Flexible Bandwidth Small Cells for Spectrum Efficiency
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Solution Overview
Problem
Wireless communication systems face challenges in utilizing portions of allocated spectrum due to non-integer multiples of channel bandwidths, leading to underutilization, especially in small cell deployments, where interference with macrocells and limited bandwidths hinder efficient resource allocation and user equipment detection.
Innovation Solution
Implementing flexible bandwidth carriers for small cells, which allow for adaptive bandwidth scaling factors to optimize spectrum usage, reduce interference, and enhance user equipment detection by adjusting chip rates and channel configurations based on traffic demand and quality of service requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If small cells use fixed bandwidth carriers, then device complexity is reduced, but spectrum utilization efficiency deteriorates due to inability to adapt to varying traffic demand and non-integer multiple spectrum portions
Solution Approach 1:
The patent implements dynamic bandwidth scaling factors that allow small cell carriers to adapt their bandwidth according to traffic demand and available spectrum portions. The bandwidth scaling factor can be adjusted in real-time to optimize spectrum utilization, transforming the fixed bandwidth system into a dynamic one that responds to changing conditions.
Solution Approach 2:
The patent changes the bandwidth parameter of small cell carriers by introducing scalable bandwidth factors. These factors allow the carrier bandwidth to be modified according to the available spectrum portions and traffic requirements, enabling efficient use of non-integer multiple spectrum allocations without requiring complete system redesign.
2Quantity of substance
If small cells use wider bandwidth carriers to support more users, then user capacity increases, but interference to macrocell users increases
Solution Approach 1:
The patent applies different bandwidth scaling factors to different small cells based on their local conditions, including user capacity requirements and interference levels to macrocells. Each small cell can optimize its bandwidth locally rather than using a uniform bandwidth across all small cells, allowing capacity optimization without excessive macrocell interference.
Solution Approach 2:
The bandwidth of small cell carriers is made dynamic and adjustable based on real-time interference conditions and user capacity needs. When interference to macrocells becomes excessive, the bandwidth scaling factor can be reduced, and when user capacity is the limiting factor, the bandwidth can be increased, creating a dynamic balance between these two competing objectives.
3Object-generated harmful factors
If small cells use narrow bandwidth carriers to reduce interference, then macrocell interference is reduced, but spectrum utilization efficiency deteriorates
Solution Approach 1:
The patent introduces bandwidth scaling factors as adjustable parameters that allow small cells to optimize their bandwidth usage. By changing the bandwidth parameter dynamically based on interference conditions and spectrum availability, the system can achieve both reduced interference and improved spectrum utilization compared to fixed narrow bandwidth configurations.
4Difficulty of detecting and measuring
If small cells use beacon carriers for discovery, then user equipment detection is improved, but system complexity increases due to multiple carrier types
Solution Approach 1:
The patent makes the bandwidth carrier multi-functional by enabling it to serve both as a data carrier and as a beacon for user equipment discovery. The same flexible bandwidth carrier that provides data service also performs the beacon function, eliminating the need for separate dedicated beacon carriers and reducing overall system complexity despite the added versatility of the carrier.
Data Source
Figure 1
Figure 2A~2B
Figure 2C~2D
AI summary
Methods, systems, and devices for utilizing flexible bandwidth carriers for small cells are provided. Bandwidth scaling factor(s) for a small cell may be determined. A flexible bandwidth carrier may be generated for the small cell utilizing the bandwidth scaling factor. Some embodiments provide assistance with active hand-in due to more available PN offsets in the flexible bandwidth domain. Some embodiments enhance small cell discovery with high bandwidth scaling factor beacon-like small cells with little more power than that corresponding to the same power spectral density for normal bandwidth small cell. Some embodiments reduce the interference caused by small cell to macrocell users using an adaptive bandwidth scaling factor for small cells based on number of users supported and their traffic demand, to control the extent of overlap the macrocell has with small cell and the interference to macrocell mobiles. Some embodiments utilize self-configuration for small cells utilizing flexible bandwidth channels.