Performance Improvement of MIMO-OFDM System PAPR Reduction Using Pulse Shaping

The peak to average power ratio of the time domain envelope is an important parameter at the physical layer of the communication system using OFDM signalling. The signals must maintain a specified average energy level in the channel to obtain the desired Bit-error- rate. The peak signal level relative to that average defines the maximum dynamic range that must be accommodated by the components in the signal flow path to support the desired average. High Peak to Average Power Ratio (PAPR) for MIMO-OFDM system is still a demanding area and difficult issue. The radio transmitter stations for covering and getting enough transmitted power in their desired area has to use High Power Amplifier (HPA). Therefore due to the high PAPR of input signals, a factor which is called memory-less nonlinear distortion will affect the communication channels. the OFDM receivers efficiency is sensitive to the HPA. If the high power amplifier doesnt work in linear region, it can cause the out-of-band power to be kept under the specified limits. This condition can cause inefficient amplification and expensive transmitters, thus it is necessary to investigate PAPR reduction techniques for MIMO-OFDM system. Some of the performance measures like Complementary Commutative Distribution Function of PAPR and BER are analysed through simulation to demonstrate the efficacy of the proposed scheme.