The auxiliary beam pair (ABP) method processes the outputs of a pair of beams to estimate the angular location of the desired receiver in a line-of-sight (LOS) millimeter wave wireless link. We show that wrong beam selection occurs about 50% of the time, even at high signal-to-noise ratio (SNR), when the desired receiver is at or near boresight of one of the beams, when certain constraints on beam separation and isotropic antennas are used. We further show that, depending on the SNR, the angle errors induced by wrong beam selection can range from 5 to 45 degrees. While the constraints enable analytical inversion of the discriminant function, they cause coincident nulls of the beams. These coincident nulls contribute to wrong beam selection. We show that slight reductions in the beam separations in the ABP method eliminate coincident nulls and reduces the root mean squared error in estimated angle by as much as 54.88%, at the cost of a small reduction in the field of view of the scanned beams and the requirement of a look-up table.
Impact of Wrong Beam Selection on Beam Pair Scanning Method for User Discovery in mmWave Systems
2020-05-01
200116 byte
Conference paper
Electronic Resource
English