RU2308160C2 - Communication system with broadband signals - Google Patents

Abstract

FIELD: radio communications, possible use for transferring information by noise-like signals.

SUBSTANCE: in the communication system, introduced to each one of (n+1), where n≥2, radio station, are searching block, delay memory block for n positions, detection block, time intervals block, block for synchronization of system of client number i. Searching block consists of n serially connected key and block of optimal synchronization signal finder, inputs of keys are connected to corresponding inputs of high frequency radio route and system synchronization block, which opens one key at each length of time, outputs of keys being connected to corresponding inputs of n optimal synchronization signal detectors, outputs of which are connected to corresponding inputs of delay memory block with n positions, and detection block comprises n blocks for optimal signal selection, each one of which is adjusted for receipt of signal from corresponding radio station, output of each one of n optimal signal selection blocks is connected to corresponding control input of the block for optimal selection of information signal.

EFFECT: reduced system synchronization time, provision of channel for communication without delay.

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Description

The invention relates to the field of radio communications and can be used to transmit information by noise-like signals. Similar systems are described in the literature:

1. Noise-like signals in information transmission systems. Edited by V.B.Pestryakova. M .: Sov. radio, 1973

2. L.E. Varakin. Communication systems with noise-like signals. M .: Radio and communications, 1985

3. CHESS A NEW Reliable High Speed HF Radio Dr David L Herrik, Dr. Poulk Lee Sanders - Alockhed Martin Company, Nashua, IEEE, 8, 1996.

4. Patent for invention No. 2209511 "Broadband communication system KB range." The inventors Bokk O.F., Makoviy V.A., Adzhemov S.S., Bokk G.O. Registered in the State Register of Inventions of the Russian Federation. Moscow, July 27, 2003

5. Bokk O. F., Kolesnichenko G. D. "Features of communication systems with ShPS." Theory and technique of radio communications. IN 2. 2001, p. 8.

The most detailed principles of the operation of these systems are discussed in the article Bokk O.F., Kolesnichenko GD “Features of communication systems with ShPS” Theory and technique of radio communication. IN 2. 2001, p. 8 and copyright certificate No. 227943 Bokk O.F., Dushchenko N.I., Kolesnichenko G.D.

In these works, the main advantages of radio channels and communication systems with a broadband carrier are shown:

- high noise immunity;

- resistance to narrowband and impulse noise;

- secrecy;

- the constancy of the amplitude of the signal and, as a consequence, the high efficiency of the transmitter;

- the ability to work in busy areas of the range.

In addition, they noted the main feature of receiving ShPS - the need for temporary synchronization of the signals of the receiver and transmitter. It can be seen from these works that, for synchronization to occur, a signal search is required in the entire uncertainty region. In [1, 2], signal detection issues are described in great detail, and it is stipulated that they are known in advance: modulating SRP, frequency of the radio signal carrier, or the range in which this frequency is located. But the time of arrival of the signal to the input of the receiver is unknown, because it is determined by the start time of the transmission and the distance between the transmitter and receiver. For this reason, synchronization of broadband signals and, as a result, the synchronization time of the entire system is a key problem.

Synchronization is carried out in two stages:

1) a signal search, in which all possible positions are checked for the presence of a signal, the position of the signal on the time axis is determined up to a correlation interval τ _and ;

2) tuning, providing verification of the presence of a signal and increasing the accuracy of its temporal position to fractions of the correlation interval (τ _and / 4 ÷ τ _and / 8). Carrier frequency allocation.

After synchronization, information can be received, in addition, the signal is constantly or periodically monitored and, in some cases, maintaining synchronism between the carrier frequency of the signal and the copy. As can be seen from the analogs, the synchronization time in the radio channel is large and increases in proportion to the square of the signal base.

Thus, all analogues have a significant drawback: systems have a long synchronization time.

In its most general form, a broadband communication system can be represented as consisting of M subscribers (radio stations) (FIG. 1). On figa, 1b shows the version of the inclusion of M subscribers (radio stations) of a broadband communication system.

On figa presents a special case of the system: the connection of the first subscriber with all others (star). A similar system is considered in the article Bokk O.F., Kolesnichenko GD

On figb shows an example of the functioning of the communication system in the form of a ring. In the process, there are various types of connections of subscribers (radio stations) of the communication system, for this reason there are no restrictions on the type of connection of subscribers.

Closest to the claimed technical solution is the communication system described in patent No. 2209511 "Broadband communication system KB range."

Functional diagram of a communication system is shown in figure 2, where it is indicated:

1, 2, 3 ... M - subscribers of the communication system.

