Adaptive Precoding for EGPRS RLC Data Blocks
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Solution Overview
Problem
In EGPRS systems, there is a conflict between maximizing precoded transmissions for optimal Signal to Noise Ratio (SNR) and minimizing non-precoded transmissions for optimal pre-coder estimation, while also managing dummy blocks and preemptive retransmissions effectively.
Innovation Solution
A network node that dynamically adjusts the percentage of precoded and non-precoded transmissions for RLC data blocks and dummy blocks, using preemptive retransmissions and pattern recognition to estimate pre-coding weights, allowing for adaptive pre-coding strategies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If precoded transmissions are used to maximize SNR, then signal quality is improved, but the ability to estimate optimal pre-coder weights deteriorates
Solution Approach 1:
The system dynamically adjusts the percentage of precoded transmissions based on channel conditions and estimation needs. The network node can vary the precoding ratio over time, switching between precoded and non-precoded modes adaptively to balance SNR performance and pre-coder estimation requirements
Solution Approach 2:
The invention changes the parameter of precoding percentage from a fixed value to a variable parameter that can be adjusted between 0% and 100%. This allows the system to optimize the trade-off between SNR and pre-coder estimation by selecting appropriate precoding percentages for different transmission scenarios
2Loss of information
If non-precoded transmissions are used to estimate optimal pre-coder, then pre-coder estimation is improved, but SNR deteriorates
Solution Approach 1:
The system uses non-precoded transmissions partially, only when needed for pre-coder estimation. The majority of transmissions can use precoding for optimal SNR, with occasional non-precoded transmissions sufficient to maintain accurate pre-coder estimates
Solution Approach 2:
The invention uses dummy blocks as copies or placeholders that can be transmitted in non-precoded mode for estimation purposes without affecting the transmission of actual data. These dummy blocks serve as training sequences for pre-coder estimation
3Loss of information
If preemptive retransmissions are made without precoding, then pre-coder estimation is improved, but transmission efficiency deteriorates
Solution Approach 1:
The system performs pre-coder estimation using non-precoded preemptive retransmissions in advance, before actual data transmission. This preliminary estimation action ensures that subsequent data transmissions can use optimal precoding for maximum efficiency
Data Source
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AI summary
A network node (10) which supports EGPRS, the network node (10) being arranged (1 1, 13) to transmit RLC data blocks to at least one other network node in the EGPRS system and to receive acknowledgments from the other network node for successfully received RLC data blocks. The network node is also arranged to make pre-emptive retransmissions of unacknowledged previously transmitted RLC data blocks, and to make its transmissions with or without precoding. The network node (10) is arranged (1 1, 13, 14) to use precoding for a first percentage of the pre-emptive retransmissions and for a second percentage of the transmissions of RLC data blocks that have not been transmitted previously.