Joint Precoding and Predistortion Techniques for Satellite Telecommunication Systems

We analyze the application of Tomlinson-Harashima precoding to satellite transmission. Precoding counteracts channel dispersion at the price of increasing the dynamic range of the signal to be transmitted. This conflicts with the requirements of typical satellite transmission, where amplifiers with nonlinear characteristics are used, and their incoming signal is desired to present a reduced dynamic range. We propose fractional predistortion as a valid countermeasure against the effects of the nonlinear amplifier. Simulations allow us to obtain the performance of the proposed scheme when applied to two typical satellite propagation environments and compare it to an equivalent scheme using standard decision-feedback equalization. We conclude that a system using predistortion is more sensitive to the effects of satellite transmission-related nonlinearities than the equivalent DFE system