Abstract: A sequence of m-bit information words is converted to a modulated signal wherein each received information word from the sequence is converted to an n-bit code word. The code word is selected from a set of codewords that depends on a coding state that is related to a digital sum value at the end of the part of the modulated signal that corresponds to the delivered code word. By at least one of the digital sum values, a first (S2, S4, S6, S8, S10, S12) or a second (S3, S5, S7, S9, S11, S13) coding state of a pair of coding states is determined. Which of the two coding states of the pair is determined depends on the information word that corresponds to the previously delivered code word. The sets (V2/V3; V4/V5; V6/V7; V8/V9; V10/V11; V12/V13) of codewords belonging to the pairs of coding states contain no codewords in common.

Abstract: A digital transmission system comprising a transmitter (3, 5, 7, 8) and a receiver (14, 15, 16, 18). The medium (6) comprises an information channel (T.sub.1, T.sub.2, . . . , T.sub.n) and an auxiliary channel (T.sub.n+1). Through the information channel information is transmitted, for example a digital audio signal. Through the auxiliary channel an auxiliary signal is transmitted. This auxiliary signal comprises sync information (100, 101, 102, 103, 104, 105) and additional information (106).The auxiliary signal is composed of successive blocks ( . . . , B.sub.n-1, B.sub.n, B.sub.n+1, . . . ). A first block (B.sub.n) comprises a first block section (header) and a second block section (body). The first block section of the block (B.sub.n) contains a sync word (101) and a first codeword (102), in this order. The first block section of the second directly successive block (B.sub.n+1) contains a sync word (104) and a second codeword (105), in this order.