An Iterative Algorithm and Low Complexity Hardware Architecture for Fast Acquisition of Long PN Codes in UWB Systems

Rapidly acquiring the code phase of the spreading sequence in an ultra-wideband system is a very difficult problem. In this paper, we present a new iterative algorithm and its hardware architecture in detail. Our algorithm is based on running iterative message passing algorithms on a standard graphical model augmented with multiple redundant models. Simulation results show that our new algorithm operates at lower signal to noise ratio than earlier works using iterative message passing algorithms. We also demonstrate an efficient hardware architecture for implementing the new algorithm. Specifically, the redundant models can be combined together so that memory usage can be reduced substantially. Our prototype achieves a combination of performance and complexity not possible with traditional approaches.