Variable Interleaving Pattern for HARQ Channel Estimation
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Solution Overview
Problem
High-speed wireless communication systems, such as LTE-A, face performance degradation due to short channel coherence times at high speeds, leading to increased error rates and reduced data transmission reliability, especially in scenarios like high-speed vehicle communications.
Innovation Solution
Implementing a data interleaving pattern in hybrid automatic repeat request (HARQ) retransmissions that varies the distance of data units from reference symbols, moving data units affected by poor channel estimation closer to reference symbols for improved channel estimation and error correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If data units are transmitted using fixed interleaving patterns in HARQ retransmissions, then transmission protocol simplicity is maintained, but channel estimation accuracy deteriorates in high-speed scenarios due to short channel coherence times
Solution Approach 1:
The patent applies dynamics by making the interleaving pattern variable rather than fixed. The interleaver size is dynamically adjusted based on the distance between data units and reference symbols, allowing the system to adapt to changing channel conditions in high-speed scenarios while maintaining a manageable level of complexity through rule-based adjustments.
Solution Approach 2:
The patent changes the parameter of interleaver size based on the positional relationship between data units and reference symbols. By modifying the interleaver size parameter dynamically, the system optimizes channel estimation accuracy for data units at different distances from reference symbols, directly addressing the measurement precision improvement while controlling complexity through parameterization.
2Reliability
If retransmissions use the same interleaving pattern as initial transmissions, then implementation simplicity is maintained, but data transmission reliability deteriorates due to persistent errors in specific positions
Solution Approach 1:
The patent implements dynamics by applying different interleaving patterns for retransmissions compared to initial transmissions. The interleaver size is adjusted based on the specific retransmission context and the distance of data units from reference symbols, thereby improving reliability by avoiding repeated errors in the same positions while keeping complexity manageable through systematic rules.
Solution Approach 2:
The patent applies local quality by treating different portions of the data transmission differently. Data units at different distances from reference symbols receive different interleaver sizes, allowing localized optimization of channel estimation accuracy for each data unit based on its specific position and channel conditions, rather than applying a uniform approach.
3Measurement precision
If uniform interleaving is applied to all data units, then processing simplicity is maintained, but channel estimation quality deteriorates for data units far from reference symbols in high-speed environments
Solution Approach 1:
The patent applies local quality by implementing different interleaver sizes for data units based on their distance from reference symbols. Data units closer to reference symbols use one interleaver size while those farther away use a different size, optimizing channel estimation quality locally for each data unit's specific position rather than applying a uniform approach to all data.
Solution Approach 2:
The patent changes the interleaver size parameter based on the distance between data units and reference symbols. This parameter adjustment allows the system to optimize channel estimation quality for data units at different positions, directly addressing the measurement precision improvement while maintaining processing simplicity through a clear parameter adjustment rule.
Data Source
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Figure 2E~2M
AI summary
Apparatus and method for communication are provided. The solution comprises controlling (300) the transmission of data in slots comprising reference symbols, the transmission applying hybrid automatic repeat and request; applying (304) a data interleaving pattern in retransmissions, the pattern varying the distance of units of data from the reference symbols compared to units of data conveying the same or related information in a previous transmission.