink pilot signal, performs FFT transformation, performs sub-carrier mapping, and then performs IFFT transformation, and then transmits the transformed downlink pilot signal.
  • Step S402 the terminal receives the downlink pilot signal, performs descrambling operation on the downlink pilot signal, acquires LxMxn downlink channel elements, and groups the acquired LxMxn downlink channel elements.
  • the terminal After the downlink pilot signal is received by the terminal, the terminal performs downlink downlink scrambling operation on the received downlink pilot signal, acquires LxMxn downlink channel elements, and then groups LxMxn downlink channel elements into n groups, each group of LxM downlinks. Channel elements, each group is downlink channel information between one antenna pair.
  • Step S403 the terminal multiplies each group of the n-m group downlink channel elements by one orthogonal to obtain a mixed pilot signal, and transmits the signal to the base station.
  • the uplink pilot signal can be used to estimate downlink channel information of the m group of downlink channel elements.
  • Step S404 The base station performs FFT on the received mixed pilot signal, de-subcarrier mapping, and IFFT operation, and estimates uplink channel information according to the acquired uplink pilot signal.
  • the base station performs FFT on the received mixed pilot signal, and demodulates the subcarrier mapping.
  • the IFFT operation is equivalent to estimating the uplink channel information by using the uplink pilot signal in the mixed pilot signal in the time domain.
  • Step S405 the base station estimates the downlink channel information of the n-m group by using the estimated uplink channel information, and the downlink pilot signal and the orthogonal code information in the mixed pilot signal, and then uses the channel reciprocity estimation to obtain the m group.
  • the downlink channel information is obtained, thereby obtaining a complete n sets of LxMxn downlink channel information.
  • the base station performs FFT transformation on the generated downlink pilot signal, performs sub-carrier mapping, and then transmits the IFFT to the terminal, and after receiving the uplink pilot signal fed back by the terminal, the base station estimates the uplink channel information. And estimating the downlink channel information by using the estimated uplink channel information, so that the base station can obtain complete downlink channel information, and perform more flexible pre-equalization processing or pre-coding processing.
  • the base station acquires the downlink channel information, the uplink does not need to open up valuable time-frequency resources, which saves signaling overhead and avoids the possibility of feedback signaling error.
  • the receiving end does not need to perform precoding matrix judgment, which greatly reduces the processing complexity of the receiving end.
  • the downlink channel parameters are known at the transmitting end, which also facilitates flexible time-frequency for different services according to channel information. Resource allocation.
  • the flowchart of the fourth embodiment of the method for obtaining downlink channel information according to the present invention is specifically shown in FIG. 5, which specifically includes the following steps:
  • Step S501 The base station generates a downlink pilot signal, and each downlink pilot signal is transmitted after being subjected to TFFT narrowband spreading and then subjected to IFFT transformation. It is of course also possible to repeat the operation of performing T-fold narrowband spreading on the downlink pilot signal a plurality of times.
  • Step S502 The terminal estimates downlink channel information at the downlink pilot signal according to the received downlink pilot signal, and groups the downlink channel elements obtained by despreading the downlink channel information. After the downlink pilot signal transmitted by the base station is received by the terminal, the downlink channel information at the downlink pilot signal is estimated according to the received downlink pilot signal, and then the downlink channel information is despreaded, and the despread L is obtained.
  • Step S503 The terminal re-spreads each group of the n-m group downlink channel elements and superimposes them on the uplink pilot signals of different transmit antennas in the m transmit antennas to obtain a mixed pilot signal, and transmits the mixed pilot signal to the base station.
  • the uplink pilot signal can be used to estimate downlink channel information of the m group of downlink channel elements.
  • Step S504 The base station performs a despreading operation on the received mixed pilot signal, and estimates uplink channel information by using the uplink pilot signal in the despread mixed pilot signal. After receiving the mixed pilot signal, the base station despreads the received mixed pilot signal, and the base station estimates the uplink channel information by using the uplink pilot signal obtained after despreading.
  • Step S505 the base station estimates the downlink channel information of the n-m group by using the estimated uplink channel information, the downlink pilot signal and the orthogonal code information in the mixed pilot signal, and then obtains the m group by channel reciprocity estimation.
