182results about How to "Reduce the amount of feedback" patented technology

A signal processing method in an MIMO multi-carrier system is disclosed comprising: receiving by a receiver signals of a plurality of sub-carriers transmitted from a transmitter; dividing the sub-carriers into a plurality of sub-carrier blocks according to the correlation between adjacent sub-carriers, each sub-carrier block containing K sub-carriers; selecting a feedback sub-carrier pre-coding matrix ( ) and a rotation matrix ( ) for each sub-carrier block, and then sending the information on the pre-coding matrix and the rotation matrix back to the transmitting end. The present invention provides the method and device for effectively settling the feedback problem in an MIMO/OFDMA system, thereby greatly reducing the number of pre-coding weight matrices needed to feed back to the transmitting device.

The invention discloses a millimeter wave large-scale MIMO system multi-user transmission method based on space division multiple access and interference suppression. A base station is provided with a millimeter wave large-scale uniform panel antenna array; a plurality of single-antenna users receive service from the base station on the same time-frequency resource; according to information of wave beam clusters selected by the users, a universal user set is divided into an interference-free user subset and an interference user subset; the space division multiple access transmission method based on double-layer pre-coded codes is adopted to the interference-free user subset, and the transmission method based on interference suppression is adopted to the interference user subset. According to the method, the advantages of two traditional multi-user transmission methods based on space division multiple access and interference suppression respectively are combined, and the bottleneck that in an FDD transmission mode, downlink channel information of a large-scale MIMO system is difficult to obtain is broken through; meanwhile, the computation complexity problem is solved, it is guaranteed that all the users can receive the service from the base station simultaneously, and considerable system performance and speed performance are achieved at limited feedback quantity.

The invention discloses a method for cooperation partner selection and precoding cooperative communications in a cellular communication system. The method comprises the following steps: (1) a user terminal with bad uplink channel quality sends a cooperative communication request to a base station; (2) the base station selects a partner terminal for the user terminal; (3) in a first frame of a cooperation period, the user terminal sends local data to the base station, and the base station and the partner terminal receive the data simultaneously; (4) in a second frame of the cooperation period, the partner terminal sends the local data to the base station, and the base station and the user terminal receive the data simultaneously; (5) in a third frame of the cooperation period, the user terminal and the partner terminal preprocess the relay data by a precoding matrix which is fed back by the base station, and send the relay data to the base station simultaneously; and (6) the base station judges the signals received in the transmission time slots of different frames in a combination way to obtain an estimated value of the sent signal. The method has the advantages of low complexity and high utilization rate of the system resources, and is used for the reliable data transmission in the cellular communication system.

A method for transmitting a multiple codeword (MCW) in a Multiple Input Multiple Output (MIMO) communication system is disclosed. A method for transmitting a multiple codeword (MCW) in a Multiple-Input Multiple-Output (MIMO) communication system includes performing a channel coding and modulation process for each codeword of the multiple codeword (MCW), multiplying the channel-coded-modulated result by a rotation matrix decided by either a spatial multiplexing rate or a layer (R), and performing a codeword permutation (CP) on the multiple codeword (MCW), performing a MIMO encoding on the multiple codeword (MCW), and transmitting the multiple codeword (MCW) via a multi-antenna.

The invention discloses a method and a system for sending a sounding reference signal (SRS) used in a coordinated multi-point (CoMP) transmission system. The method comprises the following steps: base stations set configuration information for sending the SRS and issue the information to a user terminal; and the user terminal sends the SRS to the base stations according to the acquired configuration information. By utilizing the method, the quality for SRS channel estimation via each base station in a coordination set is improved so that the base stations can obtain downlink channel information by virtue of channel reciprocity, thus greatly reducing the feedback quantity of UE (user equipment).

The invented method includes following steps with characters of supporting hybrid automatic feed back request (HARQ) technique. In preparing step, the dispatching cycle is fixed. Several adjacent subcarrier waves constitute the sub band. The resource composed of several sub bands is dispatched once a time in each time slot. Then, the mobile station feeds back the word of data rate control (DRC) obtained by quantizing average S/N ratio based on each sub band. In the step of dispatching retransmission data, after calling out the parameters of the scheme at last transmission for retransmission data, the retransmission data are fed back for several transmissions, which have largest DRC, in user's all available sub bands. The invention uses the low error rate of HARQ method and gives attention to both of fairness and system efficiency, and processes low feedback quantity and control amount of information.

