Low Complexity Receiver for Cell-Free mMIMO Networks with THz Wireless Fronthaul Connectivity

Recently, there has been a transition from fiber-based to mm-wave wireless fronthaul connectivity from access points (APs) to the central processing unit (CPU) of the cell-free architecture. In this paper, we analyze the performance of an uplink cell-free network assisted by fronthaul connectivity over the THz band. We also develop a multiuser detector based on the minimum output energy (MOE) criteria for uplink transmission of the considered network. The MOE receiver can be continuously adapted using real-time received signals without explicit knowledge of the noise-covariance matrix estimated during training, as required by the minimum mean square error (MMSE) based receivers. We evaluate the performance of the proposed detector by deriving analytical expressions for signal-to-noise ratio (SNR) and per-user transmission rate. Our simulations indicate that the THz band can provide highspeed fronthaul link supporting several APs. Further, the MOE receiver exhibits performance closely approaching that of the MMSE detector across various practical scenarios.