On the AOA Estimation Accuracy of Finite-Resolution Low-Rate IR-UWB Receiver

Impulse Radio Ultra-Wideband (IR-UWB) technology uses narrow pulses with nanosecond widths to estimate time of flight and angle of arrival, offering superior spatial resolution and robust multipath mitigation. Low-rate UWB technology, which uses low-repetition-rate pulses, has ultra-low power consumption and is advantageous in IoT applications. However, it loses most carrier phase information under finite resolution quantization, making angle of arrival estimation almost impossible. This paper proposes an angle of arrival estimation scheme for low-rate IR-UWB signals under ternary quantization. We used the interferometry method to directly measure the carrier phase between two UWB signals. Comprehensive simulations evaluated the algorithm’s performance across various scenarios, including free space and dense multipath environments. The results show that the proposed algorithm achieves high angle of arrival estimation accuracy even in dense multipath conditions while maintaining low computational complexity. This approach significantly enhances the ranging and angle estimation accuracy of finite resolution quantized IR-UWB systems. Actual measurements demonstrate that an autonomous UWB device using this method has an average accuracy about 50% higher than a commercial HRP UWB system.