Frequency Hopping Sequence for Unlicensed IoT Systems
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Solution Overview
Problem
Current IoT systems operating in unlicensed spectrum, such as eMTC-U, face challenges in designing frequency hopping sequences that comply with regional regulations and minimize collisions with incumbent technologies, while ensuring low power consumption and extended battery life.
Innovation Solution
The design of a frequency hopping sequence for eMTC-U systems that utilizes a non-linear function incorporating system frame number, physical cell identifier, and hyperframe index, with permutation operations and pseudorandom number generators to generate unique and randomized hopping patterns, ensuring compliance with PSD limitations and coexistence with other unlicensed technologies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If frequency hopping sequence is designed to comply with regional regulations and minimize collisions with incumbent technologies, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent applies parameter changes by modifying the frequency hopping sequence parameters (hopping pattern, frequency offsets, time offsets) based on detected incumbent technology characteristics. The system dynamically adjusts hopping parameters to avoid occupied frequency-time resources, thereby reducing collisions while maintaining manageable sequence design through standardized adjustment rules.
Solution Approach 2:
The system implements feedback mechanisms by continuously monitoring the unlicensed spectrum for incumbent technology usage and adjusting the frequency hopping sequence accordingly. The detection of occupied resources feeds back into the hopping sequence generation, enabling adaptive collision avoidance without requiring complex pre-planned sequences.
2Use of energy by moving object
If frequency hopping sequence is designed to ensure low power consumption and extended battery life, then use of energy is improved, but productivity decreases
Solution Approach 1:
The patent employs periodic action by implementing discontinuous transmission and reception patterns within the frequency hopping framework. The UE alternates between active communication periods and sleep periods, performing frequency hopping and data transmission only during scheduled intervals. This periodic operation significantly reduces average power consumption while maintaining acceptable data transmission throughput for IoT applications.
Solution Approach 2:
The system applies partial action by activating the radio frequency front end and performing frequency hopping operations only when necessary for data transmission or reception. During idle periods, the system remains in low-power states, performing minimal processing. This selective activation reduces energy consumption compared to continuous operation, while the hopping sequence is designed to enable quick resumption of communication when needed.
Data Source
AI summary
The disclosure provides design of a frequency hopping sequence for an unlicensed IoT system operating in unlicensed spectrum. According to some embodiments, an apparatus for generating a frequency hopping sequence in an unlicensed Internet-of-Things (IoT) system includes baseband circuitry to generate a frequency hopping sequence by conducting a permutation operation based on a physical cell identifier (PCI) and a system frame number (SFN), and to select a channel within an unlicensed spectrum according to the frequency hopping sequence. In some embodiments, the input of the permutation operation is obtained from the SFN or from the SFN and the PCI. In some embodiments, the control of the permutation operation is a function of the PCI and/or the SFN. In some embodiments, the control of the permutation operation is generated using a pseudorandom number generator with the PCI as a seed.