Uplink Data Transmission on Unlicensed Carriers
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Solution Overview
Problem
Current wireless communications systems face challenges in efficiently utilizing unlicensed spectrum resources due to low utilization efficiency, particularly in scenarios where multiple devices compete for unlicensed spectrum, leading to difficulties in ensuring service quality and meeting increasing user demands.
Innovation Solution
The proposed method involves a terminal device detecting the availability of unlicensed carriers within a subframe and adjusting the transmission start time domain symbol to optimize data transmission, allowing for puncture transmission or re-mapping of data to ensure successful communication, thereby improving the probability of successful transmission and spectrum utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the terminal device uses fixed time domain symbol for uplink transmission on unlicensed carrier, then the transmission protocol is simple, but the spectrum utilization efficiency is low
Solution Approach 1:
The patent implements dynamic selection of time domain symbols for uplink transmission. The terminal device determines at least two candidate time domain symbols within a subframe and selects the appropriate symbol based on channel detection results. This dynamic approach allows the system to adapt to varying channel conditions on unlicensed carriers, thereby improving spectrum utilization efficiency while maintaining manageable protocol complexity through predefined selection rules.
2Reliability
If the terminal device performs channel detection before each transmission, then the transmission success probability increases, but the transmission delay increases
Solution Approach 1:
The patent performs channel detection in advance at multiple candidate time domain symbols within the subframe before actual data transmission. By proactively detecting channel availability at multiple positions and preparing corresponding data mapping configurations, the system reduces the need for retransmissions and minimizes transmission delays when the channel becomes available, thus balancing reliability improvement with time efficiency.
3Productivity
If the terminal device supports flexible time domain symbol selection, then the spectrum utilization improves, but the processor load increases
Solution Approach 1:
The patent segments the subframe into multiple candidate time domain symbols and pre-configures data mapping relationships for each symbol position. By dividing the transmission opportunity into discrete, pre-planned segments with predetermined mapping rules, the terminal device can select from these pre-computed options without requiring complex real-time processing, thus achieving flexible symbol selection while controlling processor load through upfront preparation.
Data Source
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AI summary
This application provides an uplink data sending method and apparatus. The method includes: receiving, by a terminal device, first scheduling information from an access network device, where the first scheduling information is used to schedule the terminal device to transmit a first transport block by using an unlicensed carrier; performing, by the terminal device, rate matching on the first transport block, to obtain uplink data; detecting, by the terminal device, the unlicensed carrier, and determining, based on a detection result, a start time domain symbol, used to send the uplink data, in at least two time domain symbols included in a first sub frame, where the at least two time domain symbols include a first time domain symbol and a second time domain symbol, the second time domain symbol is later than the first time domain symbol, and the start time domain symbol is the first time domain symbol or the second time domain symbol; and sending, by the terminal device, the uplink data to the access network device from the start time domain symbol. Therefore, utilization of an unlicensed spectrum for uplink data transmission is improved.