A novel spreading sequence and its performances for code-diversity in DS/CDMA communication systems

This paper proposes a novel spreading sequence for code-diversity in direct sequence/ code division multiple access (DS/CDMA) communication systems. In code-diversity, a composite sequence which is a sum of several branch sequences is adopted. By the proposed sequences, both the composite sequence and the branch sequences can be constructed from digital signal. Therefore, the hardware of the system can be simplified. By evaluations of computer simulations, bit error rate (BER) performance of the system to suppress multiple access interference (MAI) has a little degradation compared with that of the system using a conventional analog composite sequence. However, it can be obtained almost same BER performance of the system using a previous digital composite sequence by analog branch sequences.