| 摘要 |
An asymmetrical sideband modulated (ASM) signal, such as an RF NTSC television signal is demodulated into in-phase and quadrature phase components, each of which are sampled at a sampling rate that is less than the Nyquist rate for the components. The signals, each of which includes aliasing distortion, are respective real and imaginary parts of a complex signal that is not subject to aliasing distortion at the chosen sampling frequency. The in-phase component of the signal is recovered by inserting zero-valued samples interstitially into each of the sampled in-phase and quadrature phase signals and then applying the modified signals to a complex filter. The resultant interpolated in-phase signal is a full bandwidth signal and is substantially free of aliasing distortion.
|
