A signal processing device includes: a transmission path estimator that estimates a first transmission path characteristic of a transmission signal using a vertical signal out of vertical and horizontal signals resulting from being received by a vertical polarization antenna and a horizontal polarization antenna; a transmission path estimator that estimates a second transmission path characteristic of the transmission signal using the horizontal signal; a weight calculator that calculates a first weight for the vertical signal and a second weight for the horizontal signal, using the first transmission path characteristic and the second transmission path characteristic; and a weighting applier that applies weighted summation to the vertical signal and the horizontal signal using the first weight and the second weight.

This disclosure provides methods, devices and systems for determining unavailable spatial streams in uplink multiuser (MU) multiple-in multiple-out (MIMO) communication. In one example, a device transmits, to wireless stations including a first wireless station, a trigger frame configured to elicit a joint transmission, to the device, of a MU packet over spatial streams respectively associated with the wireless stations. The device receives the MU packet over the spatial streams, where each spatial stream of the spatial streams is received by receive chains of the device. The device performs a channel estimation associated with each spatial stream of the spatial streams using each receive chain of the receive chains. The device determines that at least one spatial stream associated with the first wireless station is unavailable based on the channel estimation. The device processes the MU packet from the plurality of spatial streams without the at least one spatial stream.

Disclosed are a user detection technique, and a method and apparatus for channel estimation in a wireless communication system supporting massive multiple-input multiple-output. The method comprises the steps of: receiving a superimposed signal including a transmission signal of at least one user equipment (UE) from among a plurality of user equipments, wherein each transmission signal includes a pilot signal of a corresponding user equipment; calculating a sample covariance matrix from the received superimposed signal by using the number of antennas of a base station and a pilot signal matrix of the at least one user equipment; calculating a likelihood function indicating the likelihood probability of the received superimposed signal, on the basis of the number of antennas of the base station and the received superimposed signal; detecting a user index set indicating whether or not the plurality of user equipments have transmitted signals, by using the calculated likelihood function and sample covariance matrix; and performing channel estimation of the at least one user equipment that is transmitting the signal, on the basis of the detected user index set.

Aspects of the subject disclosure may include, for example, obtaining channel cross correlation data relating to multiple user equipment (UEs) being served in a cell, wherein the channel cross correlation data comprises a correlation coefficient associated with a first UE of the multiple UEs and a second UE of the multiple UEs, identifying that the first UE is experiencing decreasing throughput, responsive to the identifying that the first UE is experiencing decreasing throughput, determining whether the correlation coefficient associated with the first UE and the second UE satisfies a correlation threshold, and, based on a first determination that the correlation coefficient does not satisfy the correlation threshold, adjusting a downlink (DL) transmit power allocation for transmissions directed to the first UE. Other embodiments are disclosed.

A method for minimizing a time domain mean square error (MSE) of channel estimation (CE) includes estimating, by a processor, a power delay profile (PDP) from a time domain observation of reference signal (RS) channels; estimating, by the processor, a noise variance of the RS channels; and determining, by the processor, a first arrival path (FAP) value and a delay spread estimation (DSE) value based on the estimated PDP and the estimated noise variance for minimizing the MSE of CE.

One embodiment is directed to adaptive predictive uplink receive chain processing that involves determining predicted data for one or more early data symbols of a slot based on first baseband IQ data received for the slot. The predicted data for the early data symbols of the slot comprises a predicted version of data used at some point in performing a first portion of uplink receive processing for the early data symbols. The first portion of the uplink receive processing for the early data symbols of the slot is performed using the predicted data. Actual data corresponding to the predicted data is determined based on at least second baseband IQ data received for the slot. In connection with performing a remaining portion of the uplink receive processing for the early data symbols, the preliminary output data for the early data symbols of the slot are adapted based on the actual data.

Aspects of the subject disclosure may include, for example, determining a coherence block for each user equipment (UE) of a plurality of UEs being served by the first cell, resulting in a plurality of coherence blocks, responsive to the determining, identifying a smallest coherence block from the plurality of coherence blocks, identifying a pilot sequence length based on the smallest coherence block, determining a plurality of orthogonal pilot sequences based on the identifying the pilot sequence length, designating, from the plurality of orthogonal pilot sequences, a first group of orthogonal pilot sequences for use in the first cell, and distributing, to each neighboring cell of a plurality of neighboring cells adjacent to the first cell, a respective group of orthogonal pilot sequences from a remainder of the plurality of orthogonal pilot sequences, to prevent pilot contamination between the first cell and the plurality of neighboring cells. Other embodiments are disclosed.

A distributed unit (DU) may include a transceiver configured to communicate with a plurality of radio units (RUs) that are configured to serve a plurality of user equipments (UEs). The DU may include a processor configured to determine RU precoding parameters for UEs served by a first RU set from the plurality of RUs based on estimated channel parameters for communication channels between the first RU set and at least one of interfering UEs served by other RUs from the plurality of RUs; to encode information indicating the determined precoding parameters for downlink transmissions to the first RU set and determine DU precoding parameters for downlink transmissions to the UEs served by the first RU set based on the determined RU precoding parameters; and/or precode communication signals based on the determined DU precoding parameters.

The present disclosure relates to methods and devices for Channel State Information, (CSI) prediction. More particularly the disclosure pertains to predicting CSI for a dynamic channel that is varying over time, e.g. because the receiver is moving. This object is obtained by a method performed in a first wireless node of predicting CSI of a dynamic wireless channel H between the first wireless node and a second wireless node. The method comprises deriving channel covariance estimates C.sub.k(n), . . . , C.sub.k(n−M) of the dynamic wireless channel H, estimating one or more channel properties of the dynamic wireless channel H, wherein one of the estimated channel properties defines a spectrum spread of the dynamic wireless channel H, and determining a covariance prediction filter, based on the estimated one or more channel properties. The method further comprises predicting one or more channel covariance estimates Ĉ.sub.k(n+N|n) by applying the determined covariance prediction filter to the derived channel covariance estimates C.sub.k(n), . . . , C.sub.k(n−M) and calculating a predicted CSI using the predicted covariance estimates Ĉ.sub.k(n+N|n). Hence, this disclosure proposes predicting CSI by predicting channel covariance using a methodology which implies deriving optimal covariance prediction filters.

Aspects of the subject disclosure may include, for example, receiving sounding reference signal (SRS) symbols from antenna elements of each of multiple modular antenna arrays, wherein the multiple modular antenna arrays are operatively combined to form a coherent antenna system, performing an uplink (UL) channel estimation and a downlink (DL) channel estimation, across a plurality of physical resource blocks (PRBs), based on the SRS symbols, calculating, for the antenna elements, a plurality of uplink (UL) combining weights based on the UL channel estimation and a plurality of downlink (DL) precoder weights based on the DL channel estimation, and causing the plurality of UL combining weights and the plurality of DL precoder weights to be applied to the antenna elements, thereby adjusting beamforming of the coherent antenna system. Other embodiments are disclosed.