Tracking device for signal delay

 

(57) Abstract:

The invention relates to radio engineering, in particular to a device time synchronization for communication systems, including broadband signals. The invention also relates, but is not limited to this, the mobile radio communications, multiple access, code-division multiplexing (D), mobile and base stations, using the methods of time synchronization. The tracking device delay signal contains at least three parallel branches of the processing, the first branch of which contains the first multiplier and the second and third branches are connected in series multiplier, the integrator is reset and the unit functional transformation. The new device is that the first branch processing is formed similarly to the second and third branches, i.e. further comprises serially connected integrator with reset and block functional transformation, thus all three branches of processing simultaneously performing the equivalent functions convert the input signal. Also, the evaluation unit of fading for detecting loss of signal and generation of the corresponding commands control the CSOs values mutually correlation function and the control unit for code generation frequency depending on the magnitude of the current detuning and speed control adjustment temporary mismatch. The technical result is the acceleration of the transition process delay adjustment at large shift in time due to the expansion band filter low frequency in the feedback loop and avoid interference in the presence of fading in thedinghausen communication channels, improving the accuracy of estimation of the delay due to the narrow band filter low frequency in the feedback loop and avoid interference in the presence of fading in thedinghausen communication channels. 5 C.p. f-crystals, 7 Il.

This invention relates to radio engineering, in particular to a device time synchronization for communication systems, including broadband signals. The invention also relates, but is not limited to, cellular radio communications multiple access code division multiple access (CDMA), mobile and base stations, using the methods of time synchronization.

The nonstationarity of real communication channels, multipath propagation of the transmitted signal, including systems multiple access code division multiple access (CDMA), impose strict requirements to the characteristics of modern tracking systems for the delay. Successful implementation, in particular, the multibeam receiver is a bookmark channels (CDMA) is possible provided the device tracking signal delay will satisfy contradictory requirements: high precision, high performance and resistance to fading. While occurrences in synchronism, it is desirable that the speed of the tracking device for the delay of the signal maximum. But it must be optimal and filtering properties of the device to ensure minimal errors in tracking delay. In addition, the fading of the signal should not cause large errors in the estimation of temporal errors in the tracking device for the delay of the signal in terms of fading arising from multipath propagation of the signal in the communication channel and, in particular, for mobile communication systems.

The solution to the problem of timing given enough attention in the work of [1, j. Spilker. Digital satellite communications. M. "Communication" 1979, S. 387 - 404].

A typical embodiment of such a device tracking signal delay is considered in [2, monographs A. Viterbi. "D. Principles of broadband ("CDMA. Principles of Spread Spectrum Communication"), Copyright. 1995 by Addison-Wesley Publishing Company, 1995], where it is analyzed tracking device for delay type "ahead of the curve-Sebastiano device is rigidly fixed (i.e., do not depend on external conditions: the bandwidth of the filter in the feedback loop and the gain constant), therefore, fixed and its possibilities for dynamic and filtering properties. As a result, in terms of fading this device works accurately and with an interruption of tracking or poor performance.

You know the tracking device delay [3, j. J. Olmos, R. Agusti, "Analysis and design scheme of the tracking delay of the second order in the CDMA system", published in IEEE 0-7803-0673-2/92. 1992, p. 221 - 224], which contains three parallel branches of the processing, the first and the second of which contain connected in series multiplier, filter and squarer in each branch processing, the multiplier and filter in each branch of the processing function of the correlator, the output of which values are formed mutually correlation functions of the input signal and its delayed and anticipatory copies, and the third branch processing contains a multiplier, the output of which appears an information signal contained in the input broadband signal. Further, this device comprises a generator of pseudo-random sequences, the adder, the filter of low frequencies in the ring is e with high precision in tracking mode it has a long transitional compensation process initial shift delay, due to the narrow band filter ring regulation. In addition, the tracking accuracy is significantly reduced under conditions of fading.

Filter low frequency ring regulation provides greater accuracy in the tracking mode when the narrow band, but this increases the transition time of compensation of the initial shift. So if you want to reduce the time of the transition process, it is necessary to increase the bandwidth of the filter, which leads to deterioration of the noise, i.e., to increase the RMS value of the error signal.

Thus, this device does not allow to exclude the impact of fading on the estimation accuracy of the delay device tracking delay in the non-stationary channel. Therefore, the operation of this device is ineffective in terms of fading arising from multipath propagation of the signal in the communication channel.

