NB-IoT Frequency Hopping for Diversity Gain
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Solution Overview
Problem
The Narrowband Internet of Things (NB-IoT) technology faces a challenge due to its narrow transmission bandwidth, resulting in a relatively small gain of frequency diversity, which affects its communication efficiency.
Innovation Solution
The introduction of frequency hopping in NB-IoT systems, where the NB-IoT base station determines time-frequency resource locations based on frequency hopping information, allowing for intra-group and inter-group frequency hopping within a larger frequency range, and positioning frequency hops within LTE system guard bands to enhance frequency diversity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If frequency hopping is not introduced in NB-IoT, then the transmission bandwidth remains narrow, but the frequency diversity gain is small
Solution Approach 1:
The patent applies frequency hopping to dynamically change the frequency location of NB-IoT signals across different time slots. By introducing time-varying frequency transmission patterns, the system transforms from a static narrowband transmission to a dynamic multi-frequency transmission, thereby achieving frequency diversity gain without requiring a permanently expanded bandwidth allocation.
Solution Approach 2:
The patent extends the transmission from a single narrow frequency dimension to multiple frequency dimensions by implementing frequency hopping across different frequency locations. This dimensional expansion allows the system to access a larger effective frequency range while maintaining the narrowband constraint at any given time slot, thus improving frequency diversity without permanently increasing bandwidth occupation.
2Reliability
If frequency hopping is implemented across a larger frequency range, then frequency diversity gain increases, but the complexity of resource management increases
Solution Approach 1:
The patent implements frequency hopping by changing the frequency parameter of NB-IoT transmission across different time slots. The system uses predefined hopping patterns and frequency offsets to systematically vary the transmission frequency, transforming a static transmission parameter into a dynamic one. This parameter change approach enables frequency diversity while maintaining manageable complexity through standardized hopping rules.
3Device complexity
If NB-IoT uses a narrow transmission bandwidth, then device complexity is reduced, but the frequency diversity gain is limited
Solution Approach 1:
The patent implements periodic frequency hopping where the NB-IoT transmission frequency changes at regular time intervals according to predefined patterns. This periodic frequency variation allows the system to maintain simple narrowband device architecture while periodically accessing different frequency regions to harvest frequency diversity gains, thus resolving the contradiction between device simplicity and reliability.
Data Source
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AI summary
This application provides a channel transmission method, apparatus, and system for NB-IoT. An NB-IoT base station determines, based on the frequency hopping information, a time-frequency resource location of the channel after frequency hopping, and performs channel transmission with an NB-IoT terminal on a time-frequency resource corresponding to the time-frequency resource location, so that the frequency hopping is introduced into the NB-IoT, thereby increasing a gain of frequency diversity through the frequency hopping.