Embodiments of the present invention relates to a MIMO communication system and its user scheduling method. The MIMO communication system includes: a transmitter that is configured to transmit the data frame including at least the channel estimation signal and the user data; and a receiver that is configured to receive the data frame from the transmitter and to produce the corresponding feedback information according to the channel fading matrix between the transmitter and the receiver and to recover the user data. The method includes the following steps: (a) the receiver produces the feedback information according to the channel fading condition between the transmit antenna and the receiving antenna and feeds back the feedback information to the transmitter; (b) the transmitter receives the feedback information, produces the scheduling information according to the feedback information and schedules the user according to the scheduling information. Embodiments of the present invention can change the user scheduling information at real time according to the change of the channel condition in order to obtain higher system capacity.

Disclosed herein are a user scheduling and beamformer design method, apparatus, and storage medium for multi-user MIMO downlink based on two-stage beamforming or single-stage beamforming. The user scheduling and beamformer design method includes 1) a two-step feedback approach, 2) the use of orthonormal reference beam vectors, 3) computation of the angle between the user's channel vector and each of the orthonormal reference beam vectors, 4) first-step feedback of the reference beam index to which the user's channel vector's angle is less than a certain threshold and feedback of the user's channel vector's norm, 5) selection of roughly orthogonal users with large channel norm based on the use of reference beam vectors and the channel norm feedback, 6) second-step feedback of the channel state information (CSI) from the scheduled users, 7) design of multi-user downlink beamformer for the scheduled users based on the second-step feedback of the CSI of the scheduled users. The main key point of this invention is that in the first step of user selection, we propose to use the channel norm or noise-plus-interference-divided channel norm as the feedback quantity and we propose to use only the angle between each of the reference beam vectors and the user's channel vector to identify the closest reference beam vector.

The invention discloses a multi-antenna relay transmission method of decomposing zero-forcing beam-forming based on singular value, which is characterized in that the relay station only makes use of the channel state information from the relay station to the user, and selects the transmission user congregation according to the semi-orthogonal user selection algorithm; the base station and the relay station jointly design the linear pre-processing matrix according to the singular value decomposition of the channel matrix from the base station to the relay station and the zero-forcing beam-forming matrix from the relay station to the user channel matrix; the base station allocates the power by using the power injection algorithm according to the channel state information from the base station to the relay station, and the relay station splits the power in accordance with the sub-flow number of the allocated power from the base station, so as to determine signals for the base station to send and signals for the relay station to transmit; and the transmission method system has advantages of small feedback amount, low complexity, effective control of noise amplification from the relay station, representing asymptotic optimal functions under the conditions that the power of the relay station is very large and that the number of system users are very large, and being suitable to be used in actual systems.

The invention discloses a double-layer pre-coding method applicable to a 3D MIMO system. In the 3D MIMO system, an active antenna array system is adopted for a base station, a receiving terminal conducts channel estimation on a signal after receiving the signal, and a three-dimensional channel matrix is obtained; as relevancy in the vertical direction is stronger than relevancy in the horizontal direction in a channel, a vertical pre-coding matrix is designed first according to the three-dimensional channel matrix, mergence in the vertical direction is carried out on the three-dimensional channel matrix then, and a horizontal pre-coding matrix is designed next; finally, the two pre-coding matrixes are merged and fed back to the base station. The double-layer pre-coding method applicable to the 3D MIMO system has the advantages that vertical and horizontal state information in the channel is fully utilized, complexity rather than performance is reduced greatly compared with a method in which a pre-coding matrix is obtained by directly carrying out singular value decomposition on the three-dimensional channel matrix, further codebook design and limiting feedback are carried out conveniently, and performance of the system is improved largely.

Disclosed is a downlink channel sate information (CSI) feedback method in a time division duplex (TDD) system, wherein the CSI means downlink interference and additive noise; the method comprises the following steps: receiving signals from a base station; obtaining covariance matrix omega of the downlink interference and the additive noise according to the received signals; obtaining space sub-channel response mu after interference whitening on the basis of singular value decomposition (SVD) according to the covariance matrix omega of the downlink interference and additive noise and downlink channel response hardware description language (HDL); obtaining downlink CSI according to the covariance matrix omega of the downlink interference and additive noise and the space sub-channel response mu; and feeding the downlink CSI back to the base station. Compared with the prior art, the method reduces the feedback quantity of the downlink interference and noise, and effectively uses the limited uplink pilot signal resource. According to various linear downlink multiple user multiple antenna pre-coding scheme, such as the memory enhancement technology (MET) pre-coding scheme, the effective improvement can be directly changed into better downlink transmission performances.

