Base Station Subframe Scheduling for MTC Timing
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Solution Overview
Problem
In LTE/LTE-A systems, the timing relationship between downlink control channels and traffic channels is not ensured, particularly in narrow band systems and coverage enhancement scenarios, leading to affected communication quality for MTC UE, due to MBSFN subframes occupying entire bandwidth.
Innovation Solution
A base station determines subframe sets for downlink control and traffic channels and performs across subframe scheduling to maintain timing relationships, using high-layer signaling or predefined modes to configure subframe sets and scheduling intervals, ensuring that MTC UE operates normally.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If MBSFN subframes occupy the entire bandwidth for multicast/broadcast service, then the system can provide efficient multicast/broadcast transmission, but the timing relationship between downlink control channel and downlink traffic channel is disrupted
Solution Approach 1:
The patent divides the system bandwidth into multiple subframe sets, where some subframes are allocated for MBSFN multicast/broadcast services while other subframes are reserved for unicast control channels and traffic channels. This segmentation allows different services to operate in dedicated time resources without interfering with each other's timing relationships.
Solution Approach 2:
The patent applies different quality characteristics to different subframe sets: MBSFN subframes are optimized for multicast/broadcast transmission with full bandwidth, while non-MBSFN subframes are optimized for unicast communication with guaranteed timing relationships. Each subframe set has locally optimized properties suitable for its specific service type.
2Ease of manufacture
If the system uses narrow band bandwidth (1.4MHz) for MTC UE to reduce cost, then the MTC UE cost is reduced, but the timing relationship cannot be ensured when MBSFN occupies entire bandwidth
Solution Approach 1:
The patent segments the available subframes into MBSFN subframe sets and non-MBSFN subframe sets, allowing MTC UEs to operate in narrow band mode during non-MBSFN subframes where timing relationships are preserved, while MBSFN services operate in full bandwidth during dedicated MBSFN subframes.
Solution Approach 2:
The patent enables dynamic subframe set configuration where the network can flexibly assign different subframes to MBSFN or non-MBSFN purposes based on service demands. This dynamic allocation ensures that MTC UEs always have access to subframes with guaranteed timing relationships while MBSFN services receive adequate resources.
3Adaptability or versatility
If across subframe scheduling is used for downlink traffic channel, then scheduling flexibility is improved, but timing relationship is affected when MBSFN subframes are involved
Solution Approach 1:
The patent segments the scheduling space into MBSFN subframe sets and non-MBSFN subframe sets, allowing across-subframe scheduling to operate within the non-MBSFN subframe set where timing relationships are guaranteed, while MBSFN subframes are excluded from scheduling operations that require timing precision.
Solution Approach 2:
The patent introduces subframe set configuration as an intermediary layer between the scheduling function and the physical channel transmission. This intermediary structure allows the scheduling algorithm to maintain flexibility while the subframe set boundaries ensure timing relationship preservation for critical control channels.
Data Source
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AI summary
A method and device for realizing channel transmission are provided. In the method, a base station determines a subframe set used by a downlink control channel and/or a subframe set used by a downlink traffic channel; and the base station performs across subframe scheduling for the downlink traffic channel through the downlink control channel. According to the solution, a subframe set used by a downlink control channel and/or a subframe set used by a downlink traffic channel are/is determined by a base station, and the downlink traffic channel is scheduled across subframes through the downlink control channel. By virtue of the solution, a timing relationship of channel transmission is prevented, in a narrow band system and a coverage enhancement system, from being affected due to the fact that a Multicast Broadcast Single Frequency Network (MBSFN) subframe transmitting a multicast/broadcast service may occupy the entire bandwidth of the system, and a timing relationship between a base station and a terminal may be guaranteed. In this way, normal communication of a Machine-Type Communication (MTC) terminal may be ensured, and the working quality of the system may be improved.