Backhaul Link Subframe Allocation in TDD Relay Systems
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Solution Overview
Problem
Current LTE systems lack a defined transmission frame structure and HARQ operation for the backhaul link between the eNB and the RN, leading to ineffective and unreliable communication.
Innovation Solution
Allocating uplink and downlink subframes for the backhaul link according to specific rules and conducting related HARQ operations ensures effective communication between the eNB and the RN, allowing for retransmission of incorrectly transmitted data without affecting the access link's transmission performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If relay nodes are introduced to enhance coverage and capacity, then system performance is improved, but signal interference increases requiring orthogonal radio resources
Solution Approach 1:
The patent segments the radio frame into distinct backhaul link subframes and access link subframes, allocating specific time resources for each link type. This segmentation allows orthogonal resource allocation that prevents signal interference between backhaul and access links while maintaining improved coverage and capacity through relay node deployment.
Solution Approach 2:
The patent implements periodic backhaul link subframes within the TDD frame structure, where backhaul transmission occurs in designated periodic intervals. This periodic allocation ensures orthogonal resources for backhaul and access links, reducing interference while enabling relay nodes to enhance system productivity through structured time-division multiplexing.
2Adaptability or versatility
If backhaul link communication is added to the TDD system, then relay functionality is enabled, but frame structure complexity increases due to undefined transmission structure
Solution Approach 1:
The patent designs backhaul link subframes that can operate within existing TDD frame structures, making the solution universally applicable to different TDD configurations. The backhaul link transmission structure reuses existing TDD timing relationships and subframe allocations, enabling relay functionality without creating entirely new frame structures, thus reducing complexity while maintaining versatility.
Solution Approach 2:
The patent enables dynamic configuration of backhaul link subframes that can adapt to different TDD uplink-downlink configurations. The framework allows flexible allocation of backhaul subframes based on traffic demands and interference conditions, providing adaptability for relay functionality while maintaining manageable frame structure complexity through standardized configuration rules.
3Object-affected harmful factors
If orthogonal radio resources are allocated to backhaul and access links, then signal interference is reduced, but resource utilization efficiency decreases
Solution Approach 1:
The patent implements periodic backhaul link subframes that are strategically positioned within the TDD frame structure to minimize resource waste. By allocating backhaul transmission in regular periodic intervals and reusing remaining resources for access link traffic, the system maintains orthogonal protection against interference while maximizing overall resource utilization efficiency through structured time-division multiplexing.
Solution Approach 2:
The patent enables the system to discard unused backhaul link resources in certain subframes and recover them for access link transmission when backhaul traffic is low. This dynamic resource recovery mechanism reduces resource utilization inefficiency while maintaining orthogonal allocation principles that prevent signal interference, allowing flexible adaptation to varying traffic conditions.
Data Source
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AI summary
The present invention provides a method, device and system for backhaul link communication in a TDD system. Wherein, the method includes: a base station allocating an uplink subframe for uplink transmitting of the backhaul link and a downlink subframe for downlink transmitting of the backhaul link, and notifying subframe allocating information to a relay node; and the base station communicating with the relay node by the uplink subframe and the downlink subframe of the backhaul link. The solution allocates the uplink subframe and the downlink subframe of the backhaul link according to certain rules, performs related HARQ operation based on the allocated uplink subframe and downlink subframe, and ensures the availability and reliability of backhaul link communication.