The closest technical solution to the claimed invention is a device described in [4, A. Gonzalez, C. Ruiz, M. I. Lopez, and C. Valdeolmos. Device simulation of the tracking delay of the second order in conditions of multipath propagation, published in IEEE 0-7803-1266-X/93] . This is the United multiplier, filter and squarer in each branch processing, the multiplier and filter in each branch of the processing function of the correlator, the output of which values are formed mutually correlation functions of the input signal and its delayed and anticipatory copies, and the third branch processing contains a multiplier, the output of which appears an information signal contained in the input broadband signal. The squarer in each branch processing is used to remove the modulation of the corresponding correlation functions of the information signal. Further, this device comprises a generator of pseudo-random sequences, the adder, the LPF in the feedback loop and a controllable oscillator. While the input devices are the first inputs of the multiplier products, the second inputs of which are connected with the corresponding outputs of the generator of pseudorandom sequences, the outputs of the Quad are connected with the inputs of the adder, the output of which is connected to the input filter low frequency ring feedback, the output of which is connected to the input of the controlled oscillator, the output of which is connected to the input of the generator of pseudorandom sequences.

Sumatralaan the difference between the retarded and advanced correlation functions. The error signal appearing at the output of this adder is filtered in the filter ring and controls the frequency of a controlled oscillator that generates the clock signal frequency of a pseudorandom sequence generator.

When matching pseudo-random sequence generated by the pseudo-random sequence generator, with the input broadband signal values mutually correlation functions are equal. The error signal at the output of the adder is equal to zero, and a controllable oscillator operates at a clock frequency equal to the clock frequency of the input broadband signal.

With different clock frequencies of the received broadband signal generated by the generator of pseudorandom sequences, the values of mutually correlation functions are not equal in the channels of the lead and lag. At the output of the adder accumulates the error signal of the predominant sign of the correlation function, i.e., if dominates the correlation function of anticipatory sequence, the magnitude of the error signal is negative and proportional to the temporal mismatch between the received broadband signal and the generated sequence. In the opposite cm generator, changed up until the error signal becomes equal to zero. When this is complete coincidence of the received broadband signal with the generated pseudo-random sequence for the delay.

A disadvantage of this device as well as the previous one, is that it when working with high precision in the tracking mode has a long transitional compensation process the initial shift is the delay that is caused by a narrow band filter ring of the regulation, which ensures a low RMS value of the error signal.

Filter low frequency ring regulation provides greater accuracy in the tracking mode when the narrow band, but this increases the transition time of compensation of the initial shift. If you want to reduce the time of the transition process, it is necessary to increase the bandwidth of the filter, which leads to deterioration of the noise, i.e., to increase the RMS value of the error signal. And this leads to a decrease in the accuracy of the tracking device for the delay, especially in thedinghausen communication channels, as this device does not allow to exclude the impact of fading on the estimation accuracy of the delay in the transient karajaevo multipath propagation of the signal in the communication channel.

Hence, the proposed technical solution based on the task of creating such a device tracking signal delay, which would:

to accelerate the process of transition delay adjustment at large shift in time due to the expansion band filter low frequency in the feedback loop and avoid interference in the presence of fading in thedinghausen channels of communication;

to improve the estimation accuracy of the delay due to the narrow band filter low frequency in the feedback loop and avoid interference in the presence of fading in thedinghausen communication channels.

This task is achieved by the fact that the tracking device delay signal containing at least three parallel branches of signal processing, the first branch of which contains the first multiplier and the second and third branches are connected in series multiplier, the integrator is reset and the unit functional transformation, while connected in series multiplier and integrator with reset in each branch processing is used as a correlator, a generator of pseudorandom sequences, an adder and a controllable oscillator, the first inputs of the multiplier products are the moves two blocks of functional transformations are connected respectively with the first and the second input of the adder, and the output of the controlled oscillator with the input of the generator of pseudorandom sequences, additionally introduced the following major structural characteristics:

- formed the first branch processing similarly to the second and third branches of the processing, i.e., entered serially connected integrator with reset and block functional transformation, with the input of the integrator with a reset connected to the output of the first multiplier is made to ensure that all three branches of processing simultaneously performs the equivalent function of converting the input signal;

the evaluation unit of fading for detecting loss of signal and generation of the corresponding commands to control switching of the error signal (the current value of the discriminatory characteristics) and maximum signal values mutually correlation function;

control unit for code generation frequency depending on the magnitude of the current detuning and speed control adjustment temporary mismatch;

- introduced new connections respectively:

the output of the first functional block conversion connected to the first input of the evaluation unit of fading,

the outputs of the second and third blocks potency of fading, with the first and second inputs of the adder, and the second and first inputs of the control unit,

the first output of the evaluation unit of fading is the output of the information signal,

the second output of the evaluation unit of fading is connected to the fourth input of the control unit,

the third input of the control unit is connected to the adder,

the first and second outputs of the control unit are connected with the corresponding first and second inputs of the controlled generator.

