M-ary Orthogonal Signal and BER Performance in Wireless Communication Systems

Abstract

We propose a novel M-ary orthogonal spread spectrum scheme in this paper. The proposed scheme can improve the communication performance and frequency efficiency of wireless communication systems. We detail the schedule for constructing of spreading codes and analyze the bit error rate (BER) performance. The results indicate that the proposed M-ary orthogonal signals can obtain better anti-noise performance than direct sequence spread spectrum (DSSS) system. In addition, the new scheme can dramatically improve the bit error performance of communication system, leading the BER curve to get closer to Shannon capacity. Analysis and simulation indicate that the influences of signal peaks can be eliminated by using the proposed scheme, and the scheme improves the efficiency of information transmission and information security. We also drive the closed average BER expressions of M-ary orthogonal signals with cyclic shifting operation in Nakagami-m fading channels. Simulation shows that the proposed scheme can achieve more than 5 dB coding gain at BER over the DSSS signal in additive white Gaussian noise (AWGN) channel.