TOA Estimation Enhancement based on Blind Calibration of Synthetic Arrays

The accuracy of time of arrival (TOA) measurements is significantly compromised due to the multipath components which coexist with the desired line of sight (LOS) components in the received signal. Effective mitigation of multipath is offered by using an antenna array with beamforming capabilities. However, arrays are physically large and unwieldy from a signal processing perspective and hence not suitable for a small handheld device. In this paper, a receiver consisting of a single antenna that is moved arbitrarily in space forming a synthetic antenna is considered. Blind calibration of the resultant spatial array is achieved through the use of fourth order cummulants. As demonstrated in this paper, a synthetic array, based on this blind calibration method can practically enhance the LOS signal by suppressing multipath through spatial filtering and thereby improve the TOA performance. Monte Carlo simulations are performed to demonstrate the performance of the proposed method.