Comparative analysis with the prototype of the proposed tracking device for the delay shows that the claimed technical solution is characterized by the presence of new significant features. And it is entered in the tracking device for a delay of two fundamentally important block is the block assessment fading and the control unit and respectively introduced new connections in the device map. Therefore the proposed device meets the criteria of the invention of "novelty."

A comparison of the proposed technical solutions with other technical solutions of the prior art [1-3] is not allowed to reveal the characteristics stated in the characterizing part of the invention. In addition? from known sources not identified devices that would receive equivalency by eliminating the influence of noise in the presence of fading in thedinghausen communication channels.

All of the above leads to the conclusion that the proposed device meets the criteria of "novelty", "significant differences", "non-obviousness" and corresponds to inventive step.

In Fig. 1 presents a block diagram of the inventive device tracking delay of the signal of Fig. 2 - unit assessment fading, representing the private embodiment of Fig. 3 is a control block representing the private embodiment of Fig. 4 - forming device threshold for block assessment of fading, is a private embodiment of Fig. 5 - filter low frequency control unit is private embodiment of Fig. 6 - comparison circuit for the control unit 14; Fig. 7 illustrates the algorithm of device evaluation fading 13.

Tracking device for signal delay in accordance with Fig. 1 contains three parallel branches of processing, each of which has connected in series multiplier, the integrator is reset and the unit functional transformation, i.e., the first branch includes a first multiplier 1, the first integrator reset 2, the first functional unit conversion 3, the second branch of the second multiplier 4, a second integrator with a fault reset 8 and the third functional unit conversion 9; the generator of pseudorandom sequences 10, an adder 11, a controllable oscillator 12, the evaluation unit of fading 13 and the control unit 14. The first inputs of the multiplier products 1, 4, 7 are input devices, their second inputs connected to the outputs of the generator of pseudorandom sequences 10, the output of the first functional block conversion 3 connected to the first input of the evaluation unit of fading 13, the outputs of the second 6 and third 9 units functional transformation simultaneously connected respectively with the second and third inputs of the evaluation unit of fading 13, the first and the second input of the adder 11 and the second and first inputs of the control unit 14, the first output of the evaluation unit of fading 13 is an output of the information signal, the second output is connected to the fourth input of the control unit 14, a third input connected to the output of the adder 11, and the two outputs of the control unit 14, respectively connected to first and second inputs of the controlled oscillator 12.

The evaluation unit of fading 13, which represents a particular embodiment of in accordance with Fig. 2 contains a block select maximum of 15, the forming device threshold 16, the scaling amplifier 17 and the comparison circuit 18, while the inputs of this device are when input device formation threshold 16 and the input of the scaling amplifier 17, the outputs of which are connected respectively with the first and second inputs of the comparison circuit 18, the output of which is the second release of this device.

The control unit 14 is a special version of the execution and in accordance with Fig. 3 contains the adder 19, the first managed key 20, the second managed key 21, the first filter low frequency 22, the second filter low frequency 23 and the comparison circuit 24, while the first and second inputs of the adder 19 are first and second inputs of the control unit 14, the output of the adder 19 is connected to the first input of the first managed key 20, the first input of the second controlled key 21 is the third input of the control unit 14, the second inputs of the first 20 and second 21 managed keys are managed fourth inputs of this block, outputs controlled switches respectively connected with the first inputs of the first 22 and second 23 filters low frequency, while the output of the first filter low frequency 22 is connected to the first input of the comparison circuit 24, the output of the second filter low frequency 23 is simultaneously the first output device and connected with the second input of the comparison circuit 24, one output of which is simultaneously connected with the second inputs of the first 22 and second 23 filters discomania threshold 16 for block assessment fading 13 is a special version of the execution and in accordance with Fig. 4 contains a shift register 25, containing n cells, and the block select max 26, while the input device is the input shift register, n its outputs connected to corresponding inputs of the block select maximum 26 whose output is the output device.

