CSI Measurement Timing Mapping Rule for Interference Coordination
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Solution Overview
Problem
In LTE and LTE-A systems, existing technologies face challenges in accurately measuring and reporting channel state information (CSI) due to co-channel interference between macro and home eNBs, leading to inefficient inter-cell interference coordination and inaccurate scheduling of user equipment (UE) operations.
Innovation Solution
A method and apparatus that store and use a rule to map between downlink subframes for CSI measurement and uplink subframes for reporting, allowing for periodic or aperiodic CSI measurement and reporting configurations, enabling precise control over CSI reporting to improve scheduling and interference mitigation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If TDM eICIC is applied to reduce co-channel interference between macro and home eNBs, then interference coordination is improved, but accurate scheduling of user equipment becomes difficult without knowing UE geographic location
Solution Approach 1:
The patent changes the parameter of CSI measurement timing by introducing a mapping rule between downlink subframes and uplink reporting subframes. This allows the system to measure CSI during almost blank subframes when interference conditions are known and stable, then report this CSI in subsequent uplink subframes. The eNB can use this timing-based parameter change to schedule UEs accurately without needing their geographic location, thus resolving the contradiction between interference reduction and scheduling ease.
2Measurement precision
If CSI measurement is performed during almost blank subframes to improve accuracy, then CSI precision is improved, but scheduling flexibility is reduced due to restricted uplink reporting timing
Solution Approach 1:
The patent introduces a dynamic mapping mechanism where the relationship between downlink measurement subframes and uplink reporting subframes is flexible rather than fixed. The mapping rule allows different downlink subframes to be mapped to appropriate uplink reporting subframes based on timing relationships, enabling the system to adapt to different scheduling scenarios while maintaining measurement accuracy during almost blank subframes.
3Reliability
If periodic CSI measurement configuration is used to ensure consistent measurements, then measurement reliability is improved, but responsiveness to changing channel conditions deteriorates
Solution Approach 1:
The patent employs periodic CSI measurement configurations where the eNB can configure the UE to perform CSI measurements in specific periodic subframes, particularly during almost blank subframes. The periodicity and timing of these measurements can be adjusted to balance reliability and responsiveness. By mapping these periodic measurements to appropriate uplink reporting subframes, the system maintains measurement consistency while adapting to changing channel conditions.
Data Source
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AI summary
A rule specifies a timing relation between a measurement configuration which indicates at least one subframe to measure and a reporting configuration which indicates at least one subframe in which to report. This rule is used by both user equipment UE and network to map between a downlink subframe in which channel state information is measured and an uplink subframe in which the channel state information is reported. The network may configure the UE with the measurement and reporting configurations via dedicated signaling or broadcast. If the measurement configuration is periodic and indicates multiple downlink subframes to measure the rule results in a one to one mapping of downlink to uplink subframe where less than all of the multiple downlink subframes map to an uplink subframe; if aperiodic the rule indicates a single downlink subframe to measure.