Cable Modem Pre-EQ Limiting for Subcarrier Power Balance

The patent applies parameter changes by modifying the pre-equalization values based on the boost metric. Instead of using fixed or channel-inversion-based pre-equalization, the system dynamically adjusts the pre-equalization parameters (alpha values) according to the calculated boost metric, which represents the actual power increase required. This allows the system to optimize the trade-off between signal quality improvement and power consumption by scaling pre-equalization values proportionally to the boost metric.

The patent implements local quality by applying pre-equalization selectively based on local channel conditions. Instead of uniformly equalizing all subcarriers, the system calculates the boost metric for each subcarrier and applies pre-equalization values that are locally optimized. This means that subcarriers with higher attenuation receive appropriate pre-equalization to improve their signal quality, while subcarriers with better conditions receive less pre-equalization, thereby avoiding excessive power allocation and achieving more uniform power distribution across the channel.

The patent applies self-service by having the receiving device (e.g., CMTS) calculate the boost metric and communicate it back to the transmitting device (cable modem). The transmitting device then uses this boost metric information to autonomously determine its own pre-equalization values without requiring complex channel inversion calculations. This self-service approach simplifies the overall system complexity by replacing complex iterative channel inversion algorithms with a simpler boost-metric-based pre-equalization method that achieves similar or better performance.