SU930700A1 - Broadband communication system - Google Patents

Description

I

The invention relates to radio engineering and is used in information transmission systems susceptible to interference.

A wideband communication system is known, comprising on the transmitting side a signal generating unit and an output matching unit, the output of which is connected to the antenna, and on the receiving side two antennas, which are connected respectively to the inputs of the first and second receiving units, the output of the first receiving unit being connected to one input of the adder, the other inputs of which are connected to the outputs of the controller unit, the signal inputs of which are connected to the outputs of the second receiving unit and the inputs of the correlator whose outputs are connected the control inputs of the regulators block, and an adder output connected to an input of the demodulator and the first input of a comparison unit, an output

which is connected to the corresponding input of the correlator

However, the known system has low noise immunity.

The purpose of the invention is to improve noise immunity.

The goal is achieved by the fact that the system, a broadband connection, contains on the transmitting side a signal conditioning unit and an output matching unit, the output of which is connected to the antenna, and on the receiving side two antennas, which are connected respectively to the inputs of the first and second receiver units, with the output of the first receiver unit connected to one input, the adder, the OTHER inputs of which are connected to the outputs of the controller unit, the signal inputs of which are connected to the outputs of the second receiving unit and inputs the switch, the outputs of which are connected to the control inputs of the control unit, and the output of the adder are connected to the input of the demodulator and to the first input of the comparison unit, the output of which is connected to the corresponding input of the correlator, are entered on the transmitting side of the comparison unit and serially connected generator pilot - the drive, control amplifier and adder, the second input of which is connected to the output of the signal conditioning unit and to the first input of the comparison unit j whose output is connected to the control input of the control amplifier, od is connected to the second input of the comparing unit, wherein sumiatora output is connected to the input of an output matching block and Art .On receiving Rhone administered sequentially connected nye bandpass filter, a phase shifter

and an amplifier, the output of which is connected to the first receiving unit AND, which is at the second input of the comparison unit, at. provides reinforcement voltage. In this case, the output of the adder is connected to the input-high frequency, the conversion to: the home of a bandpass filter. The intermediate frequency using a straight line. The drawing shows a structural electrode not shown in the drawing, the amplification scheme of the proposed system. intermediate frequency. With the broadband communication system, on the transmitting side, 1 signal generating unit, adder 3 comparison unit k, output matching unit 5, antenna 6, control amplifier 7 and pilot generator 8, and on receiving side 9 two antennas 10 and 11, adder 12, the demodulator 13, the first and second receiving units I and 15, respectively, the correlator 1b, the regulator unit 17, the comparison unit 18, the band-pass filter 19, the phase shifter 20, and the amplifier 21. The broadband communication system works as follows. Voltage from block 2

The signal on the transmitting side 1 goes to the first inputs of the adder 3 and the comparison block k. The narrowband pilot signal from the generator 8 through the regulating amplifier 7 is fed to the second inputs of the adder 3 and the block 4. The block k provides a comparison of the ratio of the power levels of the useful value of a given value of U. If this ratio is different from the GP, block k generates a control voltage that changes the gain of regulating amplifier 7. It provides such a change in the level of the pilot signal that the ratio of the power levels in block k approaches the specified value m. Upon reaching the wound components of the voltage, they go to the corresponding inputs of the correlator 16 and the block 17 of the regulators. Regulators of block 17 provide for changing the levels of quadrature voltage components in accordance with the established transmission coefficients. The values of the transmission coefficients are determined by the values of the control voltages P / P2 III and the formation of the output signal of the block k is stopped. Due to this, the ratio of the power of the useful and the pilot-s of the drive at the inputs of the adder 3 is maintained equal to the C output of the adder 3 is an additive mixture of signals U (t) and 2 (t) i, where) is the voltage of the useful signal, U2 (t) is the voltage of the pilot signal , through the output matching unit 5 (performing, if necessary, frequency conversion, and also power amplification) enters the antenna 6. The additive mixture of signals and interference Ui (t) U2 (t) U3 (t), where) - for example interference is fed to two antennas 10 and 11, on the receiving side 9. The voltage from the antenna 10 enters during the first reception a lot of block Ik, the intermediate frequency voltage is fed to the first input of the adder 12. From the antenna 11, the voltage is supplied to the second receiving unit 15, which amplifies the high frequency voltage, converts (using the aforementioned heterodyne) to the same intermediate frequency as in the first receiving unit 1t, the intermediate gain and the intermediate frequency voltage splitting using a phase shifter (not shown) into quadrature components (in-phase and orthogonal). From the output of the second receiving unit, 15 quadratures at the input of the block 17 regulators. The adder 12 compensates for the noise by adding the voltage of the main channel and compensating the voltage from the output of the block 17. The voltage from the output of the adder 12 u (t) (t) f U (t), where) is the residual interference voltage, demodulated demodulator 13.

