实时频谱分析仪中重叠帧频谱分析技术研究

针对实时频谱分析仪缺乏微弱信号检测能力问题,提出了重叠帧频谱分析技术.该方法既可以获取信号局部频谱的精细结构,又可以提高快速傅里叶变换（FFT）相参积累的增益,从而提高对微弱信号的检测能力.介绍了重叠帧频谱分析技术的基本原理,详细讨论了重叠因子设计准则,在此基础上,提出了实现该技术的设计方案.该方案成功地在研发实时频谱分析仪过程中得到实现.通过实验验证,相比普通频谱分析技术,重叠帧频谱分析技术能达到光谱图中展宽信号时域显示的功能,且对微弱信号,在相同检测概率下,对信噪比（SNR）要求降低至少2 dB.

Study of overlapping frames spectrum analysis techniques in real-time spectrum analyzer

The overlapping frames spectrum analysis techniques applied to the lack of weak singal detection ability of real-time spectrum analyzer is proposed. Fine structure of signal local spectrum is achieved while coherent integration gain is improved by this techniques. As a result, the weak singal detection ability are enhanced. The basic theory of overlapphag frames spectrum analysis techniques is firstly introduced,and the design criteria of overlap factor selection is discussed in detail, on the basis of these, the design scheme of overlapping frames spectrum analysis technique is proposed. The scheme is successfully implemented hy the process of developing real-time spectrum analyzer. Compared with ordinary spectral analysis techniques, the experimental results verifiy that the function of broaden singal time domain display in the spectrogram is achieved by the overlapping frames spectrum analysis techniques,and least 2 dB of SNR is decreased for weak singal at the same detection probability.