| 摘要 |
There are time division multiplex information transmission systems in which synchronisation takes place by means of code words transmitted at regular time intervals and coded in a particular code. In systems in which the signals to be transmitted are transmitted in packets of uniform length, the code words in each case contain the information of the so-called header of a packet. The test device according to the invention tests all n-bit bit groups (Xj to Xj+n-1) beginning with an (Xj) of the successive bits of the bit sequence received successively for whether they are coded in the particular code. This is done by calculating the syndrome (S1 to Sn-k) in several parallel networks (N1 to Nn-k), each of which calculates one syndrome component. The bit sequence received is delayed until the networks have calculated the syndrome for a particular n-bit bit group and a syndrome evaluating circuit (LS) indicates, by means of the calculated syndrome, whether the bit group is a code word. <IMAGE> |
