ePDCCH Resource Mapping Signaling for CoMP Transmission
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Solution Overview
Problem
Current communication systems lack effective signaling for resource mapping of enhanced physical downlink control channel (ePDCCH) to support cooperative multipoint (CoMP) transmission, particularly in scenarios where transmission points have different cell IDs, leading to challenges in decoding ePDCCH with CoMP operation.
Innovation Solution
The method involves signaling the common reference signal (CRS) positions and physical downlink control channel (PDCCH) region to user equipment (UE) before CoMP schemes are applied, using dedicated RRC signaling, and designing an ePDCCH search space that includes information about the set of transmission points for CoMP-ePDCCH transmission, enabling frequency selective dynamic point selection (DPS) and joint transmission (JT) to support CoMP operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If coding chain rate-matching is used around CRS and PDCCH region for ePDCCH transmission, then decoding reliability is improved, but in CoMP scenarios with different cell IDs, the UE cannot determine CRS positions and PDCCH regions for blind decoding candidates
Solution Approach 1:
The patent applies preliminary action by providing CRS position and PDCCH region information to the UE through dedicated RRC signaling before the actual ePDCCH transmission occurs. This allows the UE to have the necessary information in advance to perform blind decoding on multiple candidates in CoMP scenarios, resolving the contradiction between maintaining decoding reliability through rate-matching and having access to CRS/PDCCH region information.
2Manufacturing precision
If DCI is used to provide CRS positions to UE for PDSCH resource mapping with CoMP, then resource mapping accuracy is improved, but this approach cannot be applied to ePDCCH with CoMP operation since DCI is only accessible after correct ePDCCH decoding
Solution Approach 1:
The patent uses dedicated RRC signaling as an intermediary mechanism to provide CRS position and PDCCH region information to the UE. This intermediary approach bypasses the circular dependency problem where DCI (accessible only after ePDCCH decoding) cannot provide information needed for ePDCCH decoding itself, thereby enabling CoMP operation for ePDCCH.
3Adaptability or versatility
If ePDCCH supports CoMP transmission from multiple TPs with different cell IDs, then system versatility is improved, but device complexity increases due to multiple blind decoding candidates with different CRS positions and PDCCH regions
Solution Approach 1:
By providing all necessary CRS position and PDCCH region information through dedicated RRC signaling in advance, the patent enables the UE to efficiently handle multiple blind decoding candidates for CoMP ePDCCH transmission without increasing operational complexity during actual decoding, thus supporting system versatility while managing device complexity.
Data Source
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AI summary
Communication systems may benefit from signaling for resource mapping. For example, third generation partnership project (3GPP) long term evolution advanced (LTE-Advanced) may benefit from signaling for enhanced downlink control channel (ePDCCH) resource mapping in support of coordinated multipoint (CoMP) transmission.