Energy Efficiency of Uplink Cell-Free Massive MIMO With Transmit Power Control in Measured Propagation Channel

Cell-free massive MIMO (CF-mMIMO) provides wireless connectivity for a large number of user equipments (UEs) using access points (APs) distributed across wide area with high spectral efficiency (SE). The energy (EE) the uplink is determined by (i) transmit power control (TPC) algorithms, (ii) numbers, configurations, and locations APs UEs, (iii) propagation channels between UEs. This paper investigates all three aspects, based on extensive (~30,000 possible AP 128 UE locations) channel measurement data at 3.5 GHz. We compare different TPC namely maximization (max-power), minimum SE (max-min SE), EE EE) while guaranteeing target SE. also various antenna arrangements including fully-distributed semi-distributed systems, where can be located regular grid or randomly, UEs placed in clusters far apart. Overall, we show that max-min highly effective improving EE, especially when no within set served bad condition BS antennas are fully-distributed.