  • the downlink channel information is obtained, thereby obtaining a complete n sets of LxMxn downlink channel information.
  • the base station performs despreading operation on the received uplink pilot signal to reduce the downlink noise variance to the original 1/sqrt (T), perform narrowband spreading operation on the downlink pilot signal, and repeat Narrowband spread spectrum operation can effectively resist Frequency selective fading.
  • the terminal can estimate the downlink channel information well even if the terminal allocates a very low power to the received downlink pilot signal.
  • Embodiment 5 reduces the impact of frequency selective fading.
  • the method for obtaining downlink channel information provided in Embodiment 5 specifically includes the following. Steps:
  • Step S601 The base station generates a downlink pilot signal, performs OFDM modulation on the downlink pilot signal, and adds the CP to transmit.
  • the downlink pilot signal is composed of S sequences, each sequence occupies a narrow band bandwidth, and the uplink pilot signal and the downlink pilot signal comprise the same number of sequences, and corresponding to orthogonal.
  • Step S602 The terminal receives the downlink pilot signal transmitted by the base station, performs OFDM demodulation on the received downlink pilot signal, acquires LxMxn downlink channel elements, divides the acquired LxMxn downlink channel elements into n groups, and further groups n groups of downlink channels.
  • the channel elements are divided into S groups.
  • the terminal receives the downlink pilot signal transmitted by the base station, performs OFDM demodulation on the received downlink pilot signal, acquires LxMxn downlink channel elements, and divides the acquired LxMxn downlink channel elements into N groups, each group of LxM downlink channel elements, each The group is the downlink channel information between one antenna pair, and then each group of LxM downlink channel elements is further divided into S groups, each group (LxM) / S downlink channel elements.
  • Step S603 the terminal divides the nxS group downlink channel element into two parts according to the number of subchannels included in the uplink pilot channel, and multiplies a part of the downlink channel elements by an orthogonal code and superimposes them on different uplink pilot subchannels to obtain a hybrid.
  • the pilot signal is transmitted to the base station.
  • the nxS group downlink channel elements can be divided into mxP group and nxS-mxP group.
  • the mxP group downlink channel element uses channel reciprocity to estimate the uplink channel information, and the remaining nxS-mxP group downlink channel elements are respectively multiplied by an orthogonal code and then superimposed on different uplink pilots of different antennas of the m transmit antennas.
  • P is an integer greater than zero and less than S, of course P can also be equal to S.
  • Step S604 after receiving the mixed pilot signal transmitted by the uplink pilot subchannel, the base station estimates the uplink channel information by using the uplink pilot signal in the received mixed pilot signal.
  • Step S605 The base station estimates the downlink channel information of the nxS-mxP group by using the estimated uplink channel information, and the downlink pilot signal and the orthogonal code information in the mixed pilot signal, and then uses the channel reciprocity to the mxP group.
  • the downlink channel information is estimated to obtain complete LxMxn downlink channel information.
  • the base station performs OFDM modulation on the generated downlink pilot signal, and adds the CP to the terminal, and the terminal receives the downlink channel element according to the number of receiving antennas of the base station and the sequence number of the downlink pilot signal.
  • the uplink does not need to open up valuable time-frequency resources, which saves signaling overhead and avoids the possibility of feedback signaling error.
  • the receiving end does not need to perform precoding matrix judgment, which greatly reduces the processing complexity of the receiving end.
  • a structural diagram of a system for acquiring downlink channel information includes a receiving end 71 and a transmitting end 72,
  • the receiving end 71 is configured to receive a downlink signal that is sent by the transmitting end 72 and that carries the downlink pilot signal, and demodulate the received downlink signal to obtain a downlink channel element at the downlink signal that carries the downlink pilot signal, and according to the receiving
  • the number of receiving antennas of the terminal 71 groups the acquired downlink channel elements, and divides the grouped downlink channel elements into a first packet downlink channel element and a second packet downlink channel element, and each of the first packet downlink channel elements
  • the downlink channel elements are respectively multiplied by an orthogonal code and then superimposed on the uplink pilot signal to obtain a mixed pilot signal and transmit the mixed pilot signal to the transmitting end 72 through the uplink pilot channel of the receiving end 71 for the transmitting end 72.
