Decentralized Interference Control in Cognitive Radio Networks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for controlling aggregate interference in wireless communication systems, particularly in TV white spaces, face challenges such as inaccurate location determination of secondary users, computational complexity, and privacy concerns when using geolocation databases and stochastic geometric approaches, especially in indoor and dense urban scenarios.
Innovation Solution
A decentralized method and system that compute power density, footprint, and service area for each cell in a secondary system to control aggregate interference, allowing local computation and reducing the need for central administration, thereby enhancing flexibility and privacy by using power density-based computations and shadow fading weighted summations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If geolocation databases store and use exact location information of secondary users, then interference control accuracy is improved, but user privacy is compromised and computational complexity increases
Solution Approach 1:
The patent extracts only the essential information needed for interference control (power density, footprint, service area) while leaving out sensitive location data. The geolocation database stores and processes aggregated statistical parameters rather than individual user location information, achieving interference control without compromising privacy.
Solution Approach 2:
The patent transforms exact location parameters into statistical power density parameters. Instead of tracking precise positions of secondary users, the system uses power density distributions and footprint measurements that capture interference characteristics without revealing location information, thus resolving the privacy-accuracy contradiction.
2Measurement precision
If exact position of all secondary users is used to compute aggregate interference, then interference measurement precision is improved, but computational demand increases
Solution Approach 1:
The patent segments the complex task of aggregate interference computation by dividing it into cell-level contributions. Each cell's interference is characterized by power density and footprint parameters, allowing the total interference to be computed as a sum of independent cell contributions rather than processing all individual user positions simultaneously.
Solution Approach 2:
The patent changes the computational parameters from individual user positions to aggregated cell-level power density distributions. This transformation reduces the computational burden by working with statistical parameters that capture the essential interference characteristics without requiring detailed position information for each user.
3Measurement precision
If centralized geolocation database approach is used, then interference control accuracy is improved, but system flexibility and ease of operation deteriorate
Solution Approach 1:
The patent segments the centralized interference control function into distributed cell-level computations. Each cell independently computes its power density and footprint parameters, and these local computations are aggregated to determine overall interference. This segmentation enables decentralized operation while maintaining control accuracy.
Solution Approach 2:
The patent enables each cell to self-determine its interference contribution through local computation of power density and footprint parameters. This self-service approach allows cells to autonomously manage their interference characteristics without requiring centralized coordination, thereby improving system flexibility and ease of operation.
Data Source
AI summary
A method and a system for controlling the aggregate interference in cognitive radio networks A method for controlling the aggregate interference of a secondary system (10) in a cognitive radio network comprises the steps of: -computing the power density (Pd,i), footprint (Afoot,i) and service area (Ai) for each of the cells (100) of the secondary system (10) that satisfy the interference constraint at a given point (P) in a primary system (50); -summing the power densities (Pd,i) for all cells (100) for the point (P); and -using the sum of the power density at the point (P) to decide which power level a new secondary system (10) user is allowed to use in a given cell (100). In addition, the patent application has an independent system claim.