On the channel capacity of communications with low-resolution ADCs over fading channels

Future wireless systems are expected to rely on large antenna arrays at the base station (BS) to meet growing demands for data rates. However, the power consumption and hardware complexity of high-resolution analog-to-digital converters (ADCs) pose significant challenges to the practical deployment of such arrays. Low-resolution ADCs offer a power- and cost-effective alternative, motivating a deeper understanding of information-theoretic limits with low-resolution quantization. This letter establishes capacity scaling laws for both single-input single-output (SISO) and multi-antenna systems with low-resolution quantization. We show that, unlike the classical O (log SNR) capacity growth in unquantized systems, the capacity of low-resolution systems approaches n at a rate O ((Formula presented)) for SISO and multiple-input single-output (MISO) systems, where n is the number of quantization bits and SNR is the signal-to-noise ratio. For single-input multiple-output (SIMO) systems, the scaling follows O ((Formula presented)) , where N_r is the number of receive antennas. These findings offer valuable insights for future wireless system design.