Implementation of a Cloud-Based Cell-Free Distributed Massive MIMO System

With the ever increasing requirements for ultra efficiency, advanced technologies such as massive multiple-input multiple-output (MIMO) have been considered. By offering more flexility of antenna deployment, a distributed setup of a massive MIMO system can benefit from considerable efficiency improvement over the colocated counterpart. However, distributed massive MIMO antennas will result in design and implementation challenges regarding synchronization, calibration, real-time baseband processing, and so on. Thus, equipped with general-purpose processors, we propose a cloud-based cell-free distributed massive MIMO system, which can not only archive 5G NR requirements but also easily be extended to different application scales. As an illustrative example, a 128 x 128 distributed MU-MIMO system with frequency 100 MHz@3.5 GHz is given. Test results show that 10.185 Gb/s throughput and more than 100 b/s/Hz spectrum utilization can be obtained. Flexibly scaling to the target deployment density, this system can support various applications on cross-industry collaboration.