Coherent Delay-Locked Code Tracking Loop Using Time-Multiplexed Pilot for DS-CDMA Mobile Radio

摘要

Pilot symbol-assisted coherent delay-locked code tracking loop (PSA-CDLL) is proposed for DS-CDMA mobile radio. PSA-CDLL applies pilot symbol-assisted coher- ent channel estimation and uses only the in-phase component of the despread signal for controlling the received spreading code timing. The impact of the multiple access interference (MAI) and background noise can be decreased by about 3 dB compared to non-coherent DLL. The performance of the proposed PSA- CDLL is evaluated by computer simulation. Computer simula- tion results show that it can significantly reduce the rms tracking jitter of regenerated spreading code replica, thereby improving the bit error rate (BER) performance in fading environments.