A Companding Technique to Reduce Peak-to-Average Ratio in Discrete Multitone Wireline Receivers

Abstract

Multicarrier modulation, while providing a theoretical pathway to data rates approaching the Shannon limit and being extensively utilized in wireless communication, has encountered limited application in high-speed wireline communication. This limitation is primarily due to substantial large amplitude peaks, which necessitates a reduction in the signal’s power levels to circumvent signal clipping. This, in turn, results in a low signal-to-noise ratio (SNR) which puts these modulations at a serious disadvantage compared to conventional modulation schemes. This work proposes a novel companding solution in the design of the Continuous Time Linear Equalizer (CTLE) alongside nonlinear blocks to reduce Peak to Average Power Ratio (PAPR), therefore improving the overall link performance. This paper presents a PAPR reduction technique and its implementation in the receiver, distinguishing it from previous studies that place the compander at the transmitter where it fails to work in the presence of an Inter-Symbol Interference (ISI) channel. A theoretical study as well as an implementation of this method is provided, and the merits and performance improvements are demonstrated.

Keywords

• Continuous time linear equalizer (CTLE)
• discrete multi-tone (DMT)
• OFDM
• peak-to-average power ratio (PAPR)
• SERDES
• single-tap equalization