PDSCH Muting on Inter-Cell CRS Locations for CoMP
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Solution Overview
Problem
In wireless communication systems, advanced User Equipment (UEs) experiencing poor coverage due to single-cell service face challenges in accurately measuring channel state information (CSI) without coordinated multipoint reception (CoMP), as existing technologies lack effective methods for inter-cell CSI estimation.
Innovation Solution
The eNodeB transmits Physical Downlink Shared Channel (PDSCH) with zero energy on inter-cell CRS resource element locations, computed using cell IDs of coordinating cells, to enable accurate CSI measurement for UEs and reduce interference, employing PDSCH muting schemes across multiple cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If PDSCH is transmitted on inter-cell CRS resource element locations, then resource utilization is improved, but CSI measurement accuracy deteriorates due to interference from non-serving cells
Solution Approach 1:
The patent extracts the PDSCH transmission from the CRS resource element locations of non-serving cells by implementing muting. The serving cell specifically mutes PDSCH on resource elements that correspond to inter-cell CRS pilot locations, thereby removing the interference source and enabling accurate CSI measurement without sacrificing overall resource utilization in non-muted regions
Solution Approach 2:
The patent applies local quality by differentiating treatment of resource elements based on their function. CRS resource elements are protected from PDSCH transmission (muting applied) to ensure measurement quality, while other resource elements continue normal PDSCH transmission to maintain resource utilization. This localized approach ensures measurement accuracy where needed without compromising overall system productivity
2Productivity
If CoMP cells transmit PDSCH simultaneously, then network capacity is improved, but interference on CRS positions increases, deteriorating CSI estimation accuracy
Solution Approach 1:
The patent implements periodic muting patterns where CoMP cells alternately mute PDSCH on inter-cell CRS locations in different subframes. This periodic action allows each cell to have clear CRS positions for CSI measurement in its designated subframes while maintaining network capacity through coordinated transmission in other subframes, effectively managing interference over time
Solution Approach 2:
The patent introduces a coordination mechanism as an intermediary between CoMP cells. The serving cell acts as a mediator by coordinating with non-serving cells to implement muting patterns, where the serving cell mutes PDSCH on inter-cell CRS locations based on cell ID calculations, enabling CSI measurement while maintaining overall network capacity through coordinated scheduling
Data Source
AI summary
The primary serving base station transmits PDSCH with zero energy on the inter-cell CRS resource element location. This is called mute PDSCH. Within the first Physical Resource Block (PRB 0), the RE positions in the frequency domain are indexed between 0 and 11. The muted PDSCH RE positions per antenna port are computed using the cell IDs of all CoMP cells other than the cell ID i. The invention defines the Orthogonal Frequency Division Multiplexing (OFDM) symbols in which muting occurs.