TOA estimation after power transformation in IR UWB ranging with energy detection receiver

To improve time based impulse radio ultra wideband (IR UWB) ranging with energy detection (ED) receiver and make it easy to operate, we consider the power transformation in the study. TOA estimation accuracy depends on the detection of the first path (FP). However, the FP is hard to detect under low signal to noise ratios (SNR). Theoretically, the output of the receiver follows the central or non-central chi-squared distribution, but the distribution is not easy to operate. Many detectors are under the assumption that the signal is normally distributed. The power transformation can transform the non-normal signal into a normal one when the power transformation parameter is smaller than one. Traditionally, most do not use the transformation when the power transformation parameter is bigger than one. We find it useful. Then the transformed data in the noise region follow the lognormal distribution. Based on these characteristics, we can detect the FP in dense multipath. Simulation results under the IEEE 802.15.4a channels demonstrate that they are effective.