面向智能信号测试系统的MIMO通信调制分类方法

A MIMO communication modulation classification method for intelligent signal test systems

电力系统继电保护日趋智能化、数字化,继电保护测试性能要求也日趋复杂。保护设备型号复杂,对测试系统的信号调制兼容提出了更高要求。因此,提出了一种新的调制分类方法,可以对二进制相移键控、正交相移键控、16正交幅度调制等多种调制信号进行分类。所提出的分类方法可在存在未知频率、时间和相位偏移并且没有信道状态信息的情况下工作。首先,对接收信号进行预处理,消除时间偏移的影响。其次,通过计算频域信号的高阶累积量来提取关键特征。然后,使用似然比检验确定阈值并进行正确分类概率的封闭式理论推导。最后,在仿真中将该方法与其他方法进行了对比,结果表明,所提出的方法在准确度与计算速度方面均优于其他方法,验证了该方法的有效性。

As the relay protection for power systems is growing more intelligent and digital,the test performance requirements of relay protection are becoming increasingly complex.The complexity of the protection equipment models puts forward higher requirements for the signal modulation compatibility of the test system.Therefore,this paper proposes a new modulation classification method to classify a variety of modulation signals,such as binary phase-shift keying,quadrature phase-shift keying,and 16 quadrature amplitude modulation.The proposed classification method can work in the presence of unknown frequency,time and phase offsets as well as without channel state information.First,the received signal is preprocessed to eliminate the effect of time offset.Second,key features are extracted by calculating the higher-order cumulants of the frequency-domain signal.Third,a likelihood ratio test is used to determine the threshold and perform a closed-form theoretical derivation of the probability of correct classification.Finally,the method is compared with other methods by simulation,and the results show that the proposed method outperforms other methods in terms of accuracy and computational speed,which verifies its effectiveness.