Noncoherent adaptive code synchronization for DS/CDMA systems

In this paper, a noncoherent adaptive code acquisition scheme is proposed by combining an adaptive filter with a differential detector. The carrier phase offset in the PN signal component of the filter input is removed by a differential detector. The probabilities for detection and false alarm are derived, and the mean acquisition time is evaluated under AWGN channel. The performance of the proposed system is compared with the conventional system using a matched filter. Simulation results show that the proposed system has a good performance under overall channel conditions, especially at low SNR. And the proposed system outperforms the matched filter by 4-6dB under AWGN channel for 16 taps, as measured by the mean acquisition time.