Polarity-Invariant Square Law Technology for Monobit Impulse Radio Ultra Wideband Receivers

In this paper, a novel nonlinear signal processing technology, which is denoted as the polarity-invariant square law (PISL) algorithm, is proposed to compensate nonlinear distortions caused by monobit digitization and to mitigate the performance degradation of impulse radio ultra wideband (IR-UWB) receivers employing monobit analog-to-digital converters (ADCs). An analytical framework based on characteristic functions has been developed to evaluate bit error rates of monobit transmitted-reference (TR) receivers and performance improvement offered by the PISL algorithm. Both theoretical analysis and simulations show that by employing the PISL algorithm, the monobit weighted TR (MWTR) receivers can achieve a bit-error-rate performance that is more than 10 dB over the direct-reference algorithm and is less than 1.5 dB away from the performance bound of the MWTR receivers in intravehicle UWB channels. Furthermore, the MWTR receiver employing the PISL algorithm is insensitive to a correlation interval; this feature not only reduces complexity of the receiver design but also ensures performance robustness over various multipath channels. Therefore, the PISL algorithm can be considered an enabling technology for the monobit IR-UWB receivers that demand high performance, lower power consumption, and low complexity.