Relay Node Control Channel Resource Allocation in LTE-A Backhaul
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Solution Overview
Problem
In wireless communication systems, particularly in LTE-A systems, the allocation of control channel resources for relay nodes within backhaul subframes is inefficient due to high hardware complexity and the need for frequent blind decodings, leading to resource wastage and increased implementation complexity.
Innovation Solution
The method involves dividing the resource region for relay nodes into multiple resource groups and allocating the same resource group to relays operating in the same transmission mode, reducing the number of blind decodings and maximizing frequency diversity gain by supporting both interleaved and non-interleaved resource groups.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the control channel resource is allocated semi-statically to relay nodes, then the resource allocation is simplified and easier to manage, but the resource utilization efficiency deteriorates due to inability to adapt to varying transmission needs
Solution Approach 1:
The patent applies dynamics by enabling the relay node to dynamically select between two resource allocation modes: semi-static allocation (for stability and ease of management) and frequency-selective allocation (for high efficiency). The system transitions between these modes based on transmission requirements, allowing the resource allocation mechanism to adapt its degree of flexibility rather than being fixed in one approach.
2Productivity
If frequency selective resource allocation is performed for relay nodes, then resource utilization efficiency is improved, but the relay implementation complexity increases due to the need for multiple blind decodings
Solution Approach 1:
The patent segments the control channel search space into two distinct parts: a first search space for semi-static resource allocation and a second search space for frequency-selective resource allocation. This segmentation allows the relay node to limit blind decoding attempts to specific segments based on the allocated mode, reducing overall complexity while preserving the benefits of frequency-selective allocation when needed.
Solution Approach 2:
The patent implements partial action by allowing the relay node to perform blind decoding only in the extent necessary for its configured mode. For semi-static allocation, the relay performs blind decoding only in the first search space. For frequency-selective allocation, it performs blind decoding in the second search space. This partial approach avoids the excessive blind decoding that would occur if the relay had to search both spaces simultaneously.
3Adaptability or versatility
If a large amount of semi-static resource is informed to the relay node, then frequency selective resource allocation can be supported, but the number of blind decodings increases resulting in degradation of efficiency
Solution Approach 1:
The patent segments the control channel resources into two separate search spaces with distinct functions. The first search space handles semi-static resource information, while the second search space handles frequency-selective resource information. This segmentation allows the system to support both allocation types without requiring the relay to perform blind decoding across the entire combined resource space, thus maintaining adaptability while preserving decoding efficiency.
4Adaptability or versatility
If the control channel structure imitates the LTE system control channel structure, then compatibility is maintained, but resource waste occurs due to blank areas distributed across the control channel
Solution Approach 1:
The patent applies local quality by creating a specialized control channel structure for relay nodes that differs from the standard LTE control channel structure. Instead of uniformly imitating the LTE structure across all resources, the patent introduces a dedicated search space with tailored resource allocation characteristics optimized for relay-specific control channels, thereby reducing the blank areas and resource waste while maintaining necessary LTE compatibility.
Data Source
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AI summary
A method and apparatus for allocating control channels of a relay within a backhaul subframe in a wireless communication system is provided. The method for allocating control channel resources includes grouping relays according to channel conditions; transmitting resource group information on the same resource group allocated to use the same transmission mode for the relays belonging to the same relay group; transmitting a control channel message to the relays according to the allocated resource; and transmitting data to the relays according to the control channel message.