LTE In-Band Relay Resource Allocation for Interference Mitigation
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Solution Overview
Problem
In LTE in-band relay systems, interference between backhaul and access links limits spectral efficiency, and existing solutions require hardware modifications for MBSFN subframes, which are not supported by all devices, leading to compatibility issues and increased costs.
Innovation Solution
The method involves using separate radio bearer resources for backhaul and access links, with allocation information sent by a donor eNodeB to a relay node, allowing simultaneous transmission without interference, and eliminating the need for MBSFN subframes, thus avoiding hardware modifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If time division multiplexing is used to avoid interference between backhaul and access links, then interference is reduced, but the relay node cannot send data to common user equipment when the downlink backhaul link is active
Solution Approach 1:
The patent divides the radio bearer resources into separate first radio bearer resources for the backhaul link and second radio bearer resources for the access link. This segmentation allows the relay node to simultaneously maintain both backhaul and access transmissions without interference, as each link has dedicated resources rather than sharing the same time slots.
2Productivity
If MBSFN subframes are used to allow simultaneous backhaul and access transmissions, then spectral efficiency is improved, but hardware modifications are required which increases costs and reduces device compatibility
Solution Approach 1:
The patent changes the resource allocation parameters by assigning separate radio bearer resources (first radio bearer resources and second radio bearer resources) to different links. This parameter change enables simultaneous backhaul and access transmissions using standard hardware without requiring MBSFN subframe modifications, thus maintaining device compatibility while achieving spectral efficiency.
3Object-affected harmful factors
If separate frequency bands are used for backhaul and access links (out-of-band relay), then interference is avoided, but total spectrum occupation increases reducing spectral efficiency
Solution Approach 1:
The patent resolves the interference issue by transitioning from frequency domain separation (out-of-band) to a resource dimension separation within the same frequency band. By allocating different radio bearer resources (first and second radio bearer resources) within the same band, the system achieves both interference avoidance and efficient spectrum utilization.
Data Source
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AI summary
The present invention belongs to the field of mobile communications technologies, and discloses an LTE in-band relay method, apparatus, and system. The method includes: receiving, by a first relay node, allocation information that is sent by a donor eNodeB, where the allocation information is used to indicate a first radio bearer resource that is to be occupied by a first backhaul link in a scheduling period, and the first backhaul link is a link between the donor eNodeB and the first relay node; and communicating with first user equipment in the scheduling period by using a second radio bearer resource, where the first user equipment is user equipment to which the first relay node provides a service, and the second radio bearer resource is a radio bearer resource that is in a preset frequency band and that is different from the first radio bearer resource.