OFDM Eq Impuls Resp (DOCSIS 4.0 Downstream)
The trace for DOCSIS 4.0 Downstream modulation is the equalizer impulse response for measurement hardware.
Channel Equalizer Impulse Response shows the impulse response of the equalization filter. The Equalizer and Tracking parameters determines what technique is used to calculate the Eq Impulse Response trace.
| Equalizer Training | Description |
|---|---|
| Preamble and Pilots | The OFDM equalizer is initialized ("trained") using the Continuous Pilots, Scattered Pilots, and PLC. The advantage of Preamble and Pilots is that it is not affected by incorrect symbol decisions in the data (which can happen at lower SNR or or higher modulation orders). |
| Preamble, Pilots, and Data | The OFDM equalizer is trained using the data subcarriers as well as pilots and PLC. The advantage of Preamble, Pilots, and Data is that it usually gives a more accurate estimate of the channel response, resulting in lower EVM. |
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