This application provides an uplink multi-station channel estimation method, a station (STA), and an access point (AP), which can be applied to an uplink multi-user multiple-input multiple-output scenario. The uplink multi-station channel estimation method includes: a STA generating a frame including a first group of training sequences and a second group of training sequences, and sending the frame to the AP. The AP calculates a frequency offset value between the STA and the AP based on the received first group of training sequences and the received second group of training sequences. The AP performs channel estimation based on the calculated frequency offset value. According to the technical solutions provided in this application, the AP can more accurately learn of frequency offset values between a plurality of STAs and the AP. This improves channel estimation precision.

A method of performing channel estimation in a multiple-input-multiple-output (MIMO) communication system comprising a downlink device and an uplink device arranged to communicate over a communication channel, the method including at the uplink device: analyzing a first channel vector representing channel gains between the downlink device and a first antenna of the uplink device in the angular domain to identify a set of angular domain support points; generating from the set of angular domain support points a value vector; and feeding back from the uplink device to the downlink device an indication of the value vector; and at the downlink device: analyzing a second channel vector representing channel gains between the downlink device and a second antenna of the uplink device; generating a transmit steering matrix; and generating an estimate of the first channel vector.

Disclosed is a low-complexity linear equalization method for an Orthogonal Time Frequency Space (OTFS) system. The method may include: receiving a time domain signal passing through a linear time-varying (LTV) channel; sampling the time domain signal to obtain a sampled signal; demodulating the sampled signal to obtain a demodulated signal; performing a Symplectic Finite Fourier Transform (SFFT) on the demodulated signal to obtain a sampled delay-Doppler domain signal; determining an effective channel matrix in a delay-Doppler domain under a restriction of a rectangular window according to a time domain channel matrix; determining a linear equalization matrix according to the effective channel matrix; and equalizing the sampled delay-Doppler domain signal in a low-complexity way according to the linear equalization matrix. The disclosure also discloses a linear equalization device of an OTFS system for realizing the linear equalization method and a computer-readable storage medium.

Embodiments can include receiving transmissions over a channel at a receiver of a MIMO communication system; the transmissions are received from a plurality of transmitters in communication with the receiver. Each communication is a separate communication having a modulation and coding scheme. An estimate of the channel is converted into an estimate, for each of a plurality of transmitters, of a bit-metric decoding rate for each of a plurality of MIMO detectors. The estimated bit-metric decoding rate for each of the transmitters for each of the MIMO detectors is converted into an estimated bit error rate for each of the MIMO detectors for each of the transmitters. One of the MIMO detectors is selected for use in generating log-likelihood ratios for bits transmitted from the transmitters to the receiver. The one of the MIMO detectors is selected based on the estimated bit-error rates and a target block error rate.

This application discloses a Wi-Fi communication method and a device, and relates to the field of wireless communication technologies. In the method, a first communication device is configured to: generate a first physical frame, and send the first physical frame. The first physical frame includes signaling information and a plurality of training sequences used for channel estimation, the signaling information indicates a quantity of space-time streams and a quantity of the plurality of training sequences, and the quantity of the plurality of training sequences is greater than the quantity of space-time streams. This helps improve accuracy of an algorithm such as channel estimation in a communication system, to improve a demodulation capability of a communication device, and ensure data demodulation effect.

Mechanisms for determining directional beamforming weights are disclosed. A method performed by a radio transceiver device includes obtaining, from measurements on reference signals, channel estimates per antenna port and frequency. The channel estimates are indicative of power delay values per antenna port towards another radio transceiver device. The method includes determining modified channel estimates per antenna port and frequency with the power delay values outside a threshold delay window being suppressed. The method includes determining directional beamforming weights for beam-formed transmission towards said another radio transceiver device based on the modified channel estimates per antenna port and frequency.

The present specification relates to a reception apparatus and method for demodulating a signal in a wireless AV system. The reception apparatus estimates a transmission signal on the basis of an MMSE weight matrix. The reception apparatus divides the estimated transmission signal for respective reception antennas and performs an IFFT. The reception apparatus estimates and compensates for phase noise for the respective reception antennas on the basis of the signal for which the IFFT has been performed. The reception apparatus demodulates the estimated and compensated signal for respective streams.

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.

A multiple-input multiple-output (MIMO) communication system that addresses three major challenges in airborne MIMO communications, namely, antenna blockage due largely to the movement and orientation of the airborne platforms, the presence of unknown interference inherent to the intended application, and the lack of channel state information (CSI) at the transmitter. The system is implemented on a Diagonal Bell-Labs Layered Space-Time (D-BLAST) MIMO architecture and includes spatial spreading to counter antenna blockage, temporal spreading to mitigate signal to interference and noise ratio degradation due to intended or unintended interference, and a simple low rate feedback scheme to enable real time adaptation in the absence of full transmitter CSI.

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. The present disclosure relates to a 5th generation (5G) or pre-5G communication system for supporting a higher data transmission rate after a 4th generation (4G) communication system such as long-term evolution (LTE). A method of operating a base station according to various embodiments of the present disclosure may include: receiving channel information from at least one terminal, obtaining channel interference information based on the channel information, obtaining a precoder based on the channel interference information, and transmitting a transmit signal to the at least one terminal based on the precoder, the channel interference information may include timing alignment error (TAE) interference and multi-user interference, and the TAE interference may be determined based on a number of first radio access technology (RAT) symbols and a number of second RAT symbols allocated to the transmit signal.