Differential TDMA impulse radio systems using delay-sum scheme in UWB channel

Ultra wide-band (UWB) communication systems are expected to operate in a highly frequency-selective multipath fading environment. Multipath diversity gains can be collected to provide enhanced performance. To this end, we developed a differential time division multiple access (TDMA) impulse radio scheme that is tailored for multi-user UWB communications. In the system, the differential detector is adopted. The detector, when properly combined with the TDMA system, can fully exploit the multipath diversity of UWB channels. A novel delay-sum scheme is employed at the receiver to mitigate multi-user interference (MUI) and additive white Gaussian noise (AWGN). The proposed system shows better bit-error-rate (BER) performance than the conventional time-hopping impulse radio (TH-IR) system at high signal-to-noise ratio (SNR). Application of the system is promising because the receiver only needs to entail simple delay, integral and compare operations at the symbol rate