Enhanced-accuracy channel estimation and ranging for IR-UWB energy detectors

The high temporal resolution of impulse radio ultra wideband (IR-UWB) communication systems makes these systems capable of obtaining high accuracies in ranging and channel estimation. At the same time, the required sampling rates and the associated complexity often prohibit the use of conventional digital (coherent) receivers. The energy detector, a non-coherent receiver, employs low sampling rates but suffers from reduced performance. In this work, the idea of multiple pulse transmissions is exploited to obtain highly accurate channel and range estimates using the low-complexity energy detector. A frequency offset is introduced between the sampling clock and the pulse repetition frequency. It is shown that with proper post-processing the quality of the channel estimate can be significantly increased and that time-of-arrival estimation accuracies in the order of 0.3 ns can be achieved independently of the integration period, using a 500 MHz UWB signal. An appropriate receiver architecture is derived based on generic and IEEE 802.15.4a specific transmission parameters.