Performance Analysis of Hybrid Filtering Technique for Reduction of Papr in Alamouti Coded Mimo-ofdm Systems

Abstract Multiple-Input Multiple-Output (MIMO) technique combined with Orthogonal Frequency Division Multiplexing (OFDM) is the proficient air interface for upcoming generations of high data rate and high-speed wireless communication. Nonetheless, such a system suffers from the drawback of a high peak-to-average power ratio (PAPR) when the symbol phases in the OFDM subcarriers line up in such a fashion that constructive formation of a large signal peak in the time domain occurs. Classical amplitude clipping, one of the simplest techniques, is employed to reduce PAPR. However, such a canonical approach leads to additional distortion, which is suppressed by an appropriate hybrid of clipping and filtering in this paper. It is shown that at a clipping ratio of 1.8, a PAPR reduction of 9.818dB, equivalent to a percentage difference of 97.97% with respect to the original signal is achieved, when employing QPSK modulation and 12.42% more when using clipping only. The proposed work can find applications in Massive MIMO systems for beyond 5G networks.