Cooperative Scheme for Cell-free Massive MIMO with Radio Stripes
Yihua Ma, Zhifeng Yuan, Guanghui Yu, Yijian Chen
Abstract
To fulfill challenging requirements of 6G, cell- free massive MIMO can be used to provide ubiquitous connectivity for multiple users. There are two kinds of cell-free schemes: centralized and distributed. Centralized schemes suffer from high fronthaul loading, while distributed schemes have some performance degradation. This paper proposes a cooperative scheme to avoid these drawbacks. Unlike conventional schemes, the proposed scheme employs a spatial combining jointly using access points and central processing unit. A novel cooperative regularized zero-forcing (C-RZF) algorithm is employed, which derives from minimum-meansquare-error processing. Simulation results show that the proposed scheme is able to gain a performance close to centralized MMSE using a fronthaul cost as low as simple distributed schemes, which makes it very suitable for practical implementations.