Performance analysis of linear precoding schemes for very large Multi-user MIMO downlink system

Nowadays, Multi-user Multiple-In Multiple-Out (MU-MIMO) systems are used in new generation wireless technologies. Due to ongoing improvement in wireless technology, the numbers of users and applications increase rapidly. At the same time, wireless communication need the high data rate and link reliability. Therefore, MU-MIMO improvements have to consider 1) providing the high data rate and link reliability, 2) support all users in the same and frequency resource, and 3) using low power consumption. In practice, inter-user interference has a strong impact when more users access the wireless link. Complicated transmission techniques such as interference cancellation are used to maintain a given desired quality of service. Due to these problems, MU-MIMO systems with very large antenna arrays (known as massive MIMO) are proposed. With massive MU-MIMO systems, we mean a hundred or more serving tens of users. The channel vectors are nearly orthogonal, and the inter-user interference is reduced significantly. Therefore, the users can be served with high data rate simultaneously. In this paper, we investigate the performance of the massive MU-MIMO downlink system in a single cell where the base station utilizes linear precoding schemes to serve many users over the Rayleigh fading channel.