Comparative Analysis of Pre-Coding Techniques for the Multiuser Massive MIMO System

Abstract

The number of consumers and applications is continually expanding, which encourages the study and advancement of wireless technology. Wireless communications should ideally have a high data rate and high connection efficiency. Future wireless communication systems will have to address some fundamental needs, such as simultaneously servicing a large number of users, maintaining high throughput for each user, ensuring low energy consumption, and so on. In practice, inter-user interference occurs when multiple users access the wireless link, necessitating the adoption of complex transmission techniques such as interference cancellation to maintain a specified level of service. To overcome inter-user interference, and improve signal-to-noise ratio, a huge MIMO system with very large antenna arrays is proposed. Massive MIMO (multiple-input, multiple-output) is a promising technology that has introduced the concept of employing hundreds or thousands of antennas of the user simultaneously, Multi stream transmission in systems with many antennas possible with the aided of pre-coding (signal preprocessing), Large number of antennas will help to concentrate radiated energy into a smaller area, improving the system's throughput and energy efficiency. This thesis aims to compare and combine linear and nonlinear (hybridized) pre-coding based on iterative algorithms to retain the advantages of both linear and nonlinear pre-coding. The results reveal that the proposed pre-coding technique can be approached optimal performance in terms of decreasing bit error rate and increasing Energy Efficiency than the existing pre-coding technique such as Maximum Ratio Transmission (MRT) and zero-forcing (ZF), Wiener Filter (WF) and nonlinear pre-coder as Squared-infinity norm Douglas-Rachford splitting(SQUID), Dirty-Paper Coding(DPC).