Abstract: A block of helically interleaved codewords is received in a de-interleaving array. A succession of codewords obtained from the de-interleaving array are decoded in a process in which each error pattern in a given codeword position provides a prediction of the presence or absence of an erasure in the adjacent codeword position of the next codeword. This prediction is obtained by addressing a look-up table with the error pattern. In one embodiment of the invention, the erasure prediction is computed recursively from previous erasure predictions using individual skepticism factors and forgetting factors for each codeword symbol position.

Abstract: The n symbols of a codeword of length n are transmitted on n separate channels or frequencies simultaneously. A receiver includes n equalizers that are adapted to receive information from respective ones of the n channels. The outputs of the n equalizers are applied to n inputs of an error correcting decoder which produces the original version of the transmitted codeword. The n equalizers include n feedforward and n feedback transversal filters whose taps are updated by n tap update processors in accordance with a Kalman algorithm, or the like, once each codeword time. The feedforward registers contain successively received signal samples of each of the n channels while the n decision feedback registers contain successively corrected symbols generated at each of the n decoder outputs.

Abstract: Plural n-symbol codewords are helically interleaved and transmitted in a stream. A receiver views the transmitted stream through n time windows, each time window having a length accommodating the longest anticipated decorrelation time of the channel. Individual equalizers process the data in individual windows. The n windows simultaneously furnish the n symbols of each codeword to an error correction decoder. The n equalizers respond to feedback in which the output of the decoder is substituted in place of undecoded symbols from the n windows whenever available.