SU1107302A1 - Device for adding spaced radiotelephone signals - Google Patents

Abstract

1. DEVICE OF ADAPTATION OF EXTENDED RADIOTELEPHONE SIGNALS containing an N-input adder and N diversity branches, the output of each of which is connected to the corresponding input of an N-INPUT output adder with an automatic gain control and a weight multiplier unit, the output of which is connected to the weight setting input of the weight element, characterized in that, in order to increase the ratio A signal / / noise at the output of the device, a clock generator, the output of which is connected to the clock inputs of the weight multiplier forming units, and a noise generator, the output of which is connected to the additional inputs of the weight multiplier forming units, are entered in each branch of the automatic amplifier. the gain control is connected to the input of the weight element and the input of the weight multiplier shaping unit. 2. A device according to claim 1, characterized in that the weight multiplier unit comprises connected in series a controlled attenuator, the input of which is an additional input of the weight multiplier forming unit, a quad and an integrator, the output of which is the output of the weight multiplier shaping unit connected in series an adder, the first input of which is connected to the input of the weight multiplier shaping unit, and the second input is connected to the output of the controlled I attenuator, the pulse driver, (P the first The AND element, the first counter, the first NAND element, the output of which is connected to another input of the first AND element, the second NAND element, the trigger, the second AND element, the other input of which is connected to the clock input of the weight multiplier shaping unit, and the reversible counter, the output of which is connected to the control input of the controlled attenuator, connected in series the third element I, INPUT: which is connected to the clock input of the weight multiplier shaping unit, the second counter, the third element NAND, the output of which is connected to another input ohm of the third element is And, the first element is NOT and the fourth element is And, the other input of which is connected to the clock input of the block to form a weight multiplier, and the output to another input of the reversible counter, connected in series to the third counter, the input of which is connected to the clock input of the block

Description

and the setup input is with the output of the second NAND element, and the second item is NOT, the output of which is connected to another: the trigger input, the delay element, the input of which is connected to the clock input of the weight multiplier shaping unit, and the output - to the installation

the input of the first counter, the third element is NOT, whose input is connected to the clock input of the weight multiplier unit, and the output to another input of the second, NAND element, the fourth element NOT, the input of which is connected to the trigger output and the output to the installation input of the second counter ,

The invention relates to radio engineering and can be used in remote reception systems of radio telephone signals that perform weight summation of received signals.

A device for combining spaced-wave distributions is known, containing N reception channels, each of which contains an antenna, a high-frequency amplifier j an intermediate-frequency amplifier, a detector, and an adjustable amplifier, the transmission coefficient of which varies depending on the noise level. The outputs of all receiving channels are connected to the inputs of the adder. C The disadvantage of this device is the low accuracy of determining the weights for optimal addition, due to the fact that. These coefficients are chosen in proportion to the noise level in the diversity channel, while the signal quality is more expedient to estimate the signal-to-noise ratio.

The closest in technical essence to the present invention is a device for combining spaced radio signals containing an N-input output adder and N diversity branches, the output of each of which is connected to the corresponding input of the N-input output adder, each diversity branch contains a weight element, the output of which is output of the corresponding branch of the diversity, the input amplifier with automatic gain control and the unit for the formation of the weighting multiplier, the output of which is connected to the input of the installation ECA weight member. In addition, the device contains an additional, between the output

Each input amplifier and the corresponding 1S input of the additional adder, the output of which is connected to another input of the weight multiplier formation unit, includes an element of averaging C 2.

  However, the known device does not provide a sufficiently large signal-to-noise ratio at the output, since the noise level in each diversity branch is estimated in a narrow half, which leads to low confidence in the determination of the weighting factors in each branch.

The purpose of the invention is to increase the signal-to-noise ratio at the device output.