The block diagram of the filter of low frequencies 22 and 23 to the control unit 14 is a special version of the execution and in accordance with Fig. 5 contains the q-filter low frequency 27-1 to 27-q, parallel to, and a multiplexer 28, and the input filter low frequency 27-1 to 27-q are the first inputs of this device, the output of them is connected with the corresponding first inputs of the multiplexer 28, the second input is a second input of this device, and the output which is the output device. Structural diagram of which is shown in Fig. 5 as an example, similar to filter low frequency 22 and 23, i.e., the functional characteristics of these filters must be identical.

The comparison circuit 24 to the control unit 14 is a special version of the execution and in accordance with Fig. 6 contains i-attenuators 29-1 to 29-i and their schemes comparison 30-1 to 30-i, the first 31 and second 32 converters code, with the first whodo the texts 30-1 - 30-i, the second input is a second input of this device, the outputs of the circuits compare 30-1 to 30-i simultaneously connected to the corresponding inputs of the first 31 and second 32 code converters, the outputs of which are the outputs of this device.

Fig. 7 illustrates the algorithm of the evaluation unit of fading 13, where

a illustrates the form federowski signal at the output of the scaling amplifier 17 (Fig. 2);

in the illustrated output signal conditioning instrument threshold 16 (Fig. 2), which is a signal comparison;

c illustrates the output control signal of the comparison circuit 18 (Fig. 2).

Tracking device for signal delay in accordance with Fig. 1 operates as follows. The first inputs of the multiplier products 1, 4 and 7 receives an input broadband signal and the second input of multiplier products 1, 4 and 7 take a pseudo-random sequence generator of pseudorandom sequences 10.

The generator of pseudorandom sequences 10 generates a pseudo-random sequence in accordance with the shape of the input broadband signal.

Connected in series multiplier and integrator with reset in each of the branches, and less the first integrator reset 2, corresponds to mutually correlation function between the input broadband signal and the signal generated by the generator of pseudorandom sequences 10, with a delay relative to the received signal equal to "0". At the same time, the output signal from the first multiplier 1 can be used as information.

The output signal from the output of the second multiplier 4, passing through the second integrator with reset 5 corresponds to mutually correlation function between the input broadband signal and the signal generated by the generator of pseudorandom sequences 10, is shifted in the direction of advance .

The output signal from the output of the third multiplier 7, passing through the third integrator with reset 8 corresponds to mutually correlation function between the input broadband signal and the signal generated by the generator of pseudorandom sequences 10, is shifted in the direction of the lag .

Thus, at the output of the three correlators (at the output of the first integrator reset 2, the second integrator with reset 5 and the third integrator with reset 8) will be formed is mutually correlation function of the input signal and its copies.

Further, hung is like possible situations, in particular, when the input signal depends on an additional parameter, known or random phase, or modulated information signal. These signal parameters directly affect the output mutually correlation function from the first functional block conversion 3, the second functional unit conversion 6 and the third functional unit conversion 9.

Therefore, in each individual case it is necessary to use a specific ad-hoc algorithms, according to which you want to convert mutually correlation function so to get away from dependence on additional parameters of the input signal and to highlight its mutually correlation function in full (that is, to get the maximum possible energy response).

For example, for a signal with unknown phase in the functional blocks conversion of 3, 6 and 9 performs a calculation algorithm module mutually correlation function as follows: highlights the sin and cos components and then implemented conversion

< / BR>
where FF is mutually correlation function.

This allows you to get away from the dependence on the phase.

In another case, if the input C is of 3, 6 and 9 is the operation of constructing mutually correlation function square (or multiplying mutually correlation function within itself).

In the first block functional transformation 3 is formed mutually correlation function of the input signal and its copy with a delay relative to the received signal equal to "0".

In the second functional block conversion 6 is formed mutually correlation function of the input signal and its copy shifted by +, and the third functional unit conversion 9 is formed mutually correlation function of the input signal and its copy shifted . Further, output signals from the functional blocks conversion 6 and 9 come to the adder 11, which is used to form the discriminatory characteristics of the device.

Formed mutually correlation function of the input signal and its copies with functional blocks conversion of 3, 6 and 9 are received at the inputs of the evaluation unit of fading 13. This device selects the maximum of the received signals, which can be used as information.

Moreover, the information signal can be extracted during operation of the device at Lu output of the first integrator reset 2, or from the output of the first functional block of the Converter 3, or from the output of the block selection maximum of 15 located in the block assessment fading 13. However, the most preferred is the removal of the information signal from the output of the block selection maximum of 15, as it has the added benefit of noise immunity due to the possibility of using information messages as "Central" channel and "advanced" and "retarded" channels.

