HARQ Resource Allocation in D2D Wireless Networks

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Solution Overview

Problem

Existing HARQ mechanisms for Device-to-Device (D2D) communication in wireless networks are limited by fixed upstream and downstream resource ratios, leading to collisions and inefficiencies in resource allocation, particularly due to the specific TDD configurations for each D2D pair, which are not synchronized with cellular networks.

Innovation Solution

A method where a network node transmits information on transmission resources and determines a TDD configuration for D2D communication, enabling wireless devices to determine HARQ timing and resources without collisions, applicable to various upstream and downstream scenarios, by using subframe mapping or location separation information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a fixed TDD configuration is used for D2D communication, then the HARQ timing can be simplified, but resource allocation collisions occur due to lack of synchronization with cellular networks

Engineering Contradiction:

ImproveHARQ timing complexityVSAvoidresource allocation collision

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent applies dynamics by making the TDD configuration adjustable and adaptable rather than fixed. The system dynamically selects and switches between different TDD configurations ( Configuration 1 with 1:1 ratio and Configuration 2 with 2:1 ratio) based on current network conditions and traffic patterns, allowing the HARQ timing to adapt to changing cellular network synchronization requirements while avoiding resource allocation collisions

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the TDD configuration parameters (upstream-downstream time slot ratios) to resolve the contradiction. By switching between different parameter sets (1:1 ratio for symmetric traffic, 2:1 ratio for asymmetric traffic), the system maintains both simplified HARQ timing within each configuration and collision-free resource allocation across cellular and D2D networks

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If separate HARQ timing is configured for each D2D pair, then resource allocation flexibility is improved, but network control complexity and signaling overhead increase

Engineering Contradiction:

Improveresource allocation flexibilityVSAvoidnetwork control complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies universality by creating a standardized TDD configuration framework that serves multiple D2D pairs simultaneously. Instead of customizing HARQ timing for each individual D2D pair, the system defines universal TDD configurations (Configuration 1 and Configuration 2) that can be applied across multiple pairs, reducing network control complexity while maintaining allocation flexibility through configuration selection

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent segments the resource allocation space into distinct TDD configuration categories (1:1 ratio group and 2:1 ratio group). Each segment handles specific traffic patterns, allowing the network to control complexity by managing a limited set of segmented configurations rather than individual pair-specific parameters, while still providing flexibility within each segment

Inventive Principle:

Principle #1Segmentation

3Ease of manufacture

If TDD configuration ratio is fixed at 1:1, then implementation is simplified, but adaptability to different upstream and downstream traffic scenarios is reduced

Engineering Contradiction:

Improveimplementation simplicityVSAvoidtraffic scenario adaptability

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent makes the TDD configuration dynamic by introducing multiple pre-defined ratio options (1:1 and 2:1) that can be switched based on traffic scenarios. The system starts with the simpler 1:1 configuration for symmetric traffic but can dynamically transition to 2:1 configuration when asymmetric traffic patterns are detected, maintaining both implementation simplicity and traffic scenario adaptability

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS9532340B2Techniques for enabling and performing HARQ transmissions in a D2D communication between wireless devices in a wireless telecommunications network

Publication Date: 2016.12.27 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

A method performed by a network node for enabling Hybrid Automatic Repeat reQuest (HARQ) transmissions in a device-to-device (D2D) communication between a first wireless device and a second wireless device in a wireless telecommunications network is provided. The first and the second wireless device are served by the network node, which transmits information to at least the first and second wireless device indicating transmission resources to be used when transmitting a HARQ acknowledgement (A/N) transmission for a received data transmission in the D2D communication. The network node determines a Time-Division Duplexing (TDD) configuration for data transmissions in the D2D communication between the first and the second wireless device, and transmits the determined TDD configuration to the first and second wireless device.