Packet-Size Based Overlapping User Grouping in MU-MIMO Systems

In multi-user multiple-input multiple-output (MU-MIMO) systems, user grouping methods have been proposed to improve network capacity. Most of the related papers focus on separating users according to their channel conditions and correlations between users. However, the packet size of users also has a significant impact on system performance, especially in Internet of Things (IoT) systems where there are lots of users with small-sized packets, and this is not investigated in those papers. Therefore, we propose a low complexity overlapping user grouping method considering packet size. On the premise of ensuring the rate and delay requirement of small-packet users, we increase the resources occupied by large-packet users to improve the system performance. To analyze the performance in more practical scenarios, we use 3D MIMO channel model in simulations. Compared with existing overlapping user grouping algorithms, our method achieves higher throughput and lower complexity order.