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

Abstract

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 trans-mission 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 high-speed fronthaullink supporting several APs. Further, the MOE receiver exhibits performance closely approaching that of the MMSE detector across various practical scenarios.