Achievable Throughput as the Ultimate Performance Metric of MIMO Antenna Systems; Challengs in 5G and Beyond

This paper discusses the idea that Multiple Element Antenna (MEA) systems, or Multiple Input Multiple Output (MIMO) antenna systems should be specified and designed with their achievable throughput as a key performance metric criterion. It is shown that a complete characterization of an N-port MIMO antenna system for the purposes of its role in a wireless link consists of the full NxN S-parameter matrix of the antennas plus the N active E-field gains of each antenna element when a single port is driven while all others are terminated. The achievable throughput in a link with two MIMO antenna systems at each node depends on the aforementioned characteristics plus aspects of the propagation environment and the communications protocol used. The paper promotes the idea that, even though cumbersome and non-traditional, if achievable throughput is used as a performance target, smaller and more cost efficient products can be designed. Examples of the benefits and challenges in some of the required measurements for 5G frequencies and simulations are discussed.