Biorthogonal pulse position modulation for time-hopping multiple access UWB communications

In this paper, we propose a new modulation scheme called biorthogonal pulse position modulation (BPPM) for ultra-wideband (UWB) communication systems. A set of N=2^k+1 BPPM signals are constructed from 2^k orthogonal PPM signals by including the antipodal version of the orthogonal PPM signals. The channel capacity of BPPM is determined for a time-hopping multiple access UWB communication system. The error probability and performance bounds are derived for a multiuser environment. It is shown that N-ary BPPM has better performance than N-ary PPM with the same throughput and half the computational complexity.