Intra-cell Frequency Reuse via Power Control in Relay Networks
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Solution Overview
Problem
In traditional wireless telecommunications systems, intra-cell frequency reuse in networks with relay nodes is challenging due to overlapping coverage areas, leading to significant interference and reduced system capacity and coverage.
Innovation Solution
The implementation of a method that allows multiple relay nodes and base stations to reuse the same resource blocks with minimal cross-interference by determining channel quality indicators, pathloss differences, and adjusting transmission powers, enabling efficient communication through coordinated resource allocation and scheduling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If relay nodes and base stations use the same resource blocks for transmission, then system capacity and coverage are increased, but cross-interference between nodes increases
Solution Approach 1:
The patent applies local quality by differentiating transmission power levels between cell-center UEs and cell-edge UEs. Cell-center UEs receive transmissions at normal power levels, while cell-edge UEs receive transmissions at reduced power levels to minimize interference to relay nodes. This localized power adjustment allows frequency reuse while controlling interference in specific spatial regions.
Solution Approach 2:
The patent changes the transmission power parameter dynamically based on UE location and channel conditions. By adjusting the power spectral density (PSD) for different UE groups and transmission types, the system enables multiple relay nodes to reuse the same resource blocks with controlled interference levels, thereby increasing system capacity.
2Productivity
If relay nodes and base stations reuse the same frequency resources, then spectral efficiency is improved, but interference to cell-edge UEs increases
Solution Approach 1:
The patent implements local quality by creating different transmission power zones: cell-center UEs experience normal power transmissions from base stations, while cell-edge UEs experience reduced power transmissions. This spatial differentiation allows frequency reuse to improve spectral efficiency while protecting cell-edge UEs from excessive interference.
Solution Approach 2:
The patent introduces relay nodes as intermediaries between base stations and cell-edge UEs. The relay nodes receive transmissions from base stations and forward them to cell-edge UEs, enabling the system to achieve frequency reuse benefits while managing interference through the relay's buffering and forwarding capability.
3Object-generated harmful factors
If transmission power is reduced for cell-center UEs to enable frequency reuse, then interference to relay nodes is minimized, but signal quality for cell-center UEs may deteriorate
Solution Approach 1:
The patent applies local quality by implementing location-dependent power control: cell-center UEs receive transmissions at normal power levels to maintain signal quality, while cell-edge UEs receive transmissions at reduced power levels to minimize interference to relay nodes. This ensures that signal quality for cell-center UEs is not compromised while enabling frequency reuse.
Data Source
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AI summary
A method for communicating using a wireless communication network is presented. The method may include determining a first modulation and coding scheme, MCS, for use in communicating with a first user equipment served by a base station, the first MCS to be used when the base station transmits at a low power. The method further provides that when a spectrum efficiency of the first MCS is equal to or higher than a spectrum efficiency of a pre-determined MCS, communicating with the first UE is effected using a low power transmission.