Spread Spectrum Communications Dual-antenna Diversity Techniques

Spread spectrum system features excellent anti-jamming performance and low power density. It has been one of the significant research subject in the wireless communication domain, and applied in many systems such as CDMA and WLAN. Suffering from the multipath fading in the wireless channel, the received signal will distort and fade. When the level of the received signal is below the detecting threshold, it will cause bit error. With the application of the diversity technology in spread spectrum system, it will improve the performance of wireless link, abate multipath interference and decrease system bit error rate.Based on the antenna diversity and RAKE diversity, a new dual-antenna RAKE diversity model is put forward which features optimum combining. When the system adopts low spread factor and multicode communication, the model will restrain the interpath interference effectively, and reduce the system BER. Through concatenated combining the fingers of the dual-antenna RAKE receiver, it will increase the degree of freedom when the system is overloaded, and finally restrain the system CCI. Simulating the model, it approves that the system BER performance is extremely improved when adopting the dual-antenna RAKE model.