Performance of ZCZ codes in QS-DS-CDMA communication systems
Résumé
Zero correlation zone (ZCZ) codes have been recently adopted for many communication systems based on code division multiple access (CDMA). In this paper, we focus on the use of ZCZ codes in quasi-synchronous direct-sequence (QS-DS) CDMA. To ensure Interference-free communication, spreading ZCZ codes must be carefully designed. Indeed, numerous ZCZ code constructions with various correlation properties have been proposed and studied in literature. However, most of them are not adequately designed for communication systems. Here, we aim at determining specific criteria in order to choose the suitable ZCZ code family. A new bit error rate (BER) for QS-DS-CDMA as a function of the code's even and odd periodic correlation functions (PCFs) is derived. It is shown that the adequate spreading codes are those with zero even and odd PCFs