Advanced Micro Devices Corporation

Yong Li

Chien-Meen Hwang

Xu Zhou

Ping Hou

Christine Lee

An OFDM wireless transceiver uses a digital automatic gain control (AGC) module. The digital AGC module is configured for setting a gain to an initial gain value for mapping a received wireless signal to a first power value for an input circuit having a prescribed input range. The initial gain value is set relative to the prescribed input range and a prescribed signal to noise ratio. If the digital AGC module determines that the first power value of the received wireless signal does not exceed the prescribed input range, the digital AGC module calculates an optimum gain for the received wireless signal relative to the initial gain value and the first power value; if the first power value exceeds the prescribed input range, the AGC module determines the optimum gain based on setting the gain to a minimum gain value.

Optimal initial gain selection for wireless receiver

A channel tracking module, configured for generating updated equalization coefficients for a frequency equalizer, is configured for determining a digital-based error value between equalized signals output by the frequency equalizer relative to predicted signals, for each subcarrier frequency of an OFDM symbol. The channel tracking module determines an accumulated error based on accumulating the digital-based error values for all the subcarrier frequencies of the OFDM symbol, for a prescribed successive number of OFDM symbols. The channel tracking module also determines a step size based on the accumulated error and relative to a prescribed step function configured for optimizing equalizer adjustments within stability limits. The channel tracking updates the equalization coefficients for each subscarrier frequency based on the accumulated error and the step size. Hence, the channel tracking module can be implemented in an economical manner while ensuring optimum equalizer adjustments within stability limits that ensure convergence of the equalization coefficients.

Channel tracking using step size based on norm-1 based errors across multiple OFDM symbols

An OFDM receiver has an autocorrelation circuit configured for generating an autocorrelation result from samples of received short preamble symbols in a received data packet, where the autocorrelation circuit generates each autocorrelation result based on accumulation of the samples having been received for the short preamble symbols. Hence, by using all received samples of the short preamble symbols, the autocorrelation based on accumulated samples minimizes the effect of noise and provides a more accurate coarse frequency estimation result.

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Sunnyvale, CA, United States of America

Yong Li