提出了一种TETRA数字集群系统中估计信干比的算法。利用训练序列构成矩阵,基于所构成矩阵的列空间和左零空间的正交基,在接收信号中对信号功率与干扰加噪声功率进行分离,估计出接收信号的信干比。不仅能够快速准确地估计出信干比,而且计算量较小。仿真结果表明当移动速度为5km/h和85km/h时,平均绝对信号与噪声加干扰比估计误差接近1dB和0.3dB,所提出的算法能够实时地估计出信干比,提高TETRA数字集群系统容量和改善通信质量。
An algorithm for estimating signal-to-interference ratio in TETRA digital trunking system is proposed. Training sequence to form a matrix is used, based on the orthonormal basis for range space and left null space of the formed matrix, the signal power is separated from the interference plus noise power in the received signal, in order to estimate received signal-to-interference ratio of signal. The signal-to-interference ratio can be not only estimated quickly and accurately, but also smaller computation is required. Simulation results demonstrate that the mean absolute signal-to-interference plus noise ratio estimation error is about 1 dB and 0.3 dB at 5 km/h and 85 km/h, the proposed algorithm can estimate signal-to-interference ratio in real time, and increase system capacity and improve communication quality in TETRA digital trunking system.