MIMO-OFDM transmission systems provide a high spectral efficiency, robustness in the frequency selective channels and flexibility in the resource allocation. However, like a single-input single output (SISO) OFDM systems, similarly MIMO-OFDM has one main drawback i.e. high sensitivity to the nonlinearities in RF front-ends due to the large envelope fluctuation of OFDM-based signals. When a nonlinear high power amplifier (HPA) is used, large back-off is necessary to avoid strong nonlinear distortion causing performance degradation. On the other hand, when the HPA is operating in the linear...