Selective User Forwarded Cell-Free Massive Mimo with Quantized Symbols

We consider the uplink of a Selective User-Forwarded Cell-free massive MIMO (SUF-CF-mMIMO) system, where each access point (AP) forwards the received symbols of only a selected subset of users to the centralized processing unit (CPU) for coherent combining. SUF-CF-mMIMO gives significant savings in fronthaul signaling compared to the conventional CF-mMIMO. This paper investigates the uplink performance of SUF-CF-mMIMO with one-bit quantized symbols sent over the fronthaul to the CPU by each AP. Novel expressions for spectral efficiency (SE) are derived for the uplink in the presence of quantization distortion. Simulation results show that SUF-CF-mMIMO is more robust to quantization effects compared to the conventional CF-mMIMO.