Multi-device search wideband signals using the delay for communication systems with code division multiplexing

 

(57) Abstract:

Multi-device search wideband signals using the delay for communication systems with code division multiplexing refers to electrical engineering and can be used in communication systems with broadband signals, operating under the influence of intra-system interference. Technical result achieved - reducing the time of entering into synchronism with subscribers and increase system throughput. The named device has a crucial block, calculator, synchronous phase filter, an adder, N correlator blocks, N first and N second blocks comparison with a threshold, N generators copies of the signal, N control units search, N switches, N shapers evaluation noise, N keys. 5 Il.

The present invention relates to electrical engineering and can be used in communication systems with broadband signals.

The known device search wideband signals using the delay described in and.with. N 1104677, H 04 L 7/04, RF patent N 2020762, H 04 B 1/10 and others, the lack of which is a low immunity to structural interference.

The closest in technical essence to the present invention is the device of the CIP is a, M., "Sov. radio", 1973, page 160, Fig. 5.3.1 adopted for the prototype.

The structural scheme of the device of the prototype is shown in Fig. 1, where indicated:

11- 1Nblock correlator;

21- 2Nblocks comparison with a threshold;

3 crucial block;

4 - generator copy of the signal.

The device prototype contains N blocks correlator 11- 1Nwhose inputs are combined and are input devices, and output through the appropriate units of comparison with the threshold 21- 2Nconnected to respective inputs of the decision making unit 3, the output of which is an output device. In addition, the N outputs of the generator copy of the signal 4 is connected with the control inputs of the N blocks of the correlator 11- 1Nrespectively.

The device prototype works as follows.

The input broadband signal is sent simultaneously to the inputs of N blocks of correlator 11- 1Nthat from the generator 4 serves copies of the signal, differing delays. In each of the N blocks of the correlator 11- 1Nare the multiplication of the input signal with the reference, the filtering result of the multiplication and its detection. With the output of each block 11 the OIG. The team of the excess (does not exceed) the threshold outputs of blocks 21- 2Nserved on the block 3, which is filtered by the channel number in which a decision about the action signal.

The disadvantage of this device prototype is a low immunity to structural interference.

To eliminate this drawback in the device containing the generator copy of the signal, the deciding unit and N identical lines, each of which has connected in series block correlators and the first block of comparison with the threshold, the output of which is connected to the corresponding input of the decision making unit, and the output of the generator copy of the signal is connected with the control input of the correlator introduced successively United adder, synchronous phase filter and myCitadel, whose input is simultaneously connected with the first inputs of N lines and an input device, and the output of vicites simultaneously connected with the second inputs of the N lines. Each line entered the switch, connected in series shaper assess the interference and the key, and the second block of comparison with a threshold, and the control unit search. While the first and second inputs of the switch are respectively input lines, and its third input is connected, which is connected with the corresponding input of the adder. The output switch connected to the first input of the correlator, the second output of which is connected to one of the inputs of the driver evaluation interference, another input connected to the output of the generator copy of the signal. The output of the first block of comparison with the threshold through the control unit search is connected to the input of the generator copy of the signal. The connection point between the output of the correlator and the input of the first block of comparison with the threshold is connected to the input of the second block of comparison with the threshold, the output of which is a second output line connected to the corresponding input of the decision making unit.

Structural diagram of the inventive device shown in Fig. 2, where indicated:

11- 1Nblock correlator;

21- 2N, 81- 8Nthe first and second blocks comparison with a threshold;

3 crucial block;

41- 4Ngenerator backup alarm;

51- 5Nthe control unit searches;

61- 6Nswitch;

71- 7Ndriver evaluation interference;

91- 9N- key;

10 - myCitadel;

11 - synchronous phase filter;

12 - adder.

The proposed device contains N lines, each of which contains members who Ohm 5 and the generator copy of the signal 4, the output of which is simultaneously connected to the reference input of the correlator 1 and with one of the inputs of the driver evaluation interference 7, the other input of which is connected with the second output of correlator 1. The output of the driver 7 is connected with one input key 9. The connection point of the first output unit 1 and the input of the first block of comparison with the threshold 2 is connected to the input of the second block of comparison with the threshold 8, the outputs of blocks 2 and 8 are the outputs of the line and connected to the corresponding inputs of the decision making unit 3, the output of which is connected to another input key 9, the output of which is the third output line and connected to the appropriate input of the adder 12.

The first inputs of the switches 61- 6NUnited and are the first inputs of N lines, in addition, they are connected to the input of vicites 10, the inlet of which is an input only device.

The second inputs of the switches 61- 6Nalso are combined and second input lines and connected to the output of vicites 10, the output of which is simultaneously connected to the input of the synchronous-phase filter 11, the other input connected to the output of the adder 12, and the output of filter 11 is connected to a second input of vicites 10.

Third WMO is ageme device is a device search on the delay of the receiver of the base station of the cellular communication system, using broadband photomanipulation signals and code division multiplexing.

