A Selective Signal Combining Scheme for Noncoherent UWB Systems

We propose a selective signal combining scheme to effectively improve bit error rate (BER) performance of noncoherent ultra wide band (UWB) systems utilizing binary pulse position modulation (2PPM) based on impulse radio. First, to effectively combine multipath components at the noncoherent UWB receiver, the proposed scheme preserves the energies during the pulse width interval for the received UWB signals. Next, it calculates the approximate signal-to-noise ratio (SNR) by comparing the difference in signal energies during the pulse width interval. Finally, the proposed scheme selectively combines the preserved signal energies in order of the estimated SNR, and then performs signal detection. Hence, the proposed scheme provides effective signal combining which is proper for noncoherent 2PPM UWB receivers, thereby significantly improving BER performance compared to conventional noncoherent UWB receivers.