The communication device

 

(57) Abstract:

The invention relates to telecommunications, and is intended for the transmission of discrete information with a noise-like signals. The communication device includes a transmitting-side oscillator, forming a short videospussy that the modulator to change the polarity depending on the sign of the transmitted message source message, and the shaper is a pseudo-random sequence of pulses (SRP) and transmitting a broadband antenna, and at the receiving side receiving broadband antenna, which through a broadband amplifier is connected to the input of the matched filter, and a demodulator, the output of which is connected to the output unit, and a system of tracking and synchronization (CCC), on the transmission side shaper SRP is made in the form of a matched filter, containing a system of parallel delay lines of different lengths, with the length of each delay line corresponds to the temporal position of the elements of the SRP, which are connected through the inverter, the corresponding landmark pattern SRP, to the multi-input adder, the output of which through the filter connected to a transmitting broadband antenna, and the admissions of the parties to the od switch is connected to the input of the demodulator, moreover, the CCC made in the form of delay lines, the input of which is connected to the output of the adder, a first inlet through which the rectifier is connected to the output of the matched filter, the second output of the broadband amplifier CCC, and the output of the delay line is connected to the input of the broadband amplifier CCC and through the threshold block to the second input of the switch. 3 Il.

The group claimed invention relates to telecommunications and is designed for transmission of discrete information with a noise-like signals.

The number of known methods and devices for communication based on the use of signals with the extension of the spectrum, having a name like noise [1]. A common feature is optimal reception based on the correlation processing of the received signal and interference with a copy of the expected signal. Various implementations of this method should determine all the features of the structural scheme of the devices and subsystems.

There is a method implemented in the "ultra-wideband communication system" [2] was chosen as a prototype. In this way the quality of the signal applied pseudonoise signal representing a sequence of short videokursov large duty cycle with time-pulse modulation, ODA tracking synchronization and search ensures compliance with the time parameters of the received and reference signals.

The communication method in the prototype has a disadvantage associated with the selected structure of the signal representing the sequence of videokursov small duration with a large duty cycle and time-pulse modulation. This signal has a significant peak power. The second disadvantage is the chosen method of implementation of best practice based on the correlation processing. With a large database of signal search with high reliability detection may take a long time and lead to slow and less efficient, as it requires a lengthy process of entering into a relationship. Methods of accelerating the search latency one way or another lead to lower noise immunity and secrecy.

The expected technical result of the proposed solution is to increase the noise immunity, energy and structural secrecy signals in the communication channel.

The technical result is achieved by forming on the transmission side of broadband noise-like signal representing a continuous sequence of short VideoIn and/or temporary position of its constituent pulses. At the receiving side shall receive a mixture of signal interference and, after processing the received signal, a decision about the transmitted message. Signal processing on the transmission side and the signal processing at the receiving side is performed by the method of matched filtering. Reducing the duty cycle and alternation of the signs of videokursov signal approximates the signal parameters to broadband noise, increases energy and structural secrecy signal by reducing peak power and improve measures pseudolocality in the structure of the signal.

The communication method based on the use of noise-like signals in the form of a continuous sequence of videokursov different polarity duration of 0.1-1.0 NS, from which is formed a pseudo-random sequence. The baud rate is determined by the code length and the pulse repetition rate and can reach 100 Mbps at low spectral power density of the signal, complicating detection and provides high noise immunity. In this way there is the possibility of achieving theoretical maximum speed of transmission of information using electromagnetic waves, up to 10 Gbit/s in terms of the earth and is egovernance, corresponding to one bit of the message, change the signs on the opposite. Such pulses are emitted directly broadband antenna without the use of a modulated carrier. Implementation of the scheme for the optimal reception based on optimal filtering. Thus the received signal with interference is processed in the filter, consistent with a pseudo-random sequence, the output of which by the end of the binary message is formed by a quantity proportional to the integral of the convolution of a mixture of signal and noise with a copy of the pseudorandom sequence signal. The selection of clock pulses defining moments of the end of the signal provided by the synchronization system based on the averaging of a large sample volume and is a filter that generates a periodic sequence of the rectified signal at the output of the matched filter.

The known device [2], we have made a prototype, consists of a broadband transmitting antenna, forming lines are directly connected to the antenna circuit, a master pulse generator and modulator, determining the time-pulse modulation in accordance with the state of the source messages. At the receiving side adopted the, and solver demodulator, which is simultaneously output unit decides the character of the sent message. In the tracking system and synchronize the signal of detuning, managing through the feedback circuit parameters of the pulse generator reference signal. Tracking system relative temporal position of the transmitted and reference signals produces a signal detuning, managing parameters of the master oscillator pulse reference signal.

