Patent ID: 7254496
Filing Date: 2007-08-07
Classification: H04B

Abstract:
1. In a data demodulator that processes received baseband signals and provides soft-valued estimates of transmitted symbols, an estimator for estimating the average signal power of demodulated symbols as a function of a median based average power value m d and a mean based average power value m e of the demodulated symbols for each quadrant of a quadrature phase shift keying (QPSK) constellation, the estimator comprising: an input for receiving the demodulated signals; and means for performing the following calculation to determine an average signal power estimate E of the demodulated symbols where: wherein S k d is the k-th demodulated desired quadrature phase shift keying (QPSK) signal, Y k is the k-th demodulated symbol, Q i denotes the quadrants i of the QPSK constellation, median(Y k (Q i )) and mean(y k (Q i )) denote the median and mean values, respectively, of the demodulated symbols in the i-th quadrant Q i , and min([median value], [mean value]) represents a minimum value function for determining a minimum value between the median and mean values, wherein the data demodulator processes received baseband signals and provides soft-valued estimates of transmitted symbols based on the average signal power estimate E of the demodulated symbols as determined by the performing means of the estimator.