Impact of nonlinear power amplifiers on the performance of precoded MIMO satellite systems

We investigate the applicability of linear precoding schemes based on Singular Value Decomposition (SVD) to Multiple Input Multiple Output (MIMO) single carrier satellite communication systems, where the need for high power efficiency requires to operate nonlinear high power amplifiers (HPA) as close as possible to saturation. Precoded transmit signals have a high peak-to-average power ratio (PAPR), which might be potentially detrimental for the system performance on the nonlinear channel. We compare in this work the uncoded performance of a 2 × 2 MIMO and an equivalent SISO system operating with equal data rate and total transmit power. Our simulations show that SVD precoding does not require the MIMO system to be operated with a higher power back-off than its SISO counterpart. On the contrary, gains of almost 3 dB can be observed for some modulation schemes.