Pseudo-noise code regeneration based on noncommensurate sampling and dynamic clock phase shifting

Abstract

A pseudo-noise code regeneration method is proposed to break through the regeneration accuracy limit incurred by digital implementation. In this method, noncommensurate sampling is used to obtain subsample time-delay difference distinguishability, which is then employed to adjust the phase of the clock driving code regeneration using the dynamic fine phase shift capability of state-of-the-art FPGAs. The MATLAB-ModelSim co-simulation results show a code regeneration resolution of 11.3 ps and a greatly improved achievable code regeneration accuracy within 56.5 ps with a Vertex-6 FPGA. The method is especially suitable for precision ranging applications, and can be extended to other applications involving accurate signal regeneration in digital equipments.