This research focuses on performance of two ultra wide band (UWB) techniques for implementing multiple access (MA) communications. Specifically, a Gaussian monocycle with time hopping pulse position modulation (TH-PPM) and direct sequence binary phase shift keying (DS-BPSK) is considered. Previous research on UWB system performance using Gold spreading sequences forms the basis for this work. The knowledge base of UWB MA performance characterization is expanded here using codes generated from a random integer selection process and a simulated annealing code generation process. Communication performance is first validated for a single user operating over an AWGN channel and subsequently extended to incorporate multiusers, TH-PPM with Gold coding provides an average MA BER improvement factor of 2.0 /spl times/ 10/sup -2/ and 5.1 /spl times/ 10/sup -2/ over random integer and simulated annealing codes, respectively. Likewise, DS-BPSK with Gold coding provides an average MA BER improvement factor of 3.8/spl times/ 10/sup -4/ and 9.8 /spl times/ 10/sup -4/ over random integer and simulated annealing codes, respectively.
['Courtney M. Canadeo', 'Michael A. Temple', 'Rusty O. Baldwin', 'Richard A. Raines']
Code selection for enhancing UWB multiple access communication performance using TH-PPM and DS-BPSK modulations