| 摘要 |
PURPOSE:To reduce the operation quantity at the offset discrete Fourier conversion via the real number data which is obtained from the output of the real number part and the imaginary number part of the complex digital filter. CONSTITUTION:The SSB-FD (SSB frequency division multiple) M signal Y(z) is supplied to terminal 10, and sample series Yi(zN) is obtained through multiple separator circuit 20. Complex band filter Gi(-jzN)30 delivers complex sample value series Bi from N units of real sample value series YN-1-i(zN). And operation Di=BiR-BN-i<1> is carried out at real signal froming circuit 40 in order to extract real number part Di out of the complex sample value series, where LR and I show the real part and the imaginary part each. The operation of Eq. (13) is performed at offset discrete Fourier converter circuit 50 for N units of real signal sample value series Di, thus obtaining base band signal Xi. Thus the input to the Fourier conversion is limited to the real part only, and as a result a large amount of multiplication can be reduced in terms of the hardware and time. |
