| 摘要 |
PURPOSE:To attain a digital transmultiplexer TMUX whose frequency is not limited depending on the frequency interval and flat by receiving an output of N-set of inserted digital subfilters and applying high speed Fourier transformation at the speed of the inserted clock. CONSTITUTION:Delay circuits 12-1-12-N are connected to the output of a time/space division converting switch 11 and N-set of complex base band signals having a coincident timing are generated by applying a delay proportional to the arrival sequence of the corresponding signal. Further, the interpolation digital subfilters 17-1-17-N are connected to the delay circuits 12-1-12-N to apply prescribed filtering based on the timing by the channel clock and the interpolated clock and a filter output is generated at the sampling speed of the interpolated clock. Then the output of the digital subfilters 17-1-17-N is received to apply high speed Fourier transformation at the speed of the interpolated clock. Thus, a flat filter characteristic at each channel band is obtained. |
