Non-linear satellite channel equalization based on a low complexity Echo State Network

Abstract

Satellite communications systems designers are continuously struggling to improve the link capacity. A critical challenge comes from the limited power available aboard the satellite. To ensure a sufficient signal-to-noise power ratio (SNR) at the terrestrial receiving side, the amplifier aboard the satellite is usually operated close to the amplifier saturation point which adds non-linear distortions to the communication channel. Several algorithms have been proposed to equalize the non-linear satellite channel. The Echo State Network (ESN) algorithm, coming from the field of artificial neural networks, has been shown to perform well in this task: it can achieve a similar bit error rate (BER) as the state-of-the-art Volterra equalizer. In the present paper we show that with an appropriate design, the complexity of the ESN can be significantly lower than that of the Volterra equalizer, while conserving the low BER.