Permutation Group Channel Rendezvous for Multi-Antenna Cognitive Networks
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Solution Overview
Problem
The existing single-antenna channel rendezvous method in cognitive radio networks is inefficient, leading to prolonged rendezvous times due to limited processing capability and bottlenecks, especially in networks with multiple channels and dynamic channel availability.
Innovation Solution
A permutation group-based channel rendezvous method for multi-antenna cognitive radio networks, where channel numbers are mapped as elements in permutation groups, and channel hopping sequences are constructed through rotations of regular polyhedra or polygons, ensuring deterministic rendezvous within a finite time by utilizing multiple antennas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If a single-antenna channel rendezvous method is used, then the device complexity is low, but the rendezvous time is prolonged and search efficiency is limited
Solution Approach 1:
The patent divides the single search task into multiple parallel searches by using multiple antennas. Each antenna independently performs channel hopping and rendezvous attempts, segmenting the overall rendezvous process into concurrent sub-tasks that can be executed simultaneously, thereby reducing total rendezvous time.
Solution Approach 2:
The patent transitions from a single-antenna one-dimensional search to a multi-antenna multi-dimensional search space. By introducing the antenna dimension, the system can explore multiple channels simultaneously across different spatial dimensions, significantly improving search efficiency and reducing rendezvous time.
2Productivity
If multiple antennas are deployed to reduce rendezvous time, then the search efficiency is enhanced, but the device complexity increases
Solution Approach 1:
The patent segments the search function across multiple antennas, with each antenna handling independent channel hopping sequences. This segmentation allows parallel processing of channel searches, enhancing productivity while distributing the computational and hardware complexity across multiple independent units rather than requiring a single complex system.
3Ease of operation
If a dedicated common control channel is used, then the channel rendezvous process is simplified, but the network capacity is limited and the system becomes vulnerable to single-point failure
Solution Approach 1:
The patent extracts the rendezvous function from a dedicated common control channel and distributes it across multiple independent channels through multi-antenna channel hopping. This removes the single-point failure vulnerability of a dedicated control channel while maintaining operational simplicity through structured channel access patterns.
Solution Approach 2:
The patent changes the channel access parameters by implementing time-varying channel hopping sequences across multiple antennas. Instead of using a fixed dedicated control channel, the system dynamically changes channel parameters over time, improving reliability by distributing traffic across multiple channels while maintaining ease of operation through systematic parameter management.
4Loss of time
If channel hopping is performed frequently to achieve rendezvous, then the rendezvous time is reduced, but the energy consumption increases
Solution Approach 1:
The patent segments the energy consumption across multiple antennas, where each antenna performs channel hopping independently. By distributing the hopping workload, the system achieves faster rendezvous through parallel searches while the energy cost is distributed across multiple units, making the overall energy-time efficiency improved compared to a single-antenna system performing sequential searches.
Data Source
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AI summary
The present invention relates to wireless network technology and presents a permutation group-based channel rendezvous method for a multi-antenna cognitive radio network, allowing a cognitive user equipped with multiple antennas to achieve blind channel rendezvous without the need for clock synchronisation. The present invention defines channel hopping sequences whilst making full use of properties such as channel diversity, the closure nature of permutation groups, and multi-antenna concurrency; based on the permutation groups obtained by rotating a regular polyhedron or a regular polygon around different angles according to different types of axes of symmetry, cyclical splicing is implemented, and different antennas can, according to different rules, independently generate hopping sequences and switching channels; the sequence generating methods are various and flexible; the use of parallel search ensures that deterministic rendezvous with other cognitive users is achieved as quickly as possible and as much as possible in a limited time; and the present method is a highly efficient blind channel rendezvous method having wide applicability and suitable for use in large-scale wireless networks.