基于改进聚类算法的I/Q不平衡指标测量算法  

I/Q Imbalance Measurement and Compensation Algorithm Based on Improved K-Means Clustering

作　　者：刘智鑫 胡向晖 刘雪娇 赵琳 LIU Zhixin;HU Xianghui;LIU Xuejiao;ZHAO Lin(System Engineering Research Institute of the Academy of Military Sciences,Beijing 100141,China;Zhongke Nanjing Mobile Communication&Computing Innovation Institute,Nanjing Jiangsu 211135,China)

机构地区：[1]中国人民解放军军事科学院系统工程研究院,北京100141 [2]中科南京移动通信与计算创新研究院,江苏南京211135

出　　处：《通信技术》2024年第3期222-228,共7页Communications Technology

基　　金：国家自然科学基金(62101585);智强基金。

摘　　要：射频发射机往往将矢量调制信号分为I/Q两个完全正交的通路处理,即I/Q两路增益和时延严格一致,都不存在直流偏置,且本振信号相位严格相差90°。在实际工程中,器件的非理想因素往往会带来I/Q的不平衡,进而导致信号星座图失真,系统传输性能恶化,因此对发射机I/Q不平衡参数的测量与补偿至关重要。针对I/Q不平衡问题建模研究了3类不平衡因素对于I/Q通路的影响,提出了利用已知调制方式的星座图作为先验信息的改进聚类算法,进行I/Q不平衡参数估计,并进一步利用测量参数补偿射频信号的方法。针对不同信噪比条件和不平衡情况进行了仿真,仿真表明在不同的不平衡情况下,该算法都能有效完成I/Q不平衡参数测量和补偿,尤其是在信噪比条件较好,I/Q不平衡程度较高的情况下,该算法相较于传统的线性拟合算法有3 dB左右的信噪比增益。The RF transmitter tend to divide the vector-modulated signal into two completely orthogonal channels,I and Q,i.e.,the gain and time delay of I and Q channels are strictly consistent without DC bias,and their phase difference is strictly 90°.However,in practical engineering,the non-ideal factors of devices often cause I/Q imbalance,which further leads to distortion of the signal constellation and deterioration of the system transmission performance,thus the measurement and compensation of the I/Q imbalance parameters of the transmitter are of great importance.In respond to the I/Q imbalance problem,this paper models and investigates the impacts of 3 types of imbalance factors on the I/Q channels,proposes a modified clustering algorithm using the constellation of the known modulation modes as the a priori information for I/Q imbalance parameter evaluation,and further proposes a method for compensating the RF signals using the measured parameters.Simulations are carried out for different SNR conditions and imbalances.Simulation results indicate that the proposed algorithm can effectively measure and compensate I/Q imbalance parameters under different conditions,especially in the case of better SNR conditions and a higher degree of I/Q imbalance,the algorithm has a SNR gain of about 3 dB compared with the conventional linear fitting algorithm.

关 键 词：I/Q不平衡 矢量调制 聚类算法 射频指标测量 数字域补偿 

分 类 号：TM935.24[电气工程—电力电子与电力传动]