A method of channel estimation in a communication system includes the steps of: receiving at least one input signal associated with at least one data stream, the input signal having reference symbols and data symbols; processing the at least one input signal in a slot-wise manner; performing a channel estimation by taking at least one reference symbol per input signal into account, which is used to equalize the respective input signal and to assign the symbols to the at least one data stream, thereby generating a processed signal for each independent data stream, and processing further the processed signal while performing an additional channel estimation for each independent data stream, wherein the reference symbols and the data symbols are taken into account for the additional channel estimation. Further, a signal processing system is described.

This application relates to the field of communications technologies, and discloses a method and an apparatus for indicating a number of repetitions, so that a configuration of a number of repetitions of an SRS and/or a PUSCH is more adaptive to a channel change. The method includes: A network device sends DCI to a terminal device, where the DCI includes first indication information, and the first indication information indicates a number of repetitions of an SRS and/or a PUSCH. Because the DCI has a faster update process than RRC signaling, and overheads are smaller than those of the RRC signaling, the network side device may flexibly configure the number of repetitions of the SRS and/or the PUSCH by using the DCI, to better adapt to the channel change, and further improve a channel estimation capability and signal demodulation performance.

There is disclosed a method of operating a receiving radio node in a wireless communication network, the method including performing channel estimation based on received signaling, the channel estimation providing a channel estimate value for each subcarrier of a set of subcarriers. The received signaling covers a number NPRB of Physical Resource Blocks, PRB, in frequency domain, each PRB having a number NSC of subcarriers. The set of subcarriers has a number NSUB of subsets of subcarriers, subcarriers of the same subset being associated to the same PRB of the number NPRB of PRBs. The channel estimation associates different channel estimate values to different subcarriers of one or more of the NSUB subsets. The disclosure also pertains to related devices and methods.

The disclosed subject matter relates to employing modulation layer mapping to improve the performance of multiple-input and multiple-output (MIMO) communication systems. In one embodiment, a method comprises determining, by a device comprising a processor, codeword information in association with establishment of a wireless communication link with a network device of a wireless communication network, wherein the device and the network device are configured to communicate via the communication link using a MIMO communication scheme. The determining the codeword information comprises determining a code rate and determining a number of modulation indexes for the code rate based on signal-to-noise ratios respectively associated with channel layers included in the MIMO communication scheme. The method further comprises sending, by the device, the codeword information to the network device via a control channel of the wireless communication link.

A system and method of operating an Open Radio Access Network (O-RAN, in which O-RAN the system includes: a baseband unit (BBU) having an O-RAN centralized unit (O-CU) and an O-RAN distributed unit (O-DU); an O-RAN radio unit (O-RU) remote from the BBU; and a fronthaul interface between the O-RU and the BBU. A functional split of O-RAN functions respectively assigned to O-RU and O-DU for the fronthaul interface between the BBU and the O-RU is different for downlink (DL) and uplink (UL) so that at least one of i) demodulation reference signal (DM-RS)-based channel estimation is performed by the O-DU in the DL and by the O-RU in the UL, ii) equalization is performed by the O-DU in the DL and by the O-RU in the UL, and iii) demodulation is performed by the O-DU in the DL and by the O-RU in the UL.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive an indication of a repetition factor associated with a message or an indication that demodulation reference signal (DMRS) bundling is to be applied for the message for joint channel estimation. The UE may communicate a phase tracking reference signal (PTRS) associated with the message based at least in part on receiving the indication of the repetition factor or the indication that DMRS bundling is to be applied. Numerous other aspects are described.

This application discloses a channel estimation method and apparatus, and relates to the field of communications technologies, to help reduce indication overheads. The method may include: generating and sending indication information. The indication information is used to indicate K N-dimensional spatial-domain component vectors, L M-dimensional frequency-domain component vectors, and a weight matrix, to indicate to construct an M×N-dimensional spatial-frequency matrix, or an M×N or N×M spatial-frequency matrix.

This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media, for selecting a beam to be allocated for transmitting downlink (DL) data to user equipment (UE). In some implementations, a UE receives a reference signal on each of a number of beams associated with a base station, and determines a delay spread value for each beam. The UE identifies each beam for which the determined channel delay spread value is less than a threshold value, and determines a reference signal received power (RSRP) level for each identified beam. The UE transmits an indication of the determined RSRP levels of the identified beams to the base station, and receives, in response to the transmitted indication, a selection of the beam to be allocated for DL transmissions to the UE.

A decoder for determining an estimate of a vector of information symbols carried by optical signals propagating along a multi-core fiber in an optical fiber transmission channel according to two or more cores is provided. The decoder is implemented in an optical receiver. The optical signals are encoded using a space-time coding scheme and/or scrambled by at least one scrambling device arranged in the optical fiber transmission channel according to a predefined scrambling function. The decoder comprises a processing unit configured to adaptively: determine, in response to a temporal condition, one or more channel quality indicators from the optical signals; determine a decoding algorithm according to a target quality of service metric and on the one or more channel quality indicators; update the predefined scrambling function and/or the space-time coding scheme depending on the target quality of service metric and on the one or more channel quality indicators. The decoder further comprises a symbol estimation unit configured to determine an estimate of a vector of information symbols by applying the decoding algorithm to the optical signals.

The present disclosure provides a method for performing radio link monitoring (RLM) by a terminal for which a plurality of carriers are configured, in a wireless communication system. Specifically, the method may comprise: receiving a reference signal through one carrier among the plurality of carriers: measuring the radio link quality of the one carrier on the basis of the reference signal, and determining whether wireless communication through the plurality of carriers is possible, on the basis of the measured radio link quality.