On the performance of O3BPSK LDD with diversity combining techniques over fading channels

Zheng and Barton developed a convenient signaling scheme (orthogonal on-off BPSK (O3BPSK)) with a simple one-shot linear decorrelating detector (LDD) for near–far resistant detection in asynchronous DS/CDMA systems. This paper studies the performance of the O3BPSK LDD system over a frequency-nonselective and slowly fading channel. Three types of channel model are considered, namely Rayleigh fading, Nakagami-m fading, and Ricean fading. The analytical results show that channel fading causes a significant degradation in the performance of the O3BPSK LDD receiver. Nevertheless, the receiver still demonstrates a better near–far resistant property than a conventional CDMA receiver over fading channels. This study also analyzes the effect of two well-known diversity combining techniques on the O3BPSK LDD performance over Rayleigh fading channels. The results indicate that diversity combining techniques significantly improve the performance of the O3BPSK LDD scheme over fading channels.