To fully enjoy the benefit of adaptive modulation or bit loading in a multi-carrier wireless communication system, a bit loading control method (700) is disclosed to reduce the system complexity and signaling overhead by making use of an attribute of the communication channel, which has a declining channel response with increasing frequency. Instead of applying adaptive bit loading on a per subcarrier basis, the disclosed method (700) obtains (S703) an estimated channel response based a test signa; and determines (S704) according to the estimated channel response a bit loading scheme for allocating the plurality of subcarriers into one or more non-overlapping frequency segments. For each frequency segment, an individual modulation scheme is assigned, which is shared by the more than one adjacent subcarrier comprised in the same frequency segment. The monotonicity of the channel response is used to accelerate the algorithm, as well as to make control information more compact.

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.

Methods, systems, and devices for wireless communications are described. In some examples, a user equipment (UE) may receive a control message indicating a set of sampling beams defined for the UE. The UE may measure a set of received signal strengths for communications from a wireless node associated with a set of linear combinations of sampling beams from the set of sampling beams defined at the UE. The UE may calculate a set of entries of a channel covariance matrix based on the set of received signal strengths of the set of linear combinations of the sampling beams from the set of sampling beams defined for the UE. As such, the UE may communicate with the wireless node based on applying a set of beam weights to an antenna array of the UE. In some examples, the set of beam weights may be based on the channel covariance matrix.

A computer-implemented reconstruction method of discrete digital signals in noisy overloaded wireless communication systems that is characterized by a channel matrix of complex coefficients, the method including, receiving the signal from channel by a signal detector, measuring the noise power by a noise power estimator at the receiver , forwarding the detected signal and noise power estimation to a decoder that estimates the transmitted symbol, wherein the estimation of the decoder produces a symbol that could probably have been transmitted it is forwarded to a de-mapper, which outputs the bit estimates corresponding to the estimated transmit signal and the corresponding estimated symbol to a microprocessor for further processing.

Aspects of the subject disclosure may include, for example, causing a reference antenna element of a first set of antenna elements of a first antenna array to transmit a first signal, determining for each antenna element of a second set of antenna elements of a second antenna array, a receive-related offset, relative to the reference element, based on inter-element propagation delays between the first and second sets of elements, causing each antenna element of the second set of elements to transmit a respective second signal, based on the reference antenna element receiving the respective second signals, calculating a respective transmit-related offset for each antenna element of the second set of antenna elements relative to the reference antenna element based on the inter-element propagation delays, and performing calibration between the first antenna array and the second antenna array based on the respective receive-related and transmit-related offsets. Other embodiments are disclosed.

A communications device includes a uniform linear array of M antennas and a field programmable gate array (FPGA) having pipelined stages in which execution of overlapping instructions estimate a direction of arrival of RF signals from multiple sources. A preprocessing stage of the FPGA includes at least one configurable logic block configured to apply forward/backward averaging spatial smoothing to a signal space matrix extracted from a covariance matrix in the preprocessing stage. The FPGA further includes at least one configurable logic block configured to compute the direction of arrival angle for the RF signals using a least squares method.

An example method for providing at least one estimated parameter of a wireless communication channel includes receiving at least one sample of raw data via the wireless communication channel, processing the at least one sample using a machine learning inference algorithm and therefrom providing a first estimated value, processing the at least one sample using a signal processing algorithm and therefrom providing a second estimated value, acquiring a first confidence value for the first estimated value, acquiring a second confidence value for the second estimated value, evaluating the first confidence value and the second confidence value, and providing either the first estimated value or the second estimated value or a combination of the first and the second estimated value as the at least one estimated parameter based on the evaluation.

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.

Aspects of the subject disclosure may include, for example, receiving a plurality of orthogonal sounding reference signals (SRS) from a plurality of user equipment (UEs), wherein each SRS of the plurality of orthogonal SRS is provided by a respective UE of the plurality of UEs, determining a downlink (DL) channel, in frequency division duplex (FDD), using spatial correlations relating to the plurality of UEs, wherein the spatial correlations are based on the plurality of orthogonal SRS, calculating a plurality of DL precoding weights for a plurality of coherent modular antenna panels responsive to the determining the DL channel, and applying the plurality of DL precoding weights to the plurality of coherent modular antenna panels to enable multi-user (Mu)-multiple-input-multiple-output (MIMO) for the plurality of UEs. Other embodiments are disclosed.

Aspects of the subject disclosure may include, for example, causing a reference antenna element of a first set of antenna elements of a first antenna array to transmit a first signal, determining for each antenna element of a second set of antenna elements of a second antenna array, a receive-related offset, relative to the reference element, based on inter-element propagation delays between the first and second sets of elements, causing each antenna element of the second set of elements to transmit a respective second signal, based on the reference antenna element receiving the respective second signals, calculating a respective transmit-related offset for each antenna element of the second set of antenna elements relative to the reference antenna element based on the inter-element propagation delays, and performing calibration between the first antenna array and the second antenna array based on the respective receive-related and transmit-related offsets. Other embodiments are disclosed.