Outer Coding for Unequal Code Blocks and Selective Retransmission
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Solution Overview
Problem
Conventional outer codes in LTE wireless communication systems are inefficient when dealing with transport blocks of unequal code block sizes, as they require retransmitting redundancy bits for all code blocks, including those that were successfully decoded, leading to bandwidth wastage and limited error correction capability.
Innovation Solution
The method involves padding code blocks of unequal sizes to a common length for outer code encoding, allowing for the generation of outer code blocks that can be transmitted only for failed code blocks, thereby reducing unnecessary retransmissions and improving error correction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional outer codes retransmit redundancy bits for all code blocks, then error correction capability is maintained, but bandwidth is wasted on successfully decoded blocks
Solution Approach 1:
The patent segments the retransmission process by identifying and separating failed code blocks from successfully decoded ones. The outer code is applied only to the subset of failed code blocks rather than all code blocks, creating a segmented approach that reduces redundant retransmissions while maintaining error correction capability for the actual failures.
2Adaptability or versatility
If outer codes are applied to code blocks of unequal sizes, then flexibility is improved, but coding complexity increases
Solution Approach 1:
The patent applies local quality by treating each code block according to its specific characteristics (size and decoding status). Successfully decoded blocks are excluded from retransmission, while failed blocks are included. The outer code is applied locally to the subset of failed blocks, allowing the system to adapt to unequal code block sizes without requiring complex processing of all blocks uniformly.
Data Source
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AI summary
Methods are disclosed herein for generating and using outer codes based on non-equal length code blocks. In one embodiment, the outer code has a length equal to the length of the longest code block. This can be achieved by padding shorter code blocks such that they are also of equal length to the longest code block. The padding may be a standardized pseudo-random pattern or a standardized repeating pattern. In another embodiment, the outer code has a length shorter than the length of the longest code block. If a code block is received in error it may be recovered by using one or more of: the first outer code block, information bits of other code blocks and the parity bits of the failed code block.