基于格基约减的扩频通信多址干扰抑制算法

摘要

In the application of spread spectrum communication with limited wireless resource, Multiple Access Interference (MAI) is the main restraint element of the multiple user service capability and communication performance. Focusing on the MAI problem, lattice reduction theory is firstly applied to the MAI cancellation of spread spectrum communication. A lattice reduction aided multiple user detection method is proposed. With lattice reduction method, the orthogonality of the correlation matrix of multiple signals is improved. As a result, the error bit rate of Multiple User Detection (MUD) method is reduced, and near ML demodulation performance is reached with low complexity. High performance on near-far effect resistance is achieved with the algorithm. Contrary to the performance degradation of traditional MUD method in serious MAI scenario, lattice reduction aided multiple user detection method can maintain near ML performance. Transmission reliability, multiuser service capability and environment suitability of spread spectrum system can be improved remarkably with the algorithm.%在链路资源受限条件下的扩频通信应用中,多址干扰是限制系统多用户服务能力和通信质量的主要因素.该文针对多址干扰消除问题,首次将格基约减理论应用到扩频通信多址干扰消除中,提出基于格基约减辅助的多用户检测算法,通过格基约减变换实现对信号间互相关矩阵的正交性优化,使多用户检测算法性能得到改进,以较低的运算复杂度实现了逼近最大似然算法的检测性能.该算法在对抗强远近效应方面表现出优异性能,不同于传统多用户检测算法在恶劣多址环境下检测性能的严重退化,该算法能够保持对最大似然检测算法性能的逼近,可以使扩频通信系统的传输可靠性、多用户服务能力以及环境适应性得到显著增强.