Uplink Scheduling Frame Structure with Clear Channel Indicator
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Solution Overview
Problem
The inefficiency in utilizing unlicensed bands for mobile communications due to the lack of effective methods to identify and utilize available spectrum, leading to suboptimal data speeds and potential interference.
Innovation Solution
The implementation of a system that uses clear channel indicators (CCI) and scheduling requests (SR) to identify and select unlicensed bands for uplink data transmission, ensuring that channels are available and suitable for use, thereby optimizing data transmission in unlicensed bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If unlicensed bands are used for mobile communications, then spectrum utilization is improved, but interference and noise increase
Solution Approach 1:
The system performs Clear Channel Assessment (CCA) before transmitting data in unlicensed bands. The CCA procedure checks whether the channel is free from other transmissions by measuring the energy level or detecting specific signals. Only when the channel is determined to be clear does the system proceed with data transmission, thereby preventing interference with other users of the unlicensed spectrum.
Solution Approach 2:
The system implements Listen Before Talk (LBT) mechanism where devices continuously monitor the unlicensed channel for ongoing transmissions. Based on this real-time feedback about channel occupancy, devices dynamically adjust their transmission timing. If the channel is busy, transmission is deferred; if clear, transmission proceeds. This feedback loop enables cooperative access and reduces collisions and interference.
2Device complexity
If unlicensed bands are used without effective identification methods, then device complexity is reduced, but data transmission efficiency deteriorates
Solution Approach 1:
The system enables User Equipment (UE) to autonomously perform Clear Channel Assessment and identify available unlicensed bands without requiring complex centralized scheduling or extensive signaling from the base station. Each device independently monitors the spectrum, evaluates channel conditions, and selects appropriate bands for transmission. This self-service approach maintains relatively simple device architecture while achieving efficient spectrum utilization through distributed intelligence.
Data Source
AI summary
An arrangement configured to be employed within a user equipment (UE). The arrangement includes control circuitry. The control circuitry is configured perform a clear channel assessment (CCA) during a data transmission with an evolved Node B (eNodeB), generate a clear channel indicator (CCI) based on the CCA, orthogonally multiplex an acknowledgement (ACK)/negative acknowledgement (NACK) with the CCI, where different sequences are allocated to the CCI and/or different resource block (RB) resources are allocated to the CCI, code and modulate a physical uplink control channel (PUCCH) using the multiplexed ACK/NACK, and provide the PUCCH having the CCI within the data transmission.