Autonomous Uplink Control Information Transmission in Unlicensed Spectrum
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Solution Overview
Problem
LTE uplink performance is hindered in unlicensed spectrum due to centralized coordination and listen-before-talk regulations, leading to increased latency and inefficiencies in channel access, especially when compared to Wi-Fi systems which can asynchronously access the medium.
Innovation Solution
Implementing autonomous uplink control information transmission without a dynamic uplink grant from the base station, allowing wireless devices to transmit uplink control information on a physical uplink shared channel with specified starting and ending positions, and mapping this information to time-frequency resources for efficient and robust autonomous UL access.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If centralized coordination and dynamic uplink grants are used in LTE uplink transmission, then uplink control information can be transmitted with base station coordination, but transmission latency increases and channel access efficiency deteriorates in unlicensed spectrum
Solution Approach 1:
The patent applies preliminary action by pre-configuring uplink resources and control information parameters before actual transmission is needed. The base station pre-allocates time-frequency resources and configures transmission parameters in advance, allowing the wireless device to immediately transmit uplink control information without waiting for dynamic grants, thereby reducing latency while maintaining coordination reliability
Solution Approach 2:
The patent implements self-service by enabling the wireless device to autonomously select and transmit on pre-configured uplink resources without requiring real-time base station coordination for each transmission. The device independently manages transmission timing and resource selection based on pre-configured parameters, improving channel access efficiency while the base station maintains overall system coordination
2Reliability
If listen-before-talk method is applied in unlicensed spectrum, then channel access follows regulatory requirements, but uplink transmission performance deteriorates due to centralized coordination dependency
Solution Approach 1:
The patent applies segmentation by dividing the uplink transmission process into independent segments: the base station handles resource configuration and LBT coordination, while the wireless device independently performs transmission on pre-configured resources. This segmentation allows the device to operate more autonomously, improving uplink efficiency while the base station ensures regulatory compliance through coordinated resource management
Solution Approach 2:
The patent implements dynamics by allowing flexible adaptation of transmission parameters and resource allocation based on channel conditions and traffic requirements. The system dynamically adjusts the balance between centralized coordination and autonomous transmission, enabling efficient uplink performance while maintaining LBT compliance through configurable transmission opportunities
3Ease of operation
If dynamic uplink grants are used for every uplink transmission, then base station can control resource allocation, but device complexity and signaling overhead increase
Solution Approach 1:
The patent applies preliminary action by having the base station pre-configure multiple uplink resources and transmission parameters in advance through RRC signaling. The wireless device stores these pre-configured parameters and automatically selects appropriate resources for transmission, eliminating the need for complex real-time processing of dynamic grants while maintaining base station control over resource allocation strategy
4Productivity
If autonomous uplink transmission is implemented, then transmission latency is reduced and channel access efficiency improves, but coordination with base station and resource management complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-configuring all necessary transmission parameters, resource allocations, and control information structures before autonomous transmission begins. The base station provides comprehensive pre-configuration including time-frequency resources, modulation schemes, and coding parameters, allowing the wireless device to perform autonomous transmission with minimal complex decision-making
Solution Approach 2:
The patent implements feedback mechanisms where the base station monitors autonomous uplink transmissions and provides adjustment instructions when needed. The system uses feedback to maintain coordination between autonomous device operations and base station resource management, resolving complexity through iterative optimization rather than complex real-time coordination
Data Source
AI summary
Some embodiments advantageously provide methods, wireless devices and network nodes for unscheduled uplink access on an unlicensed cell. According to one aspect, an exemplary process includes a wireless device for autonomously transmitting uplink control information, UCI, together with autonomous uplink, UL, data transmission. The process includes mapping the UCI to time-frequency resources of the PUSCH and transmitting the PUSCH with the UCI to a base station without a dynamic uplink grant from the base station.