An enlarged functional diagram of subscribers (radio stations) included in the communication system is shown in figure 3, where the following notation is introduced.

1. RF path.

2. The input path of the receiver.

3. Power amplifier.

4. Analog-to-digital converter.

5. Broadband (SHPS) pathogen.

6. Block optimal allocation of information.

7. Optimal detector of a synchronization signal (preamble).

8. Shaper broadband signal synchronization (preamble).

9. Shaper information broadband signal.

10. The block of the central processor.

11. Terminal equipment.

The scheme of subscribers (radio stations), depicted in figure 3, has the following functional relationships.

The prototype contains a serially connected input path of the receiver 2 and an analog-to-digital converter 4, the output of which is connected to the corresponding inputs of the optimal detector of the synchronization signal 7 and the optimal information extraction unit 6, the other input of which is connected to the output of block 7, and the output of block 6 is connected to the corresponding input block of the central processor 10, the first output of which is connected to the corresponding inputs of the drivers of the broadband synchronization signals 8 and information 9. The outputs lei of wideband signals 8 and 9 are connected to respective inputs of PNS exciter 5, the output of which is connected to the input of the power amplifier 3, whose output is connected to the antenna. The second input and output of the block of the Central processor 10 are the input and output of the terminal equipment.

The radio path of RF 1 includes the input path of the receiver 2, analog-to-digital converter 4, power amplifier 3, and BPS exciter 5.

In the block of optimal extraction of the information signal 6 using a parallel spectrum analyzer, two signal detectors, commands are generated for information symbol detectors, which, taking into account synchronization, extract information signals. In fact, in the block, frequency numbers are detected in each jump, according to the frequency numbers of these signals, the decoder, which is part of this block, converts the received information into binary form.

The optimal detection unit for the synchronization signal 7 selects and detects N predetermined frequencies from all available at the output of the input path 2. Then, based on the known, assumed shape of the envelope of the signal, the width of its spectrum, the unit determines the presence of a jump and compares the sequence of frequency jumps with one of preambles, and if they match, the receiving device switches to the mode of information selection. The prototype system works as follows. Each subscriber (radio station) can establish a connection with any other. All subscribers (radio stations) are in receive (search) mode. For simplicity of understanding the operation of the system, we consider the connection between two subscribers (radio stations) g and j, let it be in the simplest case the first and second subscribers (radio stations) of Fig. 2. The connection is as follows. On the one hand, the first subscriber (radio station) g is turned on in the transmission mode, and on the other hand, the second subscriber (radio station) j remains in the reception mode. On the transmission side, terminal equipment 11 requires a connection with a subscriber (radio station) j to transmit information. The ShPS synchronization driver 8 of the subscriber (radio station) g generates, for the necessary time T _C , a synchronization signal for the subscriber (radio station) j, which is transmitted to the ShSS driver 5, and then to the power amplifier 3, which amplifies these oscillations and brings them to the antenna. Thus, the preamble is emitted. To increase the reliability of detection, reduce the likelihood of false alarms, and increase the accuracy of determining the radiation time, the NPS preamble consists of several periodic repetitions of N pulses.

After the preamble is emitted for the time T _C necessary for detecting the preamble (clock signal), at the command of the central processor unit 10, the information SHPS driver 9 starts working, which, in accordance with the transmitted information, generates commands for two frequencies out of N possible, both commands are transmitted to the SHPS exciter 5, which generates harmonic oscillations with predetermined frequencies at the output, forming a two-frequency jump at the input of the power amplifier 3. The two-frequency jump amplified in block 3 is emitted by redstvom antenna. The transmission of information lasts a certain time, for example, as shown in Fig.4. The data includes the address of the subscriber (several subscribers) to whom the transmission is addressed.

If it is not possible to determine the number of the subscriber (radio station) of the transmission source from the preamble, the information source is determined from the received data when they are processed in the unit of the central processor 10, which, in addition, converts the information into the form determined by the terminal equipment 11.

On the receiving side, the second subscriber (radio station) operates as follows.

The radio signal goes to the input of the receiving device j, received by the antenna, amplified, frequency-converted by the input path of the receiver 2, fed to the ADC 4, the output of which is digitally fed to the optimal detector of the synchronization signal 7, one of the channels of which is tuned to the clock signal from the subscriber ( radio stations) g. The synchronization signal is received by the subscriber (radio station) j and according to the signal from block 6 to the block of the central processor 10, which determines that the subscriber (radio station) j is called, the subscriber (radio station) j enters the transmission mode. During the required time T _C, the synchronization signal for the subscriber (radio station) g is generated by the shaper of the broadband synchronization signal 8 and transmitted to the BPS exciter 5, and then to the power amplifier 3 of the subscriber (radio station) j. Thus, the radio signal is emitted by the subscriber (radio station) j.

