A multiple-input multiple-output (MIMO) wireless transceiver with N transmit and receive chains and a bandwidth evaluation circuit, a chain partitioning circuit and a switchable radio frequency RF filter bank. The bandwidth evaluation circuit evaluates both the utilization of the WLAN(s) and any remaining communications channels and determines whether to operate the MIMO chains synchronously as a single radio or asynchronously as multiple radios. The chain partitioning circuit either partitions subsets of the MIMO chains for asynchronous operation as distinct radios or combines all MIMO chains for synchronous operation as a single radio. The switchable RF filter bank is responsive to a partitioning of subsets of the chains into distinct radios to add RF filters to a RF portion of the chains to isolate each radio from one another, and responsive to a combining of all MIMO chains into a single radio to remove all RF filters.

A method and system for providing sub-band whitening are herein provided. According to one embodiment, a method estimating an interference whitening (IW) factor based on a legacy-long training field (LLTF) signal, updating the estimated IW factor during transmission of a data symbol, and scaling the data symbol based on the updated IW factor and the estimated IW factor.

Orthogonal frequency division multiplexing schemes are described for power line communications to combat frequency-selective fading and intersymbol interference. These orthogonal frequency division multiplexing systems may employ space-time coding and/or parallel cancellation to provide low receiver complexity, two-branch diversity, and much higher carrier-to-intercarrier-interference ratio as compared to other methods, such as self-cancellation.

In one embodiment, an apparatus includes first and second tuners to receive and process a radio frequency (RF) signal and output a first and second plurality of frequency domain sub-carriers. The apparatus may further include a combiner circuit to combine a first plurality of demodulated frequency domain sub-carriers and a second plurality of demodulated frequency domain sub-carriers into a plurality of combined frequency domain sub-carriers, and an output circuit coupled to the combiner circuit. In a first mode, the output circuit is to embed a format indicator with each of the plurality of combined frequency domain sub-carriers to indicate a frequency domain format, and to output the plurality of combined frequency domain sub-carriers with the embedded format indicator to a downstream processing circuit for channel decoding.

Disclosed are a wireless transmitter and a reference signal transmission method that improve channel estimation accuracy. In a terminal, which transmits a reference signal using n (n is a non-negative integer 2 or greater) band blocks (which correspond to clusters here), which are disposed with spaces therebetween in a frequency direction, a reference signal controller switches the reference signal formation method of a reference signal generator between a first formation method and a second formation method based on the number (n) of band blocks. In addition, a threshold value setting unit adjusts a switching threshold value based on the frequency spacing between band blocks. Thus, the reference signal formation method can be selected with good accuracy and, as a result, channel estimation accuracy is further improved.

In one embodiment, an apparatus includes first and second tuners to receive and process a radio frequency (RF) signal and output a first and second plurality of frequency domain sub-carriers. The apparatus may further include a combiner circuit to combine a first plurality of demodulated frequency domain sub-carriers and a second plurality of demodulated frequency domain sub-carriers into a plurality of combined frequency domain sub-carriers, and an output circuit coupled to the combiner circuit. In a first mode, the output circuit is to embed a format indicator with each of the plurality of combined frequency domain sub-carriers to indicate a frequency domain format, and to output the plurality of combined frequency domain sub-carriers with the embedded format indicator to a downstream processing circuit for channel decoding.

A method and system for providing sub-band whitening are herein provided. According to one embodiment, a method estimating an interference whitening (IW) factor based on a legacy-long training field (LLTF) signal, updating the estimated IW factor during transmission of a data symbol, and scaling the data symbol based on the updated IW factor and the estimated IW factor.

A method includes: acquiring, by a second base station, time-frequency position information corresponding to cell key information of a first base station, where the time-frequency position information is used for determining a time-frequency position that is corresponding to the cell key information of the first base station and that is on a shared time-frequency resource, and the cell key information includes at least one of a cell-specific reference signal (CRS), a channel state indication-reference signal (CSI-RS), a physical broadcast channel (PBCH), and a synchronization signal. The method also includes performing, by the second base station, interference coordination on the first base station.

Systems and methods are provided for phased array passband calibration, which permits repeated calibration of the antenna system in the field without a moving far field sensor. An implementation includes an equalization filter coupled to a phased array feed; a calibration probe disposed to couple with an antenna array to transfer radio frequency (RF) energy; a database of probe-to-far-field (FF) transforms having a probe-to-FF transform for each of a plurality of incidence angles; a calibration component operable to: receive calibration probe measurements for a plurality of frequencies; and determine a calculated phased array passband response for at least a first incidence angle, based at least on the calibration probe measurements and a probe-to-FF transform for the first incidence angle; and a filter generation component operable to generate a tuning configuration for the equalization filter, based at least on the calculated phased array passband response.

An adaptive filter includes a frequency domain adaptation block that analyzes a statistic of coefficient movement in the frequency domain. The adaption block adjusts, in the frequency domain, a parameter (step size or leakage factor) that affects speed of convergence of the adaptive filter based on the analyzed statistic of filter coefficient movement. The filter includes an associated coefficient, statistic of coefficient movement, and parameter for each frequency bin. The coefficients may be complex numbers, and separate real and imaginary statistics and parameters are maintained. The statistic may be direction counts of the filter coefficient movement. The step size may be adjusted to a predetermined minimum value when the current direction of movement of the filter coefficient is different than the predominant direction and otherwise the step size is adjusted approximately proportionally to an amount of predominance by a value based on a direction count of the filter coefficient movement.