Study On Capacity Of Ultra-Wideband Communication System

As an emerging transmission scheme for short-range wireless communications, ultra-wideband (UWB) has become a key technology for high-data-rate wireless applications, such as wireless USB and wireless 1394. In this paper, we investigate the capacity of time-hopping UWB(TH-UWB) and direct-sequence UWB (DS-UWB) communication systems, correct the formula of bit error probability (BEP) given by G. Durisi and propose a new capacity formula taking into account of more practical factors in UWB system.In the capacity research of UWB communication, we consider the multi-user interference and multi-path interference, we also consider the orthogonal of pseudo noise (PN) code keep or has been destroyed in DS-UWB. Numerical simulation results show that the performance of DS-UWB communication system(PN code's orthogonal keep) is superiority than TH-PPM UWB in multipath AWGN channel; When the number of user increase, the performance of DS-UWB(PN code's orthogonal has been destroyed) will deteriorate; In this occasion, the performance of TH- UWB is superior than DS-UWB(PN code's orthogonal has been destroyed).