Power Line Communication Modem Power Allocation FM Interference
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Solution Overview
Problem
Power line communication modems interfere with FM radio broadcasts in frequency ranges above 30 MHz, causing disturbances in signal reception, despite existing limitations on power spectral density and notch filtering.
Innovation Solution
A power line communication modem system that allocates transmit powers to individual carriers across multiple frequency ranges, ensuring the sum of powers in each range does not exceed predetermined maximum values to minimize interference with FM radio broadcasts, using a processor to dynamically adjust power allocation based on channel conditions and frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If higher power spectral density is used in frequency ranges above 30 MHz to achieve higher data rates and coverage, then productivity is improved, but FM radio broadcast interference increases
Solution Approach 1:
The patent applies local quality by implementing frequency-specific power spectral density limits that differentiate between various frequency ranges. Instead of uniform power distribution, the system assigns different maximum PSD values to different frequency bands, allowing higher power in non-critical bands while protecting FM radio frequencies from interference. This enables optimized data transmission in permitted bands while locally suppressing harmful emissions near 88-108 MHz.
Solution Approach 2:
The patent implements dynamics through adaptive power allocation that adjusts transmit power levels based on detected radio frequency conditions. The system continuously monitors for FM radio signals and dynamically modifies its power spectral density distribution in response, reducing power in frequencies that would interfere with detected radio broadcasts while maintaining or adjusting power in other frequencies to preserve data throughput.
2Reliability
If higher power spectral density is used in frequency ranges above 30 MHz to achieve better coverage, then reliability is improved, but FM radio broadcast interference increases
Solution Approach 1:
The patent applies local quality by implementing frequency-specific power spectral density limits that differentiate between various frequency ranges. Instead of uniform power distribution, the system assigns different maximum PSD values to different frequency bands, allowing higher power in non-critical bands while protecting FM radio frequencies from interference. This enables optimized data transmission in permitted bands while locally suppressing harmful emissions near 88-108 MHz.
Solution Approach 2:
The patent converts the potential harm of high-power transmissions into benefit by using the same transmission infrastructure to provide both PLC service and protective monitoring. The system uses its own transmission capability to detect the presence of FM radio signals and automatically adjusts its power distribution to protect those signals, turning what could be a source of interference into a mechanism for protecting other services.
3Object-generated harmful factors
If fixed notch filters are used for amateur radio bands, then FM radio broadcast interference is reduced, but data throughput decreases
Solution Approach 1:
The patent implements dynamics by replacing static fixed notch filters with adaptive power spectral density management. Instead of permanent frequency notches that continuously reduce available bandwidth, the system dynamically adjusts power levels based on actual detected interference conditions. This allows the full frequency spectrum to remain available for data transmission unless and until interference is detected, maximizing throughput while providing targeted protection when needed.
Solution Approach 2:
The patent applies parameter changes by modifying the power spectral density parameter across different frequency ranges rather than using fixed frequency notches. The system changes the power distribution parameters adaptively based on detected radio conditions, allowing flexible adjustment of transmission characteristics to maintain data throughput while suppressing interference only when and where necessary.
Data Source
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AI summary
A power line communication modem is provided including a transmitter configured to transmit a power line signal on at least one carrier of a plurality of carriers via a power line to a further power line communication modem; and a processor configured to allocate transmit powers to individual carriers of the plurality of carriers, wherein the sum of the transmit powers of individual carriers located in the first frequency range is below or equal to a first predetermined power maximum value for the first frequency range. A corresponding power line communication system and a power line communication method are provided as well.