Transport Block Retransmission Mode Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In MIMO wireless communication systems, closed-loop spatial multiplexing can lead to increased residual block error rates and packet loss rates due to incorrect precoding matrix indicators, resulting in reduced network performance.
Innovation Solution
The method involves maintaining closed-loop spatial multiplexing for the first m retransmissions of a transport block and switching to open-loop transmit manner for the last N-m retransmissions, improving transmission reliability and reducing error rates, while ensuring effective acquisition of closed-loop gain by maintaining the transmission mode unchanged.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If closed-loop spatial multiplexing is used for data transmission, then transmission capacity is improved, but residual block error rate increases due to incorrect PMI reporting
Solution Approach 1:
The patent segments the retransmission process into two phases: initial transmissions use closed-loop spatial multiplexing to maintain high transmission capacity, while subsequent retransmissions switch to open-loop spatial multiplexing to ensure reliability. This segmentation allows the system to optimize for different objectives at different stages of the transmission process.
Solution Approach 2:
The patent changes the transmission mode parameter from closed-loop spatial multiplexing to open-loop spatial multiplexing based on the transmission stage. By adjusting this parameter dynamically, the system achieves both high capacity during initial transmission and high reliability during retransmission without requiring complex reconfiguration.
2Reliability
If closed-loop spatial multiplexing is used, then network performance is reduced due to packet loss, but switching to open-loop reduces transmission capacity
Solution Approach 1:
The patent implements a dynamic transmission strategy where the spatial multiplexing mode is adapted based on the transmission stage. The system transitions from closed-loop (high capacity) to open-loop (high reliability) spatial multiplexing as needed, creating a flexible and adaptive transmission system that optimizes performance metrics at different phases.
Solution Approach 2:
The patent performs preliminary action by using closed-loop spatial multiplexing for initial transmissions to maximize capacity, then proactively switches to open-loop spatial multiplexing for retransmissions to prevent packet loss. This preliminary optimization of each transmission stage ensures overall system performance.
3Reliability
If transmission mode is changed to fix PMI errors, then reliability improves, but signaling overhead and delays increase
Solution Approach 1:
The patent uses a simple and lightweight approach by switching to open-loop spatial multiplexing for retransmissions, which requires minimal signaling overhead. This disposable-like strategy of using a simpler transmission mode for retransmission tasks resolves reliability issues without incurring significant time penalties for mode switching or reconfiguration.
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
Embodiments of the present invention provide a transport block retransmission method and a base station. In the method, for first m retransmissions of a TB, a closed-loop spatial multiplexing transmit manner for initial transmission of the TB is maintained, and for last N-m retransmissions of the TB, a transmit manner is changed into an open-loop transmit manner when a transmission mode remains unchanged. Retransmission of the TB in the open-loop transmit manner can improve reliability of data transmission, reduce a quantity of retransmissions of the TB, reduce a residual block error rate and a voice packet loss rate, and ensure that a closed-loop gain can be effectively obtained.