D2D Communication Resource Allocation in TDD Systems
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Solution Overview
Problem
In cellular communication systems, Device-to-Device (D2D) communication faces challenges in scheduling radio resources, especially in TDD systems with varying uplink-to-downlink subframe ratios, which affects the reliability and flexibility of D2D communication scheduling for different service types.
Innovation Solution
A method where a first resource set for D2D control information and a second resource set for D2D data are determined based on received configuration parameters and pre-configuration information, allowing for flexible scheduling by adjusting the number of transmission times and resource patterns, even in partial or non-coverage scenarios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If D2D communication uses uplink resources in TDD systems, then spectrum efficiency is improved, but scheduling complexity increases due to varying UL-DL configurations
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the number of transmission times based on the TDD UL-DL configuration. Different configurations (0-6) have different ratios of uplink to downlink subframes, and the patent modifies the transmission parameter (number of transmissions) to adapt to each configuration, thereby maintaining scheduling feasibility while using uplink resources for D2D communication.
2Adaptability or versatility
If D2D communication scheduling is adapted to different TDD configurations, then adaptability is improved, but device complexity increases
Solution Approach 1:
The patent applies local quality by providing different scheduling parameters for different TDD configurations. Each configuration (0-6) has specific characteristics in terms of uplink-downlink subframe distribution, and the patent tailors the transmission parameters locally to each configuration type, allowing the system to adapt to local conditions without requiring a completely different scheduling mechanism for each case.
Solution Approach 2:
The patent implements dynamics by making the number of transmissions a dynamic parameter that changes according to the TDD configuration. Rather than using a fixed number of transmissions, the system dynamically adjusts this parameter based on the detected UL-DL configuration, enabling flexible adaptation to varying network conditions while maintaining a unified scheduling framework.
3Reliability
If multiple transmission times are used for D2D data, then reliability is improved, but resource usage increases
Solution Approach 1:
The patent applies partial or excessive action by using multiple transmissions of D2D data, where the number of transmissions exceeds the single transmission case to improve reliability. The system performs more transmissions than the minimum required, trading additional resource consumption for enhanced transmission reliability, particularly important in D2D communication where direct links may be less reliable than cellular links.
Data Source
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AI summary
Device-to-Device (D2D) communication methods and apparatuses are provided. In the method, a first resource set for transmitting D2D control information is determined according to a received D2D resource configuration parameter and/or stored radio resource pre-configuration information; a second resource for transmitting D2D data is determined; and D2D control information is sent in the first resource set and/or D2D data is sent in the second resource. The methods and the apparatuses address the scheduling problem existing in the direct communication of D2D UEs on the radio resource of a cellular communication system in the related art. In particular, facing the characteristic of a cellular system of TDD system that the ratio of uplink subframes to downlink subframes varies under different TDD configurations, the reliability of the transmission of D2D communication control information and data information and the flexibility of D2D communication scheduling under each TDD configuration for different types of services when D2D communication can only use uplink resources can be guaranteed.