Pairing and Scheduling for Large Array MIMO Using Regularized Channel Inversion Receivers Over Nakagami-m Fading

Multiple-antenna (MIMO) technology is becoming mature for wireless communications and has been incorporated into wireless broadband standards like LTE and WiFi. Basically, the more the number of antennas the transmitter/receiver is equipped with, the more the possible independent signal paths and the better the performance in terms of data rate and link reliability. Massive MIMO (also known as large-scale antenna systems, very large MIMO, hyper MIMO and full-dimension MIMO) makes a clean break with current practice through the use of a very large number of service antennas (e.g., hundreds or thousands) that are operated fully coherently and adaptively. Extra antennas help by focusing the transmission and reception of signal energy into ever-smaller regions of space. This brings huge improvements in throughput and energy efficiency, in particularly when combined with simultaneous scheduling for a large number of user terminals (e.g., tens or hundreds). This Paper focuses on the efficiency of the throughput and fairness of large MIMO. In multi-user MIMO (MU-MIMO), fewer antennas were used, so the only concern was to mitigate the interference of the users. The interference was mitigated by using zero forcing (ZF) receivers while the fairness of the system was maintained by using Rayleigh Fading channel. MU-MIMO was sufficient for only smaller number of users as the number of antennas were fixed and all the users had to be entertained within the same bandwidth. But, in Massive MIMO, along with the interference of the users, the interference of the antennas themselves is also a big concern, as, the number of antennas were increased contrary to the fixed fewer number of antennas in MU-MIMO. Rayleigh Fading channel and ZF receivers were not sufficient for increased number of users and antennas respectively. The problem of interference amongst the antennas was addressed by using regularized channel inversion receivers that increase the throughput of the system while, the fairness of the system is increased by using Nakagami-m channel.