SU454702A1 - Device for asynchronous pairing in synchronous communication channel - Google Patents

Description

one

The invention relates to multi-channel communication systems, namely, devices for asynchronous pairing in a synchronous communication channel and can be used in equipment for asynchronous transfer of digital information.

Devices for asynchronous input of binary information into a synchronous communication channel without an additional channel are known. In these cases, not only the information about the polarity of the transmitted signal, but also the EE formation about its clock frequency has to be entered into the communication channel. This additional information is usually transmitted by inserting into the transmitted signal auxiliary bursts, which are detected at the reception and signal certain values of the phase shift between the bursts of the input signal and the clock signals of the Qaal connection that are transmitted for its transmission.

As ancillary parcels, they use either duplicate parcels, i.e., they repeat the second, previous ones, or duplicate parcels together with inverse parcels, i.e., having a polarity, the inverse of the floor of the previous parcels. In this case, the signaling about the phase shift is carried out by changing the transmission sequence of inverse and duplicate parcels.

2

However, when implementing the known devices, the appearance in the input signal of long groups of parcels of one polarity corresponds to the transmission of a large number of repeating, i.e. duplicating each other, parcels over the communication line. These parcels mask auxiliary duplicate parcels, making it difficult to find them in the received signal. It is also difficult to find a single auxiliary inverse burst, since the data burst transmitted after the auxiliary inversion and which repeats the previous burst in the received signal turns out to be an inverse burst. In inverse devices, the time of detection of the auxiliary premises (the time for searching for synchronism) depends on the statistical properties of the transmitted signal.

The aim of the invention is to increase the reliability of information transfer and reduce the time of entry into synchronism.

To do this, on the transmitting side (m-fl) -M and () -and the distributor outputs on the one hand and the output of the duplicate parcel formation unit on the other hand, connected in series are the P1LI and Zairet circuits and the inverse parcel shaping unit, with the second input of the circuit "The ban is connected to the output of the periodic switching unit, to one input

which is connected to the output of the unit of one-time period change, and to the other input is (t4-2) -th output of the distributor, and on the receiving side - input of the input and (t + 2) -th output of the distributor, the periodical switching unit is turned on, the output of which is connected to the second to the input of the synchronization receiver through a sequence of inverse package selection block, the signal input of which is connected to the corresponding input of the duplicate package selection block, and the RSHI circuit, to the second input of which the output of the duplication block sylok, where m - number of data parcels cycle broadcast signal.

In the proposed device, dual auxiliary parcels are inserted into the transmitted signal, dividing the signals into cycles, each of which contains t information and two auxiliary parcels.

The drawing shows a block diagram of the device.

The device for synchronous conjugation contains on the transmitting part a phase shift fixing unit 1, a unit of a single period change, a periodic switching unit 3, a distributor 4, an OR circuit 5, a Ban 6 circuit, a memory block 7, a duplicate parcel forming unit 8 and block 9 of the formation of inverse parcels, and at the receiving part, the receiver of synchronization 10, block 11 of a single period change, distributor 12, block 13 of recovery of the clock frequency, block 14 of the allocation of duplicate parcels, the OR 15 scheme, block 16 of the inverse nose The cell, the periodic switching unit 17, the memory block 18.

The operation of the device on the example t 3 and

where D is small, chosen so that for all possible frequency detuning the sign A, defining the direction of change of the phase of the pulsed carrier relative to the input signal, remains empty, illustrated by the table, where the letter C denotes the clock positions in the communication channel for asynchronous the transmitted signal, and the letters D and I respectively denote the positions of auxiliary duplicate

and auxiliary inverse assemblies.

Table

At the transmitting station, the input signal is recorded in the memory block 7 and rewritten by the distributor 4 for the clock positions of the communication channel. The output pulses of the memory unit are stretched for the entire period of the reading pulses in the block 8 of forming the duplicate parcels. No (t + 1) -th and (t - | -2) -th pulses are received from block 8 to block 8, therefore packages replacing the m-th information packet are formed in place of these pulses. The output voltage of the block 8 is fed to the block 9 of the formation of inverse parcels, to the input of which through the circuit "OR 5" and the circuit "Ban 6" receive (t + 1) -th and (t-4-2) -th pulses of the distributor 4. At the arrival Inverse pulses are formed by these pulses. At the same time, the (t - | -2) th pulse arrives at block 3 of the periodic switching, which locks the “Ban 6, prohibiting the passage of (t -} -) - th and (m-f2) -ro pulses to the block in every second cycle 9. In the absence of these pulses, block 9 passes to the output the parcels formed by block 8.

