FDD TDD Spectrum Aggregation HARQ Timing Optimization
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Solution Overview
Problem
Existing LTE/LTE-A systems face challenges in efficiently aggregating FDD and TDD cells, leading to reduced power amplification efficiency, uplink coverage, and limited resource utilization, particularly in downlink and uplink HARQ processes.
Innovation Solution
A data sending method and device that configures multiple cells for a UE, centralizing downlink HARQ information on a TDD primary cell and optimizing subframe configurations for FDD cells to align with specific uplink-downlink configurations, allowing for simultaneous FDD and TDD spectrum aggregation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If FDD and TDD cells are aggregated simultaneously, then resource utilization is improved, but power amplification efficiency deteriorates
Solution Approach 1:
The patent segments the aggregated carrier into FDD portion and TDD portion, allowing independent processing and timing management for each mode. This segmentation enables the system to maintain separate HARQ timing relationships for FDD and TDD cells, preventing interference between the two modes and preserving power amplification efficiency while still achieving resource utilization benefits through aggregation.
Solution Approach 2:
The patent introduces dynamic timing adjustment mechanisms that adapt HARQ timing based on whether the system is operating in FDD or TDD mode. The timing relationship between downlink and uplink subframes is dynamically configured to match the specific mode being used, allowing the system to optimize performance for each mode while aggregated, thereby maintaining power amplification efficiency.
2Productivity
If FDD and TDD cells are aggregated simultaneously, then resource utilization is improved, but uplink coverage deteriorates
Solution Approach 1:
The patent segments the uplink transmission resources by mode, assigning separate uplink subframes for FDD and TDD operations. This segmentation ensures that uplink transmissions from FDD cells do not conflict with uplink transmissions from TDD cells, maintaining proper timing relationships and preventing coverage degradation while still utilizing both FDD and TDD resources.
Solution Approach 2:
The patent introduces a coordination mechanism that acts as an intermediary between FDD and TDD uplink transmissions. This intermediary manages the timing and resource allocation to ensure that uplink signals from both modes can be received properly without interference, thereby maintaining uplink coverage while achieving improved resource utilization through aggregation.
3Reliability
If separate HARQ timing is used for FDD and TDD cells, then transmission reliability is improved, but system complexity increases
Solution Approach 1:
The patent implements a universal HARQ timing management mechanism that can handle both FDD and TDD modes through a unified framework. The system uses a common control structure that adapts to different modes, allowing the same base station and UE to manage both FDD and TDD cells with appropriate timing relationships without requiring completely separate processing paths, thereby reducing overall system complexity.
Solution Approach 2:
The patent employs dynamic configuration of HARQ timing parameters that automatically adjust based on the operating mode. The system dynamically selects appropriate timing relationships for FDD or TDD cells, allowing reliable transmission for each mode while using a flexible control mechanism that reduces complexity compared to static, mode-specific implementations.
4Productivity
If FDD and TDD cells are aggregated, then spectrum utilization is improved, but HARQ process complexity increases
Solution Approach 1:
The patent segments the HARQ process management by cell type, maintaining separate timing relationships and process identifiers for FDD and TDD cells. This segmentation allows the system to handle HARQ processes for each mode independently with appropriate timing, preventing confusion and reducing complexity while still utilizing both FDD and TDD spectra for improved overall utilization.
Solution Approach 2:
The patent implements a universal HARQ management framework that can handle both FDD and TDD cells through a unified control structure. The system uses mode-aware timing configuration that adapts to the specific cell type, allowing a single HARQ management entity to handle both modes with appropriate timing relationships, thereby reducing complexity compared to completely separate management systems while achieving improved spectrum utilization.
Data Source
AI summary
Provided are a data sending method and device in spectrum aggregation. When downlink aggregation is performed on the plurality of cells of different types, the method includes that: HARQ information of the plurality of cells is centralized and sent on uplink subframes corresponding to a TDD cell among the plurality of cells, wherein the TDD cell is a primary cell while other cells are secondary cells and it is given that an uplink-downlink configuration of the primary cell is configuration X, where X∈{0,1,2,3,4,5,6}, downlink subframes are configured on each FDD cell for a UE so that a network can send a PDCCH/a PDSCH for the UE only on the configured downlink subframes while the UE detects and receives the PDCCH/PDSCH on the configured downlink subframes.