Next, the maximum of the received signals in the evaluation unit of fading 13 simultaneously measured at the level of the received signal during several periods of fading and scaled, then compares the levels of the filtered and scaled signals, and the decision about the presence of fading. The output signal of the evaluation unit of fading 13 is supplied as a control signal to the control unit 14.

Along with the sinking of the signal caused by fading, may be a loss of signal, for example, when operating in the reverse channel D, where the nature of information transfer is of a pulsed nature. In accordance with this, the evaluation unit of fading 13 generates control commands to the control unit 14. The control unit 14 in accordance with this control is when the signal is absent. The code size is proportional to the time distance (error), which is formed in the adder 11. The output signals of the control unit 14 (with the appropriate code and sign) are control signals for the controlled oscillator 12.

Then the output signal of the controlled oscillator 12 is supplied to the generator of pseudorandom sequences 10, resulting in a ring device is closed. With a generator of pseudorandom sequences 10 output signals (current mismatch in time) are fed to the inputs of the respective multiplier products 1, 4 and 7.

The evaluation unit of fading 13 entered for detecting loss of signal and generation of the corresponding commands to control switching of the error signal (the current value of the discriminatory characteristics) and maximum signal values mutually correlation function.

The evaluation unit of fading in accordance with Fig. 2 operates as follows.

The inputs of the block select maximum of 15 the output signals from the three functional blocks conversion of 3, 6 and 9 for comparison and selection of the maximum mutually correlation function of the transformed blocks functional transformation is temporary information signal and is fed to the input of the device formation threshold 16 and the input of the scaling amplifier 17.

In cases where an information signal is generated (extracted) from the output of the block select max 15, functional converters select the maximum values mutually correlation functions without removing informational messages on their outputs.

The forming device threshold 16 evaluates the maximum received signal level during several periods of fading. The output signal of the device 16 is a signal comparison.

The scaling amplifier 17, the input of which also receives the output signal of the block selection maximum of 15, selects the appropriate signal level (i.e., how weakens it and amplifies it).

Output signals from the device formation threshold 16 and the scaling amplifier 17 is fed to the comparison circuit 18 for selecting intervals fading input federowski signal and provide a control output signal. The comparison circuit 18 generates the control signal of two kinds. If the level of the output signal from the scaling amplifier 17 exceeds the level of the output signal from the device formation threshold 16 (fading is not detected), the output of the comparison circuit 18 there is an output control signal to the circuit the circuit is ignal break on these circuits in the device 14.

The control unit 14 in accordance with a control signal from the evaluation unit of fading 13 generates frequencies in the time intervals when the signal fading is not detected, or in the time intervals when the signal is absent.

The control unit 14 in accordance with Fig. 3 operates as follows.

The output signal from the functional blocks conversion of 6 and 9 is fed to the inputs of the adder 19, which summarizes these signals, which will then output a signal corresponding to the maximum value mutually correlation function.

The output signal from the adder 19 with a maximum value of mutually correlation function is supplied to the first input of the first managed key 20. And then the first key 20 performs switching in accordance with a control signal from the device estimates the fading 13, which is supplied to the second input key 20. The first managed key 20 performs switching as follows: at the signal, above the level of the generated signal of the comparison in the comparison circuit 18), the switch is open and the circuit is closed, and the signal below the level of the generated signal key is closed and the circuit is open.

The output signal from the adder 11 with the current value discriminat the th control signal from the evaluation unit of fading 13. The second managed key 21 performs switching as follows: the signal above the level of the generated signal of the comparison in the comparison circuit 18), the switch is open and the circuit is closed, and the signal below the level of the generated signal key is closed and the circuit is open.

The output signal from the first key 20 is supplied to the first filter low frequency 22 for filtering of the signal maximum value mutually correlation function (output signal) of the adder 19. Output a filtered signal at the first input of the comparison circuit 24.

The output signal from the second key 21 is fed to the second filter low frequency 23 for filtering the current value of the discriminatory characteristics (output signal) of the adder 11. Output a filtered signal from the second filter low frequency 23 simultaneously supplied to the second input of the controlled oscillator 12, is the Manager (on the sign of detuning for him and is supplied to the second input of the comparison circuit 24, and is a control signal (mismatch) for her.

