An Efficient Combined Scheme of Proposed PAPR Reduction Approach and Digital Predistortion in MIMO-OFDM Systems

摘要

The combination of Multiple Input Multiple Output (MIMO) system with Orthogonal Frequency Division Multiplexing (OFDM) technology provides a powerful choice to increase channel capacity and improves the quality of service of wireless mobile communication systems. However, MIMO-OFDM systems are prone to high Peak-to-Average Power Ratio (PAPR), which leads to more interference and greatly limits the efficiency of the transmit high power amplifier (HPA). In this article, we propose a combinational approach is proposed, a PAPR reduction with memoryless digital predistortion (PRDPD) in order to combat PAPR in MIMO-OFDM, to improve HPA efficiency as well as linearity, and to mitigate in-band distortion and spectrum regrowth. The main idea of PAPR reduction is the rotation of phase independently in frequency and time domain based on Partial Transmit Sequence (PTS) and Selected Mapping (SLM) techniques with minimum complexity. This analysis is carried out based on Solid State Power Amplifiers (SSPA) of Saleh model and digital predistortion (DPD) as linearization technique. The simulation results show that the proposed scheme cannot only significantly reduce the PAPR, but also improves out-of-band radiation over other conventional techniques.