Event-Triggered MCS Reporting for Mobile Station Signaling Overhead
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Solution Overview
Problem
In 4G mobile communication systems using Adaptive Modulation and Coding (AMC), Mobile Stations (MS) face high signaling overhead due to periodic reporting of Channel State Information (CSI), which does not accurately reflect the channel state, leading to inefficient resource usage and potential link disconnection when channel states are stable.
Innovation Solution
A method where the MS measures the downlink channel state, determines the Modulation and Coding Scheme (MCS) level, and reports only changes in MCS levels to the Base Station (BS), reducing unnecessary signaling by reporting only when the MCS level changes, and using timers to manage reporting intervals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the MS periodically transmits CSI to the BS, then the BS can determine MCS levels based on channel state, but the signaling overhead increases
Solution Approach 1:
The patent applies periodic action by transitioning from continuous periodic CSI reporting to event-triggered reporting. The MS reports channel state information only when specific events occur (MCS level change, timer expiration, or link quality degradation), rather than continuously periodically. This reduces signaling overhead while maintaining reliable channel state information availability for MCS determination.
Solution Approach 2:
The patent implements self-service by having the MS autonomously determine when to report based on local conditions. The MS monitors its own channel state and MCS level, and triggers reports only when necessary (when MCS changes, timer expires, or link quality degrades). This self-driven approach eliminates unnecessary reporting while ensuring critical information is transmitted.
2Quantity of substance
If the MS reports CINR or RSSI to the BS, then channel state information is provided, but the report does not reflect correct channel state
Solution Approach 1:
The patent applies parameter changes by shifting from reporting raw channel state metrics (CINR, RSSI) to reporting processed MCS level information. The MS converts channel state measurements into corresponding MCS levels, which are then reported to the BS. This parameter transformation ensures that the reported information accurately reflects the effective channel state for modulation and coding purposes.
3Reliability
If the MS reports channel state continuously, then the BS has up-to-date information, but resource consumption increases
Solution Approach 1:
The patent implements periodic action through event-triggered reporting mechanisms. The MS continuously monitors channel conditions but only transmits reports when specific events occur (MCS level change, timer expiration, or link quality degradation). This selective periodic reporting maintains reliable channel state information availability while significantly reducing resource consumption compared to continuous reporting.
Solution Approach 2:
The patent applies feedback by implementing a timer mechanism and event-driven reporting. The timer expires after a predetermined period without reporting, triggering a report to ensure freshness of channel state information. This feedback mechanism ensures the BS receives updated information when needed while avoiding unnecessary transmissions during stable conditions.
Data Source
AI summary
A method of reporting channel state information by a Mobile Station (MS) in a mobile communication system is disclosed. The method includes measuring a state of a downlink channel for the entire frequency band, determining a first Modulation and Coding Scheme (MCS) level corresponding to the measured channel state, and reporting the determined MCS level to a Base Station (BS).