Konvolutsioonikoode

Konvolutsioonikoode, known in English as convolutional codes, are a type of error-correcting code widely used in digital communication and data storage. They are defined by a finite impulse response (FIR) filter, where the output bits are generated by a linear combination of the current and a finite number of past input bits. This process can be visualized as a sliding window operation.

The key parameters of a convolutional code are its constraint length, denoted by K, and its code rate, R. The constraint length determines the number of previous input bits that influence the current output, effectively defining the memory of the encoder. The code rate R is the ratio of information bits to coded bits, often expressed as k/n, where k is the number of input bits and n is the number of output bits per time step.

Convolutional codes are typically decoded using algorithms such as the Viterbi algorithm, which finds the most likely sequence of transmitted bits given the received sequence. The Viterbi algorithm is a dynamic programming approach that efficiently searches for the optimal path through a trellis diagram representing the code's state transitions. These codes offer good performance, especially at high signal-to-noise ratios, and are robust against channel noise. They have found applications in satellite communications, mobile telephony, and deep-space probes.