Residue number system based multiple code DS-CDMA systems

A novel multi-code direct-sequence code division multiple-access (DS-CDMA) system based on the so-called residue number system (RNS) or the redundant residue number system (RRNS) is proposed. Concatenated codes employing RNS product codes (RNS-PC) as the inner codes and non-binary Reed-Solomon (RS) codes as the outer codes are adopted to improve the system performance. The results show that, for a given outer RS code and a given number of moduli of the inner RNS-PC, the performance of the system can be optimized by varying the relative number of information moduli and redundant moduli of the inner RNS-PC, as well as by appropriately choosing the moduli's values.