The comparison circuit 24 generates the control band of the first 22 and second strip 23 filters the low frequency depending on the magnitude of the error temporary Rasso the I frequency adjustment depending on the magnitude of the detuning (errors). The inputs of the comparison circuit 24 the output signals respectively of the first 22 and second 23 filters the low frequency, the first output signal of the comparison circuit 24 is a control for the first 22 and second 23 filters the low frequency and the second output signal is a control for a controlled oscillator 12.

The forming device threshold 16 for block assessment fading 13 is a special version of the execution and in accordance with Fig. 4 operates as follows. The output signal of the block selection maximum 15 is fed to the input shift register 25, the n output signals from shift register 25 receives at respective inputs of the block select max 26, the output of which (as the signal comparison) is supplied to the comparison circuit 18.

Filters low frequency 22 and 23, which are shown as an example for practical use in the control unit 14, in accordance with Fig. 5 are as follows.

This device filters the low frequency 27-1 to 27-q, parallel and with different bandwidths, the inputs are the output signals from the managed the first 20 and second 21 keys. And the outputs of filters 27-1 to 27-q switched by diplexer 28 selects the appropriate filter with the required bandwidth and delivers a filtered signal to the comparison circuit 24. Therefore, by enabling the required filter is governed by the bandwidth of the feedback loop.

For the practical implementation of the filter of low frequencies must include at least two filter low frequency and one multiplexer.

The comparison circuit 24 to the control unit 14 is a special version of the execution and in accordance with Fig. 6 operates as follows. The input attenuators 29-1 to 29-i receives the output signal from the LPF 22, which is proportional shares attenuators. The output signals of the attenuators 29-1 to 29-i, which is the threshold signals and the corresponding specific values shift, arrive at the first inputs of the corresponding schema comparison 30-1 to 30-i.

On second input schema comparison 30-1 to 30-i simultaneously receives the output signal from the LPF 23 that corresponds to the current value of the time the detuning of the pseudo-random sequence relative to the received signal.

In the schema comparison 30-1 to 30-i compares the absolute value of the output signal from the LPF 23 with the output signals of the attenuators 29-1 to 29-i. Then the comparison circuit 30-1 to 30-i form a management team with the who 32 converters code in accordance with this team build the code.

The output signal of the first code Converter 31 (corresponding to the current value of the time the detuning of the pseudo-random sequence relative to the received signal) is supplied to a controllable oscillator 12. The output signal of the second code Converter 32 is the code for the control bandwidth of the filter and is supplied to the control inputs of the first 22 and second 23 filters the low frequency.

Fig. 7 illustrates the algorithm of device evaluation fading, where

a illustrates the form federowski signal at the output of the scaling amplifier 17 (Fig. 2);

in the illustrated output signal conditioning instrument threshold 16 (Fig. 2), which is a signal comparison:

c illustrates the output control signal of the comparison circuit 18 (Fig. 2).

Thus, examined in detail the operation of the claimed device tracking delay of the signal, and the circuit blocks included in this device and its operation, refer again to Fig. 1 and consider the principles of processing of the input signal (including broadband signal) inherent in the invention.

First, the width of the signal spectrum, including selectra, in which the processed signal, the narrower its correlation function and less time correlation between adjacent uncorrelated samples of the analyzed signal. Therefore, it is possible, by varying a frequency band in which the signal is processed to have the same time interval different number of uncorrelated values of samples of the estimated signal. This principle is embodied in the inventive device tracking delay of the signal to improve its dynamic characteristics, i.e., performance in capture mode. Mode capture refers to the process of transition delay adjustment at large shift in time.

The speed of adjustment of temporary mismatch between the input and reference signals in the tracking device for the signal delay is determined by the inertia (the width of the frequency band) filters low frequency 22 and 23 (Fig. 3) in the feedback loop. The output of the first filter low frequency 22 (Fig. 3) is formed by a signal of the maximum value mutually correlation function. The output of the second filter low frequency 23 is formed error signal a temporary mismatch between the input broadband signal and pseudorandom PEFC is trow low frequency ring feedback the more time is needed to assess uncorrelated values of the error on the delay and the less speed possible fine tuning of the controlled oscillator 12 and the generator of pseudorandom sequences 10 ring device tracking delay.

Conversely, when a broad swath of the first 22 and second 23 filters low frequency in the feedback loop (Fig. 3) it takes less time to obtain an estimate of uncorrelated values of the error on the delay. Resulting in the adjustment of the delay can be run more frequently (proportional band of the first 22 and second 23 filters). Therefore, the speed of adjustment of temporary mismatch can be increased, thereby decreasing transition time tracking device for signal delay in the capture mode.