Once at the input of the subscriber’s receiving device (radio station) g, the radio signal in the input path of receiver 2 is amplified and converted in frequency, digitized in an analog-to-digital converter 4 and fed to the optimal detector of the synchronization signal 7, one of whose channels is tuned to the synchronization signal from the subscriber ( radio stations) j. After receiving a signal from j, the subscriber (radio station) g represents a communication channel for transmitting information.

The detector of the synchronization signal 7 on the basis of the known, assumed shape of the envelope of the signal, the width of its spectrum determines the presence of a jump, and if the sequence of N jumps and one of the preambles in frequency coincide, then the receiving device switches to the information extraction mode.

In the mode of extracting information in block 6, information signals are extracted from the detected signals, taking into account synchronization from the clock detector 7. In fact, the frequency numbers are detected in each jump, according to the frequency numbers of these signals, block 6 converts the received information into binary form and transfers it to the block of the central processor 10. In the block of the central processor 10, the final processing of the received signal occurs: decoding to correct and detect errors , determining the address of the called subscriber (radio station), generating the output information signal in the form necessary for the operation of the terminal equipment, generating signals to indicate the beginning, end communication, quality of the communication channel, etc. In this block, information is processed, in particular, the allocation of overhead information. According to official information, the recipient of information (address), checksums, etc. are established.

Thus, before each information exchange session, synchronization takes place, which requires considerable time. We denote it by 2m _with. Obviously, the time required for synchronization (search) for establishing communication between the second and third subscribers (stations) will also _C 2T, and so forth for the communication between any pair of subscribers (stations) for synchronization costs will 2T _C. Total costs will be

T _CC = T _C C ² _M.

C ² _M is the number of combinations from M to 2. For example, with the number of subscribers (radio stations) M = 50 C ² _M = 50 * 49/2. Thus, the cost of synchronization in the system is significant.

The implementation of the CHESS system blocks is fundamentally known. The receiver linear path, ADC, power amplifier do not even require explanation. It should be noted that in the prototype, according to [3], it is possible to transmit jumps at frequencies that do not necessarily form a comb with a uniform pitch. Considering the strong load of the KB range with powerful radio transmitters, it is advisable to transmit at frequencies free of interference. This solution requires an additional extension of the frequency band of the transmitter and receiver.

Note that in the system taken as a prototype, in addition to significant loss of synchronization time, each communication session between subscribers (radio stations) begins with a search, i.e., firstly, signals for synchronization are emitted for a long time, and secondly, The channel is delayed. If we take into account the multiple calls of subscribers (radio stations), then the time loss for synchronization compared with 2T _With additionally increase.

The disadvantage of the prototype system is a long time to synchronize and search for a signal.

To eliminate this drawback, a broadband signal communication system is proposed, consisting of (n + 1), where n≥2 radio stations, each of which contains an optimal detector of the synchronization signal and a radio frequency path connected in series, an optimal signal extraction unit, a central processor unit, information shapers and synchronization broadband signals, the outputs of which are connected to the corresponding inputs of the RF radio path, the second input and output of the central processor unit are connected with terminal equipment, according to the invention, a search block, a delay memory block for n positions, a detection block, a time slot block, the output of which is connected to the synchronization block of the system of the i-th subscriber, n outputs of which are connected to n inputs of the search block, n are entered into each radio station the outputs of which are connected to the corresponding inputs of the delay memory unit at n positions, n outputs of which are connected to the corresponding inputs of the detection unit, n outputs of which are connected to the optimal signal allocation unit , The radio link RF output coupled to respective inputs of the search blocks and the detection unit transmitter synchronization output of the synchronization system i-th subscriber is connected to the input of the wideband synchronization signal. Moreover, the search unit consists of n series-connected key and the optimal synchronization signal detector unit, the key inputs are connected to the corresponding inputs of the RF radio path and the synchronization unit of the i-th subscriber, the key outputs are connected to the corresponding inputs of the n optimal synchronization signal detectors, the outputs of which are connected to the corresponding the inputs of the delay memory block at n positions.

Functional diagram of the system is presented in figure 2 and figure 5.

Figure 5 is indicated:

1 - RF path.

2 - search block.

3 - input path of the receiver.

4 - analog-to-digital Converter.

5 - power amplifier.

