Error Vector Magnitude Analysis for OFDM Systems

Error vector magnitude (EVM) is a popular figure-of-merit adopted by various communication standards for evaluating in-band distortions introduced in a communication system. In this paper, we regard EVM as a random variable and investigate its statistical distributions as the result of the following distortion mechanisms: phase noise, amplitude clipping, power amplifier nonlinearities, and gain/phase imbalances in orthogonal frequency division multiplexing (OFDM) systems. We relate key parameters characterizing the various distortion mechanisms to the statistical behavior of EVM; such statistical behavior can be used to verify compliance of the transmit signals to the requirements of the standard.