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 (O^3BPSK)) 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 O^3BPSK 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 O^3BPSK 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 O^3BPSK LDD performance over Rayleigh fading channels. The results indicate that diversity combining techniques significantly improve the performance of the O^3BPSK LDD scheme over fading channels.