Rejection of FHMA signal in DS spread spectrum system using complex adaptive filtering

The performance of a direct-sequence quadrature phase shift keying (QPSK) spread spectrum receiver using adaptive filtering to reject a frequency-hopping multiple access (FHMA) signal is analyzed. Two types of filters are considered: the adaptive prediction error filter and the adaptive transversal filter with two-sided taps. Time-frequency hopping signals in a FHMA system are based on the theory on linear or quadratic congruences or on modified Reed-Solomon codes. The basic parameters used for the evaluation are the filter processing gain, bit error probability, and the adaptation rate.