Use Multicarrier Filter (DOCSIS 4.0 Downstream)

When Use Multicarrier Filter is selected, the VSA applies a software filter at baseband to remove out-of-band signals to reduce EVM. When DOCSIS downstream signals are fully loaded, there are multiple DOCSIS carriers in one signal. Applying a filter before demodulation generally results in better EVM.

Selected: A filter is applied before demodulation to reduce out-of-band emissions and improve EVM. This is especially needed for DOCSIS multicarrier signals.

Cleared: No filtering is applied.

The multicarrier filter cannot resolve the 1st mixer tuner level.

Multicarrier Filter vs. Notch Filter

Use the Multicarrier Filter to filter out the out-of-band signals, namely the adjacent signals outside the range of the first and the last active subcarrier like below:

Use the Notch Filter in case of other signals inside the DOCSIS spectrum, namely within the range of the first and the last active subcarriers but in the exclusion band.