| 摘要 |
An equaliser with adaptive quantised feedback to equalise a severely distorted digital received signal is improved according to the invention by using a frame alignment word, transmitted at periodic time intervals to the receiving end, in the equaliser at the receiving end to re-adjust the coefficients. This is achieved by using, at times when the frame alignment word is received, a distortion-free frame alignment word which is identical to the former frame alignment word and which is stored in a memory (9) at the receiving end, instead of the output signal of the quantiser (3), for coefficient re-adjustment. This achieves a fast convergence of the coefficient re-adjustment, and a test signal which would otherwise normally precede the data transmission is no longer required. A linear equalising component (10, 11), connected if necessary upstream from this equaliser, uses the same error signal for coefficient re-adjustment, where the receiving-end frame alignment word is used at periodic intervals to determine this signal. The changeover from the output signal of the quantiser (3) to the frame alignment word stored in the memory (9) is provided by a frame recognition circuit (8) which is required in any case in the receiver for the purpose of phase synchronisation of the receiving-end sampling clock. <IMAGE>
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