In the framework implemented in the known device [2] communication method lies correlation processing of the received signal. This leads to the need at the receiving side of the system monitoring parameters of the received signal, which should contain frequency-dependent feedback circuit. Such schemes have limited swath and retention, and overcoming contradictions between the parameters of the discriminator and the feedback circuit complicates the tracking system and reduces the potential for noise immunity.

Such systems have a low resistance by changing the position of the receiver and transmitter, which excludes the possibility of using the device on a mobile object, in addition to t the tat of the proposed use of communication devices is to simplify circuit design and reduce the influence of the deviation of the system parameters, including by changing the position of the receiver and transmitter, for example when mounted on mobile objects, reliability and noise immunity of the reception.

This technical result in the implementation of the claimed device is achieved by the fact that the basis of the signal in the transmitter and the realization of potential noise on the receiving side put a coherent filter based on a system of electrical delay lines. Signal compression in a consistent filter is implemented in the system of parallel delay lines and the multi-input adder. The use of matched filter eliminates the search procedure and makes the system preset, which is especially effective in a batch mode. System synchronization and detection provides a selection of clock pulses by accumulation of the rectified signal at the output of the matched filter.

The proposed communication device includes transmitting and receiving broadband antennas. On the transmission side contains also specifies the pulse generator and modulator, and at the receiving - tracking system and the synchronization of the demodulator and an output unit. The proposed device is different from the known fact that it is mutation at the receiving side, the system of tracking and synchronization is made in the form of delay lines, the input of which is connected to the output of the adder, a first inlet through which the rectifier is connected to the output of the matched filter. The second input of the adder coupled to the output of the broadband amplifier. The output of the delay line is connected to the input of the broadband amplifier and through the threshold block to the second input of the switch. Agreed filters made on the basis of a system of delay lines connected through inverters to the multi-input adder, the output of which through a filter attached on the transmission side for transmitting a broadband antenna. The structure of the matched filter that is installed at the receiving side, similar to that installed on the transmission side, and paired with him. At the receiving side, the output of a broadband receiving antenna through a broadband amplifier is connected to the input of the matched filter, and its output connected to the first input of the switch and to the input of the tracking and synchronization. The output of the switch via a demodulator connected to the output block.

Fig 1 shows the block diagram of the transmitting part of the system. The common structural element of a transmitter and a receiver - consistent filte the claimed method, consists of transmitting and receiving parts. Part of the transmitting part, block diagram, which is shown in Fig. 1, includes a broadband antenna 1, for example discolora, consistent filter 2, a modulator 3, the message source 4 and sets the pulse generator 5. In Fig.2 shows a diagram of the matched filter transmitting device containing a system of parallel delay lines 6 different lengths, the length of each delay line corresponds to the temporal position of the elements of the pseudo-random sequence. Inverters 7 correspond to the sign pattern of pseudo-random sequence signal. The composition of the matched filter includes a multi-input adder 8, which is the sum of the signals from the outputs of the inverters 7 and filter 9 that specifies the desired shape of the video impulse. In the scheme of the receiver (Fig.3) includes a broadband antenna 10, a broadband amplifier 11, a coherent filter 12, a conjugate is transmitted, the switch 13, the demodulator 14 and the output unit 15. The switch is controlled by clock pulses generated in the tracking system and synchronization, consisting of a rectifier 16, adder 17, line zadarski 18, broadband amplifier 19 in the feedback circuit and the threshold of the block 20. moptophaha signal and is equal to the maximum delay in a consistent filter.

The communication device operates as follows: in the master oscillator 5 transmitting device form a short videospussy that the modulator 3 change the polarity depending on the sign of the transmitted message source of the message 4. The generated sequence of pulses with a transmission rate fed to the input of the matched filter 2. Each pulse in the system of delay lines 6, made for example on the basis of lengths of coaxial cable, is delayed by the time corresponding to the temporal position of the signal in a pseudo-random sequence, change the sign of the inverter 7 in accordance with the iconic pattern and after a multi-input adder 8 is transformed into a pseudo-random sequence with the desired sign and temporal structure. The final shape of each pulse is determined by the output filter 9. Thus formed a pseudo-random sequence of pulses required forms comes to broadband antenna 1 and is radiated in the air.

