Relay Node Resource Scheduling for Uplink Conflict Avoidance
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Solution Overview
Problem
In mobile communication systems with Relay Nodes (RN) using Time Division Dual (TDD) mode, uplink transmission conflicts arise due to interference between backhaul and access links, and there is a lack of clear indication of Multicast/Broadcast over Single Frequency Network (MBSFN) subframes, leading to uncertainty in uplink scheduling and conflict resolution.
Innovation Solution
A resource scheduling method where the Base Station (BS) allocates and informs RN of uplink and downlink subframes, allowing RN to determine MBSFN subframes based on predefined timing relationships, such as HARQ timing, to avoid uplink transmission conflicts and reduce signaling overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the RN receives data from eNB using downlink backhaul link, then the RN cannot transmit data to UE on access link at the same time to avoid interference, but this creates uplink transmission conflict when both backhaul and access links need to use the same frequency resources
Solution Approach 1:
The patent segments the subframe structure by introducing MBSFN subframes that are further divided into front portion (for R-PDCCH transmission) and rear portion (for PUSCH transmission). This segmentation allows different types of transmissions to coexist within the same subframe by separating them in time within that subframe, thus resolving the interference issue while maintaining uplink transmission capability.
Solution Approach 2:
The patent dynamically configures MBSFN subframes where the RN can receive downlink data from eNB in the front portion and simultaneously transmit uplink data in the rear portion. This dynamic time-division approach within subframes allows flexible resource allocation that adapts to varying traffic conditions on both backhaul and access links, eliminating fixed interference constraints.
2Object-affected harmful factors
If MBSFN subframe is used to create gap for downlink transmission, then interference between backhaul and access links is avoided, but it is unclear how the RN learns which subframe will be taken as MBSFN subframe
Solution Approach 1:
The patent implements feedback mechanisms where the eNB configures and informs the RN about MBSFN subframe locations through control signaling. The RN receives configuration information indicating which subframes are designated as MBSFN subframes, enabling it to properly schedule both downlink reception and uplink transmission without interference while maintaining synchronization with the eNB.
3Productivity
If the RN performs uplink transmission in the same subframe where it receives DCI from eNB, then uplink data transmission is efficient, but uplink transmission conflict occurs because the RN also needs to receive R-PDCCH
Solution Approach 1:
The patent segments the uplink subframe into distinct time portions: the front portion is dedicated to receiving R-PDCCH from eNB, while the rear portion is allocated for PUSCH transmission to UEs. This temporal segmentation within the same subframe allows the RN to perform both reception and transmission operations without conflict, maintaining both reliability and efficiency.
Data Source
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AI summary
The present invention discloses a resource scheduling method and system, an eNB and a RN, which include that: the eNB allocates an uplink subframe for performing uplink transmission of a backhaul link and a downlink subframe for performing downlink transmission of the backhaul link, and informs the RN of the allocation information of the uplink subframe and the downlink subframe of the backhaul link, or the eNB only informs the RN of the allocation information of the uplink subframe or the downlink subframe of the backhaul link; the RN may determine, according to the received allocation information and a predefined timing relationship, an uplink subframe and a downlink subframe of the backhaul link of which the eNB does not inform. By the solution of the present invention, an MBSFN subframe can be indicated to the RN, and uplink transmission conflict can be avoided.