  • the downlink channel information is obtained according to the mixed pilot signal.
  • the receiving end 71 groups the obtained downlink channel elements according to the number of receiving antennas of the receiving end 71, and divides the grouped downlink channel elements into the first packet downlink channel element and the second packet downlink channel element, which may be:
  • the number of groups in which the received downlink channel element is divided by the receiving end 71 is the number of receiving antennas of the receiving end 71
  • the number of groups included in the first packet is the number of receiving antennas of the receiving end 71 and receiving.
  • the difference in the number of transmitting antennas of the terminal 71, and the number of groups included in the second packet is the number of transmitting antennas at the receiving end 71.
  • the receiving end 71 groups the acquired downlink channel elements according to the number of receiving antennas of the receiving end 71, and further divides the grouped downlink channel elements into the first packet downlink channel element and the second packet downlink channel element.
  • the receiving end 71 divides the obtained number of downlink channel elements into the number of receiving antennas of the receiving end 71, and further groups each group of downlink channel elements after the grouping according to the number of sequences included in the downlink pilot signal, and each grouped after the grouping
  • the number of groups further divided by the group downlink channel element is the number of sequences included in the downlink pilot signal;
  • the number of groups included in the first packet is the difference between the total number of downlink channel element divisions minus the product of the number of transmit antennas at the receiving end 71 and the number of subchannels included in the uplink pilot channel of the receiving end 71.
  • the number of groups included in the packet is the product of the number of transmitting antennas of the receiving end 71 and the number of subchannels included in the uplink pilot channel of the receiving end 71.
  • the total number of groups of downlink channel elements is the number of receiving antennas and downlink pilots of the receiving end 71. The product of the number of sequences contained in the signal.
  • the receiving end 71 transmits the mixed pilot signal to the transmitting end 72 through the different subchannels included in the uplink pilot channel of the receiving end 71.
  • the transmitting end 72 is configured to receive the mixed pilot signal transmitted by the receiving end 71, and obtain downlink channel information according to the received mixed pilot signal. Specifically, the transmitting end 72 estimates the first packet uplink channel information according to the received mixed pilot signal, and estimates the first according to the first packet uplink channel information and the downlink pilot signal and the orthogonal code information in the mixed pilot signal. The downlink channel information is grouped, and the second packet downlink channel information is estimated by using channel reciprocity.
  • the receiving end 71 multiplies the downlink channel element by the orthogonal code and superimposes it on the uplink pilot signal, acquires the mixed pilot signal, and transmits the mixed pilot signal to the transmitting end 72, the transmitting end.
  • 72 according to the received mixed pilot signal, a part of the downlink channel information can be estimated, and another part of the downlink channel information can be estimated according to the channel reciprocity, so that the transmitting end 72 can obtain complete downlink channel information, thereby performing more flexible pre-equalization. Processing or precoding processing.
  • the transmitting end 72 obtains the downlink letter In the case of channel information, the uplink does not need to open up valuable time-frequency resources, which saves signaling overhead and avoids the possibility of feedback signaling error.
  • the precoding matrix can be flexibly designed to avoid the accuracy degradation caused by the limited number of codebooks.
  • the receiving end 71 does not need to perform precoding matrix judgment, which greatly reduces the processing complexity of the receiving end.
  • the structure of the receiving end 71 of the embodiment of the present invention includes: a receiving module 711, configured to receive a downlink signal that is transmitted by the transmitting end 72 and carries a downlink pilot signal.
  • the demodulation module 712 is configured to demodulate the downlink signal received by the receiving module 711 to obtain a downlink channel element at the downlink pilot signal.
  • the grouping module 713 is configured to group the downlink channel elements acquired by the demodulation module 712 according to the number of receiving antennas of the receiving end 71, and divide the grouped downlink channel elements into the first packet downlink channel element and the second packet downlink channel element. .
