Characterization of OFDM Radio Link Under PLL-Based Oscillator Phase Noise and Multipath Fading Channel

We propose a discrete-time model for phase noise processes occurring in phase locked loop (PLL) based oscillators. By using linear time-invariant analysis in the phase domain, we arrive at a parallel auto-regressive moving-average phase noise model that captures the major noise sources and corresponding loop transfer functions of the PLL circuitry. The acquired model allows us to derive analytically the distribution of the inter-carrier interference (ICI) power in the receiver, shown to be a sum of correlated gamma random variables with a model-specific covariance matrix. Finally, we utilize the derived ICI distribution and proceed to analyze the effects of phase noise and multipath fading on the performance of OFDM radio links. For example, we evaluate the rate loss without ICI compensation or knowledge at the receiver, and illustrate the trade-off introduced by phase noise between the OFDM symbol length and the overhead caused by the cyclic prefix. Throughout the paper, simulations confirm the accuracy of the analytical expressions.