A novel orthogonal minimum cross-correlation spreading code in CDMA system

Abstract

Code Division Multiple Access (CDMA) had been used as an emergent technology in present generation Wireless Communication System. In CDMA system, a large number of users could be served over the same bandwidth by assigning a unique code to each of the users. In order to support large number of users in CDMA system, one of the primary objectives of the mobile system designers had been to create a large number of spreading codes by maintaining low Cross-correlation values between them to mitigate the effect of Multiple Access Interference (MAI). In this paper, we have proposed an algorithm to generate an “Orthogonal Minimum Cross-correlation Spreading Code” (OMCCSC), which can provide a large number of distinct spreading codes as compared to the existing orthogonal and near orthogonal spreading codes, namely Walsh code, Orthogonal Gold code and Orthogonal Kasami code. The study of cross-correlation property of the proposed code proves its superiority over other existing codes. The proposed code has been used as a spreading code in synchronous CDMA system and its Bit Error Rate (BER) performance has been compared with other existing spreading codes, in multi-user scenario.