Adaptive hybrid DS/SFH spread-spectrum multiple access communications

Abstract

The performance of coherent reception in asynchronous hybrid-direct/slow-frequency-hopped spread-spectrum multiple-access communications system operating through lognormal shadowing is investigated. System with BPSK and GMSK modulations and demodulations, as well as systems with adaptive filter (DFE) equalizer are examined and their probability of error is evaluated. Comparison of hybrid systems without and with adaptive equalizer using BPSK and GMSK modulation technique shows a considerable improvement in the performance of the system with adaptive equalizer and GMSK modulation outperform the BPSK modulation.