In the receiving part of the device (agg. 3) signal, adopted broadband receiving antenna 10 receives the necessary gain broadband amplifier 11 and fed to the input of an agreed Phil is ve, the main difference is that the sign pattern of the inverter 8 is paired transmitted, i.e. the desired alternation of characters starts from the lines with the largest time delay, whereas in sending a consistent filter this sequence starts from the line with the lowest latency. When the described pair of significant patterns in the adder matched filter receiver to the end of the pseudorandom sequence is the addition of one character elements of the signal and is implemented compression of complex pseudonoise signal. Filtering completed in the filter 9, the impulse response is consistent with the element signal in the sense that its amplitude-frequency response has the same form as the phase-frequency inverted and shifted by the duration element signal. This condition is necessary in the scheme of realization of optimum reception on the background noise in the form of white noise during the implementation of the method of matched filtering.

The switch 13 connects the output of the matched filter 12 to the demodulator 14 in moments the end of the compression process pseudonoise signal and is controlled by the pulses of the tracking and synchronization. In the demodulator 14 Khujand is determined by the sign of the transmitted message. This eliminates the uncertainty of the polarity of the pulses, and the decision to sign the message is received based on the relative polarities of the two following assumptions. Such functions can be implemented using known devices used, for example, in systems relative phase telegraphy. The output unit 15 carries out the pairing between the demodulator and the input device of the user and can be performed, for example, in the form of a serial port.

As the main host system tracking and synchronization, providing a selection of clock pulses, use the drive-recirculator recursive type. When this signal-to-noise ratio in the system of accumulation increases, and the decision to end the signal is based on a statistical sampling of a large volume. Synchronization system works as follows: rectified in the rectifier 16, the outputs of the matched filter 12 is folded detained for the duration of the message value. This node is a filter consistent with a periodic sequence, and the signal-to-noise ratio in steady state is improved in accordance with the gain of the amplifier 19. A connection must be less than unity. Near threshold produces the largest value of the gain in signal-to-noise ratio at the output of the drive. The same site can be used to form the voltage gain is automatically adjusted according to the level of the useful signal. Synchronization system performs the accumulation of the rectified signal at the output of the adder 17. Filtered periodic sequence is fed to a threshold device 20 forming the gate pulses for the switch 13. In the applied method, exponential weighting observations representing sample values included in the assessment with the weights decreasing with age data. This method has the advantage in respect of the implementation compared to, for example, with the method of moving average, in the latter case, the required filter length impulse response equal to the time averaging, and the corresponding delay line of great length.

Claimed in the invention, the communication method is intended for transmission of discrete information and has certain advantages in comparison with known solutions. The use of noise-like signals with low duty cycle and a pseudo-random sign-amplitude structure increases energy and structuro the s nodes with a frequency corresponding width and is based on a simple circuit designs. There is no need significant strengthening in the path of the transmitting device, since the radiated power is provided by increasing the energy of the pulse oscillator having a relatively large duty cycle. The use of electrical delay lines in a consistent filter reduces high demands on the stability of temporal parameters.

Literature:

1. Dixon R. C., Spread spectrum systems with commercial applications. John Wiley & sons. Inc. 1994.-573 R.

2. U.S. patent 5363108, CL 342/27, publ. 1994 (prototype).

Communication device, containing on the transmission side sets a pulse generator that generates a short videospussy that the modulator to change the polarity depending on the sign of the transmitted message source of the message, the generated sequence of videokursov arrives at the shaper pseudo-random sequence of pulses (SRP), which is supplied to the transmitting broadband antenna, and at the receiving side receiving broadband antenna, the output of which is through a broadband amplifier is connected to the input of the matched filter, and a demodulator, the output of which is connected to the output unit, and a system of tracking and synchronization (CCC) than the parallel delay lines of different lengths, with the length of each delay line corresponds to the temporal position of the elements of the SRP, which are connected through the inverter, the corresponding landmark pattern SRP, to the multi-input adder, the output of which through the filter connected to a transmitting broadband antenna, and at the receiving side entered the switch, the output of the matched filter connected to the first input of the switch and to the input of the CCC, the output switch is connected to the input of the demodulator, and CAS made in the form of delay lines, the input of which is connected to the output of the adder, a first inlet through which the rectifier is connected to the output of the matched filter, the second output of the broadband amplifier CCC, and the output of the delay line is connected to the input of the broadband amplifier CCC and through the threshold block to the second input of the switch.

 

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