LDPC Decoder Post-Processing for Trapping Set Error Floors

The patent applies preliminary action by performing post-processing operations after standard LDPC decoding to detect and correct trapping sets. The system first executes standard decoding, then checks for unsatisfied checks and identifies trapping set patterns in the tentative codeword. If a trapping set is detected, the system performs additional corrective operations (such as flipping bits associated with unsatisfied checks) before final validation. This two-stage approach maintains low complexity for the primary decoding while adding targeted corrections only when needed, thus improving error floor performance without significantly increasing overall decoding complexity.

The patent applies self-service by enabling the decoding system to automatically detect when it has converged to a trapping set and trigger corrective actions without external intervention. The post-processing module continuously monitors the decoding output for unsatisfied checks and characteristic trapping set patterns. When a trapping set is identified, the system autonomously performs bit flipping operations on the problematic positions and re-validates the codeword. This self-correcting mechanism improves error correction capability by specifically addressing trapping set failures, while avoiding unnecessary additional iterations for correctly decoded words, thus minimizing the increase in decoding time.

The patent applies local quality by implementing post-processing operations that focus specifically on localized trapping set regions rather than processing the entire codeword uniformly. The system identifies unsatisfied checks and determines the specific bit positions associated with these checks, then applies corrective operations only to the bits involved in the trapping set. This localized approach allows the system to improve error floor performance by targeting problematic regions while avoiding unnecessary processing of correctly decoded portions, thereby limiting the increase in device complexity to only the essential post-processing components.