Efficient PGA LFSR Implementation Whitens Pseudorandom Numbers

Abstract

Linear feedback shift registers (LFSR) are commonly utilized in digital communication system simulations as noise and data sources because they are easily implemented and require minimal resources. However, the LFSR exhibits a deficiency common to all multiplicative congruential pseudorandom number generators (PNG). This class of PNG exhibits a correlation between successive values that gives an undesired low-pass characteristic to the generated sequence. This characteristic can affect the simulation results when whiteness of the pseudorandom random sequence is assumed. Several techniques have been proposed to mitigate this deficiency. In this paper we demonstrate how one of these proposed techniques, multiple-bit skip-ahead, can be efficiently implemented in programmable gate array hardware (PGA) so that under specific conditions, the computational complexity and required hardware resources are minimal.