Two-Stage Code Acquisition Employing Search Space Reduction and Iterative Detection in the DS-UWB Downlink

In this paper we propose and investigate an iterative code acquisition scheme assisted by both search space reduction and iterative massage passing (MP), which was designed for the direct sequence-ultra wideband (DS-UWB) downlink (DL). The performance of this iterative code acquisition scheme is analysed in terms of both the correct detection probability and the achievable mean acquisition time (MAT). We propose an improved criterion for designing the iterative MP based two- stage acquisition regime. Our proposed scheme is capable of reducing the MAT by several orders of magnitude compared to the benchmark scenarios, when considering the employment of long pseudonoise (PN) codes suitable for a variety of applications.