Multi-Frequency FM Transmission Chain for Interference-Free Coexistence
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Solution Overview
Problem
Conventional FM broadcast systems face interference issues with personal FM microtransmitters, and there is a need for enhanced coexistence between FM broadcast stations and personal FM devices, particularly in scenarios where low-power transmitters are used to share the same frequency spectrum.
Innovation Solution
A method and system for simultaneous signal transmission on multiple selected frequencies, where a single baseband signal is modulated to generate radio frequency signals at different frequencies, allowing for the transmission of FM signals on multiple channels while using a shared antenna and incorporating Radio Data System (RDS) signals to automatically switch to optimal reception frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If personal FM microtransmitters operate at low power in the FM broadcast spectrum, then portability and media availability are improved, but interference with FM broadcast stations occurs
Solution Approach 1:
The patent segments the FM broadcast spectrum into multiple discrete frequency channels. The microtransmitter can select from multiple available frequencies (e.g., 87.5 MHz, 88.0 MHz, 88.5 MHz, etc.) rather than operating on a single fixed frequency. This segmentation allows the system to divide the spectrum resource and avoid interference by transmitting on frequencies that are currently free from broadcast station signals.
Solution Approach 2:
The patent implements dynamic frequency selection where the microtransmitter automatically changes operating frequencies based on real-time spectrum conditions. The system monitors the current frequency for interference and dynamically switches to alternative frequencies when needed, enabling adaptive coexistence with FM broadcast stations while maintaining continuous operation.
2Adaptability or versatility
If multiple transmitters operate on the same frequency, then media availability is improved, but signal interference increases
Solution Approach 1:
The patent transitions from single-frequency operation to multi-frequency operation, adding the frequency selection dimension to the transmission system. Instead of multiple transmitters competing on the same one-dimensional frequency, the system operates across a multi-dimensional frequency spectrum, allowing simultaneous transmissions on different frequency channels without mutual interference.
3Reliability
If frequency switching is implemented to avoid interference, then coexistence is improved, but system complexity increases
Solution Approach 1:
The patent implements self-service frequency management where the microtransmitter autonomously monitors spectrum conditions and performs frequency switching without external control. The device includes built-in frequency synthesis capability and automatic frequency selection logic, allowing it to serve itself in avoiding interference without requiring complex external coordination systems.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables seamless and interference-free transmission of audio content on multiple channels, improving the coexistence of FM broadcast stations and personal FM devices by allowing automatic frequency switching based on reception quality, thus enhancing the 'anytime, anywhere' paradigm for media availability.
Implementation Method 1
a single baseband signal is modulated to generate a plurality of radio frequency transmission signals each at a different radio frequency, wherein the single baseband signal is modulated in a single radio frequency transmission chain comprising intermediate frequency modulation and radio frequency modulation
Data Source
AI summary
Aspects of a method and system for simultaneous signal transmission on multiple selected frequencies may include generating from a single baseband signal, a plurality of radio frequency transmission signals each at a different radio frequency, wherein the single baseband signal comprises an in-phase signal component and/or a quadrature signal component. The single baseband signal, to generate said plurality of radio frequency transmission signals, may be modulated in a single radio frequency transmission chain, the radio frequency transmission chain comprising intermediate frequency modulation and radio frequency modulation. The plurality of radio frequency transmission signals may be a radio frequency signal and a corresponding image frequency signal, based on the intermediate frequency modulation and the radio frequency modulation. The signals resulting from the intermediate frequency modulation and the radio frequency modulation may be filtered to preserve the radio frequency signal and the corresponding image frequency signal.