MTC UE Downlink Control Search Space Configuration
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Solution Overview
Problem
In machine type communication (MTC) systems, MTC UEs with varying coverage enhancement levels in a single cell face inefficiencies in radio resource utilization due to repetitive transmissions of downlink control information across multiple subframes, lacking a clear method to determine the start subframe for repetitive transmission.
Innovation Solution
A method and apparatus for MTC UEs and base stations to receive and transmit downlink control information by using higher layer signaling to calculate and determine the start subframe for repetitive transmission, allowing accurate monitoring and reception of downlink control channels across multiple subframes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If repetitive transmission of downlink control information is performed across multiple subframes for MTC UEs with different coverage enhancement levels, then coverage enhancement is improved, but radio resource utilization efficiency deteriorates
Solution Approach 1:
The patent segments MTC UEs into different coverage enhancement levels and allocates different UE-specific search space configurations to each level. This segmentation allows targeted repetitive transmissions only for UEs that actually need coverage enhancement, rather than applying repetitive transmissions uniformly to all MTC UEs, thus improving radio resource utilization efficiency while maintaining coverage enhancement for those who need it.
Solution Approach 2:
The patent applies different transmission configurations (repetitive or non-repetitive) to different local groups of UEs based on their coverage enhancement levels. Instead of a uniform approach, each UE group receives appropriately tailored transmission parameters, ensuring that resources are not wasted on UEs that don't require repetitive transmissions while still providing coverage enhancement to those that do.
2Device complexity
If the same UE-specific search space is set for all MTC UEs in a single cell, then device complexity is reduced, but radio resource utilization efficiency deteriorates
Solution Approach 1:
The patent introduces dynamic UE-specific search space configurations that adapt based on coverage enhancement levels. Rather than using a static, uniform search space for all MTC UEs, the system dynamically adjusts search space parameters (such as monitoring occasions and resource allocations) according to each UE's coverage requirements, optimizing resource utilization while maintaining manageable complexity through standardized configuration methods.
3Reliability
If repetitive transmission is performed without clear start subframe determination, then coverage enhancement is improved, but loss of time increases
Solution Approach 1:
The patent establishes predetermined rules and higher layer signaling mechanisms that define start subframe locations for repetitive transmissions in advance. By pre-configuring timing parameters and start subframe determination methods through higher layer signaling, the system eliminates timing uncertainty without requiring complex real-time negotiations, thus reducing time loss while maintaining coverage enhancement benefits.
Data Source
AI summary
The present disclosure relates to a method of transmitting and receiving downlink control information and an apparatus thereof. Particularly, the present disclosure relates to a method and apparatus for configuring aUE-USS when a downlink control search space is configured for a UE that supports a coverage enhancement operation or a low complexity UE category/type for a machine type communication (MTC) operation. Particularly, a method may include: receiving a higher layer signaling including at least one of maximum repetition level information and offset information; calculating a location of a start subframe where the repetitive transmission of a downlink control channel starts by using a higher layer signaling; monitoring a UE-specific search space in two or more subframes including the start subframe; and repetitively receiving a downlink control channel including downlink control information through the UE-specific search space.