Time-Division Duplex Data Transmission With Early Rough Feedback
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Solution Overview
Problem
The 5G communications system faces challenges in meeting ultra-reliable and low latency requirements for URLLC services, particularly in time division duplex systems, due to high processing demands and delays in feedback mechanisms, which hinder efficient data retransmission.
Innovation Solution
A data transmission method in a time division duplex system that involves generating and sending rough feedback based on intermediate data reception results, allowing for quicker feedback and reduced processing capabilities at the terminal device, while enabling timely retransmission decisions by the network device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If early HARQ feedback based on decoder prediction is used, then URLLC latency is reduced, but false positive predictions increase reliability risks
Solution Approach 1:
The patent introduces an intermediary mechanism where the terminal device sends rough feedback based on intermediate reception results (before complete decoding) to the network device. This rough feedback serves as an early indicator that triggers selective early decoding at the network side, rather than relying on potentially error-prone terminal-side decoder predictions. The intermediary rough feedback reduces latency while maintaining reliability by enabling the network device to make informed decisions about whether to perform early decoding operations.
2Measurement precision
If complete data decoding is performed at the terminal device, then decoding accuracy is ensured, but processing time and complexity increase
Solution Approach 1:
The patent applies partial action by having the terminal device perform only initial reception and generate rough feedback based on intermediate results, rather than completing full decoding. The network device then performs selective early decoding based on this rough feedback. This partial processing at the terminal reduces its processing time and complexity requirements, while the network device completes the decoding task when needed, maintaining overall system accuracy without requiring the terminal to have high processing capabilities.
3Reliability
If data is transmitted multiple times for coverage enhancement, then reception reliability is improved, but transmission latency increases
Solution Approach 1:
The patent implements a feedback mechanism where the terminal device sends rough feedback after receiving a portion of the repeatedly transmitted data. This feedback informs the network device about reception status, enabling the network device to perform early decoding when confidence is high. This feedback-driven approach allows the system to potentially stop early retransmissions when decoding succeeds, reducing the average number of transmissions needed for coverage enhancement while maintaining reliability and reducing latency compared to fixed multiple transmissions.
Data Source
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AI summary
A data transmission method and apparatus in a time division duplex system is disclosed, where the method includes: receiving, by a terminal device in a downlink control part, first downlink control information and a first downlink reference signal that are sent by a network device; receiving, by the terminal device in a first downlink data part according to the first downlink control information, first data sent by the network device; generating, by the terminal device, feedback information based on the first downlink reference signal and the first data; sending, by the terminal device, the feedback information to the network device in an uplink feedback part; and receiving, by the terminal device in a second downlink data part according to the first downlink control information, second data sent by the network device; where the downlink control part, the first downlink data part, the uplink feedback part, and the second downlink data part constitute a first time unit. With the present invention, a transmission latency can be reduced in a communications system.