DCI Format 3B for Wireless Control Channel Overhead Reduction
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Solution Overview
Problem
Current wireless communication systems, particularly LTE, face limitations in efficiently managing Machine-Type Communications (MTC) due to high control channel overhead and inflexibility in resource allocation, especially for applications requiring regular transmission of small packets with variable sizes or intermittent data, leading to increased costs and reduced network efficiency.
Innovation Solution
A new DCI format (Format 3B) is introduced, allowing multiple UE-specific resource allocations in a single PDCCH message, with a predefined format size matching existing formats, using a group RNTI for common parameter settings and individual settings for each UE, enabling flexible scheduling and reduced overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate PDCCH message is transmitted to each UE for resource allocation, then each UE receives dedicated control information, but the control channel overhead increases significantly when serving many UEs
Solution Approach 1:
The patent merges multiple UE-specific resource allocation messages into a single PDCCH message by introducing a compact DCI format that can carry resource allocation information for multiple UEs simultaneously. This is achieved by using a group RNTI to address multiple UEs and employing a compressed representation of resource allocation parameters that reduces the overall message size while maintaining the ability to convey dedicated control information to each UE.
Solution Approach 2:
The patent creates a universal PDCCH message format that can serve multiple UEs with different resource allocation requirements. The DCI format is designed to be multi-functional, capable of addressing different UE groups through RNTI-based filtering and providing resource allocation information that can be interpreted by multiple UEs according to their specific configurations and capabilities.
2Quantity of substance
If semi-persistent scheduling is used to reduce control channel overhead, then fewer PDCCH messages are needed, but the system loses flexibility in handling variable packet sizes and intermittent data transmissions
Solution Approach 1:
The patent introduces dynamic adaptability into the semi-persistent scheduling framework by enabling UEs to be configured with multiple DCI formats and allowing the network to switch between different resource allocation modes based on traffic conditions. The system can dynamically adjust the level of persistence in scheduling, transitioning between fully dynamic per-UE messaging and more compact group-based messaging depending on the variability of traffic patterns and packet sizes.
Solution Approach 2:
The patent employs parameter changes to achieve flexibility within a reduced overhead framework. By configuring UEs with multiple DCI formats and allowing dynamic selection among them, the system can change parameters such as resource allocation granularity, persistence level, and message compactness to match the specific requirements of different traffic patterns, thereby maintaining adaptability while reducing overall control channel overhead.
3Quantity of substance
If the DCI format size is reduced to fit more allocations in a single PDCCH message, then control channel overhead decreases, but the amount of information that can be conveyed to each UE is limited
Solution Approach 1:
The patent segments the resource allocation information into multiple fields within the compact DCI format, allowing different aspects of resource allocation to be conveyed efficiently. The segmentation enables the format to include essential resource allocation parameters for multiple UEs while maintaining a compact size. Additional detailed parameters can be conveyed through configured defaults or subsequent messaging, balancing information completeness with overhead reduction.
Solution Approach 2:
The patent uses RNTI-based filtering as an intermediary mechanism to enable UEs to efficiently extract their specific resource allocation information from the consolidated PDCCH message. The group RNTI acts as a mediator that allows multiple UEs to share a common message while still receiving UE-specific information through RNTI-based identification and filtering, thereby conveying complete resource allocation information without requiring separate full-size messages for each UE.
Data Source
AI summary
A terminal apparatus performs transmission and/or reception in units of subframes, and receives the control signal arranged in accordance with a predefined format having a predetermined size in bits and comprising one or more sets of bits each containing one or more bits from a base station; wherein within the format, a first set of bits is intended for one or more terminal apparatus and a second set of bits distinct from the first set of bits is intended for other terminal apparatus; and wherein transmission and/or reception by the terminal apparatus in a subsequent subframe is determined by the said set of bits of the control signal.