A key problem in code-division multiple access(CDMA)system is to mitigate the multiple access interference(MAI)from other users while detecting the desired user.The performance of the conventional minimum output energ...A key problem in code-division multiple access(CDMA)system is to mitigate the multiple access interference(MAI)from other users while detecting the desired user.The performance of the conventional minimum output energy(MOE)multiuser detector for CDMA system significantly degrades in the presence of signature waveform distortions induced by multipath propagation or timing asynchronism.In this paper,a robust linear programming(ROLP)algorithm for blind multiuser detection is proposed.Different from the existing MOE-based multiuser detection techniques,the proposed ROLP minimizes the l_∞-norm of the output to exploit the non-Gaussianity of the communication signals.To achieve robustness against signature waveform mismatch,the proposed method constrains the magnitude response of any signature vector within a specified uncertainty set to exceed unity.The uncertainty set is modeled as a rhombus,which differs from the spherical uncertainty region widely taken in the existing robust multiuser detectors.The resulting optimization problem is reformulated into a linear programming program and hence can be solved efficiently.The proposed ROLP is computationally simpler than its robust counterparts that requires solving a second-order cone programming.Simulation results demonstrate the superiority of the ROLP over several robust detectors,which indicate that its performance approaches the optimal performance bound.展开更多
基金supported by the National Natural Science Foundation of China under(Grants No.62022054 and 61971279).
文摘A key problem in code-division multiple access(CDMA)system is to mitigate the multiple access interference(MAI)from other users while detecting the desired user.The performance of the conventional minimum output energy(MOE)multiuser detector for CDMA system significantly degrades in the presence of signature waveform distortions induced by multipath propagation or timing asynchronism.In this paper,a robust linear programming(ROLP)algorithm for blind multiuser detection is proposed.Different from the existing MOE-based multiuser detection techniques,the proposed ROLP minimizes the l_∞-norm of the output to exploit the non-Gaussianity of the communication signals.To achieve robustness against signature waveform mismatch,the proposed method constrains the magnitude response of any signature vector within a specified uncertainty set to exceed unity.The uncertainty set is modeled as a rhombus,which differs from the spherical uncertainty region widely taken in the existing robust multiuser detectors.The resulting optimization problem is reformulated into a linear programming program and hence can be solved efficiently.The proposed ROLP is computationally simpler than its robust counterparts that requires solving a second-order cone programming.Simulation results demonstrate the superiority of the ROLP over several robust detectors,which indicate that its performance approaches the optimal performance bound.
