Master-Slave White Space Device Power Control
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Solution Overview
Problem
Current technologies face challenges in efficiently utilizing unassigned radio frequency bands, known as white spaces, for unlicensed use without interfering with existing licensed services, particularly in TV white spaces, maritime radio, and satellite communication bands, due to the lack of effective methods for determining available spectrum and ensuring coexistence with primary users.
Innovation Solution
A system architecture that employs a master white space device querying a geo-location database to determine allowed emission levels and operating parameters for associated slave devices, ensuring non-interference with primary users by dynamically adjusting transmission power and frequency usage based on geographic location and device capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If unlicensed devices operate in white spaces without strict power control, then device simplicity is improved, but interference with primary users increases
Solution Approach 1:
The patent implements dynamic transmit power adjustment where slave white space devices continuously monitor the master device's transmission power and adjust their own power levels accordingly. The slave device receives power information from the master device and dynamically modifies its transmission power to maintain acceptable interference levels, ensuring coexistence with primary users while maintaining operational simplicity.
Solution Approach 2:
The system employs feedback mechanisms where the master white space device transmits power information to slave devices, which then use this feedback to adjust their transmission power. This closed-loop feedback system enables automatic power control without complex manual intervention, resolving the contradiction between operational simplicity and interference prevention.
2Device complexity
If fixed transmission power is used for all slave devices, then system complexity is reduced, but spectral efficiency decreases
Solution Approach 1:
The patent transitions from fixed to dynamic transmission power control. Slave devices adjust their transmit power based on real-time conditions including distance from primary users, channel conditions, and master device power levels. This dynamic adjustment maximizes spectral efficiency by allowing devices to operate at optimal power levels rather than fixed conservative settings.
Solution Approach 2:
The system changes the transmission power parameter dynamically based on operational conditions. The master device determines appropriate power levels considering geographic location, primary user proximity, and channel conditions, then communicates these parameters to slave devices. This parameter adaptation enables higher spectral efficiency without proportionally increasing system complexity.
3Object-affected harmful factors
If master devices provide detailed power control to slave devices, then interference management is improved, but communication overhead increases
Solution Approach 1:
The patent extracts essential power control information from complex interference management requirements. Instead of transmitting detailed interference models and complete power control algorithms, the master device extracts and communicates only the necessary power level parameters to slave devices. This extraction approach achieves effective interference management while minimizing communication overhead by sharing only critical control information.
Solution Approach 2:
The master white space device acts as an intermediary that performs complex power control calculations and then simplifies the control signals for slave devices. The master device processes geographic location data, primary user information, and channel conditions to determine appropriate power levels, then communicates these as straightforward power parameters to slaves, reducing the complexity of information exchange while maintaining effective interference management.
Data Source
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AI summary
Method, apparatus, and computer program product embodiments are disclosed for efficient radio spectrum use, for example in TV white spaces and radio coexistence, wherein link parameters are selected based on the available spectrum and radio device characteristics and capabilities. An example embodiment includes a method of receiving, in a first white space device, information relating to allowed emission levels (25) in a white space radio system; receiving by the first white space device, information relating to emission characteristics (10) of a second white space device or at least one slave white space device, received from the second white space device; computing by the first white space device, one or more allowed operating parameters (12) for the second white space device or the at least one slave white space device, based on the received information relating to allowed emission levels (25) and the received emission characteristics (10); and transmitting at least one of the allowed operating parameters (12) to the second white space device.