Dynamic CSI-RS Configuration for D2D V2X Operation Clarity
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Solution Overview
Problem
D2D communication in LTE systems experiences operation ambiguity due to simultaneous D2D and cellular UL transmissions, leading to issues in vehicle-to-everything (V2X) communication, and existing CSI-RS configurations are limited, causing problems with multiple CSI-RSs and inefficient scheduling in unlicensed bands.
Innovation Solution
The method proposes variable CSI-RS configurations with {20, 24, 28, 32} ports, CDM-4/CDM-8 mapping, and power boosting for array antennas, along with efficient scheduling and resource allocation to resolve operation ambiguity and support different transmission/reception schemes in 5G systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If D2D transmission and cellular UL transmission occur simultaneously using UL resources, then resource utilization is improved, but operation ambiguity arises
Solution Approach 1:
The patent segments the uplink resources by introducing separate resource pools: one for cellular UL transmission and another for D2D transmission. This segmentation allows both transmissions to occur simultaneously without ambiguity, as each transmission type has dedicated resources. The base station configures distinct resource pools for different transmission purposes, eliminating the operation ambiguity that would arise from sharing the same UL resources.
2Quantity of substance
If the number of CSI-RS ports is increased to support large-scale array antennas, then antenna capability is improved, but existing CSI-RS configuration becomes insufficient
Solution Approach 1:
The patent introduces dynamic CSI-RS configuration that adapts to the number of antenna ports. The base station can flexibly configure CSI-RS resources based on the actual array antenna setup, supporting variable numbers of ports (e.g., 20, 24, 28, 32 ports). This dynamic configuration capability allows the system to scale with large-scale array antennas while maintaining appropriate reference signal resources for channel estimation and beam management.
3Measurement precision
If power boosting is applied to CSI-RS for array antennas, then signal quality is improved, but power allocation complexity increases
Solution Approach 1:
The patent employs power boosting by adjusting the transmit power parameter of CSI-RS specifically for array antenna configurations. The base station increases the power of CSI-RS signals to ensure adequate signal quality for channel estimation in large-scale MIMO scenarios. This parameter change approach maintains signal quality while managing power allocation through configured power offsets and boosting factors that are communicated to the terminal.
Data Source
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AI summary
The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The present disclosure provides a method and an apparatus for coexistence of device-to-device communications and cellular communications in a mobile communications system.