6 - block optimal allocation of the information signal.

7a, 7b, ... 7n is a group of optimal detectors of a synchronization signal (preamble).

8 - shaper broadband signal synchronization (preamble).

9 - shaper information broadband signal.

10 - block of the central processor.

11 - ShPS pathogen.

12 is a detection unit.

13 - terminal equipment.

14a, 14b, ... 14n are blocks of optimal signal isolation with a fixed setting for "their" correspondent.

15a, 15b ... 15n are keys.

16 - block memory delays n positions.

17 - block synchronization system of the i-th subscriber.

18 is a block of time intervals.

The proposed radio station has the following functional connections.

The antenna is connected to the RF path 1, the output of which is connected to the inputs of the block of optimal allocation of the information signal 6 of the search unit 2 and the detection unit 12, the outputs of which are connected to the corresponding inputs of the unit 6, the output of which is connected to the central processor unit 10, the first output of which is connected to the formers information 9 and sync 8 broadband signals, the outputs of which are connected to the corresponding inputs of the BPS of the pathogen 10, the output of which is connected to a power amplifier 5, the output of which is connected to the ant Noah. The second input and output of the central processor 10 are connected to the input and output of the terminal equipment 13. The outputs of the search unit 2 are connected to the corresponding inputs of the delay memory unit 16, the outputs of which are connected to the second inputs of the corresponding blocks of the optimal signal allocation 14a, 14b ... 14n, to the first the input of which the ADC output is connected 4. The control inputs of the keys 15a, 15b ... 15n are connected to the corresponding outputs of the system synchronization block 17i, the input of which is connected to the output of the time interval forming unit 18. The search block consists of n sequentially connected keys 15 and optimal detectors of the synchronization signal 7. The detection unit 12 contains n blocks of optimal signal isolation 14. The radio path HF 1 contains serially connected the input path of the receiver 3 and ADC 4 and serially connected SHPS exciter 11 and power amplifier 5.

The system works as follows. At the initial moment of time, the block of time intervals 18 generates timestamp marks and feeds them to the input of the system synchronization block of the i-th subscriber 17, which generates n time slices, the duration of which is equal to the detection time of the BSS T _C at an unknown time position of the PSP transmitter. To clarify the description, imagine that in the first time interval the first subscriber (radio station) of FIG. 2 is turned on for transmission, that is, the system synchronization unit 17 ₁ includes a broadband synchronization signal shaper 8, the output voltage of which is supplied through a pulse generator to the power amplifier 5 and radiated by an antenna.

All other subscribers (radio stations), except the first, during the first period of time work in the reception mode. Specifically, the block of time intervals 18 generates timestamp marks and feeds them to the input of the corresponding system synchronization block of the i-th subscriber 17, which includes keys 15a for the search time Т _С. Here i = 2,3 ... n. The signal from the subscriber’s antenna enters the input path of its receiver 3, the analog-to-digital converter 4, enters through the closed key 15a to the blocks of optimal signal detection 7a, which are tuned to the clock signal of the ith first subscriber (radio station), after the signal is detected in blocks 7a of his the temporary position is recorded in the delay memory blocks 16 in all subscribers (radio stations), except the first. In the second time interval Т _С , worked out in the synchronization blocks of the system of the i-th subscriber 17 under the influence of time interval blocks 18, the second subscriber (radio station) works on the radiation, and all the others are received. At the time T _C , the keys 15b are opened in all subscribers (radio stations), except the second. As in the first case, the time position of the synchronization signal is determined in blocks 7b and its time position is recorded in the delay memory blocks 16 in all subscribers (radio stations) except the second. The process occurs n times. Each subscriber (radio station) "knows" the time of arrival of the synchronization signal from all other n-1 subscribers (radio stations).

The operation algorithm corresponds to the table.

Table Step number Emitting Subscriber (Radio Station) Receiving subscribers (radio stations) one one 2, 3, 4 ... n 2 2 1, 3, 4, 5 ... n ... ... ................................. n n 1, 2, 3, 4, 5 ...... n-1

Thus, after a time (n T _C ), each subscriber (radio station) “knows” the time of arrival of the signal from all other n-1 subscribers (radio stations) and can receive signals from them without searching. It should be noted that for the proposed communication system in the synchronization mode, to increase the power of the synchronization signal, only one sync-PSP can be emitted with the information transmission channel off. After the completion of the time interval (nT _C ), the block of time intervals 18 stops generating time stamps and the system proceeds to the second stage of operation - the mode of exchange of information between subscribers (radio stations) i and k.

