NB-IoT Base Station TDD Subframe Configuration
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Solution Overview
Problem
Current NB-IoT systems are incompatible with the TDD technology in LTE systems due to insufficient downlink subframes, limiting spectrum resource utilization and deployment flexibility.
Innovation Solution
A data transmission method that enables NB-IoT systems to support TDD technology by using a TDD uplink-downlink subframe configuration, allowing the base station to send downlink signals using radio frames with a combination of downlink and uplink subframes, thereby improving spectrum resource utilization and compatibility with LTE TDD systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If NB-IoT system uses HD-FDD technology with all downlink subframes, then sufficient downlink subframes are available for broadcasting, but the system cannot be compatible with TDD technology in LTE system
Solution Approach 1:
The patent applies dynamics by making the subframe configuration flexible and adaptable. The base station can dynamically select between HD-FDD mode (all downlink subframes) and TDD mode (mixed uplink-downlink subframes) based on deployment requirements. This dynamic switching capability resolves the contradiction by allowing the system to adapt its subframe structure rather than being fixed in one configuration.
Solution Approach 2:
The patent changes the parameter of subframe configuration from a fixed state to a variable state. By introducing TDD uplink-downlink subframe configurations, the system can adjust the proportion of downlink subframes according to actual needs. This parameter change enables compatibility with TDD technology while maintaining sufficient downlink resources for synchronization signals and system information broadcasting.
2Adaptability or versatility
If NB-IoT system supports TDD technology with mixed uplink and downlink subframes, then compatibility with LTE TDD system is achieved, but spectrum resource utilization and deployment flexibility are limited
Solution Approach 1:
The patent implements universality by designing the NB-IoT system to support multiple operational modes within the same framework. The base station can operate in HD-FDD mode for scenarios requiring maximum downlink capacity, or switch to TDD mode for scenarios requiring uplink-downlink balance and LTE compatibility. This multi-functionality allows the system to universally serve different deployment scenarios without being constrained by a single mode, thereby improving spectrum resource utilization.
Data Source
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AI summary
A data transmission method, device, and system are disclosed, so that an NB-IoT system can be compatible with a TDD technology in an LTE system, and spectrum resource utilization in data transmission between a base station and UE can be improved. A specific solution includes: sending, by a base station, an NPSS to UE by using a first subframe in a first radio frame and a first subframe in a second radio frame, where the first radio frame and the second radio frame are consecutive, and both the first radio frame and the second radio frame use a TDD uplink-downlink subframe configuration; sending, by the base station, an NPBCH to the UE by using a second subframe in the first radio frame and a second subframe in the second radio frame; sending, by the base station, an NSSS to the UE by using a third subframe in the first radio frame; and sending, by the base station, a SIB1-NB to the UE by using a third subframe in the second radio frame.