High-Precision Phase-Based Ranging Algorithm in Multipath Environments

With the development of the internet of things (IoT), localizing IoT gadgets has become very important, which can benefit various applications. Using the ranging-based method for target localization only needs a single antenna, which is very suitable for size-constrained IoT devices. However, phase errors due to the lack of time synchronization between the transmitter and receiver and multipath effects usually seriously affect the accuracy of ranging. This paper uses the two-way channel response to eliminate the phase errors. Then, the generation of additional unknown multipath signals is suppressed by taking the square root of the two-way channel response. Finally, the orthogonal matching pursuit (OMP) algorithm is used to estimate multipath signals. Experiment results show that the proposed method can achieve high-precision ranging in indoor multipath environments.