Coordinated Multipoint Link Adaptation via Interference Segmentation
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Solution Overview
Problem
Coordinated multipoint (CoMP) systems face challenges in accurately estimating interference on the physical downlink shared channel (PDSCH) outside of the CoMP measurement set, particularly due to lack of information on beamforming and scheduling decisions at cooperating nodes, leading to inaccurate interference estimation, especially in bursty traffic conditions.
Innovation Solution
The proposed solution involves alternative schemes for channel quality indicator (CQI) calculation and interference estimation, where the channel measurement module (CMM) performs per-point CQI calculation and the channel interference module (CIM) adjusts CQIs to account for differences in total interference power and interference power outside the CoMP measurement set using a correction coefficient, approximated from reference signal received power (RSRP) reports and scheduling information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If per-point CQI feedback is used assuming interference outside CoMP measurement set, then CQI calculation is simplified, but interference estimation accuracy deteriorates
Solution Approach 1:
The interference estimation is segmented into two parts: interference from CoMP measurement set nodes (which can be measured directly) and interference from outside CoMP measurement set nodes (which must be estimated). The patent separates these interference sources and processes them differently to improve overall accuracy while managing complexity.
Solution Approach 2:
The patent introduces an intermediary estimation approach using RSRP measurements and path loss calculations to estimate interference from nodes outside the CoMP measurement set. This intermediary method bridges the gap between measurable quantities (RSRP) and the desired quantity (interference power) without requiring direct measurement of unmeasurable interference sources.
2Measurement precision
If interference estimation includes all nodes, then interference estimation accuracy improves, but information requirements increase
Solution Approach 1:
The system uses readily available information (RSRP measurements and path loss data) to self-estimate the interference from outside CoMP measurement set nodes without requiring additional information exchange or coordination with external nodes. Each node performs the estimation autonomously using its own measurements and pre-configured path loss information.
3Reliability
If CQI adjustment uses correction coefficient, then link adaptation accuracy improves, but calculation complexity increases
Solution Approach 1:
The patent adjusts the CQI parameter by applying a correction coefficient that accounts for the difference between total interference and CoMP measurement set interference. This parameter transformation converts the raw CQI measurement into an adjusted CQI that better reflects the actual interference conditions, improving link adaptation accuracy through a straightforward mathematical adjustment.
Data Source
AI summary
Embodiments of the present disclosure describe devices, methods, computer-readable media and systems configurations for link adaptation within coordinated multipoint systems. In various embodiments, a mobile terminal may determine link adaptation feedback information and feed back the information to a base station. The base station may adjust a channel quality indicator of the link adaptation feedback information based on loading of nodes within a coordinated multipoint measurement set. Other embodiments may be described and/or claimed.