LDPC Block Decoding With Variable Iteration Reservoir
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Solution Overview
Problem
Existing LDPC decoding methods require a fixed maximum number of iterations, which can lead to reduced decoding performance if the decoding process does not converge within the set limit, and increasing iterations affects bit rate and decoding duration.
Innovation Solution
A method and decoder architecture that allows for a variable number of iterations by storing multiple blocks in an input memory, using a controller to dynamically update the maximum permitted iterations based on the memory size and previous decoding performance, enabling an additional 'reservoir' of iterations for subsequent blocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the maximum number of iterations is increased to improve decoding performance, then the bit error rate decreases, but the bit rate and decoding duration are reduced
Solution Approach 1:
The patent applies dynamics by making the number of iterations variable rather than fixed. The iteration counter is dynamically adjusted based on whether decoding convergence is achieved, allowing the system to adapt the number of iterations to the actual decoding needs of each block, thus resolving the contradiction between reliability and productivity.
Solution Approach 2:
The patent changes the parameter of iteration count from a static fixed value to a dynamic variable that can be adjusted during the decoding process. By modifying the iteration parameter based on convergence criteria, the system optimizes both decoding performance and bit rate, addressing the technical contradiction.
2Productivity
If a fixed maximum number of iterations is used to maintain decoding duration, then the bit rate is maintained, but decoding performance deteriorates when convergence is not achieved
Solution Approach 1:
The system dynamically adjusts the iteration count based on convergence feedback. When convergence is achieved within the fixed maximum iterations, the bit rate is maintained. When convergence is not achieved, the system can extend iterations beyond the fixed limit, thus maintaining both productivity and reliability adaptively.
Solution Approach 2:
The patent implements feedback by monitoring decoding convergence and using this information to adjust the number of iterations. The feedback mechanism allows the system to determine whether to stop at the fixed maximum or continue with additional iterations, resolving the contradiction between maintaining decoding duration and improving performance.
3Reliability
If additional iterations are performed beyond the fixed maximum, then decoding performance improves, but the decoding duration increases
Solution Approach 1:
The patent changes the iteration parameter dynamically based on convergence status. Additional iterations are only performed when necessary (when convergence is not achieved), and the exact number of additional iterations is adjusted based on the specific decoding needs, thus optimizing the trade-off between reliability and time loss.
Solution Approach 2:
The patent applies partial action by performing additional iterations only when and to the extent needed for convergence. Rather than always performing a fixed large number of iterations, the system performs the minimum necessary iterations plus any additional iterations required for convergence, reducing unnecessary time loss while improving block error rate when needed.
Data Source
AI summary
A method is for decoding a succession of blocks of data encoded with an LDPC code. The method includes storing the blocks temporarily and successively in an input memory before decoding the blocks successively in an iterative manner, the input memory having a memory size for storage of at least two blocks, and defining a current indication representative of a threshold number of iterations for decoding a current block. The method includes decoding the current block until a decoding criterion is satisfied or so long as a number of iterations performed for decoding the current block has not reached the current indication while at least one of a first subsequent block and a part of a second subsequent block are stored in the input memory, and updating the current indication for decoding the first subsequent block as a function of the number of iterations performed for decoding the current block.