IT1225680B - Equipment for rapid recognition of packets of data in digital telecommunications systems without prior linking of the clock to the word of alignment - Google Patents

Abstract

In order to recognise rapidly packets of data in digital telecommunications systems, without having to link the clock in advance to the word of alignment, preferably at least three or more search clocks are generated, which are unrelated to the incoming signal, isofrequential to each other and out of phase by an amplitude at 1/n of 360 degrees, where "n" equals the number of clocks in question. The search clocks control the respective shift registers (SR1-SR2-SR3), which receive the incoming packets of data with the alignment word and the output from the registers goes into a memory (17), which recognises the alignment word and which gives an output enable signal (Ic), only when at an entry point it receives, from one of the said registers, the signal corresponding to reading and storage upon the alignment word stage having taken place. The output form the memory goes to a selector (18) which receives the input of the search clocks and which allows only that clock to exit which has carried out the reading each time at the alignment word stage. The selector's exit, together with the signal with the packets of data received, finally goes to a known reading unit (19) for the information data.