Error-rate Analysis of OFDM Operating over Mobile Rayleigh Radio Channel under Multiple RF Impairments

We investigate the sensitivity of Orthogonal Frequency Division Multiplexing (OFDM) waveforms to the joint distortion effects of various coexisting non-idealities in the implementation of transceiver radio frequency (RF) electronics, combined also with time variations of the multipath radio channel. We report closed-form performance analysis for a general OFDM mobile radio link, which includes amplitude and phase mismatches between the in-phase (I) and quadrature (Q) rails of both transmitting and receiving devices, as well as carrier frequency offset and oscillator phase noise in the receiving device. The performance metric used here is the detector symbol-error rate built on detailed impairment modeling at link level. To cope with the challenge in evaluation of error rates under non-Gaussian joint interference, we propose a semi-analytical technique that provides accurate estimation of the uncoded symbol-error rate for an arbitrary rectangular QAM. The presented method provides a convenient and time-efficient tool that can be used directly in RF circuit and module design and implementation processes, to derive maximum allowable impairment levels such that the link detection error rate is kept at target level. Also the relative impacts of different impairments can be directly addressed and compared using the provided analysis results.