Abstract: A method and apparatus to adaptively puncture bits within QAM modulated data symbols transmitted in a communication system in order to effect a signaling channel. The method and apparatus utilize inherent characteristics of a particular mapping scheme for the QAM constellation to selectively puncture particular bits within a data symbol with signaling information and predetermined binary values to selectively increase the log-likelihood ratio gains of those particular bits punctured with the signaling information. The log-likelihood ratios are used to obtain the signaling information and, thus, increasing the gain of the log-likelihood ratios affords greater reliability for the signaling information without increasing the required system resources.

Abstract: A receiving communication device synchronizes to a timing reference of a transmitting communication device based on a determined timing error. The receiving communication device determines the timing error by processing a synchronization signal via a first stage filtering and interpolation process that includes predetermined coefficients and a second stage interpolation process that includes a minimal number of dynamically determined coefficients. By dividing the process into a predetermined coefficient stage and a dynamically determined coefficient stage, the receiving communication device is able to make timing adjustments in a more efficient manner, that is, at a lesser processor loading, than a communication device in which all filtering and interpolation coefficients are dynamically determined.

Abstract: A method, apparatus and system for use in determining a pilot-to-data power ratio by receiving a data symbol (122) having a data amplitude, receiving a pilot signal (124) having a pilot amplitude, reverse training (350) an automatic gain (154) based on the data amplitude and the pilot amplitude, and determining a pilot-to-data power ratio (250) according to the reverse training of the automatic gain. In some embodiments the method further compensates for channel fading in the data symbol by providing for channel correction (340) on the data symbol, providing for channel correction (344) on the pilot signal and dividing the channel corrected data symbol by the channel corrected pilot signal providing a fading compensated data symbol, where the fading compensated data symbol (150) is provided prior to reverse training such that the reverse training is based at least in part on the fading compensated data symbol.

Abstract: A method and apparatus to efficiently calculate log-likelihood ratios for each bit within M-ary QAM modulated symbols transmitted in a communication system. The method and apparatus utilize characteristics of square Karnaugh mapping of the QAM symbol constellation in order to reduce the number of distance calculations needed to determine the log-likelihood ratios for each of the bits within a demodulated symbol. The reduction in the number of calculations affords significant reduction in the time needed to determine log-likelihood ratios, especially for higher order M-ary QAM systems.

Abstract: A method and system for dynamic rate switching via medium access channel layer signaling is disclosed, wherein data rates for high data rate channels are automatically shifted up or down based on a predetermined metric. In a preferred embodiment, data rates are automatically shifted up or down based on transmit channel gain required to maintain a required signal to noise ratio.

Abstract: A method and system for retransmitting data packets in a communication system having variable data rates is disclosed. In a preferred embodiment, data packets are packetized to an atomic packet size equal to that of a lowest rate packet. If a data packet requires retransmission at a rate different than that at which the data packet was initially transmitted, the rate is dynamically changed based upon a multiple of the atomic packet size.

Abstract: A current mode of operation is provided to a Walsh spreader (203), and based on the current mode of operation, the Walsh spreader (203) either varies a Walsh code at a symbol rate, or holds the Walsh code constant. During multi-carrier transmission a first symbol within a data stream (210) is spread with a first Walsh code, while symbols immediately preceding and following the first symbol are spread by a another, differing Walsh code. The sequence of Walsh codes exiting the spreader (201) is further scrambled by a pair of Pseudo-Noise (PN) codes (224) that are held constant for three Walsh code periods during multi-carrier transmission, and are not held constant during direct-spread transmission.

Abstract: A current mode of operation is provided to a Walsh spreader (203), and based on the current mode of operation, the Walsh spreader (203) either varies a Walsh code at a symbol rate, or holds the Walsh code constant. During multi-carrier transmission a first symbol within a data stream (210) is spread with a first Walsh code, while symbols immediately preceding and following the first symbol are spread by a another, differing Walsh code. The sequence of Walsh codes exiting the spreader (201) is further scrambled by a pair of Pseudo-Noise (PN) codes (224) that are held constant for three Walsh code periods during multi-carrier transmission, and are not held constant during direct-spread transmission.