Distributed Uplink Reception in Cloud Radio Access Networks: A Linear Coding Approach

Abstract

This paper considers an uplink cloud radio access network (C-RAN), in which L antenna terminals (ATs) are connected to a central process (CP) via digital error-free links of a finite-capacity R-0, and serves K user terminals. In this network, novel low-complexity detection methods at the CP are proposed by incorporating a lattice-quantize-and-forward (LQF) framework, which converts the C-RAN into an equivalent finite-field multiple-input-multiple-output (FF-MIMO) channel. In particular, under this equivalent FF single-input-multiple-output channel, an optimal receive combining method is presented by using a simple repetition code. In addition, using linear block codes, a low-complexity detection method is presented for the equivalent FF-MIMO channel. Finally, by simulations, it is demonstrated that the proposed detection method combined with the LQF framework provides high achievable sum rates for uplink C-RANs especially when a lot of low-cost ATs are deployed.