Multiuser Massive MIMO Relaying With Mixed-ADC Receiver

In this letter, a multiuser relay network with massive multiple-input multiple-output is investigated with mixed-analog-to-digital converter (ADC) at receiver. We first characterize the uplink achievable rate by deriving a tight approximation, which embraces the conventional unquantized system as a special case. Both power scaling laws at sources and relay are presented. It is validated that the performance loss due to low-precision ADCs can be compensated by increasing the number of antennas M, obeying a logarithmical scaling law, rather than by increasing the transmit power at sources and/or relay. We show that the performance suffers from a loss factor interpreted as a nominal effective resolution of the entire mixed-ADC structure. Simulation results verify our observations.