Uplink Control Information Transmission in Unlicensed Spectrum
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Solution Overview
Problem
In current NR systems, transmitting UCI (Uplink Control Information) simultaneously with PUSCH (Physical Uplink Shared Channel) using LBT (Listen Before Talk) in partial subbands leads to performance issues, as piggybacked UCI is dropped in subbands not passing LBT, affecting transmission performance.
Innovation Solution
A method where UCI is transmitted in both available and unavailable subbands by monitoring channel availability, allowing UCI to be transmitted on either PUCCH (Physical Uplink Control Channel) or PUSCH based on LBT results, ensuring performance without recoding or resource remapping, and using specific schemes for piggybacking and non-piggybacking modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If UCI is transmitted by piggybacking on PUSCH in subbands passing LBT, then uplink transmit power is sufficient and PAPR is controlled, but UCI transmission performance deteriorates when PUSCH is transmitted only in partial subbands
Solution Approach 1:
The patent implements dynamic transmission mode selection for UCI based on LBT results. When PUSCH passes LBT in sufficient subbands (>=K1), UCI piggybacks on PUSCH. When PUSCH fails LBT in most subbands (<K1), UCI transmits independently on PUCCH. This dynamic adaptation resolves the contradiction by switching between piggybacking mode (for power efficiency) and independent mode (for reliability) based on real-time channel conditions.
Solution Approach 2:
The patent changes the transmission parameter (piggybacking vs. independent transmission) based on the LBT success rate parameter. By monitoring the number of idle subbands and comparing against threshold K1, the system dynamically adjusts whether UCI piggybacks on PUSCH or uses dedicated PUCCH resources, thereby optimizing both reliability and transmission efficiency under different channel conditions.
2Device complexity
If UCI follows PUSCH transmission mode and is transmitted only in subbands passing LBT, then resource allocation is simplified, but UCI transmission performance is obviously affected
Solution Approach 1:
The patent introduces dynamic switching between two resource allocation modes. In the first mode (LBT success rate >=K1), UCI resources are dynamically allocated within PUSCH subbands, simplifying resource management. In the second mode (LBT success rate <K1), UCI uses dedicated PUCCH resources independent of PUSCH allocation, ensuring reliable transmission. This dynamic approach resolves the contradiction between simplicity and reliability.
3Reliability
If UCI is transmitted on PUCCH when PUSCH LBT fails in most subbands, then UCI transmission reliability is ensured, but PUCCH resources are consumed
Solution Approach 1:
The patent uses the LBT success rate (number of idle subbands vs. threshold K1) as a parameter to control resource allocation. When the success rate is high (>=K1), resources are efficiently used by piggybacking on PUSCH. When the success rate is low (<K1), the system switches to PUCCH transmission to ensure reliability, accepting the resource consumption as necessary under poor channel conditions. This parameter-based switching resolves the contradiction between reliability and resource efficiency.
Data Source
AI summary
The present disclosure provides a method and device for use in wireless communication nodes. A first node executes a first monitoring and a second monitoring, judges whether a first channel and a second channel are available respectively according to the first monitoring and the second monitoring; a target bit block being transmitted on which of a first channel or a second channel is related to whether the second channel is judged to be unavailable; the first channel overlaps with the second channel in time domain; the second channel occupies K subbands in frequency domain; when a number of idle subbands on the second channel is less than K1, the second channel is judged to be unavailable. The present disclosure establishes a connection between frequency-domain resources occupied by a target bit block and a monitoring result to improve uplink transmission efficiency on unlicensed spectrum.