Upstream Channel Power Allocation for Higher Bit-Loading
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Solution Overview
Problem
Upstream transmit power levels in cable communication systems are set to maintain a constant receive power versus frequency at the network node, leading to underutilization of the available upstream spectrum despite advancements like DOCSIS 4.0, which increases bandwidth.
Innovation Solution
Implementing a water-filling algorithm to allocate upstream transmit power across multiple channels, adjusting power levels based on individual peak power limits derived from signal-to-noise ratio thresholds for orthogonal frequency-division multiplexing modulation orders, and reallocating excess power to optimize average bit-loading.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If upstream transmit power levels are set to maintain constant receive power versus frequency at the network node, then receive power stability is improved, but upstream spectrum utilization deteriorates
Solution Approach 1:
The patent applies local quality by allocating different transmit power levels to different frequency channels based on their individual characteristics. Instead of maintaining constant receive power across all channels, the system identifies channels with better signal-to-noise ratios and allocates higher power to them, while reducing power on channels with poorer conditions. This selective power allocation optimizes overall upstream capacity while maintaining acceptable performance on each channel.
Solution Approach 2:
The system dynamically changes the transmit power parameter across different frequency channels based on channel conditions. By adjusting power levels according to signal-to-noise ratio measurements and water-filling calculations, the system transforms the fixed power allocation into a variable parameter that adapts to spectral conditions, thereby improving spectrum utilization without compromising receive power stability below threshold levels.
2Productivity
If water-filling algorithm allocates higher transmit power to channels with better signal-to-noise ratio, then upstream capacity is improved, but transmit power distribution becomes unbalanced
Solution Approach 1:
The system implements feedback by continuously monitoring signal-to-noise ratios on each channel and using this information to adjust power allocation. The water-filling algorithm receives feedback about channel conditions and dynamically redistributes power to maximize capacity. This feedback mechanism ensures that power distribution remains optimized while adapting to changing spectral conditions, resolving the imbalance between capacity optimization and power distribution stability.
3Manufacturing precision
If transmit power is increased on channels exceeding threshold SNR, then bit-loading is improved, but energy efficiency deteriorates
Solution Approach 1:
The system applies partial action by allocating power only to the extent necessary to achieve threshold signal-to-noise ratios on each channel. Instead of uniformly increasing power across all channels, the water-filling algorithm identifies the minimum power required to reach acceptable bit-loading levels and allocates power selectively. This approach achieves sufficient bit-loading improvement without excessive energy consumption, as power is applied only where and only to the degree needed.
Data Source
AI summary
Methods and systems for managing transmit power are disclosed. A separate transmit power may be determined (e.g., based on a water-filling algorithm) for each of a plurality of channels. The plurality of upstream channels may be used to transmit upstream signals from a computing device to a network node in an upstream frequency band of a communication medium. The transmit power determined, based on the water-filling algorithm, for at least one channel of the plurality of channels may exceed an amount of transmit power required to achieve a first threshold signal-to-noise ratio (SNR) associated with the at least one channel at the network node. A portion of the transmit power determined, based on the water-filling algorithm, for the at least one channel may be re-allocated to at least one other channel of the plurality of channels, thereby increasing an average bit-loading across the plurality of channels.