  • the grouping module 713 groups the obtained downlink channel elements according to the number of receiving antennas of the receiving end 71, and divides the grouped downlink channel elements into the first packet downlink channel element and the second packet downlink channel element, which may be:
  • the grouping module 713 divides the number of groups of the obtained downlink channel elements into the number of receiving antennas of the receiving end 71, and the number of groups included in the first group is the difference between the number of receiving antennas of the receiving end 71 and the number of transmitting antennas of the receiving end 71.
  • the number of groups included in the second packet is the number of transmitting antennas at the receiving end 71.
  • the grouping module 713 groups the acquired downlink channel elements according to the number of receiving antennas of the receiving end 71, and further divides the grouped downlink channel elements into the first packet downlink channel element and the second packet downlink channel element.
  • the grouping module 713 divides the number of groups of the acquired downlink channel elements into the number of receiving antennas of the receiving end 71, and further groups each group of downlink channel elements after the grouping according to the number of sequences included in the downlink pilot signal, and each grouped after the grouping
  • the number of groups further divided by the group downlink channel element is the number of sequences included in the downlink pilot signal;
  • the number of groups included in the first packet is the total number of groups divided by the downlink channel elements minus the number of transmit antennas at the receiving end 71 and the number of subchannels included in the uplink pilot channel of the receiving end 71.
  • the difference between the products, the number of groups included in the second packet is the product of the number of transmitting antennas of the receiving end 71 and the number of subchannels included in the uplink pilot channel of the receiving end 71, and the total number of groups of downlink channel elements is the receiving end 71.
  • the product of the number of receiving antennas and the number of sequences included in the downlink pilot signal is the product of the number of receiving antennas and the number of sequences included in the downlink pilot signal.
  • the superimposing module 714 is configured to multiply each group of downlink channel elements in the first packet downlink channel element divided by the grouping module 713 by an orthogonal code and superimpose the uplink pilot signal to obtain a mixed pilot signal.
  • the orthogonal codes corresponding to different receiving ends are orthogonal to each other. Therefore, the orthogonal code can be used to distinguish downlink pilot signals at different receiving ends.
  • the orthogonal codes corresponding to different receiving ends may be orthogonal to each other:
  • the orthogonal code corresponding to the receiving end other than the receiving end 71 is a cyclic shift of the orthogonal code corresponding to the receiving end 71, and the length of the cyclic shift is greater than the maximum delay spread of the channel; or
  • the corresponding orthogonal codes of 71 are different spreading codes.
  • the specific orthogonal code may be a Walsh code, a CAZAC code, or the like.
  • the downlink pilot signal and the uplink pilot signal are orthogonal to each other.
  • the uplink pilot signal is a cyclic shift of the downlink pilot signal, and the length of the cyclic shift is greater than a maximum delay spread of the channel; or
  • the downlink pilot signal is spread by an orthogonal code and then superimposed on the uplink pilot signal to obtain a mixed pilot signal.
  • the spreading factor is large enough and the design makes the average value of the uplink pilot signal to be zero, then the influence of the uplink pilot signal on the downlink channel estimation is considered to be almost negligible;
  • the uplink pilot signals of different receiving ends are orthogonal to each other.
  • the uplink pilot signal of the other receiving end except the receiving end 71 is a cyclic shift of the uplink pilot signal of the receiving end 71, and the length of the cyclic shift is greater than the maximum delay spread of the channel. or,
  • the uplink pilot signals of different receiving ends are spread by different orthogonal codes respectively.
  • the transmitting module 715 is configured to transmit, by using the uplink pilot channel of the receiving end 71, the mixed pilot signal acquired by the superimposing module 714 to the transmitting end 72, so that the transmitting end 72 acquires downlink channel information.
  • the receiving end 71 mixes the pilot signals by using different subchannels included in the uplink pilot channel of the receiving end 71. It is transmitted to the transmitting end 72.
  • the receiving end 71 may further include: a compression encoding module 716, configured to: after the superimposing module 714 multiplies each group of downlink channel elements in the first packet downlink channel element by an orthogonal code and superimposes on the uplink pilot signal, respectively And compressing and encoding the first packet downlink channel element.
