Constrained LS Channel Estimation for Massive MIMO Communication Systems

In recent years, the manufacturing of mobile and IoT devices has increased dramatically. For the service provider, the requirement for high throughput and extensive connectivity became a major obstacle. In B5G and 6G, different advanced technologies have been introduced to cater demands of users effectively. One of the most important technologies of nextgeneration networks is massive MIMO systems. In multiuser communication systems, transmission and reception of signals occur simultaneously which creates multiuser interference (MUI). The presence of MUI in the system is the major challenge for the effective operation of massive MIMO receivers. The influence of MUI must be minimized using a channel estimation technique in order to fully utilize the capabilities of a massive MIMO system. This work proposes the constrained least square (LS) channel estimate technique to improve the massive MIMO downlink system's overall performance. The Mean Square Error shows that the unconstrained LS performance is poor as compared to the constrained LS channel estimation. Additionally, the effectiveness of the proposed constraint LS channel estimate is assessed in communication systems using varying transmission antennas at the base station and number of users.