The present disclosure describes methods and apparatuses for singular value decomposition with norm sorting. In some aspects, a sounding frame is received through a channel of a wireless medium. Based on the sounding frame, a channel covariance matrix describing conditions of the channel can be determined. The channel covariance matrix is then decomposed, with an ortho-normal matrix, to provide an intermediate matrix of vectors. One or more vectors of the intermediate matrix are sorted based on a respective norm to provide a norm-sorted matrix of the vectors. A steering matrix for the channel is then generated by ortho-normalizing at least two vectors of the norm-sorted matrix. By so doing, a steering matrix can be generated quickly and efficiently for use in subsequent communication operations.

A device includes a selection circuit that is configured to generate a bias level. The device also includes a combinational circuit coupled to the selection circuit. The combinational circuit is configured to generate a distortion correction factor used offset inter-symbol interference from a data stream on a distorted bit based on the bias level to generate a correction signal. The device additionally includes a latching element coupled to the combinational circuit and configured to receive the first correction signal.

A channel estimation method in multiple-input multiple-output (MIMO) communication systems using a temporal correlation and an apparatus therefor are provided. The method includes quantizing a receive signal received via each of MIMO antennas using an analog-to-digital converter (ADC) and reflecting a temporal correlation in the quantized receive signal and estimating a channel for the receive signal, received via each of the MIMO antennas, based on the receive signal in which the temporal correlation is reflected.

This document discloses a solution for performing interference cancellation in a radio receiver. According to an aspect, there is provided a method for an apparatus of an access node, comprising: receiving, by the apparatus from a first radio unit of the access node via a first interface, a first spectrally whitened channel parameter and a first spectrally whitened data stream; receiving, by the apparatus from a second radio unit of the access node via a second interface, a second spectrally whitened channel parameter and a second spectrally whitened data stream; summing, by the apparatus, the first spectrally whitened channel parameter with the second spectrally whitened channel parameter and summing the first spectrally whitened data stream with the second spectrally whitened data stream; and extracting, by the apparatus, a desired data stream from the summed spectrally whitened data streams by using the sum of the first spectrally whitened channel parameter and the second spectrally whitened channel parameter.

Techniques and examples of overhead reduction for linear combination codebook and feedback mechanism in mobile communications are described. A user equipment (UE) receives from a base station of a network one or more reference signals via a communication link between the UE and the base station. The UE constructs a channel state information (CSI) feedback by utilizing a correlation of channel responses in a frequency domain to reduce feedback overhead. The UE then transmits the CSI feedback to the base station.

A method for channel state information (CSI) feedback by a user equipment (UE) is provided. The method comprises receiving, by the UE from a base station (BS), CSI feedback configuration information to report a covariance matrix indicator (CMI) indicating a NN channel covariance matrix (K) associated with a downlink channel matrix, wherein N is a number of antenna ports at the BS; identifying, by the UE, the CMI that indicates a set of L basis vectors {a.sub.i}, i=0, 1, 2, . . . , L1, each comprising a dimension N1, and a set of L.sup.2 coefficients, {c.sub.i,j}, i,j=0, 1, 2, . . . , L1, and that represent the covariance matrix (K) as a weighted linear sum {tilde over (K)}=.sub.i=0.sup.L-1.sub.j=0.sup.L-1c.sub.i,ja.sub.ia.sub.j.sup.H, wherein LN and .sup.H denotes a Hermitian transpose, and transmitting, by the UE to the BS, the CSI feedback including the identified CMI over an uplink channel.

Various aspects of the disclosure relate to ensuring that beamforming feedback is substantially coherent across frequency, time, or some other condition. The disclosure relates in some aspects to generating steering matrix feedback (e.g., at an IEEE 802.11 STA). In some aspects, the generation of the steering matrix feedback uses a singular value decomposition (SVD) algorithm that helps ensure coherence of beamforming feedback. In some aspects, coherence may be achieved by ensuring that the Givens rotations of a matrix are always in the same direction.

A wireless communication system includes an RF reception unit configured to receive a radio signal from a terminal; a channel estimation unit configured to estimate channel information of a wireless transmission path with respect to the terminal on the basis of the radio signal received by the RF reception unit; a demodulation unit configured to perform soft decision demodulation on the radio signal on the basis of the channel information estimated by the channel estimation unit; a quantization unit configured to quantize a log likelihood ratio obtained through soft decision demodulation in the demodulation unit, on the basis of a statistical distribution determined using an average value of the log likelihood ratio determined in accordance with a modulation scheme used in wireless communication with the terminal and a variance of a log likelihood ratio obtained on the basis of the channel information; and a decoding unit configured to perform a decoding process on the log likelihood ratio quantized by the quantization unit.

Methods for determining variability in a state of a medium, include monitoring the medium and determining the variability in the state of the medium based on the processing of the response over time based on the response detected at the at least one receive element over time. Monitoring the medium can include generating a transmit signal, transmitting it into the medium using a transmit element, and receiving a signal from the medium at a receive element. The transmit and receive elements can be decoupled from one another. The transmit and receive elements can have differing geometry. The determined variability in the state of the medium can be used to provide notifications and/or take automated actions.

A wireless communication device comprises at least one antenna array configured to receive a radio signal; a first compressor configured to determine a first compression operator based on a predetermined set of receive configurations for the antenna array, and to apply the first compression operator to the radio signal to generate a first compressed signal; a second compressor configured to apply a second compression operator to the first compressed signal to generate a second compressed signal; a channel estimator configured to determine a channel covariance of the radio signal, determine at least one eigenvector of the channel covariance to obtain a second compression operator, and provide the second compression operator to the second compressor; and a baseband processor configured to receive the second compressed signal from the second compressor and to process the second compressed signal to obtain output data.