SU1376264A1 - Frequency- and phase-manipulated signal transmitter - Google Patents

Abstract

This invention relates to communications. The purpose of the invention is to improve noise immunity. The device contains detector filters 3 and 5, phase detectors 4 and 6, channel separation unit 7, local oscillator 8. Mixer 1, band-pass filter (PF) 2, two frequency multipliers 9 and 14, two dividers frequencies 10 and 13, adder 11, narrowband filter (UV) 12. PF 2 filters out oscillations with frequencies: and when Ugy arrives with frequency co, and 2 a co when Ug arrives with frequency 2. Transfer the frequency of the input signal to frequencies and co and 2 liters co allows the simplest method to obtain reference voltages (OH). Frequency multipliers 9 and 14, adder 11, UV 12, frequency dividers 10 and 13 are used to create the OH. The device allows coherent integrated signal reception, thereby having high noise immunity. 1 il. i O)

Description

I

SAE 1

The invention relates to communications and can be used to receive signals modulated simultaneously in frequency and phase.

The purpose of the invention is improving noise immunity.

The drawing shows a structural electrical circuit of the device.

The device contains a mixer 1, a bandpass filter 2, a first notch filter 3, a first phase detector 4, a second notch filter 5, a second phase detector 6, a channel separation unit 7, a local oscillator 8, a first frequency multiplier 9, the first divider 10 frequency, adder 11, narrow-band filter 12, the second frequency divider 13, the second frequency multiplier 14 and the clock generator 15.

The device works as follows.

Let the input signal to the receiver input

 ,

Ug and cos (Q; t ± y),

where i 1,2,

acOr-uj uco.

This signal is fed to the input of the mixer 1, the reference input of which receives the voltage of the local oscillator 8, the frequency of which is selected so that COf- (-0, -UCO. The band-pass filter 2 filters out the oscillations with the frequency U CO when the input signal U. comes with frequency Q,, and with a frequency of 2 UCO when arriving with a frequency of cOj. Thus, at the output of the band-pass filter 2 there are phase-shift-manipulated oscillations of the following type:, U cos (iCiC.5 ±

L

+ -), where i 1,2, For such a Transformation of Ug to, you can use a mixer, a local oscillator and a bandpass filter, which are part of the intermediate path of the radio receiver.

Let the signal with frequency oz, act at the receiver input. Then ipf

 and cos (fvto + y). This signal is the first

notch filter 3 is passed, and the second notch filter 5 is not passed. The first phase detector 4 determines the phase of the signal, for which the voltage from the second frequency divider 13, which has frequency M, is supplied to its supporting input.

Similarly, demodulation occurs when entering with a frequency of co,.

Then both „and cos (2uw + j), which is passed only by the second notch filter 5 and, therefore, there will be no signal at the output of the first phase detector 4. The reference input of the second phase detector 6 receives the reference voltage from the output of the first frequency divider 10, having a frequency of 2iu.

Transferring the frequency of the input signal to frequencies й со and 2 ps allows the simplest way to obtain reference voltages. The first 9 and second 14 frequency multipliers, adder 11, narrowband filter 12, the first 10 and second 13 frequency dividers are used to create the reference voltages.

To remove the FM, in the first multiplier 9 frequency, the frequency 603 is multiplied by 2, and in the second multiplier 14 frequency - by 4. Let

and „and co-±). At the output of the first y Y-frequency 9, we have U, -, - and cos (2uCO tTT). At the output of the second frequency multiplier 14, we have U - and cos (2Т). At the output of the adder 11, we have the sum of unmodulated oscillations

and, - and cos 2uW + and cos 4uQ.

Using a narrow-band filter 12, filter the oscillation} w with a frequency of 4 ° CO-if and cos 4uG). If at the output of the bandpass filter 2 we have a signal with a frequency of 2O, then at the output of the adder 11 we have Uj and cos 4bco + U cos 8uCO. Using a narrowband filter 12, oscillations with a frequency of 4 ° are also filtered out. Thus, at the output of the narrowband filter 12, regardless of the frequency of the input signal C0 (or 7, there will be oscillations with a frequency of 4AO.

At the output of the first frequency divider 10, we receive a signal with a frequency of 2LSO, which is fed to the reference input of the second phase detector 6 and to the input of the second frequency divider 13. The reference input of the first phase detector 4 receives a signal with a frequency of Li. The decision on the frequency and phase of the input signal is made in block 7 of channel separation.

Upon receipt of the input signal with a frequency co, at the output of the first phase detector 4 we have the voltage

 sin (± -y), while the voltage at the output of the second phase detector 6 is absent, i.e. Pf.

By the sign of the voltage U (,

fz

Jm, the phase of the input signal is determined, and based on the result of the comparison U, and Ua, it is decided that a signal with the frequency с, is present at the device input.

In the case of an input signal with frequency

and, -0, and

Tg

and sin (±).

Based on the sign of the voltage and, the phase of the input signal is determined, and the result of the comparison between uL and Um makes a decision that the frequency of the input signal is CO.

Thus, if, as a result of equal to f and the signal modules, it turns out that | U (p, l) ,, then it is decided that the input signal has

frequency of co, and if

| and „

that

/ and - til

it is decided that the input signal has a frequency cj

The proposed device allows coherent integrated signal reception, thereby having a high noise immunity.

Claims (1)

Invention Formula A device for receiving signals modulated in frequency and phase, containing a local oscillator and a clock oscillator, as well as the first and second rejector filters, whose inputs are combined, and the outputs are connected to the signal inputs of the first and the second phase detectors, the outputs of which are connected to the signal inputs of the channel separation unit, are t that, in order to increase the noise immunity, A first frequency multiplier, a serially connected mixer and a KGS filter, a second unposh.- frequency band, an adder, a narrowband the filter, the first frequency divider and the second frequency divider, the output of which is connected to the reference input of the first phase detector, the output r of the homeland is connected to the reference input mixer, the output of the bandpass filter is connected to the inputs of the first notch filter, the second corner of the frequency and the first frequency multiplier, the output of which is connected to the second the input of the adder, the output of the first frequency divider is connected to the reference input of the second phase detector, and the output of the clock generator to the clock input of the channel separation unit.