The present prevent relates to a method of sparsifying a channel using beamforming in a wireless communication system, the method including inserting pilot symbols into resources allocated among resource elements constituting a time-frequency grid; calculating beamforming weights for sparsifying a beamformed time-domain channel; and beamforming frequency-domain channels of a plurality of antennas mapping the pilot symbols by using the beamforming weights.

Embodiments of inventive concepts are provided wherein a mobile device, such as a smartphone, may be configured to communicate with a base station, using a first mode, and to communicate with an access point using a second mode that comprises a level of security exceeding that of the first mode. The second mode communications between the mobile device and the access point are conducted over a short-range wireless link responsive to an identity of the mobile device and/or responsive to a biometric data being provided by a user of the mobile device. Such second mode wireless communications may include data relating to a financial transaction and/or other data that may require an increased level of privacy and/or security.

A method and apparatus may include receiving a transmission. The method can also include determining a sparsifying dictionary that sparsely approximates a data vector of the transmission. The determining the sparsifying dictionary includes performing a fast Fourier transform and/or an inverse fast Fourier transform. The method also includes configuring a filter based on the determined sparsifying dictionary.

The present application relates to an adaptive filter using resource sharing and a method of operating the adaptive filter. The filter comprises at least one computational block, a monitoring block and an offset calculation block. The computational block is configured for adjusting a filter coefficient, c.sub.i(n), in an iterative procedure according to an adaptive convergence algorithm. The monitoring block is configured for monitoring the development of the determined filter coefficient, c.sub.i(n), during the performing of the iterative procedure. The offset calculation block is configured for determining an offset, Off.sub.i, based on a monitored change of the filter coefficient, c.sub.i(n), each first time period, T.sub.1, and for outputting the determined offset, Off.sub.i, to the computational block if the determined filter coefficient, c.sub.i(n), has not reached the steady state. The computational block is configured to accept the determined offset, Off.sub.i, and to inject the determined offset, Off.sub.i, into the iterative procedure.

A receiver including an equalization component to receive a signal comprising a sequence of samples corresponding to symbols and generate an equalized signal with an estimated sequence of symbols corresponding to the signal. The receiver further includes a decision generation component to receive the equalized signal and generate, based on the equalized signal, a decision comprising a sequence of one or more bits that represent each symbol of the sequence of symbols and a confidence level corresponding to the decision.

A receiver to generate a first vector of a first sequence of a portion of symbols of a signal. The receiver further generates a second vector of a second sequence of the portion of symbols, wherein the second sequence comprises a flipped version of the first sequence. Based at least in part on the first vector and the second vector, a decision including a sequence of one or more bits that represent at least a portion of the signal and a confidence level corresponding to the decision are generated.

Wireless communications systems and methods related to over-the-air uplink-downlink (UL-DL) reciprocity calibration. A central unit transmits downlink (DL) calibration reference signal (RS) and a calibration request. The central unit receives, in response to the calibration request, a first uplink (UL) calibration RS and a first DL channel estimate associated with a first transmission point (TP) and a first wireless communication device. The central unit transmits a DL coordinated multipoint (CoMP) joint transmission signal according to an uplink-downlink (UL-DL) reciprocity calibration. The UL-DL reciprocity calibration is based on at least a first UL channel estimate based on the first UL calibration RS, the first DL channel estimate, a second UL channel estimate associated with a second TP and the first wireless communication device, and a second DL channel estimate associated with the second TP and the first wireless communication device.

One embodiment provides a network controller having physical interface (PHY) circuitry that includes transmitter circuitry configured to transmit data frames to a link partner over a channel link. The network controller also includes a link speed cycling module configured to cause the transmitter circuitry to transmit data frames to the link partner using at least one high rate link speed. The network controller also includes an equalization presets module configured to apply at least one equalization preset setting to the transmitter circuitry while the transmitter circuitry is transmitting the data frames to the link partner. The link speed module is further configured to cause the transmitter circuitry to dwell, for a transmitter dwell time period, for the at least one equalization preset setting at the at least one high rate link speed. The transmitter dwell time period allows the link partner to lock on to the transmitted data frames.

A method of estimating a channel for mobile systems with insufficient cyclic prefix length, wherein the channel comprises a plurality of multipath components (,), includes: receiving a signal (y.sub.n) comprising a plurality of contributions of a transmit signal (x.sub.n[k], x.sub.n-1[k]) transmitted during a plurality of transmission time intervals (n, n1) on a plurality of sub-carriers of known pilots (kP.sub.b) and a plurality of sub-carriers of unknown data (k.Math.P.sub.b); determining an estimate of the plurality of multipath components (,) based on a probabilistic relation between the plurality of first contributions (x.sub.n[k], x.sub.n-1[k]) of the transmit signal, wherein the plurality of first contributions are transmitted during adjacent transmission time intervals (n, n1), and an observation of the received signal (y.sub.n[k]) at a subcarrier (kP.sub.b) of the known pilots, wherein the probabilistic relation is based on statistical properties of the plurality of first contributions (x.sub.n[k], x.sub.n-1[k]) of the transmit signal.

The channel estimation method for millimeter-wave communication includes virtual multipath acquisition and sparse reconstruction. In the virtual multipath acquisition stage, instead of searching the real multipath components (MPCs), the virtual representation of the real MPCs is derived, and the hierarchical search is utilized to acquire the virtual MPCs based on a normal limited-resolution codebook. In the sparse reconstruction stage, the real MPCs are reconstructed from the virtual MPCs acquired in the virtual multipath acquisition stage. An enhanced sub-array scheme is used to design a hierarchical codebook under a strict constant-modulus constraint. The designed codebook can be used for both analog and hybrid beamforming/combining devices. The training overhead of channel estimation and the complexity of the search are significantly reduced, and the size of the dictionary matrix is greatly reduced by exploiting the results of the virtual multipath acquisition.