Equalizer Properties (DOCSIS 4.0 Upstream)

Allows users to select the equalization type.

Off: No equalization is used.

Full: Full automatic equalization is used.

Partial: Partial equalization (time-limited response) is used.

User: The equalizer is specified by the user.

Partial EQ Length: When Partial is selected, this setting specifies the length of the partial equalization.

Default: 200 ns

Equalizer Coeff.: When User is selected, use this setting to enter custom equalizer coefficients.

When enabled and when using Full or Partial EQ Control, a smoothing filter is applied to the equalizer channel frequency response.

Use the editable field to the right to set the smoothing interval (in subcarriers). The field becomes active when this setting is enabled.

Default: 5 Subcarriers

When using Full or Partial EQ Control, Equalizer Training allows user to select the training mode for equalizer construction

Pilots: The OFDM equalizer is initialized ("trained") using the Pilots.

Pilots and Complementary Pilots: The OFDM equalizer is initialized trained using the Pilots and Complementary Pilots.

Pilots, Complementary Pilots, and Data: The OFDM equalizer is trained using the Pilots and Complementary Pilots as well as data subcarriers.

Selects the averaging method used to determine the equalizer filter coefficients across multiple symbols:

Equal Weight:   Equalizer averaging calculated using the Equal Weight method.

Signal impairments other than additive white gaussian noise may make Equal Weight work better than Least Squares.

Least Squares   Equalizer training calculated using the Least Squares method.

If the only signal impairment is additive white gaussian noise, Least Squares should result in the best estimate of channel response, and therefore the lowest EVM for the measurement.