A method for implementing uplink and downlink channel reciprocity, a communication node, and a storage medium are provided. The method for implementing uplink and downlink channel reciprocity includes: performing channel estimation in real time according to a received reference signal to obtain a channel estimation result; inputting the channel estimation result into a pre-trained neural network model, to output a channel adaptive matrix; and performing channel adaptation processing on a transmission signal by applying the channel adaptive matrix to the transmission signal.

A radio communication device that receives signals by using a plurality of reception antennas in a radio communication system employing multi-station simultaneous transmission includes: processing circuitry that estimates channel information on the basis of training symbol sequences, which are different depending on the base-station antennas, included in received signals, and outputs a channel information estimation result; performs a channel matrix extending process of extending dimension of a channel matrix on the basis of the channel information estimation result and a coding rule of the received signals, and extending array's degree of freedom; generates an interference suppression weight by using the channel matrix resulting from the channel matrix extending process; and extends dimension of a received signal vector by using a result of observation over symbol duration time for a plurality of symbols, and multiplies the received signal vector resulting from the extension of dimension by the interference suppression weight.

A physical layer protocol data unit (PPDU) transmission method is provided. The method includes generating a PPDU, where the PPDU includes an extremely high throughput-long training field (EHT-LTF). The EHT-LTF is obtained based on a P matrix and a predefined EHT-LTF sequence. The P matrix is an n×n orthogonal matrix, n is an integer greater than 8, and a first row of the P matrix includes at least one element whose value is 1 and at least one element whose value is −1. The method further includes sending the PPDU. This application may be applied to a wireless local area network (WLAN) system supporting a next-generation wireless fidelity (Wi-Fi) extremely high throughput (EHT) protocol of IEEE 802.11, for example, 802.11 protocols such as 802.11be.

A method of sparse digital cancellation of receiver nonlinear distortion in carrier aggregation systems is proposed. A reference signal generator generates possible candidate reference signals to be included in a dictionary matrix D. A sparsity-based solution is then applied to dynamically select reference signals based on the RF transceiver configuration. Based on the auto-correlation and cross-correlation with an observed radio signal, a subset of reference signals is selected from the dictionary matrix to match the distortion signal. The number of selected reference signals is flexibly determined based on the design constraints on complexity and power consumption. A greedy sparse estimation approaches, e.g., Orthogonal Matching Pursuit (OMP) can be used for reference signal selection. The reference signal selection is dynamic and adapts itself for different channel responses through correlating the observed radio signal with the dictionary reference signals.

Embodiments of a method and an apparatus for beamforming are disclosed. In an embodiment, a method for beamforming involves transmitting, by a beamformer to a beamformee, a sounding packet that includes training symbols, receiving, at the beamformee, the sounding packet that includes the training symbols, deriving, at the beamformee, channel estimates from the training symbols included in the sounding packet, computing, at the beamformee, a feedback matrix from the derived channel estimates, transmitting, by the beamformee to the beamformer, a packet that includes two sets of symbols, where the feedback matrix is applied to at least one of the two sets of symbols, receiving, at the beamformer, the packet that includes the two sets of symbols, and operating the beamformer according to the two sets of symbols included in the packet.

A method of estimating a spatial filter matrix is provided. A conjugate of a received first signal defines a conjugate first signal. A Kronecker product of the defined first signal and a received second signal define a differential measurement signal. The computations are repeated for a plurality of first and second signals sufficient to compute an estimate of a channel matrix from the differential measurement signals. A spatial filter matrix is computed from the computed estimate of the channel matrix. The computed spatial filter matrix is used in a data communication phase between the first plurality of antennas and the second plurality of antennas.

Embodiments herein provide a method of estimating channel states of a plurality of user equipments (UEs) in a single instance. The method includes receiving pilot samples from the plurality of UEs. The method includes selecting a predetermined number of tones, wherein the channel associated with each UE across the selected pre-determined number of tones is same. The method includes collecting the received pilot samples from each pilot symbol and stacking the received pilot samples as a vector. Further, the method includes constructing a matrix. The matrix includes known pilot values used by each UE. Furthermore, the method includes estimating channel states of the plurality of UEs by applying a filter on the vector formed from the received pilot samples. The number of channel states to be estimated is reduced by selecting the pre-determined number of tones.

A signal detection method for a MIMO-OFDM wireless communication system includes obtaining a channel matrix of each subcarrier through channel estimation for each MIMO-OFDM data packet in a plurality of MIMO-OFDM data packets; receiving a reception vector of each subcarrier; performing MIMO detection for a first OFDM symbol in a MIMO-OFDM pack and channel matrix preprocessing for the channel matrix of each subcarrier to generate a global dynamic K-value table; performing MIMO detection for each subsequent OFDM symbol in the MIMO-OFDM data packet, in which the MIMO detection includes: performing the following steps for each subcarrier of a current OFDM symbol: reading channel matrix preprocessing results and reception vector of the current subcarrier; transforming the reception vector of the current subcarrier into an LR search domain; and performing K-best search for the current subcarrier to obtain an LR domain candidate transmission vector of the current subcarrier, in which a K-value applied to each search layer of the current subcarrier during the K-best search is a global dynamic K-value in the global dynamic K-value table corresponding to the search layer.

Embodiments of the present disclosure provide a pilot transmission method and a data transmission apparatus in a wireless local area network. The pilot transmission method in a wireless local area network in the present disclosure includes: applying a pilot matrix to an LTF to generate a pilot, and sending the pilot, where the pilot matrix includes: a matrix formed from pilot sequences each having a pilot coefficient of each of the spatial flows, where the spatial flow is on M subcarriers in N symbol periods, the pilot matrix is an orthogonal matrix, M is a positive integer multiple of L, and L is a quantity of spatial flows. According to the present disclosure, channel estimation precision can be improved.

All data symbols used in data transmission of a modulated signal are precoded by switching between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol along the frequency axis and the time axis all differ. A modulated signal with such data symbols arranged therein is transmitted.