Abstract:

In this paper,based on the factor graph and sum-product algorithm,we get the extend model of FG-Turbo multiuser detection with LDPC coded,simulate and compare the performances of MAP algorithm and soft interference cancellation algorithm,and propose a new method to estimate interference symbols,that is based on sensitive bits algorithm.Simulation results show that in the case of the computational complexity unchanged,the soft interference cancellation algorithm modified can improve the performance of system effectively.

Key words: factor graph, sum-product algorithm, FG-Turbo multiuser detection, soft interference cancellation, sensitive bit