Adaptive broadband amplifier-limiter - band amplifier
The invention relates to electrical engineering and can be used as part of foster radar, radio navigation and radio communication devices. The technical result consists in increasing the efficiency of detection of weak signals on the background of additive broadband noise in conditions of a priori uncertainty about the statistical characteristics of the interference, for this sample input additive mixture of signal and noise at low signal-to-noise ratio at the input, calculates the current parameter estimate of noise variance, which is used to form level fluctuations at the output of the broadband amplifier (SHU) (2), the Device also contains discretization (1), guard (3), narrow-band amplifier (4), squarer (5), calculator square root (6), the amplifier (7), the adder (8), integrator (9), the first and second multiplier products (10, 13), the drive (11) and the divisor (12). 1 Il.The invention relates to electrical engineering and can be used as part of foster radar, radio navigation and radio communication devices operating in the conditions of additive effects of broadband noise, detection of weak signals.Know the th amplifier (SHOW) (Y. S. Lezin introduction to theory and technique of radio systems: textbook for universities. - M.: Radio and communication, 1986, - 280 C.) a Disadvantage of the known device SHOWS is that the principle of its action is based on the selection of the first harmonic of the input additive mixture at the output of the broadband amplifier while limiting fluctuations to meander, it fails to account for possible changes in the intensity of additive broadband noise and narrowband energy input device.The technical result of the invention is to improve the efficiency of detection of weak signals on the background of additive broadband noise.The invention consists in that the known device is a SHOW consisting of series-connected broadband amplifier, limiter and narrow-band amplifier is additionally connected to the input of the broadband amplifier discretization, the entrance of which is an input device, in addition, the output of discriminator connected serially connected squarer, calculator square root, amplifier, adder, integrator and the first multiplier, the output of which is connected to the second regulating the input of the limiter, in addition, to the output of the Quad are connected serially connected drive and the divider output share is resident, the second input is connected to the output of the first multiplier and the output of the second multiplier connected to the second input of the adder, the output of the limiter is connected to the input of the narrowband amplifier whose output is the output of the adaptive device SHOWS.The drawing shows a block diagram of an adaptive device SHOWS.Adaptive device SHOW contains serially connected discretization 1, a broadband amplifier (SHU) 2, terminator 3, and narrow-band amplifier (SU) 4 whose output is the output device, the output of discriminator connected serially connected squarer 5, calculator square root (CWC) 6, the amplifier 7, the adder 8, the integrator 9 and the first multiplier 10, the output of which is connected to the second regulating the input of the limiter 3, the output of the Quad 5 connected in series United drive 11 and the divider 12, the output of which is connected to the second input of the first multiplier 10, in addition, to the output of the Quad 5 connected to the first input of the second multiplier 13, the second input is connected to the output of the first multiplier 10, and the output connected to the second subtractive input of the adder 8.Under ideal limit input additive mixture from the outside of the U0the output swing of the limiter is a meander ħU0. The signal energy E and the spectral intensity of the interference at the output of the limiter are defined respectively by the expressionswhere=4/the coefficient of the first harmonic, the resulting limitation to the level U0;FW- bandwidth SHU.For xed U0signal-to-noise ratio at the input YYdoes not depend on the energy ratio of the useful signal and additive noise, and when changing the noise intensity of the selected scheme becomes ineffective.When describing the probabilistic characteristics of the broadband noise can be used the Laplace distribution as the probability density functionswhere>0 is a parameter of the noise intensity.Adaptation-level restrictions on the parameter of the intensity of interferenceis implemented using instantaneous nonlinear transducer characteristic of the speciesIf e is the amplitude of the useful signal.Parameter estimation of intensity of interferencerequired for installation of level fluctuations at the output of SHU, is formed using a criterion based on the minimization of the average value of the functionalwhere n is 0, 1, 2,...In the absence of a priori data, replacing the averaging over the ensemble averaged over time, taking into account the sampling input of the additive mixture according to the time, when n=2, the procedure of finding the rootequation (6) is expressed by the following recurrent algorithmwhere xi=x(ti); ti=it; i=1...N; N is the sample size;t=1/f;f is the bandwidth of the linear channel receiver; Gi- element of a sequence of positive numbers.The choice of Gidetermines the convergence of the adaptation algorithm (7). In the absence of a priori data, you can use the following nextThus, in the inventive adaptive device SHOWS calculated current tint setting the intensity of additive broadband pomaceae formation threshold level of the limiter, proportional to the value of the noise intensity.Adaptive device SHOW works as follows. At the entrance of discriminator 1 is an additive mixture of the useful signal s(t) and noise n(t)x(t)=s(t)+n(t).At the output of discriminator 1 is a sequence of xi=si+nithat is simultaneously applied to the inputs SHU 2 and Quad 5. Output SHU 2 sequence of samples enhanced additive mixture xiserved on a first information input of the limiter 3. Output Quad 5 sequence of samplescomes in parallel to the inputs of VPC 6, the drive 11 and the first input of the multiplier 13. Output VCC 6 are formed ADUthat are amplified with the amplification factor equal to 2 in the amplifier 7, and fed to a first input of the adder 8. At the output of the memory 11 are formed ADUserved on the input of the divider 12. At the output of divider 12 are formed ADU -served to the second input of the multiplier 10. To the second input of the multiplier 13 are samples of the current parameter estimation of noise variancethe fot to the second input of the adder 8. At the output of the adder generates samplesthrough the integrator 9 is served at the first input of the multiplier 10. From the output of the multiplier 10 times the current parameter estimation of noise varianceserved on the second regulating the input of the limiter 3, so you can install level fluctuations, coming to the first input of the limiter 3. From the output of the limiter 3, the resulting oscillation is fed to the input SU 4 whose output is the output of the adaptive device SHOWS.The comparison of the proposed solutions with other technical solutions shows that the device SHOWS widely known. However, their use in combination with the proposed method of obtaining the current parameter estimation of noise variance, allows to obtain new properties that increases the efficiency of detection of weak signals in terms of additive effects of broadband noise with unknown statistics.