Secondly, in conditions of multipath propagation input device tracking delay is the result of the interference of the addition of several signals. However, depending on the specific parameters of the combination of the received component signal, the possible fading. For mobile communication systems, this picture is complicated and takes a dynamic character. The exception intervocalically order delay relative to the input signal increases the noise immunity of the device tracking delay. Having the ability to identify time intervals of a failure of the input signal due to the fading and impulsive nature of information transmission in the CDMA system, it can adapt to this situation by changing the signal processing.

One possible option is switching error signal (the current value of the discriminatory characteristics), the input filter low frequency ring feedback 23 and maximum signal values mutually correlation function at the input of the LPF 22 depending on the magnitude of the fading of the processed signal. To perform this operation in the inventive device introduced the evaluation unit of fading 13, the output of which is formed the Manager (switching) signal and the control unit 14, which uses this signal to generate code frequency depending on the magnitude of the current detuning and speed control adjustment temporary error.

The control algorithm (switching) is as follows: at the signal, exceeding the level of the generated signal of the comparison in the comparison circuit 18, the first and second keys 20 and 21, Fig. 3 ) are opened, and the feedback circuit is closed, and the signal below UB is the W in the inventive device adaptable for two settings described previously (band filter low frequency in the feedback loop depending on the magnitude of the detuning errors over time, and the sign of fading) helped to create the invention tracking device for signal delay, including federowski communication channel. This device has a significant advantage in comparison with known solutions in this field of technology, as it accelerates the process of transition delay adjustment time and improves the accuracy of estimates of delay.

1. The tracking device delay signal containing at least three parallel branches of the processing, the first branch of which contains the first multiplier and the second and third branches are connected in series multiplier, the integrator is reset and the unit functional transformation, while connected in series multiplier and integrator with reset in each branch processing is the correlator, the generator of pseudorandom sequences, an adder and a controllable oscillator, the first inputs of the multiplier products are the device inputs, the second inputs connected to the outputs of the generator of pseudorandom sequences, the outputs of the two blocks of functional transformations are connected respectively with the first and second inputs of the adder, and the output of the controlled oscillator with the input of the generator of pseudorandom sequences, different clock functional transformation, when this input integrator reset is connected to the output of the first multiplier, introduced the evaluation unit of the fading and the control unit, while the output of the first functional block conversion connected to the first input of the evaluation unit of fading, the outputs of the second and third functional blocks conversion simultaneously connected respectively with the second and third inputs of the evaluation unit of fading, the first and second inputs of the adder, and the second and first inputs of the control unit, the first output of the evaluation unit of fading is the output of the information signal, the second output is connected to the fourth input of the control unit, a third input connected to the output of the adder, and the two outputs of the control unit respectively connected to first and second inputs of the controlled generator.

2. The device under item 1, characterized in that the evaluation unit of fading contains the node selection maximum shaper threshold, the scaling amplifier and a comparison element, while the inputs of the evaluation unit of fading are the inputs of the node in the selection of the maximum, the output of which is the output of the information signal and is connected to the input of the shaper threshold and the input of the scaling amplifier, the outputs of which are connected with the first and the second input is>3. The device according to p. 2, characterized in that the shaper threshold contains a shift register containing n cells, and the element of choice is high, while the input of the shaper threshold is the input shift register, n outputs which are connected to the corresponding inputs of the selection item is high, the output of which is the output of the shaper threshold.

4. The device under item 1, characterized in that the control unit includes an adder, a first driven key, the second driven key, the first filtering unit, the second filtering unit and site compare with the first and second inputs of the adder are the first and second inputs of the control unit, the output of the adder connected to the first input of the first controlled key, the first input of the second controlled switch is the third input of the control unit, the second inputs of the first and second controlled switches are the fourth input of the control unit, outputs controlled switches respectively connected with the first inputs of the first and second filter units, thus the output of the first filtering unit connected to the first input node of the comparison, the output of the second filtering unit is the first output of the control unit and is connected with the second input node of the comparison, Odie who is the second output of the control unit.

5. The device according to p. 4, wherein each node of the filter contains q filters low frequency, the inputs of which are connected and are the first input node of the filter, and the outputs q filters low frequency connected to the corresponding first q - inputs multiplexer, the second input is a second input node of the filter, and the output of the multiplexer is the output of the filtering unit.

6. The device according to p. 4, characterized in that the node comparison contains i attenuators and their elements of comparison, the first and second converters code, and the input node of the comparison are input attenuators, the outputs of which are connected with the first inputs of the elements of the comparison, the second input of which is the second input node of the comparison, outputs the elements of comparison are connected to their corresponding i - inputs of the first and second code converters, the outputs of which are the outputs of node comparisons.

