The receiver phase-shift keyed signals in conditions of interference

 

The device relates to the field of radio engineering and can be used for receiving information via the communication channels. The proposed device comprises a mixer 1, the intermediate frequency amplifier 2, the correlator 3, a demodulator 4, a receiver 5, an oscillator 6, a generator of reference signals 7 and synchronizer 8. In such a receiving device in the presence of interference sharply decreases the noise immunity of the received signal. Introduction functional Converter 9, performing the operation f(x)=1/(1-x), helped greatly to improve the noise immunity of the received signal. 5 Il.

The device relates to the field of radio engineering and can be used for receiving information via the communication channels.

Known preset receiving device is constructed on the basis of agreed filters or multi-channel correlators. The search signal in such devices commensurate with the period used binary sequence.

However, to implement such receptors at the large bases of the signal is extremely complex (see Alekseev, A. I., Sheremetiev A. G., Aces, I., Glazov B. I. Theory and application of pseudorandom signals. - M.: Nauka, 1969).

A disadvantage of this device is that in the presence of the input structural interference sharply decreases the noise immunity with respect to the received useful signal, and at a sufficiently large level of this interference occurs in a breakdown of communication.

The closest to the technical nature of the claimed object is a receiver with photomanipulating pseudonoise signal, given in the book Varakin L. E. communication Systems with noise-like signals. - M.: Radio and communication, 1985, S. 18, Fig. 1.9 b adopted for the prototype.

Functional diagram of the device of the prototype is shown in Fig.1, where we have introduced the following notation: 1 - mixer; 2 - intermediate frequency amplifier (if amplifier); 3 - correlator; 4 - demodulator; 5 - the recipient of the information; 6 - lo; 7 - generator of reference signals; 8 - synchronizer; 9 - receiving antenna.

The device prototype has the following functional relationships: connected in series mixer 1, the first signal input of which is connected to the receiving antenna 10, an intermediate frequency amplifier 2, the correlator 3, a demodulator 4 and Pol the local oscillator 6 is connected with the second, heterodyne input of the mixer 1, the second output of the synchronizer 8 is connected with a synchronizing generator input reference signal 7, the output of which is connected to the second reference input of the correlator 3, a third clock input connected to the second clock input of the demodulator 4 and the third output of the synchronizer 8.

The device prototype works as follows.

The received signal at the first signal input of the mixer 1, the second reference input signal from a local oscillator 6. At the output of the mixer 1, thus, there is a signal at the intermediate frequency, and after amplification to the required size in the intermediate frequency amplifier (if amplifier) 2 signal is supplied to the correlator 3. In the correlator 3, which consists of a multiplier and integrator, is optimal signal processing, providing high noise immunity receive information. Second, the reference input of the correlator 3 is fed a reference signal generator reference signal 7 in the form of FM PSS. The voltage output from the correlator 3 is supplied to the synchronizer 8 and the demodulator 4.

The synchronizer 8 searches photomanipulating signal frequency, which sweeps the frequency of the local oscillator 6 and the mode in synchronism at the output of the correlator 3 is the voltage telephone messages in the form of a PWM signal (pulse-width modulation), served on the first input of the demodulator 4. From the output of the demodulator 4 information signal to the telephone message is transmitted to the receiver 5. The synchronizer 8, in addition to the above local oscillator 6 and the oscillator reference signals 7, synchronizes the operation of the correlator 3 and demodulator 4.

But this device has the disadvantage that, when the interference information signal may be unstable sync, and this will lead to failures of the received signal, which, in turn, leads to decrease in the reliability of the received information.

To eliminate this drawback in the receiver phase-shift keyed signals in conditions of interference, containing connected in series mixer, the first signal input of which is connected to the transmitting antenna, the amplifier intermediate frequency and the correlator; connected in series demodulator and the recipient information; sequentially connected to the synchronizer and the local oscillator, the output of which is connected to the second reference input of the mixer; in addition, the second output of the synchronizer is connected to the clock generator input reference signals, the output of which is connected to the second reference shadora and the third output of the synchronizer, an input connected to the first signal input of the demodulator, introduced functional Converter, whose input is connected to the output of the correlator and the output function of the Converter is connected to the clock input.

In Fig. 2 shows a functional diagram of the proposed device, where we have introduced the following notation:
1 - mixer;
2 - intermediate frequency amplifier (if amplifier);
3 - correlator;
4 - demodulator;
5 - the recipient of the information;
6 - heterodyne;
7 is a generator of reference signals;
8 - synchronizer;
9 - functional transducer;
10 is a transmitting antenna.

The proposed device has the following functional relationships: connected in series mixer 1, the first signal input of which is connected to the transmitting antenna 10, an intermediate frequency amplifier (if amplifier) 2, the correlator 3, functional Converter 9. the demodulator 4 and the receiver 5; connected in series synchronizer 8 and the local oscillator 6, the output of which is connected to the second heterodyne input of the mixer 1; the second output of the synchronizer 8 is connected with a synchronizing generator input reference signal 7, the output of which is connected to the second reference input correlation the input of the demodulator 4, and the clock input 8 is connected to the first signal input of the demodulator 4.

The proposed device operates as follows.

The received signal at the first signal input of the mixer 1, the second input of which is applied the signal from the local oscillator 6. At the output of the mixer 1, thus, there is a signal at the intermediate frequency. After amplification to the required size in the intermediate frequency amplifier 2 - this signal is applied to the first input of the correlator 3, which consists of a multiplier and integrator, is optimal signal processing, providing high noise immunity receive information. To the second input of the correlator 3 is fed a reference signal generator reference signal 7 in the form of photomanipulating broadband signal (FM PSS). The voltage output from the correlator 3 is supplied to the functional input of the inverter 9.

