PAPR reduction in MIMO-OFDM systems using joint channel estimation and Precoding

Orthogonal Frequency Division Multiplexing (OFDM) is one of the multi-carrier modulation (MCM) techniques, offers a considerable high spectral efficiency, multipath delay spread tolerance, immunity to the frequency selective fading channels and power efficiency. Multiple Input Multiple Output (MIMO) has been known as a technique to enhance the transmission quality and capacity. OFDM can be obtained with Multiple-Input Multiple-Output (MIMO) configuration to increase the diversity gain and to enhance the system capacity. One of the major drawbacks in OFDM communication is the high peak-to-average power ratio (PAPR). The subcarrier waveform shaping in OFDM is a form of precoding scheme, where each OFDM block is linearly transformed by shaping matrix before modulation and transmission. This approach has the potential of reducing the PAPR of the OFDM without affecting the bandwidth efficiency of the system and the Bit Error Rate (BER) performance. The PAPR reductions of MIMO-OFDM systems are obtained using the precoding scheme. The simulations show that the precoding scheme performs better with MIMO-OFDM systems.