Uniform Linear Arrays With Optimized Inter-Element Spacing for LOS Massive MIMO

In this letter, a uniform linear array (ULA) is proposed for line-of-sight massive multiple-input-multiple-output (MIMO). It assumed that the number of antennas fixed. For given ULA with an arbitrary inter-element spacing, probability correlation among channel vectors two users being above threshold value derived. The spacing one which aforementioned minimized. To show effectiveness ULA, simulation results scenarios are 64-antenna serves 6 single-antenna users. By using instead conventional half-wavelength 5th percentile sum-rate zero-forcing precoder improved by 9.90 bits/channel use in first scenario without dropping, and 1.43 second dropping 1 user.