V-BLAST algorithm performance in non-linear channel

High power amplifier impact on the signal power spectrum spreading into neighbouring frequency bands and degradation of the BER system performance due to nonlinear high power amplifier distortions are analysed for 4-QAM and 16-QAM signals in MIMO communication systems, using the V-BLAST algorithm for signal detection. The high power amplifier model is based on measured AM/AM and AM/PM characteristics of a 28GHz solid state power amplifier. The signal power emission in neighbouring frequency bands mostly depends on the peak to average power ratio of the transmitted signal, and it is higher for 16-QAM than for 4-QAM signal. The degradation in BER performance is larger for higher modulation level and higher number of transmit antennas.