SU1614122A2 - Slocking device - Google Patents

Abstract

The invention relates to communication technology. The purpose of the invention is to reduce the time of entry into synchronism. The device contains a block of transient noise meters, consisting of channel measuring blocks 2, switching unit 3, differential energy meter 4, minimum selector 5, reference g-6, distributors 7 and 25 pulses, and a multichannel switch 26. The device also includes a block 14, an accumulation and classification unit 15, an adder 19, a subtraction unit 20, an integrator 21, a forced adjustment block 22, a mode selection block 23, and a parcel boundary adjustment block 24. For operation in a pseudo-random frequency tuning channel, the sync setting algorithm is changed. This change is provided by the introduction of the distributor 25, the key 26 and the control element And 27. The goal is achieved by the fact that the "synchronization" mode is implemented on each transmission quantum, but with a small discreteness (with increased accuracy) of setting the clock phase. 1 il.

Description

Command „pspch („ 1)

The invention relates to communication technology, can be used in multi-channel demodulators with phase-difference modulation, working in radio channels with a high level of concentrated interference, and is complementary to auth. Ms 1169185,

The purpose of the invention is to reduce the time taken to synchronize.

The drawing shows a block diagram of a clock synchronization device.

The clock synchronization device contains a block 1 transient noise meters, consisting of channel measuring units 2, switching unit 3, differential energy meter 4, minimum selector 5, reference generator 6, pulse distributor 7, each measuring unit 2 consists of multipliers 8i and integrators 9i-9N with feedback circuits 10i-10N, each of which includes a capacitor 11, an output switch 12, a reset switch 13, a distribution block 14, accumulation and classification blocks 15i-15, each of which consists of a drive 16 , channel classifier 17, key 18, adder 19, subtraction unit 20, integrator 21, forced adjustment unit 22, mode selection unit 23, parcel boundary adjustment unit 24, an additional distributor 25 pulses, a multi-channel key 26 and the And element 27.

The clock synchronization device operates as follows.

The input group signal S (t), which in the transmission interval of duration T is the sum of L harmonic signals with phase difference modulation

S (t) 2: aicos ((U | t + y i)

I I

where ai is the amplitude; ft)) - frequency;

(p is the phase of the 1st channel signal, is fed to the input of block 1. The number of channel measuring blocks in it is determined by the number of frequency channels of the synchronization device. Usually N L. In each channel measuring block 2, the input signal is fed to the outputs of two multipliers 8i and 82 , the control inputs of which receive the in-phase and quadrature voltage of the reference signal with a frequency equal to the tuning frequency of the channel measuring unit 2. The entire set of reference signals is produced by the reference generator 6, which is part of in block 1. The series-connected multiplier 8 and integrator 9 with chains 10 are a correlator that calculates the projections X | and YI of the input group

of the signal S (t) to the reference harmonic oscillation over time That corresponds to the orthogonality interval of the channel signals, i.e. 5. ti -1 something

X I t / S (t) cos (Y 11 d t;

I 0 t-i

tl

0

five

0

five

0

1/1 S (t) sinwitdt,

lo ti

The presence of M circuits 10 for each integrator 9 makes it possible to calculate the value of the projections for M time intervals shifted relative to each other, duration T o, on two adjacent signals of duration T and T T + T3, where T e is the guard interval for combating intersymbol interference. The required mode of operation of the circuits 10 is determined either by the distributor 7, or by an additional distributor 25 pulses. For operation of the synchronization device in a continuous channel, the control of the chains 10 and block 3 is carried out only by the distributor 7 through the multi-channel switch 26, which is in the lower position. The output voltages of the channel measuring units 2, which are the magnitudes of the projections X |, are removed from the capacitors 11 of the circuits 10, through the unit 3, are applied successively in time for all M shifts and frequency N channels to the meter 4.

The device works as follows.

During the operation of the demodulator in the pseudo-random frequency tuning channel (HR PN), the transmission is conducted by short communication sessions (quanta) at different operating frequencies. The use of synchronization device algorithms for operation at a fixed frequency in this mode does not result in synchronization, since the synchronization phase setting for the Bd one of the M time shift overlays (the Synchrophisation mode) is rather coarse, and the inertial smooth phase adjustment (Tracking mode) ) does not increase the accuracy of synchronism on a short transmission quantum. In order to work in the channel with the HRSP, the synchronization setup by the synchronization device is changed. This change is provided by the inclusion in the synchronization unit of the additional distributor 25 pulses, the multichannel key 26 and the control element AND 27. One of the bhodes of the element 27 is given the command to enable operation of the channel with the control gear from an external control device. Availability of this ko0

Mandas are considered a logical signal 1, its absence is O. An additional distributor 25 pulses is implemented in the same way as distributor 7, for example, in the form of a programmed permanent memory device (ROM) controlled from a clock counter, received for distributor 7, from block 24. The input of the clock counter is the input of the additional distributor 25 pulses. The output signals of the pulse distributor 25 are supplied to the control inputs of the feedback circuits 10 and the unit 3 via a multi-channel switch 26, which switches to the upper position according to a logic signal 1 from the output of the element 27.

Thus, the process of establishing synchronism during the operation of the channel with the HR control channel proceeds as follows. At the beginning of a communication session, as well as for operation at a fixed frequency, the synchronization device implements the acquisition mode. In this case, the key 26 is in the lower position and the distributor 7 generates M time shifts, overlapping in time almost 2 adjacent signals. As a result of the analysis of crosstalk intersymbol interference, block 22 records a time shift with minimal crosstalk interference, i.e. The one that enters the interval of the signal sending T. To set this shift in block 24, block 22 outputs a signal to the integrator 21 and at the same time this signal as a logical 1 is fed to the input of the element AND 27. If there is a signal from the PCH element And 27 translates the multi-channel switch 26 to the upper position, as a result of which control inputs of the circuits 10 and block 3 receive control signals from the additional distributor

25 pulses. Thus, all M time shifts are located within the interval of signal sending T. In the process of working with HR, on each new transmission quantum, due to changes in signal propagation conditions in the air, it is possible to switch to a new time shift from 25 pulses set by the additional distributor. This is equivalent to the implementation of the Climbing mode on each quantum of transmission, but with a small discreteness (with increased accuracy) of setting the clock phase.

The blocking mode during the operation of the HR control panel prohibits the installation of a new time shift in block 24 with a significant deterioration in the disturbance situation in the communication channel, i.e. operates similarly to work at a fixed frequency.

Claims (1)

The invention of the device clock synchronization auth.St. No. 1169185, characterized in that, in order to reduce the time to synchronization, in the block of transient noise meters, the outputs of the pulse distributors are connected via multi-channel switch to the control inputs of the switching unit and feedback circuits of the integrators, the pulse distributor is connected to the input of the additional pulse distributor and is the output of the block of transient noise meters, the output of the additional pulse distributor is connected to the second input of the multichannel key, the first input of the AND element It is connected to the output of the forced trimming unit, the second descent of the AND element is the input of the HR command signal, and the output of the AND element is connected to the control input of the multi-channel key.