Novel SISO Detection Algorithms for Nonlinear Satellite Channels

We propose novel detection algorithms for linear modulations transmitted over nonlinear satellite channels, also impaired by additive white Gaussian noise. These algorithms are derived by using a Volterra-series expansion of the useful signal and by applying the sum-product algorithm to a suitably-designed factor graph. Being soft-input soft-output (SISO) in nature, the proposed detectors can be adopted in turbo processing without additional modifications. Typical linear modulations employed in satellite transmissions are considered in the numerical results. When compared with the optimal detection algorithm for these channels, whose complexity is exponential in the channel memory, the proposed schemes result very appealing in terms of tradeoff between performance and computational complexity. Particularly, the proposed schemes can approach the optimal performance with a complexity only linear in the channel memory.