Comparision between SLM-companding and precoding-companding techniques in OFDM systems

OFDM is a multicarrier modulation technique which is used in communication systems like Wireless Personal Area Network (WPAN), Wireless Local Area Network (WLAN), Wireless Metropolitan Area Network (WMAN), Wi-Max, DVB-T etc for the high rate transmission over wireless radio channels. It is commonly known as a transmission technique of high spectral efficiency and robustness against frequency selective fading. The advantages of OFDM include simple digital realization, compatibility with multipath fading channel, less complex receivers and improve the bandwidth efficiency. At the same time, it also increases system capacity providing reliable transmission. But the main problem of OFDM systems is Peak to average power ratio due to its envelope fluctuation. The objective of this project this to provide a broader understanding in peak-to-average power ratio (PAPR) problem in orthogonal frequency division multiplexing (OFDM) systems. This paper showcases main three reduction techniques, precoding and SLM in combination with nonlinear companding in detail considering advantages and disadvantages of each technique.