Sum Rate Analysis of Cell-Free Massive MIMO with 1-Bit ADCs and Comparator Networks

Abstract:
Cell-Free Massive MIMO (CF mMIMO) offers a compelling alternative to traditional cellular systems by leveraging distributed antennas and centralized processing to eliminate inter-cell interference. However, its practical deployment faces challenges due to the high cost and power demand of highresolution analog-to-digital converters (ADC)s at each access point (AP). This work explores using 1-bit ADCs to reduce energy and hardware complexity, coupled with a comparator network (CN) at each AP to mitigate quantization distortions. We analyze the sum rate performance of this extended architecture and show through simulations that adding CNs significantly improves the achievable sum rate. Notably, using a full CN with only 4 antennas outperforms the case of 1-bit ADCs with 8 antennas, highlighting that introducing CNs can yield greater gains than merely doubling the number of antennas.