A Novel Channel Estimator for a Superposition-based Cooperative System

This paper investigates channel estimation and equaliza- tion for the relay node of a cooperative diversity system based on superposition modulation. Exploring the superpo- sition structure of the transmission data, we propose a novel channel estimator for the relay node. Without any pilot se- quence, the proposed estimator can converge to the ideal case as if the transmission data is known to the receiver. We also re-derive the soft-input-soft-output MMSE equalizer to match the superimposed data structure of the cooperative scheme. Finally computer simulation results are given to ver- ify the proposed algorithm.