LTE-U Power Control via CCA Thresholds
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Solution Overview
Problem
In wireless communication systems using unlicensed bands, interference between different communication protocols is a significant issue, leading to unpredictable quality of service and mobility problems due to power control methods that do not account for co-existing radio access techniques.
Innovation Solution
A method for controlling transmit power in LTE-U systems by adjusting the power of fixed and variable band signals to ensure that the total transmit power exceeds the clear channel assessment threshold, using correction signals and power headroom reports to optimize power distribution and minimize interference with other communication nodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If power control based on legacy LTE is used in unlicensed band, then LTE communication quality is maintained, but interference with other radio access techniques increases
Solution Approach 1:
The patent changes the power control parameters by introducing clear channel assessment (CCA) thresholds and adjusting transmit power based on channel occupancy time requirements. This allows the system to adapt power levels to coexist with other radio access techniques while maintaining LTE communication quality through dynamic parameter adjustment.
Solution Approach 2:
The patent implements dynamic power control that adjusts transmit power based on real-time channel conditions, CCA results, and channel occupancy time. This dynamic approach allows the system to respond to changing environmental conditions and other radio access techniques' presence, reducing interference while maintaining communication quality.
2Reliability
If transmit power is increased to ensure communication quality, then signal reliability improves, but interference with other communication protocols increases
Solution Approach 1:
The patent implements feedback mechanisms where the base station monitors channel conditions, CCA thresholds, and communication quality metrics. Based on this feedback, the system dynamically adjusts transmit power to maintain signal reliability while preventing excessive interference to other communication protocols through continuous monitoring and adjustment.
Solution Approach 2:
The system dynamically changes power control parameters including transmit power level, channel occupancy time, and CCA thresholds based on real-time channel conditions. This allows the system to maintain signal reliability when needed while reducing power when other protocols are present, thereby minimizing interference.
3Productivity
If power control is optimized for licensed band, then LTE performance is maximized, but adaptability to unlicensed band coexistence deteriorates
Solution Approach 1:
The patent creates a universal power control mechanism that functions in both licensed and unlicensed bands. The base station implements a multi-functional power control system that can operate with LTE in licensed band while adapting to unlicensed band requirements through CCA procedures and channel occupancy time management, enabling seamless operation across different band types.
Solution Approach 2:
The patent implements a dynamic power control system that adapts its behavior based on the operating band. In licensed band, it optimizes for LTE performance with standard power control. In unlicensed band, it dynamically adjusts to incorporate CCA thresholds, channel occupancy time requirements, and coexistence mechanisms, providing adaptability while maintaining LTE performance where applicable.
Data Source
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AI summary
Provided are a method and an user equipment (UE) for reporting a power headroom in a wireless communication system. Scheduling information corresponding to a physical uplink shared channel (PUSCH) is received for transmission on a Licensed-Assisted Access (LAA) cell operating in an unlicensed band and a power headroom for the LAA cell is computed assuming that the UE performs the PUSCH transmission on the LAA cell irrespective of whether the UE can access the LAA cell for the PUSCH transmission according to a channel access procedure.