Tone injection with aggressive clipping projection for OFDM PAPR reduction

Abstract

The main drawback of Orthogonal Frequency Division Multiplexing (OFDM) systems is the high peak-to-average power ratio (PAPR), which leads to a significant reduction in performance and power efficiency. Tone injection (TI) is a promising PAPR reduction technique that cyclically extends QAM constellations to allow an alternative encoding with lower PAPR at the transmitter. We present a new efficient complex-baseband algorithm which performs TI by using aggressive clipping to combat large peaks. An approximated-analog PAPR reduction of up to 5.1 dB at a 10–5 symbol-clip probability is obtained for 64-channel 16-QAM OFDM. This is a very fast and practical peak-power reduction method for OFDM systems that essentially achieves the same PAPR as single-carrier modulation for large constellations.