Variable TTI HARQ-ACK Timing for Large TA Wireless Systems
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Solution Overview
Problem
In wireless communication systems, particularly in LTE and 5G networks, the existing technologies face challenges in ensuring timely HARQ-ACK feedback and uplink data transmission across varying distances between base stations and terminals, leading to potential delays and power consumption issues due to limitations in timing advance (TA) values, especially when the transmission time interval (TTI) is shortened or when terminals require early timing for uplink scheduling and HARQ-ACK/NACK feedback.
Innovation Solution
The proposed method and apparatus allow for HARQ-ACK feedback and uplink data transmission in multiple timings based on a Timing Advance (TA) value and a fallback mode, enabling efficient operation by reducing transmission delays and power consumption, even when the TA value exceeds the maximum assumed value, by adjusting the processing time and transmission timing for terminals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the transmission time interval (TTI) is shortened to reduce latency, then the speed of data transmission is improved, but the processing time for terminals becomes insufficient especially when TA values are large
Solution Approach 1:
The patent applies dynamics by making the TTI length variable rather than fixed. The base station configures different TTI lengths (first TTI and second TTI) based on terminal capabilities and TA values. Terminals with large TA values receive longer TTIs to ensure sufficient processing time, while terminals with small TA values can use shorter TTIs for lower latency. This dynamic adaptation resolves the contradiction between transmission speed and processing time.
Solution Approach 2:
The patent changes the TTI parameter based on terminal conditions. By configuring different TTI lengths (first TTI for normal operation, second TTI for extended processing) according to TA values and terminal capabilities, the system adjusts the time parameter to balance between transmission speed and processing requirements, resolving the contradiction.
2Length of stationary object
If the TA value is increased to support longer distances between base station and terminal, then the coverage area is improved, but the timing synchronization becomes more difficult to maintain
Solution Approach 1:
The patent applies dynamics by adjusting the TTI length based on the TA value. For terminals with large TA values (long distance), the system configures a second TTI that is longer than the first TTI, providing sufficient processing time while maintaining synchronization. This dynamic adjustment allows the system to support longer distances without sacrificing timing synchronization reliability.
3Adaptability or versatility
If multiple timing transmission schemes are implemented to support various TA values, then the adaptability of the system is improved, but the device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the timing transmission schemes into distinct configurations. The base station configures different TTI lengths (first TTI and second TTI) and different HARQ-ACK feedback timings based on terminal conditions. This segmentation allows the system to handle different TA value ranges with appropriate timing schemes without requiring a completely complex reconfiguration for each case.
Solution Approach 2:
The patent applies universality by creating a multi-functional timing configuration system. The base station can configure terminals to use different TTI lengths and HARQ-ACK feedback timings based on terminal capabilities and TA values. This universal configuration approach allows a single system to handle multiple scenarios (different distances, different terminal capabilities) without requiring separate specialized systems for each case, thus managing complexity while maintaining adaptability.
4Speed
If the terminal transmits HARQ-ACK feedback at earlier timing to reduce latency, then the speed of feedback is improved, but the processing time becomes insufficient for terminals with large TA values
Solution Approach 1:
The patent applies dynamics by making the HARQ-ACK feedback timing variable. The base station configures different feedback timings based on the TTI length and terminal TA value. For terminals using the second (longer) TTI, the feedback timing is adjusted accordingly to ensure sufficient processing time. This dynamic adjustment allows the system to optimize feedback speed for each terminal without compromising processing time requirements.
Data Source
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AI summary
A communication method and system for converging a 5G communication system supports higher data rates beyond a 4G system with IoT technology. The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The present disclosure provides a method for transmission and reception between a base station and a terminal, which can transmit a HARQ-ACK feedback of downlink data or uplink data in various or multiple timings, in accordance with a TA value and a fallback mode.