LAA Base Station TDD Frame Configuration for Unlicensed Band
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Solution Overview
Problem
The 5G communication system faces challenges in determining an effective TDD frame structure and configuration for Licensed Assisted Access (LAA) systems operating in unlicensed bands, leading to increased channel occupancy failures and resource waste due to non-consecutive downlink subframes and interference from Wi-Fi in special subframes.
Innovation Solution
A method is proposed to dynamically determine TDD frame structures and configurations based on channel conditions, allowing for consecutive downlink subframes and adaptive CCA/ECCA durations to optimize channel occupancy in LAA systems, enabling efficient data transmission and minimizing resource waste.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If TDD frame structure with non-consecutive downlink subframes is used in LAA system, then standard LTE TDD configuration is maintained, but channel occupancy failures increase and resource waste occurs
Solution Approach 1:
The patent applies dynamics by making the TDD frame structure configurable and adaptable. The base station can dynamically determine whether to use consecutive or non-consecutive downlink subframes based on channel conditions and traffic requirements. This dynamic configuration allows the system to optimize for channel occupancy efficiency when needed while maintaining standard LTE TDD configurations when appropriate, thereby resolving the contradiction between structural stability and productivity.
Solution Approach 2:
The patent employs parameter changes by modifying the TDD frame structure parameters, specifically the arrangement of downlink subframes. The system can change the configuration parameter to use consecutive downlink subframes (e.g., all downlink subframes at the beginning of the frame) instead of the traditional non-consecutive arrangement. This parameter modification enables better channel occupancy in LAA systems while maintaining compatibility with LTE TDD standards.
2Reliability
If CCA/ECCA is performed in special subframes, then channel access procedure is followed, but interference from Wi-Fi increases and resource waste occurs
Solution Approach 1:
The patent applies the extraction principle by removing the CCA/ECCA procedure from special subframes. The invention explicitly states that CCA/ECCA should be performed only in common subframes, not in special subframes. This extraction eliminates the source of interference and resource waste associated with performing channel access procedures in special subframes, while maintaining reliable channel access in common subframes where it is still needed.
Solution Approach 2:
The patent uses segmentation by dividing the frame structure into different types of subframes (common subframes and special subframes) with different CCA/ECCA requirements. Common subframes perform full CCA/ECCA procedures for reliable channel access, while special subframes are excluded from CCA/ECCA to reduce interference and resource waste. This segmentation allows the system to optimize channel access reliability where needed while minimizing resource consumption.
3Ease of manufacture
If fixed TDD configuration is used, then LTE standard compliance is maintained, but adaptability to channel conditions is reduced
Solution Approach 1:
The patent applies dynamics by enabling the TDD frame structure to be dynamically configured based on channel conditions and traffic requirements. The base station can adaptively determine the optimal TDD configuration, including whether to use consecutive or non-consecutive downlink subframes and which subframes should perform CCA/ECCA. This dynamic approach maintains LTE standard compliance through configurable parameters while providing adaptability to varying channel conditions.
Solution Approach 2:
The patent employs universality by designing a TDD frame structure that can serve multiple functions and configurations. The same LTE-based TDD framework can operate in different modes: standard non-consecutive downlink subframes for traditional LTE operation, consecutive downlink subframes for optimized LAA operation, and flexible CCA/ECCA configurations for different channel conditions. This multi-functional design maintains standard compliance while adapting to various operational requirements.
Data Source
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AI summary
The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE).. The present invention relates to a method by a base station in a mobile communication system, the method comprising the steps of: checking a channel state in an unlicensed band; determining a parameter for checking whether a channel is occupied, according to the channel state; and transmitting the determined parameter to a terminal.