Apparatus and methods for use in transmitting and relieving a digital signal and a record carrier obtained by a transmitted apparatus or method

Abstract

A transmitter apparatus for transmitting a digital data signal via a transmission medium (10) includes an error protection encoder (3) for carrying out an error protection encoding on the digital data signal so as to obtain an error protection encoded digital data signal, and a channel encoder (6) for converting the error protection encoded digital data signal processed into a channel encoded digital data signal. The channel encoded digital data signal is supplied to the transmission medium. The error protection encoder (3) is adapted to carry out an error protection encoding step on packets of p m-bit digital words in the digital data signal, and for supplying error protection encoded packets (Q) of n m-bit digital words to an output, where n, m and p are integers larger than 1, and n>p. The channel encoder (6) is adapted to convert the error protection encoded packets of n digital words into converted packets (CP, CP') of digital words to form the channel encoded digital data signal and has a generator (60) for supplying at least fixed auxiliary packet (Q.sub.f.1, Q.sub.f.2) also having the length of n digital words. The channel encoder further includes a calculator (58, 66) for calculating, in a Galois field GF(2.sup.m), a converted digital word CW.sub.i in accordance with the formula DW.sub.i +.alpha..sub.1 .multidot.FW.sub.1.i +.alpha..sub.2 .multidot.FW.sub.2.i + . . . , where DW.sub.i is the binary value corresponding to the i-th digital word in the packet (Q), FW.sub.1.i and FW.sub.2.i being the fixed binary values corresponding to the i-th digital word in the first and second fixed auxiliary packet (Q.sub.f.1, Q.sub.f.2), respectively, and CW.sub.i is the binary value of the i-th converted digital word in the converted packet (CP, CP') of digital words, where i is an integer value running from 1 to n.

Dependencies are inferred from the claim text.