HARQ Processing Adaptation for C-RAN Transmission Delays
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Solution Overview
Problem
The increasing bandwidth requirements for CPRI in 5G radio communication systems lead to higher installation costs and transmission delays, particularly when using IP transmission paths like Ethernet, which can reduce user data throughput and cause fluctuations in HARQ processing due to varying transmission delays.
Innovation Solution
The solution involves adapting HARQ processing methods based on measured transmission delays between central and remote base stations, by increasing the number of HARQ processes and adjusting the HARQ round trip time, to optimize data transmission and reduce the impact of transmission delays on user data throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If IP transmission path (Ethernet) is used instead of optical fiber for CPRI, then installation cost is reduced, but transmission delay increases and user data throughput decreases
Solution Approach 1:
The patent changes the transmission delay parameter by adjusting the HARQ round trip time setting to accommodate the higher delay characteristics of IP transmission paths. This allows the system to adapt to different transmission medium characteristics, enabling the use of cost-effective Ethernet infrastructure while maintaining acceptable performance through parameter optimization.
2Ease of manufacture
If optical fiber with bandwidth less than peak rate is used for CPRI, then installation cost is reduced, but transmission delay increases and reliability decreases
Solution Approach 1:
The patent implements dynamic adaptation of HARQ processing parameters based on measured transmission delay characteristics. The system dynamically adjusts the number of HARQ processes and round trip time settings to compensate for bandwidth limitations and delay variations, maintaining reliable operation even with undersized optical fiber infrastructure.
3Productivity
If number of HARQ processes is increased to compensate for transmission delay, then user data throughput is maintained, but device complexity increases
Solution Approach 1:
The patent performs preliminary measurement of transmission delay characteristics between central and remote base stations, and based on these measurements, pre-configures the appropriate number of HARQ processes and round trip time parameters. This preliminary action allows the system to optimize throughput without requiring complex real-time adjustments, reducing operational complexity while maintaining high productivity.
Data Source
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AI summary
A user apparatus is provided. The user apparatus is included in a mobile communication system including a first base station, a second base station communicating with the first base station, and the user apparatus communicating with the first base station. The user apparatus includes an obtaining unit configured to obtain from the second base station instruction information indicating an error correction processing operation performed between the first base station and the user apparatus; and a communication unit configured to communicate with the first base station by performing the error correction processing based on the instruction information.