Feilrettende

Feilrettende refers to methods and systems that can identify and correct errors in data or processes, often within the transmission, storage, or processing chain, without requiring retransmission of the original information. In information theory and computing, feilretting is typically achieved by adding redundant information that makes it possible to detect and fix errors at the receiving end.

Feilretting is commonly implemented through forward error correction (FEC), where an encoder appends redundancy to the data, and a decoder uses this redundancy to correct errors. This contrasts with automatic repeat request (ARQ), where damaged data are resent. Common error-correcting codes include Hamming codes, Reed-Solomon, BCH, LDPC, and turbo codes. The choice of code influences the level of protection, throughput, and decoding complexity.

Applications are widespread: ECC memory uses feilretting to detect and correct single-bit errors in DRAM; storage media such as CDs, DVDs and Blu-ray discs use FEC to recover data corrupted by scratches or degradation; data transmission standards for satellite, cellular networks and Wi-Fi employ FEC to sustain performance in noisy channels; QR codes employ Reed-Solomon coding to recover data despite damage or distortion.

Limitations include the trade-off between redundancy and data rate, as well as computational requirements for encoding and decoding and potential latency. Feilretting is a fundamental concept in communications, data storage, and digital systems, evolving alongside newer codes and decoding techniques to improve reliability in imperfect channels.