Nonparametric PN code acquisition using the signed-rank statistic for DS/CDMA systems in frequency-selective Rician fading channels

In this paper, signed-rank based nonparametric detectors are used for pseudonoise (PN) code acquisition in frequency-selective Rician fading channels. We first derive the locally optimum rank detector and then propose the locally suboptimum rank (LSR) and kth order modified signed-rank (MSR_k) detectors using approximate score functions. We compare the hybrid parallel double-dwell scheme using the LSR and MSR_k detectors with that using the conventional squared-sum (SS) and modified sign (MS) detectors. From the simulation results, it is shown that the LSR and MSR_k detectors perform better than the SS detector using the cell averaging constant false-alarm rate processor and the MS detector by about 2-3 dB.