  • a compression encoding module 716 configured to: after the superimposing module 714 multiplies each group of downlink channel elements in the first packet downlink channel element by an orthogonal code and superimposes on the uplink pilot signal, respectively And compressing and encoding the first packet downlink channel element.
  • the receiving end 71 is configured to receive the downlink signal that is transmitted by the transmitting end 72 and carry the downlink pilot signal, and the superimposing module 714 multiplies the downlink channel element by the orthogonal code and then superimposes the uplink pilot signal to obtain the mixed pilot signal.
  • the mixed pilot signal is transmitted to the transmitting end 72, so that the transmitting end 72 obtains the downlink channel information, so that the transmitting end 72 can obtain the complete downlink channel information, and the receiving end 71 does not need to perform the precoding matrix judgment, thereby greatly reducing the receiving end.
  • the processing complexity of 71 is configured to receive the downlink signal that is transmitted by the transmitting end 72 and carry the downlink pilot signal, and the superimposing module 714 multiplies the downlink channel element by the orthogonal code and then superimposes the uplink pilot signal to obtain the mixed pilot signal.
  • the mixed pilot signal is transmitted to the transmitting end 72, so that the transmitting end 72 obtains the downlink channel information, so that the transmitting end 72 can obtain the complete downlink
  • a structural diagram of a transmitting end 72 includes: a signal receiving module 721, configured to receive a mixed pilot signal transmitted by the receiving end 71.
  • the uplink channel information estimation module 722 is configured to estimate the first packet uplink channel information according to the uplink pilot signal in the mixed pilot signal received by the signal receiving module 721.
  • the uplink channel information estimation module 722 estimates the uplink channel information, which may be:
  • the hybrid pilot signal received at the transmitting end 72 is multiplied by the conjugate of the uplink pilot signal in the frequency domain:
  • the uplink channel information of the i-th terminal estimated by the uplink channel information estimation module 722 is: H ul . (k)
  • An I 2 downlink channel information estimating module 723, configured to calculate, according to an uplink channel information module,
  • the estimated first packet uplink channel information and the downlink pilot signal and the orthogonal code information in the mixed pilot estimate the first packet downlink channel information, and estimate the second packet downlink channel information by using channel reciprocity. Specifically, the mixed pilot signal received by the transmitting end 72 is multiplied by the conjugate of the downlink pilot signal in the frequency domain to obtain the downlink information of the first packet.
  • the second packet downlink channel information can be estimated according to the prior art.
  • the uplink channel information estimation module 722 of the transmitting end 72 estimates the first packet uplink channel information according to the uplink pilot signal in the mixed pilot signal received by the signal receiving module 721, and the downlink channel information estimating module 723 estimates according to the uplink channel information estimating module 722.
  • the first packet uplink channel information estimates the first packet downlink channel information, and uses the channel reciprocity to estimate the second packet downlink channel information, so the transmitting end 72 can obtain complete downlink channel information, thereby enabling more flexible pre-equalization processing. Or precoding processing.
  • the uplink does not need to open up valuable time-frequency resources, which saves signaling overhead and avoids the possibility of feedback signaling error.
  • the precoding matrix can be flexibly designed to avoid the accuracy degradation caused by the limited number of codebooks.
  • the transmitting end 72 knows the downlink channel parameters, and also facilitates flexible time-frequency resource allocation for different services according to the channel information. Also, the destruction of pilot orthogonality due to frequency selective fading is avoided, and the above modules may be distributed in one device or distributed in multiple devices. The above modules can be combined into one module, or can be further split into multiple sub-modules.
  • the present invention can be implemented by hardware, or can be implemented by means of software plus necessary general hardware platform.
  • the technical solution of the present invention may be embodied in the form of a software product, which may be stored in a non-volatile storage medium (which may be a CD-ROM, a USB flash drive, a mobile hard disk, etc.), including several The instructions are for causing a computer device (which may be a personal computer, server, or network device, etc.) to perform the methods described in various embodiments of the present invention.