The input device receives signals from the N subscribers. The signals are N identical lines, each of which are searching for the delay of the signal of one of the N subscribers and formation evaluation interference generated by the given subscriber to other subscribers of the system.

Evaluation of interference generated in the lines are fed through the adder 12 and the synchronous phase filter 11 to the input of vicites 10, the other input of which is fed the input mixture from the input device. Thus, the input of each line of the input mixture flows either directly from input device or via myCitadel 10, in which the compensation of structural interference, that is, signals of the subscribers of this system, the levels which exceeded the permissible value. All N lines on the composition of the blocks are identical. The difference between the lines lies in the structure of the reference signals of the blocks 41- 4N, each of which corresponds to a particular subscriber.

Let's consider a line.

At the first input of the switch 6 receives an input mixture from the input device, the second input - input mixture to 3, the switch 6 connects to the input unit 1 or the input device, either the output of block 10. In the initial moment of time the unit 3 through the switch 6 connects to the input block 1 input device. In this case, the input mixture is fed to unit 1 where are its multiplication with a reference signal block 4, the filtering result of the multiplication and its detection. From the output of the unit 1, the signal is simultaneously supplied to the blocks comparison with thresholds 2 and 8, block 2 is set to a lower threshold level which is determined by the given probability of false alarm in the search mode. The threshold in block 8 is set higher than a threshold unit 2. Its level is determined by the acceptable level of system signals, the exceeding of which leads to the impossibility of receiving signals from remote subscribers. Signals exceeds (does not exceed) the threshold output blocks 2 and 8 are fed to the inputs of unit 3. Simultaneously with the output of block 2 signals is supplied to the unit 5, which translates the generator copy of the signal 4 in the scanning mode using the delay when the command input is "0" and the stop mode scan (complete search) if the input command is "1".

The reference signal from the output of block 4 is supplied simultaneously to the reference inputs of the blocks 1 and 7.

In block 7 Khujand is a scrap block of 4 with subsequent filtering. As a result, the output unit 7 estimation of the received signal, which through the key 9, the managed unit 3 can do (when you open the key 9) connected in series through the adder 12 and the synchronous phase filter 11 myCitadel 10. The output signal from myCitadel 10 is applied to a second input of the filter 11, which carries out automatic adjustment of the amplitude and phase estimates of interference, ensuring effective compensation for the interference in the input mixture.

The control algorithm unit 3, the blocks 6 and 9, each of the lines is as follows.

If the thresholds in blocks 2 and 8 in this range is not exceeded, then the input unit 1 of this line with the unit 6 is connected directly to the input device, and the switch 9 is closed, i.e. the assessment of the noise generated in the range, not connected to the unit 12.

In the case of simultaneous threshold in blocks 2 and 8 unit 3 sends the command to the key 9 of this line, opening it and providing an evaluation of the interference generated in the range, to the input unit 12, and a command supplied from the output of block 3 block 6 of this line, block 1 this line is connected directly to the input device. At the same time blocks 1 estelline command block 3, supplied to the respective blocks 6 are connected to the input of the adder 12.

Structural block circuit 1 shown in Fig. 4, where indicated:

1.1 - multiplier (phase remodulator);

1.2 - filter;

1.3 - amplitude detector.

In box 1.1 is the multiplication of the input mixed with a reference signal block 4, the same reference signal used to generate broadband photomanipulating signal corresponding subscriber. In the result of multiplying the input mixed with a reference signal, synchronous with the broadband signal of the subscriber, in box 1.1 is and convolution signal of the subscriber, which is filtered in block 1.2 and is detected in block 1.3. The output unit 1.2 is applied to the input unit 7.

Structural block circuit 3 shown in Fig. 3, where indicated:

311-Nelement OR;

321-N- inverter;

331-Nelement AND;

34 - item OR.

Block 3 contains an element OR 34 and N identical channels, each of which contains blocks 311-N, 321-N, 331-N.

The input of each channel received command of the excess ("1") or does not exceed ("0") thresholds from the outputs of blocks 2 and 8, which is OK 6.

Consider the different modes of the decision making unit 3.

If the channel of the subscriber exceeded both thresholds, the output of block 31 is formed "1", which inverters in block 32, is supplied to the unit 33 in the form of a command "0".

In this case, for any value of the command generated at the output of block 34, the output of block 33 is formed command "0". This command is supplied to the unit 6 of this line, which connects input devices directly to the entrance of block 1 of this series (in this case, the compensation of interference at the input unit 1 is not possible). Simultaneously, the command "1" output of block 31 is supplied to the key 9, providing connectivity for the assessment of noise generated in the range, to the adder 12, which through the block 11 is supplied to the unit 10.

In case does not exceed the threshold in at least one of the blocks 2 or 8 output block 31 is formed "0" which is supplied to the key 9 and locks it. In this case, the assessment of the noise generated in the channel is not supplied to the adder 12.

