An objective of the application is to provide a method and apparatus for obtaining downlink data in a massive MIMO system. Specifically, the base station transmits a downlink control signaling indicating downlink channel estimation information to a user equipment, wherein the downlink control signaling comprises corresponding effective channel mean value information; performs zero-forcing precoding to a to-be-transmitted signal on each subcarrier of a transmission sub-band; transmits the zero-forcing precoded signal to the user equipment. Compared with the prior art, the base station in the present application can perform zero-forcing precoding to signals on each subcarrier and transmitting a DL control signaling indicating downlink channel estimation information to a user equipment, such that the user equipment can perform demodulation based on an effective channel mean value information in the DL control signaling but does not rely on the DL reference signal, thereby achieving reduction of precoding granularity and signaling overheads, system performance also be enhanced greatly.

The present invention relates to a reception apparatus. The reception apparatus includes a plurality of reception antennas; and a signal processing unit configured to use reception characteristic of the plurality of reception antennas, wherein the signal processing unit comprises a channel estimation unit configured to respectively estimate a channel response matrix of each signal received via the plurality of reception antennas, and a coding unit configured to define a coding matrix based on an inverse matrix of the estimated channel response matrix, and to obtain a final output signal corresponding to each reception antenna by applying the coding matrix to each received signal.

A system and a method are disclosed for performing data-aided channel tracking for a subcarrier, including obtaining a reference channel estimate (CE) at a first time instance using a reference signal; determining, based on the obtained reference CE and based on received data symbols, a data-aided CE at a second time instance that is subsequent to the first time instance; and sequentially determining one or more additional data-aided CEs, for one or more time instances subsequent to the second time instance, based on a data-aided CE obtained at a previous time instance and based on the received data symbols.

A wireless transmit/receive unit (WTRU) may be comprised of a processor and memory. The WTRU may receive a configuration from a network that configures the WTRU to perform an inverse deep learning model. The WTRU may receive a plurality of reference signals from the network. The WTRU may determine a number of MPCs using the inverse deep learning model and based on the plurality of reference signals. The WTRU may determine an angle of arrival (AoA), an angle of departure (AoD), and a gain associated with each MPC of the number of MPC's using the inverse deep learning model and based on the plurality of reference signals. The WTRU may send an indication of the number of MPCs and the AoA, the AoD, and the gain associated with each MPC of the number of MPCs to the network.

There are provided apparatuses, methods and computer program products. In accordance with an embodiment, there is disclosed a method including receiving positioning reference signals from a positioning signal transmitter; forming a delay search space from the received positioning reference signals to obtain a plurality of channel taps; estimating a noise precision for the channel taps; estimating channel gains for the channel taps; and estimating a probability of line of sight signal for the channel taps.

Systems and methods are provided for channel sounding techniques, such as High-Accuracy-Distance-Measurement (HADM), for phase-based ranging. By utilization of a coupler, antennas on a multi-radio device can be shared to provide the diversity for HADM, without affecting other radio functions. Examples include at least a first antenna coupled to a first radio. The first radio is configured to process signals received from a peripheral device via the first antenna. Examples also include a first radio coupled to a second antenna and configured to selectively receive signals from the peripheral device via the second antenna. The second radio is configured for a different communication technology than the first radio.

An operating method of a first device which communicates with a second device based on time division duplex (TDD), includes: receiving a first signal from the second device; estimating a channel between the first device and the second device based on the first signal; generating, by applying singular value decomposition (SVD) to the estimated channel, a first orthogonal matrix including one or more left singular vectors, a diagonal matrix including one or more singular values, and a second orthogonal matrix including one or more right singular vectors; selecting at least one right singular vector from the second orthogonal matrix in descending order according to the one or more singular values, a number of the selected at least one right singular vector corresponding to a number of ranks of the channel; and transmitting, to the second device, a precoded physical sidelink shared channel (PSSCH) precoded based on a precoding matrix including the selected at least one right singular vector.