Functional Converter 9 may be performed as shown in Fig.5, where the following notation:
91 - inverter;
92 - adder;
93 - logarithmic amplifier;
94 - differentiating chain.

Functional Converter 9 includes: sequentially connected inverter 91, the input of which is the kidney 94, the output which is the output function of the Converter 9, and the first input of the adder 92 is the input DC voltage U0.

Functional Converter operates as follows.

The signal S(+) is supplied to the input of the inverter 91, the output of which the signal -8(+) is supplied to the second input of adder 92, the first input of which is applied a constant voltage0. From the output of the adder 92 signal U0-S(+) is fed to the input of the logarithmic amplifier 93, the output of which is In [U0-S(+)] is fed to the input of the differentiating chain 94, the output of which is the output function of the Converter 9, which forms the signal 1/[U0-S(+)].

In the presence of interference at the input of the correlator 3 Central peak of the correlation function forks (Fig.3). Therefore, the synchronization may not occur during the peak of the correlation function, and for "failure", which leads to a sharp deterioration in the noise immunity of the received signal, moreover, that the magnitude of this "failure" will be changed in the process ("to breathe").

In order synchronization has always been on the "peak" of the correlation function, it is proposed after the correlator to use functional Converter, ASU and (Marple ml. C. L. Digital spectral analysis with applications. - M.: Mir, 1990, S. 34-36).

In Fig.3 shows the autocorrelation function at the output of the correlation of the Converter 9.

The voltage output from the functional Converter 9 is supplied to the clock input 8 and the first signal input of the demodulator 4.

The synchronizer 8 searches the FM signal in frequency, which sweeps the frequency of the local oscillator 6 and controls the operation of the generator of reference signals 7 for time search.

After finding and entering into synchronism at the output of the correlator 3 is the voltage telephone messages in the form of a PWM signal (Fig.3), which is input to functional Converter 9, which is a division of mild "peaks" of the autocorrelation (Fig.4).

From the output of the demodulator 4 information signal to the telephone message is given to the receiver 5.

The synchronizer 8, in addition to the above the local oscillator and the oscillator reference signals 7 synchronizes the operation of the correlator 3 and demodulator 4. Thus, when the interference in the device prototype at the output of the correlator 3 Central peak of the correlation function (convolution) forks, which can lead to synchronization for ageme device eliminates this disadvantage. Implementation of functional Converter can be implemented in digital or analog devices.

Other nodes and blocks known and widely reported in the technical literature.


Claims

The receiver phase-shift keyed signals containing connected in series mixer, the first signal input of which is connected to the antenna, the amplifier intermediate frequency and the correlator, connected in series demodulator and receiver, connected in series synchronizer and the local oscillator, the output of which is connected with the second reference input of the mixer, the second output of the synchronizer is connected to the clock input reference signals, the output of which is connected with the second reference input of the correlator, the third clock input connected to the second clock input of the demodulator and the third output of the synchronizer, the input of which is connected to the first signal input of the demodulator, characterized in that the introduced functional Converter performing the operation f(x)=1/(1-x), the input connected to the output of the correlator and the output function of the Converter is connected to the input of synchronization

 

Same patents:

The invention relates to electrical engineering and can be used in communication systems with pseudorandom change the operating frequency

The invention relates to electrical engineering and can be used in communication systems with pseudorandom change the operating frequency

The invention relates to electrical engineering and can be used in communication systems with pseudorandom change the operating frequency

The invention relates to electrical engineering and can be used in communication systems with pseudorandom change the operating frequency

The invention relates to electrical engineering and can be used in communication systems with pseudorandom change the operating frequency

The invention relates to radio communications and can find application in communication systems with broadband signals

The invention relates to radio navigation, radar and communication systems discrete data using pseudonoise signals based on a pseudo-random sequence with the phase (0,) modulation, and can be used to reduce the search time of the signal in the process of entering into synchronism

The invention relates to a method and apparatus for issuing a clock signal to a device for separating signal and the clock signal frequency agreed with a synchronizing signal encoding device

The invention relates to the processing of pulse signals generated in the form of a pseudo-random binary sequence (SRP)

The invention relates to automation and computer engineering and can be used in radio communication systems with noise-like signals

The invention relates to the field of radio and can be used to improve structural secrecy of signals in noise-immune systems

The invention relates to electrical engineering and can be used in the transmission systems of discrete data to form a signal with continuous phase modulation

The invention relates to electrical engineering and can be advantageously used to generate a signal with continuous phase modulation in communication systems discrete information

The invention relates to the field of radio and can be used in communication systems operating under conditions of uncertain interference

The invention relates to communication technology and can be used in systems with a code multiplexing of signals in satellite communications

FIELD: automatic data acquisition systems.

SUBSTANCE: proposed method designed for data acquisition from burglar and fire alarm sensors, electricity, heat, and gas meters, and from fiscal memory of cash registers involves use of unique random or pseudorandom plurality of differences in initial phases of closest harmonic pairs, mentioned plurality being chosen so as to minimize peak factor of total signal. In case of operation of fire alarm sensor it is sufficient to transfer only one character to alarm control console unambiguously identifying location of operating sensor; as a rule, such character is conditional number or address pre-assigned to sensor.

EFFECT: reduced power requirement of subordinate system units and/or enhanced range of their operation.

1 cl, 2 dwg

Up!