SU836807A1 - Device for shaping terniary-coded sequences - Google Patents

Description

The invention relates to radio engineering and can be used in pulse-phase navigation systems using complex periodic signals with amplitude-phase manipulation.

A device for forming ternary-encoded sequences containing a series-connected clock generator. pulses (GTI), an M- ¹⁰ sequence generator, consisting of an odd number of memory elements in p-states, where p is an odd prime, and Legendre's character shaper DJ.

However, the known device has a low noise immunity.

The aim of the invention is to increase noise immunity.

To do this, in a known device for forming ternary-coded sequences, a trigger and a multiplier are connected in series, the second input of which is connected to the output of the Legendre symbol driver, while the GTI output is connected to the trigger input.

Figure 1 shows the structural electrical diagram of the proposed device! figure 2 - plot signals at some points of the circuit.

A device for forming ternary-encoded sequences contains a GTI 1, an M-sequence generator 2, a Legendre symbol generator 3, a multiplier 4, and a trigger 5.

The 2-sequence generator 2 consists of an odd number (2k-1) of memory elements 6-1-6- (2k-1) on p states, where p is a simple odd number, an odd number (2k-1) of multipliers 7-1- 7- (2k-1) modulo p and an odd number (2k-1) of adders 8-1-8- (2k-1) modulo p.

The device operates as follows.

Since the start of the GTI 1 (figa) at the output of the generator 2, i.e. at the output of a memory element 6- (2k-1) $, a coded sequence of a maximum period of Mr ₅ (2k-1) -1-with a character duration of one clock cycle is generated (Fig.2b).

Then, a ternary-encoded sequence is formed from the M-sequence using the 3-character shaper Le Gendre.

The obtained ternary-encoded sequence is fed to one of the inputs of the multiplier 4, to the other 15 the input of which receives a signal from trigger 5 (Fig.2c). The multiplier 4 multiplies the element of the sequence (from the output of the shaper 3) by one if the logical state of trigger 5 in this cycle is one, and by minus one if the logical state of trigger 5 is zero. As a result, the ternary-encoded sequence from the output is formed- 25. The value of unit 3 is multiplied elementwise by an alternating sequence of positive and negative units. At the output of the multiplier 4, an output sequence is formed with a period of N / 2 (Fig. 2d).

Consistent processing of a signal modulated by such a sequence gives zero side lobes, i.e. no additional interference.

Claims (1)

The invention relates to radio engineering and can be applied in pulse-phase navigation systems using complex periodic signals with amplitude-phase shift keying. A device for generating triply-coded sequences containing a series-connected clock pulse generator (GTI), an M-sequence generator consisting of an odd number of memory elements in p-states, where p is a simple odd number, and a Legendre symbol generator Dl are known However, the known device has a low noise immunity. The aim of the invention is to increase the noise immunity; 1. For this, a sequentially connected trigger and a multiplier, the output of which is connected to the second input of the Legendre symbol maker, are connected to a known device for forming three-coded sequences, and the GTI output is connected to the trigger input. Figure 1 shows a structural electrical circuit of the proposed device: figure 2 shows signal plots at some points of the circuit. A device for forming a trinity; but-coded sequences contains GTI 1, 2 M-sequence generator, 3 Legendre shaper, multiplier 4, and trigger 5. M-sequence generator 2 consists of an odd number (2k-1) of memory elements 6-1-6- (2k -1) per p states, where p is a simple odd number, an odd number (2k-1) multipliers 7-1-7- (2k-) modulo p and an odd number (2k-1) adders 8-1-8 - (2k-1) modulo p. The device works as follows. From the moment of the start of operation of the GTI 1 (Fig. 2a) at the output of the generator 2, i.e., at the output of the memory element 6- (2k-1), the coded sequence of the maximum period Mr (2k-1) -1-d characters in one period of clock pulses (figb). Then a three-coded sequence is formed from the M-sequence using the 3 LeZhandre symbol maker. The resulting ternary-coded sequence is fed to one of the inputs of multiplier 4, to the other input of which a signal from trigger 5 arrives (figv). The multiplier 4 multiplies the sequence element (from the output of the imaging unit 3) by one, if the logic state of the trigger 5 in the given cycle is one, and to the minus one if the logic state of the trigger is 5 zero. As a result, the triple-coded sequence from the output of the imaging unit 3 multiply by element: alternating sequence of positive and negative ones. At the output of the multiplier 4, an output sequence is formed with a period of N / 2 (Figure 2d). Consistent processing of a signal duplicated by such a sequence gives zero side lobes, .e. does not give additional hindrances. Apparatus of the Invention A device for generating triply-coded sequences, comprising a series-connected generator of such pulses, an M-sequence generator consisting of an odd number of memory elements in p-states, where p is a simple odd number, and a driver Legendre symbols, characterized in that, in order to increase noise immunity, a trigger and a multiplier are introduced in series, the output of which is connected to the second input of the Legendre symbol maker; A clock pulse generator is connected to the trigger input. Sources of information taken into account during the examination 1. I. Amiantov. Selected questions of the statistical theory of communication. M., Sov. Radio, 1971, p.339 (prototype). (V az.i 6M 7- (2k-1) V - B Exit