Direct-sequence code division multiple access for ultra-wide bandwidth impulse radio

In this paper, we propose direct sequence (DS) code division multiple access (CDMA) for ultra-wide bandwidth (UWB) impulse radio communications. The main design issues are outlined and performance is estimated in additive white Gaussian noise (AWGN). The performance of DS/CDMA is compared with that of time hopping (TH) using pulse position modulation (PPM). Both uncoded and convolutionally coded transmissions are considered.