Introduction - If you have any usage issues, please Google them yourself
Multiple input multiple output techniques combined
with orthogonal frequency division multiplexing (MIMO-OFDM)
provide a promising approach for wireless systems. However, a
serious drawback of the OFDM system is the high peak-toaverage
power ratio (PAPR), which may severely affect the
power efficiency of RF power amplifiers. In this paper, we
propose a simple method to reduce the PAPR of MIMO-OFDM
signals based on the use of unused subcarriers. Instead of
processing the signals at each transmitter separately, a peak
cancelling signal is generated at one antenna and is then applied
to all the others with only simple modifications. Simulation has
shown that a minimum 2 dB reduction in PAPR can be achieved
for all transmit signals using this approach. As the signal
processing is nearly all done at a single transmitter, repetition of
the operations at each transmitter is avoided, and therefore the
overall cost of the system can be significantly reduced.