Multiuser Detection in Massive MIMO with Quantized Amplitude-Only Measurements

This correspondence researches the multiuser detection (MUD) in a new massive MIMO system, where the base station (BS) acquires the quantized amplitude-only (AO) measurements of the complex baseband signals through the envelop detection and low-resolution analog-to-digital convertor (ADC) sampling. Cumbersome frequency mixers are removed and low-resolution ADCs can easily reach the Giga-sample-per-second (GSPS) rate, so massive AO-MIMO has low power and low cost, and is especially suitable for millimeter-wave (mmWave) communication. A practical multiuser detector is constructed based on the Wirtinger-flow (WF) gradient method for phase retrieval (PR), and the message passing de-quantization (MPDQ) algorithm for the quantized compressed sensing (CS). It iterates between the missing phase estimation and signal reconstruction, and involves only matrix-vector multiplication as its complex operation. Simulation results validate the effectiveness of the proposed detector, and show that massive AO-MIMO can even perform similarly as the classical massive MIMO by adopting relatively more BS antennas.