The control voltages of the controller 17 of the block 17 are formed from the output voltage of the adder 12 as follows. The bandpass filter 19 separates the pilot signal U2 (t) from the output signal of the adder 12, as well as the components of the useful signal voltage uU (t) and the residual interference voltage AU3 {t) corresponding to the filter bandwidth.

Phaser 20 compensates for the phase shift between the pilot signal voltages at the output of the bandpass field 19 and the voltage at the output of the amplifier 21, Voltage, U2 (t) D and | | (t) 4-ilJj (t) after amplification in the amplifier 21 with the transmission coefficient K-1 + Shp comes to the second input of the unit 18 of the comparison. Block 18 subtracts this voltage from the output voltage of the adder 12. From the output of block 18, the voltage LUi (t) -kuU, (t) (1-k) U2 (t) -i-Ua (t) -k & U (t) is fed to the third input of the correlator 16. At the output of the multipliers | (the drawing does not show the correlator 16, control voltages are formed, which are relative to the correlation functions of the common-mode and orthogonal components of the second block 15 and the voltage from the output of the comparison block 18. Since the voltages Uf (t), UgCt) and UjXt) are not correlated with each other, the control voltage voltage at the output of the I-channel correlator 16 is given. /

(i) -kuU t klUg | tUU3il -k & Usifcl

i4uat) .i -kai} i) .u, (i) 4

 ljjcHjj () U3 {i) -k & U3 (il

ujtt vn-uiu (t; uuM-u7it).

The control voltage at the output of the orthogonal channel of the correlator has a similar form. 16. The components of the voltage K & U (t) Ujt (t), K & U (t) U3 (t) are negligible because of the narrowband band-pass filter 19. Since the gain K of effort 1 body 21 is equal to {4-y | 4th-

T: U | tt1

then in the output voltage

16, the component of the mutual correlation function of the pilot signal is formed, opposite in sign and equal in magnitude to the component of the mutual correlation function of the useful signal, as a result of which the total mutual correlation function of the signal and the pilot signal is 0. At the outputs of the multipliers of the correlator of the 1b, control voltage components due to mutual correlation of interference in the primary and secondary channels. When the interference parameters in the main channel change, the voltage level from the outputs of the correlator 16 changes. This leads to a corresponding change in the transmission coefficients of the controllers of block 17, and, consequently, to a change in the quadrature components of the compensating voltage. Since there is no component in the voltage supplied to the cus- ing power inputs of the controllers of block 17, due to the presence of a useful signal in the receiver, the degree of noise compensation 6 of the adder 12 does not change at for-. or the absence of a useful signal. . . .

Thus, the introduction on the transmitting side of the system of a broadband connection of the pilot signal generator, as well as the comparator unit and the control amplifier, ensuring the constancy of the power ratio of the useful and pilot signals, as well as the introduction of a bandpass filter, a phase shifter and an amplifier, to the receiving side the gain factor allows independence of the degree of compensation of interference from the presence of -be; This is a useful signal in a broadband communication system and thus ensures a positive effect - to increase noise immunity.

Claims (1)

Invention Formula A broadband communication system comprising, on the transmitting side, a signal conditioning unit and an output matching unit, the output of which is connected to the antenna, and on the receiving side two antennas, which are connected respectively to the inputs of the first and second receiving units, the output of the first receiving unit being connected to one the adder's input, the other inputs of which are connected to the outputs of the regulator unit, the signal inputs of which are connected to the outputs of the second receiving unit and the inputs of the correlator whose outputs are connected to the control they block inputs regulators. 7 9 pL output of the adder is connected to the Lemodulator input and to the first input of the comparator unit, the output of which is connected to the corresponding input of the correlator, differently so that, in order to reduce the noise immunity, the comparator unit connected in series to the generator and connected in series the pilot generator a signal, a control amplifier and an adder, the second input of which is connected to the output of the signal conditioning unit and to the first input of the comparison unit, the output of which is connected to the control input of the control amplifier whose output is Connected to the second input 0 of the comparison unit, the output of the adder is connected to the input of the output matching unit, and on the receiving side serially connected band-pass filter, phase shifter and amplifier, whose output is connected to the second input of the comparator, are inserted, the output of the adder is connected to the input of the band-pass filter. information taken into account during the examination 1. Compton R.T. Adaptive antenna array in the TIIER broadband communication system, Vol. 66, No. 3, 1978 (prototype).  J