The goal is achieved by

0 that in the device of the separation of separated radiotelephone signals containing an N-input adder and N branches of diversity, the output of each of which is connected to the corresponding input

5 N-input output adder, each diversity branch contains a weight element, the output of which is the output of the corresponding diversity branch, an input amplifier with automatic adjustment of the amplifier and

. a weight multiplier unit, the output of which is connected to the weight setting input of the weight element, is introduced a clock generator,

5, the output of which is connected to the clock input of the weight multiplier formation units, and the noise generator, the output of which is connected to the additional inputs of the weight multiplier formation units, in the power diversity branch, the output of the input amplifier with automatic gain control is connected to the weight multiplier input. The weight multiplier block contains a serially controlled attenuator, whose input is an additional input of the weight multiplier block, a quad and integrator, the output of which is the output of the weight multiplier block, connected in series to the adder, the first input of which is connected to the input of the weight shaping unit multiplier, and the second input is connected to the output of the controlled attenuator, pulse shaper, the first element is AND, the first counter, the first element is NAND, in the stroke of which is connected to another input of the first element AND, the second element NAND, the trigger, the second element AND, the other input of which is connected to the clock input of the weight multiplier and the reversible counter whose output is connected to the control input of the controlled an attenuator connected. a third AND element, whose input is connected to a clock input of a weight multiplier formation unit, a second counter, a third AND-NOT element, the output of which is connected to another input of a third element, AND the first element NOT and a quarter And, the other input of which is connected to the clock input of the weight multiplier formation unit, and the output with another input of the reversible counter, connected in series to the third counter, whose input is connected to the clock input of the weight multiplier generation unit, and the installation input - with the output of the second And element - NOT, and the second element is NOT, the output of which is connected to another trigger input, the delay element, the input of which is connected to the clock input of the weight formation multiplier unit l, and the output - to the installation input of the first counter ka, the third element is NOT the input of which is connected to the clock input of the weight multiplier formation unit, and the output to the other input of the second NAND element, the fourth element NOT, the input of which is connected to the trigger output and the output to the installation input of the second counter. The drawing shows a structural electrical circuit of the proposed device. A device for spaced-apart radio telephone signals contains input amplifiers 1 with automatic gain control (AGC), 2 AGC detectors, 3 AGC integrators, 4-ARA delay elements, 5 multiplier forming units. , a clock generator 6, a noise generator 7, an N-input output adder 8 and a weight element 9. The weight multiplier units 5 comprise a pulse former 10 pulses, the first element 11 and a fourth element 12, the second element 13, the third element 14, the first counter 15, the second counter 16, the third counter 17, the first element AND-NO 18, the second element AND-NOT 19, the third element AND-NOT 20, the fourth element NOT 21, the first element NOT 22, the third element NOT 23, the second ele - ment NOT 24, trigger 25, delay element 26, reversible counter 27, control attenuator 28, quad 29, ntegrator 30 and the adder 31. The device operates as follows. The detected signal, which is a mixture of a speech signal with noise or just noise, is fed to the input of the input amplifier 1, which, together with the AGC detector 2, the AGC integrator 3, and the element 4, forms the AGC system. The normalization of the input mixture in all diversity channels is performed at the level U ,. If there is no information signal at the device input, then the AGC system to the UH level accelerates the input noise voltage. At the output of the input amplifier 1, the signal-to-noise ratio of the input mixture is preserved, and, therefore, the input mixture with a high signal-to-noise ratio will contain a lower absolute value of noise. From the output of the input amplifier 1, the signal + noise mixture arrives at one of the inputs of the adder 31, to the other input of which, from the output of the generator 7, an additional noise voltage is supplied through the level attenuator 28. The noise band of generator 7 corresponds to the band of a standard radiotelephone channel. The resulting $ 1 mixture signal + noise + additional noise from the output of the adder 31 enters the input of the imaging unit 10, which generates pulses at each positive intersection of the resultant mixture of the zero line. From the output of the driver 10, the pulses through the first element I 11 arrive at the countable input of the first counter 15, which accumulates them during the time determined by the period of the zeroing pulses. The zeroing pulses arrive at the installation input of the first counter 1 from the output of the clock generator 6 through the delay element 26. The latter delays the resetting of the pulses of the first counter 15 relative to the pulses arriving at the input of the third element HE 23 at a time of 1.5 ti, j, where t g is the pulse rate of the clock generator 6. The volume of the first counter 5 is selected from the condition C..9 . where Gsr avg is the frequency of the noise at the device input; the period of the following pulse zeroing of the first counter 15. If at the output of the adder 3f there is a resultant mixture with a signal / noise ratio less than unity at present, then its average frequency causes the first counter 15 to overflow