The invention relates to a mobile communication technique, especially a feedback control method, a device and a transceiver in orthogonal frequency division multiplexing system for solving problem of balancing feedback quantity and system throughput in prior art. The method includes: a receiver terminal determines corresponding channel feedback information of each sub-band respectively in each transmitting time interval; the receiver feeds back each sub-band channel feedback information to a transmitter terminal at interval at least one TTI; the receiver terminal feeds back channel change information of each sub-band relative to previous TTI to the transmitter terminal, or feeds back corresponding channel information or channel change information of frequency band at the same time. The device mainly includes a channel feedback information determination unit and a feedback execution unit, the transceiver mainly includes the device and a resource control unit. The technical solution provided by the invention can balance feedback quantity and system throughput commendably.

The invention discloses a channel state information reconstruction method based on deep learning. The method comprises the following steps: obtaining an NBS * Nc-dimensional channel matrix H on a frequency domain at a user side; converting the obtained channel matrix H into an angle delay domain channel matrix Ha with only non-zero elements; in the angle time delay domain, acquiring a new dimension matrix by advancing in the intercepted channel matrix Ha, converting the new matrix into a non-sparse vector X with the dimension of 2N * 1, wherein the non-sparse vector X serves as to-be-compressed data, and carrying out compression through the compressed sensing technology to obtain to-be-fed back channel state information Y; reconstructing and training a channel state information network; and according to the trained ReNet network model, recovering Y as input data of the network and as output data of the network from the obtained channel state information Y to be fed back, and performinginverse Fourier transform to obtain original CSI after obtaining. The original CSI data obtained by the user side is processed, subsequent compression and feedback are facilitated, and recovery ofthe compressed data is completed through the network trained by the known samples.

The invention relates to the wireless communication field and discloses a communication method and a device thereof in a multi-input and multi-output system; the utilization ratio of spectrum can be improved under the same total power by centrally distributing undistributed power to sub channels modulation coding orders of which can be improved most easily. By the optimization for a plurality of times, the undistributed power can be used fully; when the undistributed power can not improve the modulation coding orders of any sub channels, the undistributed power can be evenly distributed to the sub channel of each transmission data so as to further improve the error performance of the system. A codebook is used for feedbacking power distribution vector, which can effectively reduce the feedback amount of information; the use of two codebooks are used at the same time, thus respectively feedbacking the power distribution vector and pre-code matrix and improving the transmission performance of the system under the condition of limited feedback.

N sub-carriers are grouped in units of predetermined quantities in order beginning with the one exhibiting the highest communication channel quality to generate an optimal group pattern on the reception side. Then, communication channel information is calculated for each of sub-carrier groups in the optimal group pattern or a quasi-optimal group pattern which is assumed to be closest to the optimal group pattern among a plurality of previously set group pattern candidates. Communication channel information is designated as modified communication channel information. Grouping information indicative of the optimal group pattern or quasi-optimal group pattern is combined with modified communication channel information to generate feedback information. On the transmission side, sub-carriers are grouped based on reproduced feedback information reproduced from the feedback information.

The embodiments of the invention relate to a method for a first network node (NN1) for transmitting or retransmitting data to a second network node (NN2). The method contains receiving at the first network node (NN1) from the second network node (NN2) a feedback parameter (FP) in response to a first transmission (DT1) of at least two data segments (DS1-1, DS2-1, DS3-1) of a data packet. The feedback parameter (FP) is a number of counted data segments of the at least two data segments (DS1-1, DS2-1, DS3-1) incorrectly received or lost or correctly received at the second network node (NN2) by the first transmission (DT1). The method further contains determining at the first network node (NN1) for a second transmission (DT2) to the second network node (NN2) the data (DS1-2, DS2-2, DS3-2, NCS, DS1 1 R, DS21 R, DS31 R) as a function of the feedback parameter (FP) and transmitting or retransmitting the data (DS1-2, DS2-2, DS3-2, NCS, DS1 1 R, DS21 R, DS31 R) by the second transmission (DT2) from the first network node (NN1) to the second network node (NN2). The embodiments of the invention further relate to a further method for the second network node (NN2) for receiving data transmitted or retransmitted from the first network node (NN1). The further method (MET-NN2) contains determining at the second network node (NN2) the feedback parameter (FP) in response to the first transmission (DT1) from the first network node (NN1) to the second network node (NN2), transmitting from the second network node (NN2) the feedback parameter (FP) to the first network node (NN1), and receiving at the second network node (NN2) the data (DS1-2, DS2-2, DS3-2, NCS, DS1 1 R, DS21 R, DS31 R) by the second transmission (DT2) from the first network node (NN1). The embodiments of the invention further relate to a first computer program, the first network node (NN1), a second computer program and to the second network node (NN2).

