Receiver cancellation of nonlinear power amplifier distortion in SDMA-OFDM systems

FERNANDO GREGORIO; TIMO LAAKSO; JUAN COUSSEAU

Toulouse

Conferencia; IEEE International Conference on Acoustics, Speech and Signal Processing, ICASSP 200; 2005

IEEE

Space Division Multiple Access in conjunction with OFDM resultsin a robust system that increases spectral efficiency and system capacity.This combination is positioning as one of the most promisingcandidates for future WLAN implementations. One drawbackof OFDM systems is the high peak to average power ratio, whichimposes severe requirements for the linearity of the power amplifier(PA). Such linearity requirements translate into high back-off resultingin low power efficiency. In order to improve power efficiency,power amplifier nonlinearity cancellation is introduced. This techniquereduces the nonlinear distortion over the recovered symbols.The performance of the novel structure is evaluated with simulationsgiving power efficiency improvements in the order of 30 %. Alsosimulation results shows the robustness of the cancellation techniqueat channel estimation accuracy.