Spectrum Access via Interference Alignment Precoding
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Solution Overview
Problem
The existing cognitive radio technology for dynamic spectrum access leads to significant interference among users and inefficient information exchange in MIMO systems, especially when multiple secondary devices access idle frequency bands of primary devices, resulting in low utility efficiency of spectrum resources.
Innovation Solution
A method and apparatus that utilize interference alignment precoding technology to determine and manage access to idle frequency bands by processing position and antenna angle information of secondary devices, allowing only authorized devices to access and performing precoding to minimize interference, thereby optimizing spectrum usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple secondary devices access the idle frequency band of the primary device, then spectrum utility efficiency is improved, but interference among users increases significantly
Solution Approach 1:
The patent changes the parameter of signal transmission by applying interference alignment precoding matrices to transform the interference characteristics. By adjusting the precoding parameters based on channel state information, the system aligns interference signals into a lower-dimensional subspace, thereby reducing their harmful impact while maintaining high spectrum utilization.
Solution Approach 2:
The patent converts the harmful interference caused by multiple secondary devices into a beneficial alignment effect. By deliberately designing precoding matrices that align interference signals, the system transforms random interference into controlled, predictable interference patterns that can be more easily managed and exploited for improved spectrum efficiency.
2Productivity
If conventional cognitive MIMO systems allow secondary devices to access idle spectrum, then spectrum resources are better utilized, but information exchange efficiency decreases as the number of user equipments increases
Solution Approach 1:
The patent extracts the interference management function from the general information exchange process by applying dedicated interference alignment precoding. This separation allows the system to handle interference independently through precoding matrices, while information exchange proceeds through standardized protocols, thereby maintaining efficiency even as the number of user equipments increases.
3Adaptability or versatility
If secondary devices with different priorities access the idle frequency band, then service diversity is improved, but network status changes frequently making management difficult
Solution Approach 1:
The patent performs preliminary action by pre-calculating interference alignment precoding matrices based on channel state information before actual data transmission. This advance preparation allows the system to quickly adapt to different priority levels and network conditions without complex real-time adjustments, thereby supporting service diversity while simplifying network status management.
Data Source
AI summary
A spectrum access method and an apparatus utilizing the same. A spectrum management apparatus includes at least one processor configured to: determine location information and antenna angle information of each of at least one secondary apparatus; in response to a request for accessing an idle spectrum of a primary apparatus, determine, according to the location information and the antenna angle information of each of the at least one secondary apparatus, a secondary apparatus to grant access to the idle spectrum; and provide, to a serving base station of each of the secondary apparatuses having the access granted, the location information and the antenna angle information of all of the secondary apparatuses having the access granted, to enable the serving base station to perform interference alignment precoding.