Cross-Carrier TDD Subframe Configuration via Unified DCI

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current wireless communication systems, particularly in LTE, face challenges in dynamically adapting Time Division Duplex (TDD) uplink (UL)/downlink (DL) subframe configurations to manage traffic efficiently, leading to potential interference and complexity in HARQ timing management.

Innovation Solution

The method involves generating and transmitting a Downlink Control Information (DCI) message that includes UL/DL subframe configuration information for groups of cells, allowing user equipment (UE) to determine the appropriate configuration based on explicit signaling, thereby enabling cross-carrier indication and dynamic adaptation of subframe configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate DCI messages are used for each cell to indicate UL/DL subframe configurations, then each cell can be independently configured, but the signaling overhead and system complexity increase significantly

Engineering Contradiction:

ImproveIndependent cell configuration capabilityVSAvoidDCI message structure and signaling overhead

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple DCI messages into a single unified DCI structure that can carry UL/DL subframe configuration information for multiple cells simultaneously. This merging approach reduces signaling overhead and simplifies the message structure while maintaining the ability to independently configure each cell through dedicated indicator fields within the combined message.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The unified DCI message structure is designed to serve multiple functions: it can indicate UL/DL configurations for multiple cells, support both TDD and FDD operations, and provide flexible resource allocation across different cell groups. This multi-functional design eliminates the need for separate specialized messages for each cell.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Productivity

If dynamic switching of TDD subframe configurations is implemented, then traffic management efficiency improves, but interference management becomes more difficult and HARQ timing complexity increases

Engineering Contradiction:

ImproveTraffic management efficiencyVSAvoidInterference and HARQ timing complexity

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies different UL/DL configurations to different cell groups within the same system, allowing each group to be optimized for its specific traffic patterns and interference conditions. This local customization enables dynamic switching where needed while maintaining stable configurations where interference management is critical, thereby improving traffic efficiency without uniformly increasing system complexity.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The system implements dynamic switching of TDD subframe configurations through the unified DCI message, which can indicate different UL/DL patterns for different cell groups based on current traffic conditions. This dynamic adaptation improves traffic management efficiency while the coordinated control mechanism ensures that switching is managed systematically to control interference and HARQ timing complexity.

Inventive Principle:

Principle #15Dynamics

3Quantity of substance

If carrier aggregation with multiple cells is supported, then system capacity and bandwidth increase, but the complexity of managing UL/DL configurations across carriers increases

Engineering Contradiction:

ImproveSystem capacity and bandwidthVSAvoidConfiguration management complexity

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent merges the configuration management for multiple aggregated carriers into a single DCI message structure that can simultaneously handle UL/DL subframe indications for multiple cell groups. This approach maintains system capacity and bandwidth benefits of carrier aggregation while reducing the complexity of managing separate configurations for each carrier.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS10721119B2Cross-carrier indication of uplink/downlink subframe configurations

Publication Date: 2020.07.21 QUALCOMM INC

AI summary

Certain aspects of the present disclosure relate to techniques for cross-carrier indication of TDD (Time Division Duplex) UL (Uplink)/DL (Downlink) subframe configuration. A UE may receive a configuration of a first index for a first cell, wherein the first index is mapped to a first position in a Downlink Control Information (DCI) message. The UE may receive the DCI message in a subframe and determine an indication of a UL/DL subframe configuration for the first cell based on the first index and the DCI message. The UE may communicate with the first cell based on the determined UL/DL subframe configuration for the first cell.