Multipath propagation is a major source of degradation in the performance of conventional PN code tracking loops. The mean-square tracking error of a conventional delay-locked loop (DLL) exhibits an irreducible floor due to the presence of closely spaced multipath components. In this paper, we present a new PN code tracking algorithm that does not suffer from the presence of multipath component...

Aimed at solving the problems of Precision code’s complex acquisition procedures and its long acquisition time in satellite navigation, this paper makes an architecture analysis of the commonly used direct acquisition algorithms of Precision code, making an improvement of the common local pseudorandom code based glide Fast Fourier Transform acquisition architecture. Besides those, it also puts ...

We propose a new scheme for rapid acquisition of PN signals in direct-sequence spread spectrum (DS/SS) systems by estimating the phase of the received PN signal with the use of an auxiliary signal. The auxiliary signal can be generated by a sum of the phase shifted PN signals. The phase of the incoming PN signal is estimated using the properties of cross correlation between the PN signal and th...

A new receiver architecture for PN code acquisition of signals with high Doppler shifts is proposed, in which the partially correlated outputs of the parallel section of a serialparallel correlator (SPC) are subject to an FFT process before being summed by the serial section. In this way a wider range of frequencies can be searched in a single dwell time, which is particularly useful in a LEOS ...

In this chapter, we propose to use a GO CFAR processor for PN code acquisition in DS/CDMA systems. We compare the single-dwell scheme without the verification mode using the GO CFAR processor with that using the CA and OS CFAR processors. From the simulation results, we can observe that the DS/CDMA systems with the GO CFAR processor has better performance than those with the CA and OS CFAR proc...

In this paper a new -type delay acquisition/tracking appro/ ach is proposed which is based on partitioning of the PN-code matrix of the CDMA users into submatrices which are then used to form a 'state-space' -type linear combiner. The proposed / novel formulation and approach is robust to modelling errors such as overand underestimation of the number of signals present and provides a powerful r...

AbstTactIn this paper, performance of PN code acquisition is analyzed for a DS/CDMA overlay system with imperfect power control. Acquisition performance is evaluated in terms of mean acquisition time using state transition diagram for acquisition process. To apply for a DS/CDMA cellular environments, the MA1 and imperfection of power control are taken into account in the analysis of acquisition...

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 the locally suboptimum rank (LSR) and modified signed-rank (MSR) detectors using approximate score functions. We compare the single-dwell scheme without the verificatio...

In this paper, we propose a novel matchedfilter-type parallel code acquisition scheme to detect uplink short-code wideband CDMA multipath signals. A treestructured parallel adaptive network of RAKE fingers is created for all possible delay shifts and users. Employing a sequential detection scheme, only viable fingers are used to generate the output decision statistics. Monte Carlo computer simu...