SU882012A1 - Device for clock synchronization of radio channel regenerator - Google Patents

Description

(54) CONSTRUCTION OF THE TACT SYNCHGONIZATION OF THE RADIO CHANNEL REGENERATOR

T acquisition refers to radio engineering and can be used in data transmission equipment, in particular in radio channel regenerators. A clock synchronization device of a radio channel regenerator is known, comprising a series-connected reference generator, a frequency difference compensating unit, a control element, an oscillator divider, a time zone generator, a selection unit, a phase discriminator and an averaging unit, the outputs of which are connected to the inputs of the frequency divergence compensation unit and a control element, as well as a switching unit, a control unit and a front edge selector unit and a front unit dedicated to one series connected in series, while the swarm and the third outputs of the reference generator are connected respectively to the input of the edge selection unit and the second input of the phase discriminator, to the third input of which the second output of the main divider is connected to the second input and the second output of the control unit to the second and third inputs block x ek tsni, the third and fourth inputs of the averaging block 1. However, the known device has a low noise immunity. A: The purpose of the invention is to improve noise immunity. For this purpose, a radio channel regenerator clock synchronization device containing a series-connected reference oscillator, a frequency difference compensation unit, a control element, a main divider, a time zone generator, a selection unit, a phase discriminator and an averaging unit, the outputs of which are connected to the frequency divergence compensation unit and a control element, as well as a switching unit, a control unit and a series-connected edge extraction unit and a single front unit for a tact, while the second and third outputs of the reference generator are connected respectively to the input of the edge selection unit and the second input of the phase discriminator, the second output of the main divider is connected to the second input of which and the second input of the selection block of one front per cycle and the outputs of the control unit / / to the second and third inputs the selection unit, the third and fourth inputs of the averaging unit, are introduced in series the asynchronous integral receiver, the key, the decision unit and the loss of synchronization signal generator, and an integrator and a series-connected noisy signal analyzer and a memory unit, to the second input of which, combined with the first input of the noisy signal analyzer, is connected the output of the edge extraction unit, and the output of the memory unit is connected to the second input of the key, to the third and fourth inputs of which as well as the first and second inputs of the integrator and the switching unit are connected to the outputs of the control unit, the integrator's output is connected to the first input of which and the second input of the loss of synchronization signal, the third at the input of which the output of the key is connected, and the output of the loss of synchronism signal generator is connected to the fourth input of the integrator and the second input of the control unit, while the third output of the reference generator is connected to the third, fourth and fifth inputs of the switching unit, respectively, the third output of the reference oscillator and the output of the asynchronous integrated receiver, the first and second inputs of which are combined with the corresponding inputs of the edge selection unit.

The drawing shows a structural electrical circuit of the proposed device.

The clock synchronization device of the radio channel regenerator contains the reference generator 1, the frequency difference compensation unit 2, the control element 3, the main divider 4, the time zone generator 5, the averaging unit 6, the phase discriminator 7, the selection unit 8, the edge extraction unit 9, the allocation unit 10 one front per clock, noisy signal analyzer 11, memory block 12, key 13, decision block 14, integrator 15, sync loss generator 16, control block 17, asynchronous integrated receiver 18, switching block 19.

In block 9, the edge selection is used to discretize the temporal position of the edges of the input signal, for which one of the inputs of block 9 receives a signal from the output of the reference oscillator 1. The selected edges are fed to the input of the block 10 for the separation of one front per cycle, from the output of which they are in synchronous mode through the block 19 switching arrive at the input of the block 8 selekgsch. In this mode, block 8 performs selection of the fronts of the input signal according to the value of the edge distortion, i.e. only the fronts that fall into the zone of the confidence interval, which is formed in the shaper of 5 time zones and is fed to another input of the selection unit 8, arrive for adjustment. In the synchronization state search mode, the fronts of the input signal arrive at the trimming, in a zone of the confidence interval.

