Effect of beampattern on directional beacon based position location algorithm for UWB systems

Motivated from the results of previous studies, we aim to evaluate the effect of antenna beampattern on the performance of directional beacon based position location algorithm in this paper. We make use of earliest arrivals to detect the line of sight components. Directional beacons are generated using four element uniform linear antenna array (ULA) at the transmitting nodes. To achieve narrow beamwidth, we design the beampattern using Dolph-Chebyshev method that provides a way to tradeoff beamwidth for sidelobes level in an optimum manner. Simulation results show that the minimum error in time estimation (consequently position location) does not occur at the minimum beamwidth. The increase in range estimation error at the minimum beamwidth is due to the significant sidelobes level at this point. Through simulation results, we show that the minimum error in range estimation occurs at 0.33 rad beamwidth for 20 dB SNR case.