Multiplex techniques of non-spread and spread spectrum signals

摘要

This paper proposes a multiplex technique of non-spread and spread spectrum (SS) signals and describes a technique to divide a multiplex signal in the receiver for using a frequency band effectively. In this paper a multiplex signal is where non-spread quadrature phase shift keying (QPSK) and direct sequence spread spectrum (DS-SS) signals are combined, and a pilot symbol is inserted for estimation of fading distortion. Then a technique to divide a multiplex signal in the receiver is proposed and using this technique, bit error rate (BER) performances of non-spread QPSK and DS-SS are calculated under additional white Gaussian noise (AWUN) and Rayleigh fading channels. According to results of BER performances of non-spread QPSK and DS-SS, the multiplex signal can be divided and data can be detected in the receiver. Therefore the proposed multiplex technique is an effective scheme for making good use of a limited frequency band.