Relay Node Scheduling to Avoid Self-Interference
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Solution Overview
Problem
In LTE-Advanced mobile communication systems, simultaneous transmission and reception processes in Un and Uu radio bearers cause interference to the relay node's receiver, leading to signal overlap and degradation.
Innovation Solution
Implementing a mobile communication method that synchronizes System Frame Numbers (SFN) between radio base stations and relay nodes, using time division multiplexing and notifying relay nodes of Multicast Broadcast Single Frequency Network (MBSFN) subframe timings to avoid interference, allowing for controlled transmission and reception scheduling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If simultaneous transmission and reception processes are performed in Un and Uu radio bearers, then communication efficiency is improved, but interference occurs to the relay node's receiver
Solution Approach 1:
The patent segments the transmission and reception processes into separate time slots using time division multiplexing. The relay node performs reception process in Un radio bearer during first time slots and transmission process in Uu radio bearer during second time slots, preventing simultaneous operation that causes self-interference while maintaining communication efficiency through coordinated scheduling.
Solution Approach 2:
The patent implements periodic alternating transmission and reception cycles between Un and Uu radio bearers. The relay node alternates between receiving from the base station and transmitting to mobile stations in a periodic manner, ensuring that transmission signals do not overlap with reception periods, thus eliminating self-interference while maintaining continuous communication flow.
2Object-affected harmful factors
If time division multiplexing is implemented to avoid interference, then receiver interference is reduced, but system complexity increases
Solution Approach 1:
The patent employs feedback mechanisms where the base station receives capability information from relay nodes indicating their support for time division multiplexing operations. The base station then adjusts scheduling decisions based on this feedback, optimizing the allocation of time slots for transmission and reception while accounting for individual relay node capabilities and current traffic conditions.
Solution Approach 2:
The patent implements dynamic scheduling that adapts to changing traffic conditions and relay node states. The time slot allocation between Un and Uu radio bearers is not fixed but dynamically adjusted based on real-time requirements, allowing the system to optimize performance while managing complexity through flexible, condition-based scheduling decisions.
Data Source
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AI summary
A mobile communication method according to the present invention includes the steps of: (A) notifying, from a radio base station (DeNB) to a relay node (RN), a predetermined timing, when setting a connection between the radio base station (DeNB) and the relay node (RN); (B) scheduling, at the radio base station (DeNB), to transmit a downlink signal to the relay node (RN) at the predetermined timing; and (C) scheduling, at the relay node (RN), to transmit a downlink signal at a timing other than the predetermined timing.