during the time TO- At the output of the first element This AND-NOT 18 generates an impulse that has a logic zero level, which, entering the input of the first element 11, prohibits further passage of the impulses to the input of the first counter 15 before the next tilting impulse arrives. The second NE-19 element at the same time due to the delay by the element 26 of zeroing the first counter 15, the overflow pulses of the first counter 15 with the level of logical zero and the pulses from the output of the third element NOT 23 having the level of logical one. At the same time, at the output of the second element IS-NOT 19 there is a level of lot: a unit that simultaneously enters the input of the trigger 25 and the installation input of the third counter 17. The third counter 17 at 2 THIS begins to accumulate impulses arriving at its input and corresponding to the cycles zeroing the first counter 15. The volume of the third counter 17 is selected from the condition NCM n Tp / TO, where Tp is the average duration of the natural pause of the speech signal. By natural pauses is meant semantic pauses between syllables, words, and assumptions in a speech signal. In order for the device not to change the weighting factors for the time of such short pauses, the third counter 17 delays the start of adjusting the weights with respect to the moment, for example, the signal disappears by a time longer T. If the third counter 17 overflows during the time the speech signal, the overflow pulse from its output through the second element NOT 24 is fed to the input of the trigger 25, the output of which forms the level of the logical unit. Since the third counter 17 operates in the frequency division mode, after a time equal to T at its output, the logical zero level is reached, which, however, does not change the state of trigger 25, since its output still contains the level of logical one. The level of the logical unit from the output of the trigger 25 is fed to the input of the second element And 13, therefore the pulses from the output of the clock generator 6 through the second element And 13 begin to flow to the subtracting input of the reversible counter 27. Each pulse arriving at the subtracting input of the reversible counter 27 step reduces the voltage level of additional noise at the output of the controlled attenuator 28. A decrease in the level of additional noise causes an increase in the signal-to-noise ratio of the resulting mixture at the output of the adder 31 and This is a decrease in its average frequency. The decrease in the average frequency of the resulting mixture will occur until it stops causing the first counter 15 to overflow during time T. At the same time, the logical unit level and pulses from the output of the clock generator 6 through the third element NOT 23 and the second element AND-NOT 19 pass to the installation input of the third counter 17 at the output of the NE-18 element. The third counter is zeroed by the last pulse , while at the input of the trigger 25, the level of the logical unit is set, and at its output the level of the logical zero, which is inverted by the fourth element NOT and goes to the set input of the second counter 16. The second counter 16 begins to accumulate impulses, arriving at its input through the third element And 14. The volume of the second counter. 16 is chosen equal to the volume of the third counter 17. After time equal to Tf, the second counter 16 converges and the level of logical zero from the output of the third element AND-NOT 20 will prohibit further passage of pulses through the third element I 14. At the same time, the level of logical zero from the output of the third element AND-NOT 20 through the first element NOT 22 arrives at the input of the fourth element AND 12. At the same time, the pulses from the output of the clock generator 6 through the fourth element I 12 are fed to the summing input of the reversing counter 27. Each pulse arriving at The summing input of the reversing counter 27 increases the level of additional noise by one step at the controlled attenuator 28. An increase in the level of additional noise causes a decrease in the signal-to-noise ratio of the resulting mixture at the output of the adder 31 and at the same time an increase in its average frequency. An increase in the level of additional noise will occur until the average frequency of the resulting mixture begins to cause an overflow of the first counter 15. Thus, an automatic control system is formed. maintaining at the output of the adder 31 a signal-to-noise ratio of the output mixture equal to one, which is ensured by decreasing or increasing. At the same time, the decrease in the Ujivon level is made with a delay of time 1 in order that the change in the weighting factors is not affected by short pauses in the speech signal, and the delay in the increase in the level is made: in order to change the weighting factors in the background speech signal. Thus, by the level of additional noise at the output of the controlled attenuator 28, one can unambiguously judge the value of the signal / noise ratio of the input mixture in the corresponding diversity channel. Since at optimal addition the signal levels in the receive branches should be proportional to the square of the signal-to-noise ratio, the level of additional noise from the output of the controlled attenuator 28 is fed to the input of the quadrant 29, where .c) n is squared and averaged by the integrator 30. The output from the integrator 30 is used as a control voltage to change the transfer coefficient of the weight element 9. From the output of the weight element 9, the input signal + noise mixture of the corresponding diversity channel with the corresponding weight In this case, in the proposed device, the weight coefficients of the optimal addition are determined not by the noise level in a narrow band, but by the signal-to-noise ratio in the entire radiotelephone signal band, which ensures that the radiotelephone signals are close to the optimum This, in turn, makes it possible to obtain a near-optimal signal / noise ratio at the output of the device.

