A Low Complexity UWB Localization Algorithm Using Finite-Resolution Quantization

Impulse radio ultra wideband (IR-UWB) technique has attracted interest in indoor localization thanks to its sub-nanosecond (ns) narrow pulse feature offering high timing resolution. However, measuring these short pulses demands high performance analog-to-digital converter (ADC), i.e. 4 giga Hz 8-bit ADC, which is hard to implement in real systems. In this paper, a finite-resolution (FR) quantization based localization method is proposed, revealing that high performance ADCs can be replaced with high speed comparators since a 2-bit quantization is good enough. At first we approximate the post-quantization signal as Gaussian distributed using Bussgang theorem, facilitating the following derivation. Then, practical TOA estimation and iterative Taylor-series (TS) localization algorithm are derived. Subsequently the analytical expressions of Cramer-Rao lower bound (CRLB) of proposed scheme is obtained, theoretically quantifying the performance loss caused by FR quantization. Finally, compared with the full-resolution and signal-strength (SS) approaches via simulation, we prove that our finite-resolution algorithm achieves almost the same performance as traditional full-resolution scheme while dramatically decreasing the complexity.