HARQ Feedback Timing in FDD-TDD Carrier Aggregation
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Solution Overview
Problem
Current communication systems supporting Carrier Aggregation (CA) of FDD and TDD lack a solution for defining Hybrid Automatic Repeat Request (HARQ) feedback timing, which affects data transmission efficiency and spectral efficiency.
Innovation Solution
A method for determining HARQ feedback timing in a communication system supporting CA of FDD and TDD, where the timing is predetermined based on the duplex modes and scheduling modes of the primary and secondary cells, ensuring that HARQ feedback is transmitted on specific component carriers, thereby optimizing data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If HARQ feedback timing is not defined in CA systems supporting FDD and TDD, then the system lacks flexibility in handling different duplex modes, but data transmission efficiency and spectral efficiency deteriorate
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting HARQ feedback timing parameters based on the duplex mode configuration. When FDD is detected, a first timing parameter is applied; when TDD is detected, a second timing parameter is applied. This allows the system to adapt to different duplex modes while maintaining optimal data transmission efficiency for each mode.
Solution Approach 2:
The patent implements dynamics by making the HARQ feedback timing configurable and mode-dependent rather than fixed. The system dynamically selects the appropriate timing parameter based on the detected duplex mode, enabling flexible adaptation to changing network conditions and carrier configurations.
2Device complexity
If HARQ feedback timing is not optimized for CA systems, then system complexity is reduced, but feedback delay increases
Solution Approach 1:
The patent optimizes feedback delay by changing the timing parameter based on duplex mode. The first parameter for FDD and second parameter for TDD are specifically designed to minimize feedback delay appropriate to each mode's characteristics, achieving low latency without increasing system complexity.
3Productivity
If predetermined HARQ timing is implemented based on duplex modes, then data transmission efficiency is improved, but device complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-defining the first and second timing parameters for FDD and TDD modes respectively. The parameters are determined in advance based on the duplex mode configuration, so when HARQ feedback timing is needed, the system simply selects the appropriate pre-determined parameter without complex real-time calculations, thus improving efficiency while keeping device complexity manageable.
Data Source
AI summary
Methods and apparatuses for determining HARQ timing in a communication system supporting Carrier Aggregation (CA) are provided. A method for receiving, at a BS, a HARQ feedback from a UE in a communication system supporting CA of a Pcell and at least one Scell is provided. The Pcell and Scell support either FDD or TDD. The method comprises: transmitting a downlink physical channel through one of the Pcell and Scell; receiving the HARQ feedback corresponding to the downlink physical channel of the Pcell at a first timing predetermined for the Pcell; and receiving the HARQ feedback corresponding to the downlink physical channel of the Scell at a second timing. The second timing is determined according to one or more of duplex modes of the Pcell and the Scell, a scheduling mode of the Scell, and predefined rules.