Thus, in the transmitted signal, after every m of informational pulses (cycles one — the third and with a scatter — eight), alternating double inverse (fourth, fifth) and double cycles are transmitted.

duplicate parcels (ninth and tenth cycles).

The phase shift between the write and read pulses of the memory unit 7 is controlled by the phase shift locking unit 1. When

this shift reaches

t + 2

where Gs is the period of the following pulses of the input signal, block 2 is switched on a single period change, which affects distributor 4, by changing the number of read pulses in the cycle by one unit (14th clock), which leads to a phase shift offset in memory block 7. block 2 rephases; block 3 of periodic switching 1 and,: this leads to a change in the order of transmission of the I1-hop and duplicate parcels (steps IS-ii, 16th).

At the receiving station, the alternate parcel extraction unit 14 and the inverse parcel extraction unit 16 that are alternately opened by the periodic switching unit 17 are separated from the received signal by double pockets. Inputs pulses of blocks 14 and 16 through the scheme "Р1ЛИ 15 I enter r to the synchronization receiver 10, which synchronizes the operation of the distributors 4, 12 and blocks 3, 17 of the transmitting and receiving stations. At the same time, the () th pulse of the distributor 12 controls the operation of the periodic switching unit 17, and the t read pulses in the memory block 18 extract informational packets from the received signal.

The change of the cycle period on the transmission causes the information packets to be shifted by one clock relative to the read pulses of the receiving station. Odiako data reception is not happening, because instead of the information packages excluded from the received signal (cycles 14th, 19th), the second pulses of duplicate auxiliary duplicate (16th cycle) or inverse (cycle 21st) are repeated. parcels

Synchronization receiver 10 fixes the change of duplicate and inverted messages (15th, 20th cycles), and if such a violation is not caused by the case of a 1H1 error sending noises, then through / (the pickups during which the receiver checks the stability of the violation of synchronism, turns on the AND block a one-time change of the period, which rephases the distributor 12 and the periodic switching unit 17, changes the number of reading pulses in the () cycle (24-11 cycles) and restores the synchronization of the transmitting and receiving equipment.

With the help of a clock recovery unit 13, the quality of which is usually applied to narrow-band filters or PLL generators, averaging the frequency of the read pulses from the distributor 12, the frequency of the return signal is restored. If phase fluctuations in the order of 15–20% are permissible, the clock frequency of the input signal can be restored by the distributor 12 by means of sand shifted pulse sequences /. The recovered clock frequency of block 13 is used to read the signal from the memory block.

Thus, the operability of this device and the accuracy of the aspchronic transmission does not depend on the statistical characteristics of the pseudo-guided signal. The absence of a rigid time reference for the phase correction points at the transmitting and receiving stations makes it possible to simplify the equipment and increase its noise immunity. The use of this device makes it possible to reduce the time required for the equipment to synchronize, since o:; L4 b v.ia the probability of occurrence in the nnd,) signal of the parcels, analogous to alternating with dual duplexes of the opiM and P1 reverse parcels.

Subject invention

15

A device for asynchronous sleep in a synchronous communication channel, containing on its transmitting side a series-connected single-phase period unit, to the control input of which a memory unit is connected via a phase shift fixation unit, and a distributor controlling the unit for generating duplicate parcels directly and through the unit memory, and on the receiving side - a sequence of synchronization receiver, a unit of a single modified period and a distributor connected directly and through the unit

restoring the clock frequency to the inputs of the block PA :. t11, connected via a signal input to the input of the block for selecting duplicate parcels, one of the outputs of the distributive device being connected to the corresponding

to the input of the synchronization receiver, the difference is that, in order to increase the reliability of transmissions of information and reduce the time of entry into sphropism, on the transmitting side between (im-rl) -M n

() th output of the distributor, on the one hand, are connected in series the “OR” and “Prohibition and the block for the formation of the latest packages, and the second input of the“ Prohibition is connected output

the periodic switching unit, to the single input of which the output of the single-time changeover unit is connected, and to the other input - (t + 2) -th output of the distributor, and on the receiving side - between the input and

The () th output of the spreader includes a periodic switching unit, the output of which is connected to the second input of the synchronization receiver through the series-connected allocation unit of the polar packages,

The secondary input of which is connected to the corresponding input of the block for allocation of duplicate lines, and the scheme “SLI, to the second input of which is connected the output of the block for allocation of duplicate parcels, here is the number of informational packets in the broadcast terminal.

entrance

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