A Hybrid Framework for Incorporating Analog Front-End Effects in MIMO OFDM Design

This paper presents a framework including both digital signal processing and the analog RF part of the system. A MIMO OFDM system with various numbers of antennas at transmit and receive is investigated in a fast-fading urban environment. The hybrid framework is applied to assess performance degradation due to impairments in the RF part, e.g. fading, nonlinear high power amplifiers, phase noise and frequency offset of local oscillators. It is shown that bit error performance is affected most by distortion due to frequency offset of the local oscillator in the receive front-end. A simple frequency estimator designed for single antenna OFDM systems can be adopted to the MIMO case as it stands to combat for frequency offsets.