Iterative Random Search for Optimal One-Bit Precoding in Massive MIMO Downlink

We propose a simple low-complexity iterative random search (IRS) algorithm based on dithering for optimal one-bit precoding, to find transmitted signals for a base station equipped with one-bit transmitters to serve multiple users in massive MIMO downlink. The complexity increases linearly with the number of transmitter antennas and we may even achieve the global optimal performance in the worst case single user scenario. The analysis shows that the error vector magnitude (EVM) of the signals arrived at the users is inversely proportional to the square of the ratio between the number of transmitter antennas and the number of the users. We can achieve about -40 dB EVM when the ratio is 200.