Angle of Arrival based Indoor Localization with Cooperative MIMO Beamforming Scheme

We present a novel angle of arrival (AOA) based indoor localization approach in multiple-input-multiple-output (MIMO) smart antenna system. We exploit the directivity property of the smart antenna array at both transmitter and receiver sides. In contrast to conventional AOA based localization approaches, our proposed localization method combines beam steering (beamforming) transmission and receiving approach, and uses Rician fading channel model in order to simulate a more realistic environment. By setting the beamforming weights, the access point (AP) only listens to a specific direction which allows suppressing the strong signals coming from scattered paths. The angle estimation is done by analysis of the obtained angle vs. power profile. For accuracy performance analysis, we derive the expression for the location error with respect to the estimated angle of the desired user, in the presence of Rician fading. Based on the simulation results, our proposed approach provides a meter or sub-meter level accuracy and a nearly 40% decrement of location error compared to the benchmark with 4 by 4 array configuration.