Landscapes

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

Abstract

La présente invention concerne un procédé, un système et un appareil permettant d’obtenir des informations de canal de liaison descendante. Le procédé permettant d’obtenir des informations de canal de liaison descendante comprend : la réception par une extrémité de réception d’un signal de liaison descendante portant un signal pilote de liaison descendante envoyé par une extrémité d’émission ; la démodulation du signal de liaison descendante reçu, l’obtention d’éléments de canal de liaison descendante dans le signal pilote de liaison descendante, le regroupement des éléments de canal de liaison descendante obtenus en fonction du nombre d’antennes de réception de l’extrémité de réception et la division des éléments de canal de liaison descendante regroupés en un premier ensemble d’éléments de canal de liaison descendante et un second ensemble d’éléments de canal de liaison descendante ; le chevauchement de chaque groupe d’éléments de canal de liaison descendante dans le premier ensemble d’éléments de canal de liaison descendante respectivement multipliés par un code orthogonal sur un signal pilote de liaison montante, l’obtention d’un signal pilote mixte, l’émission du signal pilote mixte vers l’extrémité d’émission sur le canal pilote de liaison montante de l’extrémité de réception pour que l’extrémité d’émission obtienne des informations de canal de liaison descendante. L’extrémité d’émission peut obtenir des informations complètes de canal de liaison descendante dans le mode réalisation de la présente invention.
PCT/CN2009/071049 2008-05-05 2009-03-27 Procédé, système et appareil permettant d’obtenir des informations de canal de liaison descendante WO2009135397A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN200810094144.2 2008-05-05
CN2008100941442A CN101577968B (zh) 2008-05-05 2008-05-05 一种获取下行信道信息的方法、系统和装置

Publications (1)

Publication Number Publication Date
WO2009135397A1 true WO2009135397A1 (fr) 2009-11-12

Family

ID=41264424

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2009/071049 WO2009135397A1 (fr) 2008-05-05 2009-03-27 Procédé, système et appareil permettant d’obtenir des informations de canal de liaison descendante

Country Status (2)

Country Link
CN (1) CN101577968B (fr)
WO (1) WO2009135397A1 (fr)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102201849B (zh) * 2011-06-17 2014-01-15 电信科学技术研究院 一种信道信息获取和反馈方法、系统及装置
CN102332945B (zh) * 2011-09-30 2017-08-25 中兴通讯股份有限公司 一种信息反馈方法及用户设备
WO2014205637A1 (fr) * 2013-06-25 2014-12-31 华为技术有限公司 Procédé, dispositif et système pour pondération de signal de transmission mimo (à entrées multiples et sorties multiples)
CN104333407B (zh) * 2013-07-22 2019-02-01 中兴通讯股份有限公司 一种信道信息的获取方法及装置
CN105591683A (zh) * 2014-10-23 2016-05-18 中兴通讯股份有限公司 数据接收方法、发送方法、接收装置及发送装置
CN107733485B (zh) * 2016-08-12 2021-09-03 中兴通讯股份有限公司 信道状态信息的反馈方法及装置
CN115706612A (zh) * 2021-08-04 2023-02-17 中兴通讯股份有限公司 信道状态信息的反馈方法、接收方法及终端、基站、介质

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020172308A1 (en) * 2001-04-25 2002-11-21 Haim Harel Smart antenna based spectrum multiplexing using existing pilot signals for orthogonal frequency division multiplexing (OFDM) modulations
CN1568026A (zh) * 2003-06-20 2005-01-19 中国科学技术大学 一种多用户自适应分组分层时空信号收发系统
US6940914B1 (en) * 2001-06-11 2005-09-06 Cingular Wireless Ii, Llc Turbo channel estimation for OFDM systems
CN1889546A (zh) * 2006-07-25 2007-01-03 华为技术有限公司 一种基于叠加导频信号的信道估计方法及装置
WO2007021384A2 (fr) * 2005-08-15 2007-02-22 Motorola, Inc. Procede et appareil de transmission de signal pilote
WO2007125715A1 (fr) * 2006-04-27 2007-11-08 Kabushiki Kaisha Toshiba Procédé de transmission de signaux ofdm et émetteur et récepteur mettant en oeuvre ce procédé

