LDPC Decoder Iteration Control for Power Reduction
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Solution Overview
Problem
In wireless communication systems, particularly in WLAN and WPAN, the high latency and energy consumption associated with decoding Low Density Parity Check (LDPC) codes are significant challenges due to the iterative decoding process, where undecodable blocks require full iterations, wasting energy and processing time.
Innovation Solution
Implementing an initial decision mechanism to determine if a received encoded block is correct before decoding, allowing the decoder to operate only when necessary, thereby reducing the number of iterations, especially in high Signal to Noise Ratio (SNR) regions, and using hard decision processing and parity checks to decide on error conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If standard LDPC code decoder implementations use a fixed number of iterations to ensure decoding reliability, then decoding reliability is improved, but power consumption and latency increase linearly with the number of iterations
Solution Approach 1:
The patent implements a dynamic iteration control mechanism that adjusts the number of decoding iterations based on the decoding state. The iteration controller monitors the decoding process and terminates iterations early when the inherent stopping criterion is met, rather than executing a fixed number of iterations. This dynamic adaptation reduces power consumption while maintaining decoding reliability.
Solution Approach 2:
The patent employs feedback through an iteration controller that continuously monitors the decoding process and provides control signals to terminate iterations based on the inherent stopping criterion. The feedback mechanism allows the system to adjust the number of iterations in real-time, stopping when decoding success is achieved or when a maximum threshold is reached, thereby optimizing power consumption.
2Reliability
If standard LDPC code decoder implementations process a fixed number of iterations for all blocks, then decoding completeness is improved, but latency increases for undecodable blocks that require full iterations
Solution Approach 1:
The patent implements a dynamic iteration control mechanism that adjusts the number of decoding iterations based on the decoding state. The iteration controller monitors the decoding process and terminates iterations early when the inherent stopping criterion is met, rather than executing a fixed number of iterations. This dynamic adaptation reduces latency while ensuring decoding completeness through the stopping criterion.
Solution Approach 2:
The patent performs preliminary error detection before full decoding by checking the inherent stopping criterion at each iteration. This preliminary check allows the system to identify successfully decoded blocks early and terminate processing, preventing unnecessary latency for blocks that would have been decoded successfully with fewer iterations.
3Use of energy by moving object
If conventional methods use additional stopping criteria to reduce iterations, then power consumption is reduced, but device complexity increases due to multiple criteria checks
Solution Approach 1:
The patent utilizes the inherent stopping criterion that already exists within the LDPC decoding algorithm itself, rather than adding external complex checking mechanisms. The iteration controller leverages the natural convergence properties of the decoding process, allowing the decoder to self-determine when to stop based on its own internal state, thus reducing power consumption without significantly increasing device complexity.
Data Source
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AI summary
Method of decoding a received systematic code encoded block corresponding to an original block of information, said received encoded block (RENCB) including soft systematic values, said method comprising detecting (13) whether or not said received encoded block is considered in error, performing a decoding (15) of said received encoded block for retrieving said original block of information (BIF) if said received encoded block is considered in error, and processing only said soft systematic values (16) for retrieving said original block (BIF) of information if said received encoded block is not considered in error.