倒频 meaning in English

scramble
scrambling

Band - shift inversion
移带倒频
The virtual digital signal processing instrument is developed with vc + + 6 . 0 and matlab 6 . 0 in windows 98 . the system has realized signal generator , signal ' s sampling and averaging function , signal ' s power spectral density and cross special density analysis , the design and application of digital filter , signal analysis in time , frequency and inverted frequency domain
该系统的工作环境为windows98 ，开发工具为visualc + + 6 . 0和matlab6 . 0 。实现了波形发生器的设计、信号采集及平均处理、滤波器的设计及应用、信号的时域、频域以及倒频域分析。