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020172308A1 (en) * 2001-04-25 2002-11-21 Haim Harel Smart antenna based spectrum multiplexing using existing pilot signals for orthogonal frequency division multiplexing (OFDM) modulations
US6940914B1 (en) * 2001-06-11 2005-09-06 Cingular Wireless Ii, Llc Turbo channel estimation for OFDM systems
CN1568026A (zh) * 2003-06-20 2005-01-19 中国科学技术大学 一种多用户自适应分组分层时空信号收发系统
WO2007021384A2 (fr) * 2005-08-15 2007-02-22 Motorola, Inc. Procede et appareil de transmission de signal pilote
WO2007125715A1 (fr) * 2006-04-27 2007-11-08 Kabushiki Kaisha Toshiba Procédé de transmission de signaux ofdm et émetteur et récepteur mettant en oeuvre ce procédé
CN1889546A (zh) * 2006-07-25 2007-01-03 华为技术有限公司 一种基于叠加导频信号的信道估计方法及装置

Also Published As

Publication number Publication date
CN101577968A (zh) 2009-11-11
CN101577968B (zh) 2011-08-03

Similar Documents

Publication Publication Date Title
KR101501714B1 (ko) 미모 무선 통신 시스템에서 오버헤드를 줄이기 위한 장치 및 방법
US9681322B2 (en) Wireless communication system, communication apparatus, wireless communication method and terminal apparatus
JP5266531B2 (ja) マルチキャリア通信システム内の伝送を行うための方法および装置
EP1797691B1 (fr) Modulation de blocs
US20160020865A1 (en) Method and apparatus for pilot and data multiplexing in a wireless communication system
US8432951B2 (en) Methods for transmitting and receiving a multicarrier spread-spectrum signal, corresponding signal, computer program products and transmission and reception devices
EP1973284A2 (fr) Retour d'information en liaison montante pour un précodage MIMO
CN104734831A (zh) 无线通信系统中的基站
WO2009135397A1 (fr) Procédé, système et appareil permettant d’obtenir des informations de canal de liaison descendante
EP2452444B1 (fr) Signalisation de signaux de référence pour systèmes de transmission en multiplexage spatial mono-utilisateur
CN101572682A (zh) 获取信道信息的方法和装置
US20110228748A1 (en) Method and apparatus for transmitting data in radio communication system
EP2561653A1 (fr) Estimation de qualité de canal pour récepteur mimo mlse
KR20140074313A (ko) 미모-오에프디엠 통신 시스템에서 채널 추정을 위한 방법들 및 장치
CN103780528A (zh) 通信系统及其信号发送方法与装置、信号接收方法与装置
WO2013091546A1 (fr) Terminal de communications, appareil et procédé de détection d'indication de rang
EP2352246B1 (fr) Système mimo à utilisateurs multiples, appareil récepteur et appareil émetteur
US20130343320A1 (en) Terminal device, base station device, and wireless communication system
WO2010048129A1 (fr) Procédé et appareil permettant de mettre en œuvre des techniques de transmission en liaison montante avec des ondes porteuses multiples et des signaux de référence
JP5630898B2 (ja) 基地局装置、端末装置、および無線通信システム
KR20100048871A (ko) 다중안테나를 갖는 무선 통신 시스템에서 레퍼런스 신호를 하향 전송하는 방법
CN103780529A (zh) 通信系统及其信号发送方法与装置、信号接收方法与装置
KR20180027300A (ko) 통신 시스템에서 간섭을 제어하는 통신장치 및 방법
KR20080071065A (ko) 무선통신 시스템에서 순방향 링크 채널을 위한 송신다이버시티 방법 및 신호처리 방법
KR20110085887A (ko) 상향링크 ｍｉｍｏ 전송에서 데이터와 다중화된 상향링크 ｄｍ－ｒｓ 전송 방법

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09741672

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 09741672

Country of ref document: EP

Kind code of ref document: A1