What is disclosed is a method for wireless communication comprising receiving a wireless communication via a receiver of the mobile communication device, deriving a demodulation reference signal from a first plurality of symbols of the wireless communication; creating a channel estimation matrix using the demodulation reference signal; inverting the channel estimation matrix to obtain a channel pseudo-inverse matrix; deriving a tracking reference signal from a second plurality of symbols of the wireless communication; calculating a phase shift for one or more additional symbols based on the tracking reference signal; determining a corrected channel pseudo-inverse matrix for the one or more additional symbols by adjusting the channel pseudo-inverse matrix according to the calculated phase shift; and controlling the receiver to accomplish data detection using the corrected channel pseudo-inverse matrix on one or more orthogonal frequency division multiplexing subcarriers.

The application provides a short training sequence design method and apparatus. The method includes: determining a short training sequence, where the short training sequence may be obtained based on an existing sequence, and the short training sequence with comparatively good performance may be obtained through simulation calculation, for example, by adjusting a parameter, and sending a short training field on a target channel, where the short training field is obtained by performing inverse fast Fourier transformation IFFT on the short training sequence, and a bandwidth of the target channel is greater than 160 MHz.

Disclosed are a robust method and device for estimating frequency offset in orthogonal frequency division multiplexing communication. The method includes: performing frequency-domain cyclic shift cross-correlation on preprocessed signal sequences with a short training field sequence in multiple symbol periods respectively in an initial signal receiving stage to obtain a cross-correlation result set; detecting a short training field signal according to the cross-correlation result set; when the short training field signal is detected, performing rough frequency offset estimation to obtain a rough frequency offset estimation value; performing rough frequency offset compensation according to the rough frequency offset estimation value; fixing the rough frequency offset estimation value, performing fine frequency offset estimation, and compensating residual frequency estimation; detecting a long training field signal to obtain a frame boundary; and performing channel estimation to obtain a final signal.

Aspects of this disclosure relate receiving a reference symbol from at least one antenna. The reference symbol includes a portion of a first transmitted reference symbol and a portion of a second transmitted reference symbol. The first transmitted reference symbol includes a symbol and a cyclically shifted portion of the symbol having a cyclic shift length. The second transmitted reference symbol includes a cyclically shifted version of the first transmitted reference symbol that is cyclically shifted relative to the first transmitted reference symbol by the cyclic shift length. The reference symbol is processed. In certain embodiments, processing the reference symbol can account for (i) a frame offset between uplink symbols and downlink symbols and (ii) another timing offset between downlink transmission and uplink reception.

A method for synchronizing baseband clocks in an OFDMA wireless microphone system is disclosed. An example method includes receiving a plurality of pilot subcarriers from an audio transmitter. The method also includes determining a timing offset estimate based on the pilot subcarriers. The method further includes determining a tuning value by passing the timing offset estimate through a proportional-integral controller. The method still further includes determining a modified reference signal by modifying a reference oscillator based on the tuning value. And the method yet further includes controlling (i) an audio sample clock and (ii) an antenna data clock based on the modified reference signal.

Disclosed are a method for transmitting and receiving a signal by a terminal and a base station and a device supporting same. More particularly, disclosed are a method for transmitting and receiving a signal by a base station or a terminal by means of applying a beam-forming method which varies for each predetermined resource region, and a device supporting same.

A base station for transmitting a synchronization signal from N transmission antennas (N>=2) in orthogonal frequency division multiple access includes a signal sequence generation unit configured to generate a synchronization signal sequence to be used for the synchronization signal in a frequency domain; a subcarrier mapping unit configured to divide a transmission band of the synchronization signal into K frequency blocks (K>=2) and map the synchronization signal sequence into one or more subcarriers in the K frequency blocks; a precoding unit configured to generate N precoding vectors to be multiplied by the synchronization signal sequence in the frequency domain and multiply the synchronization signal sequence to be transmitted from an n-th antenna (1<=n<=N) by at least an n-th precoding vector; and a transmission unit configured to transmit the synchronization signal from the N transmission antennas.

A plurality of multicarrier signals is generated. Each of the plurality of multicarrier signals includes a pilot symbol sequence at a same temporal point in each multicarrier signal. Each pilot symbol sequence includes a plurality of pilot symbols with non-zero amplitude. The pilot symbol sequences are orthogonal to each other at the same temporal point. A quantity of the plurality of pilot symbols in each pilot symbol sequence is greater than or equal to a quantity of the plurality of multicarrier signals to be transmitted. The plurality of multicarrier signals are transmitted in an identical frequency band from a plurality of antennas. The plurality of antennas includes two, three, or four antennas.

Techniques are described for carrier frequency offset (CFO) and channel estimation of orthogonal frequency division multiplexing (OFDM) transmissions over multiple-input multiple-output (MIMO) frequency-selective fading channels. A wireless transmitter forms blocks of symbols by inserting training symbols within two or more blocks of information-bearing symbols. The transmitter applies a hopping code to each of the blocks of symbols to insert a null subcarrier at a different position within each of the blocks of symbols, and a modulator outputs a wireless signal in accordance with the blocks of symbols. A receiver receives the wireless signal and estimates the CFO, and outputs a stream of estimated symbols based on the estimated CFO.

A wireless apparatus includes a channel estimation part that acquires an estimated impulse response which is an estimate value of an impulse response of a channel between a wireless terminal and the wireless apparatus, a tap location error detection part that detects a tap location error between estimated impulse responses at different time points out of the estimated impulse responses, and a channel prediction part that calculates a predicted impulse response which is an impulse response of the channel at a future time point by using the estimated impulse responses and the tap location error.