SU436450A1 - METHOD OF ASYNCHRONOUS INPUT OF BINARY SIGNALS INTO SYNCHRONOUS CHANNEL OF COMMUNICATIONS • • --fjnn fiic'rir? ":" '^'?! ^ ^ T; \ a''S; * ^; ^^ m - Google Patents

Description

one

The invention relates to the field of telecommunications and can be used in the equipment for asynchronous transfer of binary information.

Known methods of asynchronous input of binary signals in the synchronous. communications, in which a subscriber signal having a text frequency fc is gated with a sequence of clock pulses of a communication channel, which follow with a higher frequency / k. In this case, some parcels of the input signal are gated with two pulses, as a result of which, in the transmitted digital stream, there appear parcels duplicating, i.e., repeating the preceding information parcel. Such duplicate (auxiliary) parcels follow quasi-periodically with the frequency / k-fc, which makes it possible to find these parcels and exclude them from the received signal, thus restoring the subscriber signal at the receiving station.

Due to the instability of the frequencies (k and / s), the auxiliary messages are shifted from time to time to the adjacent clock position, while information packages having a random nature are received at the place of the duplicate message, which serves as a signal for a corresponding correction of the device that excludes auxiliary messages.

However, the transmission of long groups of parcels of one polarity leads to the appearance of a large number of information duplicate parcels in the signal, which makes it difficult to observe the position of auxiliary duplicate parcels, which drastically reduces the permissible total instability of frequencies / s and / k and impairs the reliability of transmission. In order to increase the reliability of transmission at different ст statistics of the input signal and expand the range of allowable detuning of the clock frequency of the input signal relative to the frequency of the communication channel according to the proposed method, when generating cycles

as auxiliary parcels, not only duplicate parcels are used, but also their logical opposite — inverse parcels, i.e., parcels having a polarity opposite to the polarity of the preceding

parcels At the same time, signaling about the correction of the phase shift between the frequencies fc "fio which is carried out by changing the number

I-MPULS, in one of the CYCLOB, the transmission is carried out by such a change in the transmission sequence of inverted and duplicated parcels, in which the duplicated auxiliary parcels in the received signal fall in the place of inverse, or vice versa, inverse

.place duplicate. The transmission cycle of such a device is determined by the frequency ratio / s and / k and consists of m information and p auxiliary parcels, with m and / and + p being mutually simple numbers. FIG. 1 shows a block diagram of a transmitting part of a device implementing the proposed asynchronous input method with FIG. 2 - the same-receiving part. The operation of the device pa example is illustrated by the table, where the letters "D," And and "C denote the clock positions of duplicate and inverse auxiliary parcels and information parcels of the transmitted signal, respectively. The transmitting and receiving parts of the device contain a phase shift latch circuit 1, a single period change circuit 2, a divider 3, a distributor 4, a ban 5, an elastic memory circuit 6, a duplicate package insertion circuit 7, an inverse package insertion circuit 8, a synchronization receiver 9 , a receiver 10, distributors 11 and 12, an inverse parcel allocation circuit 13, and an elastic memory circuit 14. The subscriber signal at the transmitting station is supplied to the "elastic memory circuit 6", which serves to rewrite the input signal to the clock positions of the communication channel. The distributor 4 forms in each transmission cycle m read pulses, which are fed to an elastic memory. In circuit 7 of inscribing a double packet, the output signal of the elastic memory is delayed for a clock period of the read pulses, and a parcel duplicating the m-th information parcel is formed at the place of the missing (m-l} -TQ pulse. The output signal of circuit 7 is fed to the insight parcel insertion circuit 8, which upon arrival (r4-1) of the distributor pulse changes the polarity of the auxiliary parcel. Thus, the communication channel receives the parcel groups consisting of three information and one inverse parcel (cycles 1- eight The value of the communication channel clock frequency / k is selected in accordance with the ratio ;; т1 (where A is small, selected so that for all possible instabilities often g / s and / k is the direction of change in the phase shift between these frequencies remains constant. When the phase shift reaches the determined value, fixing phase shift circuit 1 triggers divider 3, which includes the “Forbid” circuit, which does not drive control pulses to circuit 8, in the output signal. Yu TC is duplicating (cycles 12, 16, 20, 24), and in the (/ g + 1) th cycle of the signal coming from the circuit 2 of a single period change, valve 4 reduces the number of read pulses by one (cycle 27). At the receiving station, the inverse parcel allocation circuit 13 via the synchronization receiver 10 synchronizes the operation of the distributor 11, the write pulses generated by the distributor 12 write to the elastic memory circuit 14 only the information signal, which are then read by the pulses of the clock recovery circuit 12. The receipt of duplicate auxiliary premises instead of inverse ones is recorded by the synchronization receiver 9, and in the k-u cycle (k-.n) the circuit 10 of a one-time period change affects the distributor 11, which changes the number of write pulses (tick 23). At the same time, failures of receiving information packages do not occur, since up to / r + 1 cycles instead of information packages excluded by the distributor (cycle 23), duplicate packages are repeated (cycle 24). In the presence of interference in the channel, due to failures of auxiliary parcels, a delay in the correction of the number of write pulses at the receiving station is delayed, but so far k remains less than n and the equipment is not broken. The device described as an example can only be implemented with, therefore, devices with, which are realized with any values of D, can be more widely used. Thus, in the proposed asynchronous input method, the transmission of information about

The phase shifts are completely accomplished by auxiliary premises; therefore, the equipment operability does not depend on the statistical characteristics of the input signal, which allows extending the range of allowable frequency detunings, increasing the reliability of the transmission and ensuring high utilization efficiency of the communication channel.

Subject invention

A method of asynchronous input of binary signals to a synchronous communication channel, consisting in the formation of cycles from information packets separated by auxiliary duplicate messages and modified6

The scientific research institute of the number of information packages in a cycle when a certain value of the phase shift between the input signal and the clock positions of the communication channel is reached, characterized in that, in order to increase the reliability of transmission with different statistics of the input signal and expand the range of allowable delays of the clock frequency of the input signal relative to the channel frequency connection, in the formation of cycles use not only duplicate, but also inverse auxiliary premises, the compensation of the phase shift at the receiving side is made at Amen duplicate in the received signal (inverse) of the auxiliary logic chip opposite.

entrance

“I Pe11z a; аем1 1У

Oh i u-, cvzuan