The frequency adjustment of the reference oscillator 1 in phase mismatch is carried out indirectly using control element 3, to the input of which in synchronous mode receives averaged pulses of addition and subtraction from the output of averaging unit 6. In the synchronization state search mode, the addition and subtraction pulses produced by the phase discriminator 7 are transmitted to the control element 3 without averaging. The frequency divergence compensation unit 2 performs an operation of compensating for the detuning of the frequency of the reference oscillator 1 relative to the frequency of the input signal, i.e. Makes static sync error to zero.

In the common-mode search mode, the edges of the signal arrive at the adjustment and analysis of the state of the synchronization system from the output of the asychronic integrated receiver 18, which performs the function of converting the signal splittings to edge distortion. The useful signal is sent to the input of the asynchronous integrated receiver 18, and at its output the temporal position of the edges of the transformed signal is sampled, for which one of its inputs receives a signal from the output of the reference oscillator 1. The selected edges come through the switching unit 19 for adjustment, and through a key 13 to the input of the integrator 15, in which a small integration coefficient is included to reduce the search time of the synchronism state.

In the presence of a signal at the output of the integrator 15, using the control block 17, additional trimming pulse dividers in the averaging block 6 are activated, the action of the confidence interval zone in the selection block 8 is turned on. It also includes a large integration coefficient in the integrator 15 and a noisy signal analyzer 11 and a memory unit 12 for adjustment are connected through the switching unit 19 to the fronts from the output of the allocation unit 10 of one

front for tact. I will let the signal from the output of the integrator 15 zero the shaper 16 of the loss of synchronism signal. The action of the asynchronous integrated receiver 18 is performed only in the synchronism search mode. Wherein

5, in the switching unit 19, the phase of the input signal 18 shifted during the conversion process in the asynchronous integrated receiver is adjusted.

In the synchronous mode, to eliminate the formation of a false signal of loss of synchronism, the quality of the input signal is determined using the noisy signal analyzer 11 and the memory block 12. The operation of memory block 12 is based on memorizing the number of fronts in one clock interval, i.e. in the interval between strobe pulses located in the middle relative to the elementary premise. If their number is equal to two (or more), then the noisy signal analyzer 11, generating the output signal with the arrival of the second front in the specified interval, nullifies the integrators of the memory block 12. This completely eliminates the possibility of the formation of false pulses dominating in a synchronous mode.

A large number of fronts (more than one) is formed when the clock synchronization (TCB) input to the input of the device is synchronized with a solid noise in the clock interval. But through the key 13 they do not pass due to the action of the analyzer 11 and, therefore, no loss of synchronism signal is generated, which is especially important during the tuning of the working frequencies of the transmitters and receivers of the radio link.

A sign of the lack of synchronization is the presence of an edge of the input signal in one half of the analysis time zone, which enters the input of the decision block 14 from the other output of the shaper 5 time zones. In decision block 14, the phase position of the analyzed fronts is determined. In the out-of-sync driver 16, the dominant pulses are extracted and averaged. In the presence of a loss of synchronization signal at the output of the imaging unit 16, the control unit 17 is used to disable the zone of the time confidence interval in the selection unit 8 and additional dividers in the "shock 6 averaging". The integrator 15 is nullified, and a small integration factor is turned on, the noise signal analyzer 11 and memory block 12 are also turned off, and fronts from the output of the asynchronous integral receiver 18 are fed to the trim (switching unit 19) and analysis (via key 13).

Thus, the proposed device has the following advantages as compared with the known one: it provides the optimal algorithm for determining the in-phase and non-phase state of the synchronization system under the conditions of additive and multiplicative interference, high cyclic stability in the presence of a constant predominance in the channel, exceeding the temporary trust zone value interval, the versatility of determining the modes of clock synchronization, regardless of the type of phase discriminator.

The implementation of these provisions makes it possible to significantly increase the noise immunity and capacity of the communication channel.

Claims (1)

1. USSR author's certificate N 640440, cl. H 04 L 7/08, 1976 (prototype). o 00 882012 with to ro CN4 GE Csj four. GO