A Comparative Study of Traditional PAPR Reduction Techniques in MIMO-OFDM Systems

Abstract: MIMO-OFDM (Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing) has emerged as a key technology in modern wireless communication systems due to its high data rates and robustness against multipath fading [1]. However, a significant drawback of OFDM is its high Peak-to-Average Power Ratio (PAPR), which leads to power inefficiency and nonlinear distortion in power amplifiers [3]. This paper focuses on traditional PAPR reduction techniques that have been widely used to address this issue, particularly in MIMO-OFDM systems.

The study explores three well-known methods, Partial Transmit Sequence (PTS), Selected Mapping (SLM), and Clipping and Filtering (C&F) [18]. PTS divides the OFDM block into sub-blocks and optimally rotates them to minimize PAPR without distortion, though it requires side information and increased computational complexity [2]. SLM generates multiple OFDM candidate signals using different phase sequences and selects the one with the lowest PAPR for transmission, balancing complexity and performance [11]. Clipping and Filtering, a straightforward nonlinear technique, reduces PAPR by clipping the peaks of the signal followed by filtering to suppress out-of-band radiation, though it may introduce in-band distortion and BER degradation.

A comparative analysis of these techniques is presented in terms of PAPR reduction performance, computational cost, and impact on bit error rate (BER) [20]. This work provides a foundational understanding of traditional PAPR reduction strategies for MIMO-OFDM systems and offers insights for researchers aiming to improve energy efficiency and signal integrity in future wireless networks.

Keywords: PAPR reduction, MIMO-OFDM, Peak-to-Average Power Ratio, power amplifier nonlinearity, spectral efficiency, Bit Error Rate (BER), Side Information, OFDM Signal Distortion, Partial Transmit Sequence (PTS), Selective Mapping (SLM), Clipping and Filtering (C&F).