Abstract:

A new low complexity Turbo frequency domain equalization (FDE) and channel estimation algorithm based on variational inference framework is proposed for the coded single carrier transmission in timevarying frequency selective channels. The algorithm enables an uniform handling of channel estimation error in the deign of softinput softoutput detector and the interblock interference canceler. Furthermore, by analyzing the receive signal’s factor graph, a dual iterative implementation scheme of the algorithm is considered, in which the inner iterative serves for joint FDE and soft channel estimation and the outer one performs interference cancellation and decoding. Simulation results show that the proposed receiver outperforms, both in biterrorrate and in robustness to the strength of superimposed training signal, the expectation maximum based scheme with a similar computational complexity.