ePDCCH Resource Determination in LTE PDSCH Areas
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Solution Overview
Problem
In the LTE Rel-11 system, there is no effective solution for determining enhanced physical downlink control channel (ePDCCH) resources, which affects the demodulation performance of control signaling due to varying CSI-RS configurations and available REs in the PDSCH area.
Innovation Solution
The method involves determining the number of ePDCCH resource units by defining the size of the minimum resource unit (eCCE or eREG) based on the number of symbols occupied by PDCCH, CRS ports, DMRS ports, and CSI-RS configuration, allowing for dynamic allocation of resources in the PDSCH area, with specific examples provided for different configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ePDCCH resources are allocated without considering CSI-RS configuration, then resource allocation is simple, but demodulation performance deteriorates due to varying available REs
Solution Approach 1:
The patent implements dynamic resource allocation for ePDCCH by adjusting the number of resource blocks based on CSI-RS configuration. The base station determines available REs in the PDSCH area considering CSI-RS resources, and dynamically allocates ePDCCH resources accordingly. This dynamic adjustment ensures that ePDCCH allocation adapts to different CSI-RS configurations, maintaining reliable demodulation performance while efficiently utilizing available resources.
2Productivity
If fixed number of ePDCCH resource blocks are allocated, then resource allocation is straightforward, but resource wastage occurs when CSI-RS configurations vary
Solution Approach 1:
The patent changes the parameter of ePDCCH resource block allocation from fixed to variable based on CSI-RS configuration. The base station calculates the number of available REs in the PDSCH area by considering the CSI-RS configuration, and determines the number of ePDCCH resource blocks dynamically. This parameter change enables efficient resource utilization by matching resource allocation to actual available resources, avoiding both waste and insufficiency.
3Reliability
If ePDCCH resources are determined without considering available REs in PDSCH area, then resource allocation is simple, but control signaling reliability deteriorates
Solution Approach 1:
The patent applies preliminary action by having the base station determine the CSI-RS configuration and calculate available REs in the PDSCH area before allocating ePDCCH resources. This preliminary determination of resource availability ensures that subsequent ePDCCH allocation is based on accurate information about usable resources, thereby guaranteeing control signaling reliability while maintaining an organized resource determination process.
Data Source
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AI summary
The present disclosure provides a method and an apparatus for determining number of ePDCCH resource units. The method includes: determining number of symbols occupied by PDCCH, number of CRS ports, number of DMRS ports and CSI-RS configuration in a subframe; and determining resources available for transmitting an ePDCCH in PDSCH area of the subframe according to the number of symbols occupied by the PDCCH, the number of CRS ports, the number of DMRS ports and the CSI-RS configuration. According to the present disclosure, the number of ePDCCH resource units may be determined when the ePDCCH is transmitted in the PDSCH data area.