Semi-Persistent Scheduling Release via NDI and MCS Combinations
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Solution Overview
Problem
In LTE-based mobile communication systems, semi-persistent resource allocations can lead to false activations, causing interference and service disruptions due to the limited CRC length and lack of mechanisms for efficient resource release, particularly in uplink persistent allocations.
Innovation Solution
The method involves using existing physical control channel signaling to deactivate semi-persistent resource allocations by defining specific combinations of New Data Indicator (NDI) and modulation and coding scheme indices, or through RRC signaling with a special transport block size, allowing for efficient resource release without altering the Physical layer-to-MAC layer interface or PDCCH formats.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If semi-persistent resource allocation is activated, then resource allocation efficiency is improved, but false activation occurs due to limited CRC length
Solution Approach 1:
The patent segments the deactivation mechanism into multiple independent components: a deactivation indicator field in PDCCH for downlink SPS release, and a separate deactivation timer for uplink SPS release. This segmentation allows each component to independently handle its specific function, reducing false activations while maintaining resource allocation efficiency.
Solution Approach 2:
The patent introduces a deactivation indicator as an intermediary element between the PDCCH and the SPS resource allocation. This intermediary carries explicit deactivation information, allowing the system to reliably release SPS resources without being affected by CRC limitations, thus resolving the false activation problem.
2Productivity
If semi-persistent resource allocation is used, then system throughput is improved, but resource release becomes inefficient due to lack of deactivation mechanisms
Solution Approach 1:
The patent implements preliminary deactivation actions by configuring deactivation indicators and timers before SPS resources are fully allocated. This allows the system to proactively release resources when no longer needed, preventing resource wastage and reducing the time required for resource release operations.
Solution Approach 2:
The patent establishes feedback mechanisms through deactivation indicators that provide real-time information about SPS resource status. This feedback enables the system to dynamically adjust resource allocation and release decisions, improving both throughput efficiency and resource release timing.
3Device complexity
If CRC length is kept limited, then control channel overhead is reduced, but deactivation signaling becomes unreliable
Solution Approach 1:
The patent moves the deactivation signaling function to another dimension by introducing a dedicated deactivation indicator field in the PDCCH structure. Instead of relying solely on CRC for deactivation signaling, the system uses this additional dimensional element to carry explicit deactivation information, achieving reliable signaling without increasing CRC length or control channel overhead.
Data Source
AI summary
A non-transitory, computer-readable storage medium for use with a user equipment in a radio communication system, the non-transitory, computer-readable storage medium storing instructions, that when executed by a processor, cause the processor to control the user equipment to perform operations that include receiving control signalling that includes new data information and modulation and coding scheme information, and releasing a semi-persistent resource allocation when a predetermined combination of the new data information and the modulation and coding scheme information is received. The modulation and coding scheme information in the predetermined combination includes an index of 11111 in binary format that indicates no transport block size information.