Generating and achieving Error Vector Magnitude limits while testing communication systems or their components

Error Vector Magnitude (EVM), used extensively to test a communication system's quality, is calculated by comparing the corrupt received signal (sent by the transmitter) with a clean reference signal (regenerated at the receiver). This paper provides a lower limit for EVM for a given experimental set-up and also ways to achieve that limit under certain conditions. This paper presents two different experimental communication set-ups to showcase the limit in each case and methods to achieve those limits. This makes it possible to determine not only whether a communication system or its component will work properly in the real world but also how good its quality is relative to the best achievable quality. The theory and experiments in this paper also provide a mechanism to isolate which aspect(s) to focus efforts on to improve the quality of transmitters or receivers or their components during design and manufacture.