Ch Frequency Response (Digital Demod)
When is enabled and the equalizer is ON, the (Channel Frequency Response) trace shows the channel frequency response for which the equalizer is correcting. is computed as the inverse of the equalization filter's frequency response. The data is complex and is normally displayed in units of magnitude, phase, or group delay.
The VSA applies the equalization filter to the measurement when the check box is selected. When the check box is cleared, the filter still exists but is not applied to the signal. The filter may be turned on and off without resetting the filter coefficients.
Frequency Span
The frequency span of is determined by the symbol rate and , as follows:
The segment of the displayed span that is valid is determined by the bandwidth of the input signal with the measurement filter applied. For example, a signal with a 1 MHz Megahertz: A unit of frequency equal to one million hertz or cycles per second. symbol rate and filter with an alpha of 0.2 would have a bandwidth of 1.2 MHz. The valid segment of the would be less than 1.2 MHz.
For further details, see Using the Equalization Filter.
