A Frequency-Domain LOS Angle-of-Arrival Estimation Approach in Multipath Channels

In this paper, we deal with the line-of-sight angle of arrival (AoA) estimation in a multipath channel, assuming that the first arrival path (FAP) contains the AoA information. We consider pulse transmission with a low duty cycle from the source and reception using an antenna array. We propose a simple approach that comprises the following four steps: 1) coarse frame synchronization; 2) frequency-domain channel estimation; 3) frequency-domain identification of the FAP delay with a threshold-based method; and 4) AoA estimation from the FAP coefficient. We compare the method with the joint angle and delay estimation multiple-signal classification (JADE MUSIC) algorithm. Despite the high complexity of the JADE MUSIC, our approach exhibits smaller root-mean-square error (RMSE) in the AoA estimation for various multipath channel scenarios that are characterized by different values of delay spread and angular spread correlation.