CIoT Frequency Tone Allocation for Interference Reduction
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Solution Overview
Problem
Cellular Internet of Things (CIoT) systems face interference issues due to overlapping frequency bands with adjacent wireless communication systems, affecting transmission power and efficiency, especially for devices with poor channel conditions.
Innovation Solution
Identifying a group of tones with reduced interference for CIoT systems to support higher power transmissions and employing frequency diversity techniques like frequency hopping and fractional frequency reuse to mitigate interference, allowing for optimized resource allocation based on channel conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If CIoT systems use overlapping frequency bands with adjacent wireless communication systems, then spectrum utilization is improved, but interference between systems increases
Solution Approach 1:
The patent divides the frequency spectrum into multiple tone groups (first tone group, second tone group, third tone group) with different transmission power levels. This segmentation allows the system to utilize the entire frequency band while controlling interference by transmitting at reduced power on tones that overlap with adjacent systems.
Solution Approach 2:
Different portions of the frequency spectrum are assigned different transmission power characteristics. The first tone group uses reduced power to minimize interference with adjacent systems, while the second and third tone groups can use higher power where interference is less critical, optimizing both spectrum utilization and interference control.
2Reliability
If transmission power is increased to improve communication reliability for devices with poor channel conditions, then link reliability is improved, but interference with adjacent systems increases
Solution Approach 1:
The patent segments tones into different power groups, allowing devices with poor channel conditions to use higher power on the second and third tone groups while the first tone group maintains reduced power to protect adjacent systems from interference.
Solution Approach 2:
Transmission power is optimized locally for each tone group based on channel conditions and interference considerations, enabling reliable communication for cell-edge devices while maintaining interference control through the reduced-power first tone group.
3Device complexity
If frequency resources are allocated uniformly to all UEs, then system simplicity is maintained, but efficiency for devices with different channel conditions deteriorates
Solution Approach 1:
The patent implements differentiated resource allocation where UEs are assigned to different tone groups based on their channel conditions. This allows simple, rule-based allocation that adapts to local conditions - devices with poor channel conditions receive resources in higher-power tone groups, while devices with good conditions use the first tone group.
Solution Approach 2:
The system changes the transmission power parameter for different tone groups based on UE channel conditions. This enables efficient resource allocation without complex scheduling, as the power parameter automatically adapts to device requirements through the predefined tone group structure.
Data Source
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AI summary
Improved systems, methods, and apparatuses for allocation of frequency resources, or tones, for a Cellular Internet of Things (CIoT) system are described. In various aspects, interference may be reduced for a CIoT system and an adjacent wireless communications system through identifying a first group of narrowband tones for the CIoT system that will have reduced interference with wideband tone transmissions of the adjacent wireless communications system and may thus support higher power transmissions.