DS/SS code acquisition using a locally suboptimum rank detector

In this paper signed-rank based nonparametric detectors are used for pseudonoise (PN) code acquisition in direct sequence spread spectrum (DS/SS) systems. We first derive the locally optimum rank (LOR) detector and then propose a locally suboptimum rank (LSR) detector and a modified signed-rank (MSR) detector using approximate score functions. We compare the single-dwell scheme without the verification node using the proposed LSR and MSR detectors with that using the conventional squared-sum (SS) and modified sign (MS) detectors. From the simulation results, it is shown that the proposed LSR and MSR detectors perform better than the MS detector by about 2/spl sim/3 dB and are nearly optimum.