Improved successive multiuser detection initial ranging algorithm with interference cancellation for orthogonal frequency division multiple access systems

An improved successive multiuser detection (SMUD) initial ranging (IR) algorithm with interference cancellation is presented for orthogonal frequency division multiple access systems followed by IEEE 802.16 m standard. The proposed method detects all the valid paths of IR subscriber stations, selects the path with the maximum signal-to-interference-plus-noise ratio, and estimates the parameters of the path by least-square method. The estimated parameters are further processed by the parallel interference cancellation processing to improve their accuracy, and then the signal of the selected valid path is removed from the received signal in the successive interference cancellation (SIC) process. The proposed scheme can efficiently improve the parameter estimation accuracy of the selected valid path and reduce the residual multiple access interference in the SIC process. Simulation results show that the proposed method has a much better performance than the SMUD algorithm.