The invention discloses a beam forming method, communication stations and mobile stations. The beam forming method, the communication stations and the mobile stations are applied to a wireless communication system comprising a plurality of collaborative cells. The beam forming method comprises the steps of enabling the communication station of every collaborative cell to determine weight of three-dimensional beam forming according to pitch angle instruction information and first channel information coming from the communication station of the cell and pitch angle instruction information and second channel information coming from the communication stations of other collaborative cells; and enabling the communication station of every collaborative cell to perform weighting processing on to-be-sent data according to the weight, and sending the data to the mobile station of the cell. By applying the beam forming method, the problems that two-dimensional beam forming cannot be used for distinguishing processing of the mobile stations with different pitch angles and feedback quantity is large in the prior art are solved, co-channel interference of different mobile stations is reduced while the feedback quantity is reduced, and system performance is improved.

The invention provides a method and system for realizing cooperative precoding aiming at the problem in a cooperative precoding technology among downlink base stations of a current time division duplexing (TDD) system. On the one hand, a channel estimation method based on linear interpolation is adopted to greatly reduce unmatched codebook errors of a receiving end and a base station end under an actual channel environment in the TDD system; and on the other hand, a scheme of two sets of codebooks is adopted to reduce the feedback quantity of cooperative multipoint (CoMP) local precoding, intensify the synchronization among the base stations, and greatly improve the communication quality for users at the edges of a cell at the same time of reducing the feedback quantity.

The invention provides a pre-coding method for restraining inter-user interference. The pre-coding method mainly comprises firstly designing a linear merging matrix of a user side, enabling the linear merging matrix to be combined with feedbacks of a customer satisfaction index (CSI), and reasonably using degree of spatial freedom; then precoding each user at each base station end, restraining user interference leaked from each user to other users; and finally adopting a maximization standard of signal-to-leakage-and-noise ratio (SLNR) to conduct joint optimization on an obtained precoding matrix and an obtained channel matrix and further promote system performance. The pre-coding method is not obvious in improvement of complexity and has practical application value compared with the SLNR precoding, the inter-user interference is effectively restrained, bit error rate performance and transmission rate are both obviously improved along increase of the signal noise ratio (SNR), and accordingly the precoding performance is better than BT precoding.

The invention belongs to the technical field of communication anti-jamming, in particular relates to the spatial modulation (SM) technology, a transmit precoding technology, a phase rotation (PR) technology, phase shifting keying (PSK), an antenna selection technology and multiple input multiple output (MIMO) modulation technology. A receiving end selecting a receiving antenna set and a transmitting antenna set according to an algorithm proposed by the invention according to channel information obtained through channel estimation, and feeds back the transmitting antenna set to the transmitting end; the transmitting end performs the spatial modulation mapping on the transmit data according to the transmitting antenna set fed back by the receiving end. Through the adoption of the method disclosed by the invention, the minimum Euclidean distance between constellation points is increased, the BER (Bit Error Rate) performance of the system is obviously improved under the condition of introducing tiny feedback quantity and increasing small complexity.

The invention discloses multi-user random beam forming method and system. The method comprises the following steps selecting master user ends and auxiliary user ends with the smallest interference on the master user end from user ends by a base station; defining precoding code words as first code words by the base station, and multiplying by preset first test signals to obtain first products, wherein the precoding code words are sent to the user ends when the master user ends are selected; then defining precoding code words as second code words, and multiplying by preset second test signals to obtain second products, wherein the precoding code words are sent to the user ends when the auxiliary user ends are selected; and adding the first products with the second products to form multiple beams. By adopting the method and the system, the mutual interference among multiplex users can be controlled, and moreover, bigger system capacity can be obtained only with very small feedback quantity.

A method for feeding channel quality back includes feeding channel quality indication back to sending end by receiving end according to driving condition and making said driving condition possibly be frequency of continuous feedback error response, frequency of data packet being retransmitted, relation of channel quality indication value (CQIV) at data transmission sub-channel to CQIV at the other sub-channel and relation of current CQIV to previous CQIV at data transmission sub-channel.