In this case, all subscribers (radio stations) go into the mode of receiving a signal from the antenna through the input path of the receiver 3 and the ADC 4 is simultaneously connected to the first inputs of the blocks of optimal signal allocation 14a, 14b ... 14n, each tuned to its “own” correspondent, and the block optimal selection of the information signal 6. Next, the work proceeds as follows: from the terminal equipment 13 of the calling i-th subscriber (radio station), information signals are fed to the block of the central processor 10, which in turn drives broadband synchronization signal (preamble) 8 and information broadband signal 9.

The signals from the outputs of the shapers through the SHPS exciter 11 are fed to a power amplifier 5 and emitted by the antenna.

At the receiving end, the signal from the i-th subscriber (radio station) is received and after passing blocks 3 and 4 it is at the first input of the blocks for optimal allocation of the clock signal, with a fixed setting for "your" correspondent, 14a, 14b ... 14n. However, the synchronization signal is received only by block 14i, to the second input of which a signal is sent about the possible time of arrival of the signal from the i-th correspondent, for this reason the clock signal is received without searching. From the output of block 14i, the tuning signal of block 6 is supplied to the i-th control input of the block for optimal allocation of information signal 6, due to which block 6 is matched with the incoming information signal and an information signal is output at its output, which is fed to the block of central processor 10. As noted above when describing the operation of the prototype, in the block of the central processor 10, information is processed, in particular the allocation of service information. Based on the service information (address), the recipient determines whether the information belongs to him or not. In our case, the information is addressed to the k-th subscriber (radio station). Therefore, the k-th subscriber (radio station) will be able to select useful information in the block of the central processor 10 and transmit it to the input of terminal equipment 13. While the remaining n-2 subscribers (radio stations) will go into receive mode. The terminal equipment of the k-th subscriber, having received the information, will enter the answer mode. From the terminal equipment 13 of the called k-th subscriber (radio station), information signals are fed to the block of the central processor 10, which in turn drives the formers of the broadband synchronization signal (preamble) 8 and the information broadband signal 9. The signals from the outputs of the formers through the SHPS exciter 11 served on the power amplifier 5 and emitted by the antenna of the k-th subscriber (radio station).

Now, reception is carried out by the ith subscriber (radio station) in exactly the same way as receiving and processing a signal in the kth subscriber (radio station). Thus, in the exchange of information mode, communication between two subscribers (radio stations) i and k is established without spending time searching. In the information exchange mode, the synchronization signal search block 2 is not involved.

Thus, during T * N, the system enters into synchronism. Saving time is due to the parallel operation of subscribers (radio stations) in search mode. We get a gain in the inventive system compared to the prototype.

1. The complete synchronization of the system took the time T * N, and not the time T * N (N-1) / 2, i.e. in (N-1) / 2 times less.

2. No further time is required and the system provides a channel for communication without delay.

Claims (1)

A communication system for broadband signals, consisting of (n + 1), where n≥2 radio stations, each of which contains a radio frequency path connected in series, an optimum information signal allocation unit, a central processor unit, the output of which is connected to the inputs of the information and synchronization broadband signal conditioners, the outputs of which are connected to the corresponding inputs of the RF radio path, the second input and output of the central processor unit are connected to terminal equipment, characterized in that in each radio station On May, a detection unit was introduced, containing n blocks of optimal signal extraction, each of which is configured to receive a signal from the corresponding radio station, the output of each of n blocks of optimal signal extraction is connected to the corresponding control input of the block of optimal selection of the information signal, a block of time intervals forming time marks, providing the operation of the radio in search mode, and stopping the generation of timestamps to provide a mode of information exchange, the output of which is connected with a system synchronization unit, a delay memory unit at n positions, in which the temporary position of the synchronization signal from each radio station is recorded, a search unit consisting of n serially connected keys and an optimal synchronization signal detector unit, the key inputs are connected to the corresponding outputs of the RF radio path and synchronization unit system, which at each time interval opens one of the keys, the outputs of the keys are connected to the corresponding inputs of n optimal detectors of the synchronization signal, the output of which are connected to the corresponding inputs of the delay memory block at the n position, n outputs of which are connected to the corresponding inputs of the detection block, the RF path of the RF circuit is connected to the corresponding inputs of the search and detection blocks, the synchronization output of the transmitter of the system synchronization block is connected to the input of the broadband synchronization signal generator, when this unit of the Central processor for information signals from the terminal equipment drives the shapers of the broadband synchronization signal and information broadband signal, and also selects useful information and transfers it to the input of terminal equipment.

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