 

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The invention relates to radio engineering and is intended for use in systems of discrete information transmission via communication channels with fading signal

The invention relates to techniques for transmitting digital data and can be used in wireless systems to synchronize the parcels receiving and transmitting parts of the system

The invention relates to the field of systems single time, in particular, to devices synchronization time scales of points located at a great distance, through the exchange of radio time

The invention relates to techniques for radio communication and can be used in broadband communications systems

The invention relates to systems in which separated in time monocalibre are generated from the pulse DC and transmitted to the space in which the total bursts of energy dissipated in the baths frequency where the spectral density merges with the ambient noise, and information relating to these bursts is restored

FIELD: broadband cell radio communication systems, possible use for correcting frequency of supporting generator of mobile stations, necessary for provision of coherent message receipt mode.

SUBSTANCE: serial cyclic procedure of estimating mismatch and its compensation uses original algorithm for determining maximum of solving function by two of its values from the area where frequency is undetermined, thus making it possible to decrease frequency mismatch compensation time. Proposed procedure has increased interference resistance, because it uses additional digital supporting signal. Proposed algorithm can function with different, including substantial, values of original frequency mismatch. Algorithm is efficient both at beginning stage (in frequency capture mode) and during following automatic adjustment. Proposed variant of realization of frequency automatic adjustment allows precise adjustment of frequency of supporting generator even in case of very low signal-noise ratio for signal being received.

EFFECT: increased precision of estimation of frequency of input multi-beam signal, including cases with substantial frequency mismatches.

3 cl, 9 dwg

FIELD: modulation methods, possible use during transmission and receipt of information signals.

SUBSTANCE: in accordance to method, as encoding transformation, comparison of several bits of parallel, serial digital code or information units to sample of analog signal of given duration and certain shape is used.

EFFECT: direct transformation of digital signal or units of information by means of precisely generating analog signal from samples known in advance.

3 cl, 2 dwg

FIELD: communication systems.

SUBSTANCE: proposed method includes dynamic control of subscriber station transmitter considering noise level in vicinity of base station location and information load on base station by estimating quality of communication channel and accounting for network subscriber priority.

EFFECT: enhanced reliability of mobile communication system.

1 cl, 2 dwg

FIELD: information technologies.

SUBSTANCE: mobile device of wireless communication and methods for it include signal reception, saving of received signal part, identification of all possible pilot-signals by means of determination of information on slot border for saved part of signal, determination of information on frame border and/or information of scrambling code from saved part of signal by means of correlation of saved signal part with scrambling codes on the basis of information on slot border. In other versions of realisation searching is done in real time without signal saving.

EFFECT: increased probability of signal detection.

22 cl, 7 dwg

FIELD: information technologies.

SUBSTANCE: method contains the following stages: on transmitting side they download orthogonal codes in lines from a number of multiuser communication lines, signals are sent as loaded with these codes, which correspond to lines, on receiving side they receive information on vector of transient noise according to vector of actually received signal, and quantitative value of transient noise is identified on the side of a certain line out of mentioned lines. System contains transmitting device, which sends test signals loaded with orthogonal codes, and receiving device, which receives test signals and calculates quantitative value of transient noise.

EFFECT: detection of transient noise among multiple lines for optimisation of lines operation.

13 cl, 12 dwg

FIELD: radio engineering, communication.

SUBSTANCE: method includes performing the following operations: by a test pulse, located in a fragment of message reception time interval known in the receiving end of the communication system, the ICR estimation operation is performed, each k-th time-based IN realisation, corresponding to each allowable k-th TSE alternative, is formed. This formation of IN realisations is performed taking into account the result of the ICR estimation, forming an array of differences {δk(t)}, between the analyzed TSE and each of the k-th of the indicated IN realisations separately, for each of these differences δk(t) they form the k-th decisive statistics (PC) zk, and based on the totality of these PCs they make a decision about which particular TSE is adopted. Each kth PC zk are formed by calculating the correlation between the k-th realisation of the δk(t) difference and the corresponding k-th TSE alternative, and the decision, about which particular TSE is adopted, is carried out by determining the index k =k0 for that of the collection PC zk0, which satisfies the condition zk0=maxk{zk}.

EFFECT: increase of noise immunity of reception of signals of digital communication during the operation of a communication system in the presence of multiple-beam interference.

3 dwg

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