Claims (2)

1. DEVICE FOR ADDITION OF DIVERSE RADIOTELEPHONE SIGNALS, comprising an N-input adder and N diversity branches, the output of each of which is connected to the corresponding input of the N-input output adder, each diversity branch contains a weight element, the output of which is the output of the corresponding diversity branch, an input amplifier with automatic gain control and a weighting factor forming unit, the output of which is connected to the input of setting the weight of the weighting element, characterized in that, in order to increase the ratio s drove // noise at the output of the device, a clock generator is introduced into it, the output of which is connected to the clock inputs of the weighting factor forming units, and a noise generator, the output of which is connected to additional inputs of the weighting factor forming units, in each diversity branch the output of the input amplifier with automatic adjustment gain is connected to the input of the weight element and the input of the block forming the weight factor. 2. The device according to π. 1, characterized in that the weighting factor forming unit comprises a series-controlled attenuator connected in series, the input of which is an additional input of the weighting factor forming unit, a quadrator and integrator, the output of which is the output of the weighting factor forming unit, an adder connected in series, the first input of which is connected to the input of the unit the formation of a weight factor, and the second input is connected to the output controlled by the attenuator, the pulse shaper, the first element And, the first counter, the first AND-NOT element, the output of which is connected to another input of the first AND element, the second AND-NOT element, trigger g ger, the second AND element, the other input of which is connected to the clock input of the weighting factor forming unit, and a reversible counter, the output of which connected to a control input of a controlled attenuator, connected in series with a third AND element, input: of which is connected to a clock input of a weighting factor forming unit, a second counter, a third AND-NOT element, the output of which is connected to another input of a third AND element, first the element is NOT and the fourth element is AND, the other input of which is connected to the clock input of the unit for forming the weighting factor, and the output is connected to the other input of the reverse counter, connected in series to the third counter, the input of which is connected to the clock input of the unit for forming the weighting factor, and the installation input is connected to the output of the second AND-NOT element, and the second element NOT, the output of which is connected to another trigger input, a delay element, the input of which is connected to the clock input of the weighting factor forming unit, and the output to the installation the input of the first counter, the third element is NOT, the input of which is connected to the clock input of the unit for forming the weight factor, and the output is connected to the other input of the second, the AND element, the fourth element is NOT, the input of which is connected to the trigger output, and the output with the installation input of the second counter h