Simultaneously, the command is "0", invertases in block 32, to the input of the block 33 in the form of a command "1". If at least one of the N lines is observed excess of two thresholds, the output blocks 34 and 33 formed team of "1", the VA to the entrance of block 1 through block 10. In this case, the input current range input mixture flows after payment of interference from closely spaced subscribers.

Structural block circuit 7 shown in Fig. 5, where the following notation is used:

71 - multiplier (phase manipulator);

72 - bandpass filter;

73 - amplifier with adjustable gain;

74, 75 - delay element.

Unit 7 operates as follows.

In block 71 collapsed (narrowband) signal from the second output unit 1, is multiplied by the reference signal of the unit 4 is input to the input unit 71 through the delay element 75. The output of block 71 is formed of a broadband signal (evaluation of structural interference), similar to the corresponding signal in the input mixture, which is filtered in block 72 (bandwidth which is equal to the spectrum band signal corresponding to the subscriber), passes through the adjustable blocks 74 and 75, which are provided to adjust the amplitude and phase estimation noise on stage with a view to its effective compensation.

Unit 11 provides automatic adjustment of the amplitude and phase estimates of interference and provides effective compensation of interference in the operating mode. He can be the Owls. radio. 1977, page 123, Fig. 3.6.

In the prototype, the robustness of the search to structural interference is determined by the base used broadband signals. The powerful impact of structural noise on the device prototype, exceeding the useful signal power is more than the base time, leading to a false detection and increase the time of entering into synchronism, which reduces the throughput of the communication system.

In the inventive device provides simultaneous search for the delay signals as the near and remote subscribers, thus reducing the interfering effect of signals of others subscribers on the search signals to remote users through their suppression by approximately 20 to 40 dB. The signal level subscribers not known a priori and is determined in the procedure of searching for the delay. At this stage identify interfering signals and formed their assessment, which is then used to suppress noise in the input mixture.

A feature of the claimed device is a small amount of time spent on generating estimates of noise and its suppression, which leads to a sharp reduction in the time entry in synchronism with subscribers and increase throughput spotim connection with code division multiplexing, containing the generator copy of the signal, the deciding unit and N identical lines, each of which has connected in series block correlator and the first block of comparison with the threshold, the output of which is connected to the corresponding input of the decision making unit, the generator output up signal is connected with the control input of the correlator, wherein the introduced successively United adder, synchronous phase filter and myCitadel, whose input is simultaneously connected with the first inputs of N lines and an input device, and the output of vicites simultaneously connected with the second inputs of the N lines, each of which entered the switch, connected in series shaper assess the interference and the key, and the second block of comparison with a threshold, and the control unit search, the input connected to the output of the first block of comparison with a threshold, and the output to the input of the generator copy of the signal, the output of which is simultaneously connected to one of the inputs of the driver estimates the interference, the other input of which is connected with the second output of the correlator, the input connected to the output switch, the first and second inputs of which are the inputs of the line, and the third input of the switch is connected with the corresponding output of the ith input of the adder, the connection point between the output of the correlator and the input of the first block of comparison with the threshold is connected to the input of the second block of comparison with the threshold, the output of which is the output line and connected with the respective input of the decision making unit.

 

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FIELD: radio engineering; construction of radio communication, radio navigation, and control systems using broadband signals.

SUBSTANCE: proposed device depends for its operation on comparison of read-out signal with two thresholds, probability of exceeding these thresholds being enhanced during search interval with the result that search is continued. This broadband signal search device has linear part 1, matched filter 2, clock generator 19, channel selection control unit 13, inverter 12, fourth adder 15, two detectors 8, 17, two threshold comparison units 9, 18, NOT gates 16, as well as AND gate 14. Matched filter has pre-filter 3, delay line 4, n attenuators, n phase shifters, and three adders 7, 10, 11.

EFFECT: enhanced noise immunity under structural noise impact.

1 cl, 3 dwg

FIELD: radio engineering for radio communications and radar systems.

SUBSTANCE: proposed automatically tunable band filter has series-connected limiting amplifier 1, tunable band filter 2 in the form of first series-tuned circuit with capacitor whose value varies depending on voltage applied to control input, first buffer amplifier 3, parametric correcting unit 4 in the form of second series-tuned circuit incorporating variable capacitor, second buffer amplifier 5, first differential unit 6, first amplitude detector 7, first integrating device 9, and subtraction unit 9. Inverting input of subtraction unit 9 is connected to reference-voltage generator 10 and output, to control input of variable capacitors 2 and 4. Automatically tunable band filter also has series-connected second amplitude detector 11, second integrating unit 12, and threshold unit 13. Synchronous operation of this filter during reception and processing of finite-length radio pulses is ensured by synchronizer 14 whose output is connected to units 10, 8, and 12. This automatically tunable band filter also has second differential unit whose input is connected to output of buffer amplifier 3 and output, to second control input of variable capacitor of band filter 2.

EFFECT: enhanced noise immunity due to maintaining device characteristics within wide frequency range.

1 cl, 1 dwg

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