Study on M-ary spread spectrum systems using zero correlation zone code

The M-ary spread spectrum systems with zero correlation zone (ZCZ) sequences were fabricated and investigated. The results show that the above systems are of stronger anti-multipath interference ability than the Walsh sequences M-ary spread spectrum systems (M-ary SSS). In the case of 2 number of multipath and 0.9 reflecting coefficient, for BER=4E-3, the degradation of the S/N is only 0.3 dB in ZCZ sequence 4-ary SSS and about 3.8 dB in Walsh sequence 4-ary SSS. The degradation phenomenon of the latter becomes much significant as the decreasing of BER. These results indicated that ZCZ sequences are suitable to be used as M-ary spread spectrum sequence and the present systems are of high spectrum efficiency and strong anti-multipath interference ability.