UWB Channel Impulse Response Alignment Techniques for Accurate Indoor Radio Sensing

A framework for the cost-effective, robust, and ubiquitous acquisition of hyper-reliable channel information encapsulated in channel impulse response (CIR) and other channel parameters relevant to diverse usage scenarios is one of the essential requirements for radio sensing. Due to its good temporal resolution, ultra-wideband (UWB) technology is promising to be included in the acquisition framework. The accuracy of the CIR estimated with commercially available UWB radios has to be comprehensively evaluated to satisfy the requirement for hyperreliable channel data. In this paper, we address the alignment problem of measured UWB CIRs that affects the accuracy of the final channel information provided for radio sensing. Correlation-based processing techniques for CIR alignment in the time domain are proposed as alternatives to the techniques based on the arrival time of the first multipath component provided by proprietary algorithms. Measurement campaigns using commercial IEEE 802.15.4 compliant radios and vector network analyzer (VNA) carried out in office and laboratory indoor environments confirm the validity of the correlation-based alignment techniques.