An ultra-wideband autocorrelation demodulation scheme with low-complexity time reversal enhancement

This paper presents a low-complexity time reversal technique as an enhancement for the ultra-wideband (UWB) communication system over ISI channels. Time reversal takes advantage of rich channel impulse response (CIR) to achieve signal focusing in both time domain and spatial domain. But implementing time reversal for UWB applications is extremely challenging. Aiming at designing a practical low-complexity UWB communication system, an autocorrelation demodulation (ACD) scheme with time reversal enhancement is considered. Nonlinear inter-symbol-interference (ISI) channel model and bit error rate (BER) formulae are derived. Major implementation related issues are discussed. Based on our numerical results, we find that the proposed simplified time reversal enhancement does work and significant gain over ordinary ACD scheme can be obtained in ISI scenarios. In addition, location based security supported by time reversal's spatial focusing property is also examined.