ClaimsAdaptive device detection of weak signals on the background of additive broadband noise containing connected in series broadband amplifier, limiter, and is additionally connected discretization, the input which is the input device and the output of which is connected to the input of the broadband amplifier, the output of discriminator additionally connected serially connected squarer, calculator square root, amplifier, adder, integrator and the first multiplier, the output of which is connected to the second regulating the input of the limiter, the output of the Quad is additionally connected in series connected drive and the divider, the output of which is connected to the second input of the first multiplier, the output of the Quad connected to the first input of the second multiplier, the second input is connected to the output of the first multiplier and an output connected to the input of the adder.
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
FIELD: radio communications engineering; mobile ground- and satellite-based communication systems.
SUBSTANCE: proposed modulator that incorporates provision for operation in single-channel mode with selected frequency modulation index m = 0.5 or m = 1.5, or in dual-channel mode at minimal frequency shift and without open-phase fault has phase-shifting voltage analyzer 1, continuous periodic signal train and clock train shaping unit 2, control voltage shaping unit 3 for switch unit 3, switch unit 3, switch unit 4, two amplitude-phase modulators 5, 6, phase shifter 7, carrier oscillator 8, and adder 9.
EFFECT: enlarged functional capabilities.
1 cl, 15 dwg
FIELD: electronic engineering.
SUBSTANCE: device has data processing circuit, transmitter, commutation unit, endec, receiver, computation unit, and control unit.
EFFECT: high reliability in transmitting data via radio channel.
FIELD: electronic engineering.
SUBSTANCE: method involves building unipolar pulses on each current modulating continuous information signal reading of or on each pulse or some continuous pulse sequence of modulating continuous information code group. The number of pulses, their duration, amplitude and time relations are selected from permissible approximation error of given spectral value and formed sequence parameters are modulated.
EFFECT: reduced inetrsymbol interference; high data transmission speed.
16 cl, 8 dwg
FIELD: communication system transceivers.
SUBSTANCE: transceiver 80 has digital circuit 86 for converting modulating signals into intermediate-frequency ones. Signal source 114 transmits first periodic reference signal 112 at first frequency. Direct digital synthesizer 84 receives second periodic signal 102 at second frequency from first periodic reference signal. Converter circuit affording frequency increase in digital form functions to convert and raise frequency of modulating signals into intermediate-frequency digital signals using second periodic signal 102. Digital-to-analog converter 82 converts intermediate-frequency digital signals into intermediate-frequency analog signals using first periodic reference signal 112.
EFFECT: reduced power requirement at low noise characteristics.
45 cl, 3 dwg
FIELD: radio engineering; portable composite phase-keyed signal receivers.
SUBSTANCE: proposed receiver has multiplier 4, band filter 6, demodulator 8, weighting coefficient unit 5, adding unit 7, analyzing and control unit 10, synchronizing unit 3, n pseudorandom sequence generators 21 through 2n, decoder 1, and switch unit 9. Receiver also has narrow-band noise suppression unit made in the form of transversal filter. Novelty is that this unit is transferred to correlator reference signal channel, reference signal being stationary periodic signal acting in absence of noise and having unmodulated harmonic components that can be rejected by filters of simpler design than those used for rejecting frequency band of input signal and noise mixture. Group of synchronized pseudorandom sequence generators used instead of delay line does not need in-service tuning.
EFFECT: facilitated realization of narrow-band noise suppression unit; simplified design of rejection filters.
1 cl, 8 dwg
FIELD: mobile radio communication systems.
SUBSTANCE: proposed method and device are intended to control transmission power levels for plurality of various data streams transferred from at least one base station to mobile one in mobile radio communication system. First and second data streams are transmitted from base station and received by mobile station. Power-control instruction stream is generated in mobile station in compliance with first or second data stream received. Power control signal is shaped in mobile station from first power control instruction stream and transferred to base station. Received power control instruction stream is produced from power control signal received by base station; power transmission levels of first and second data streams coming from base station are controlled in compliance with power control instruction stream received. In this way control is effected of transmission power levels of first data stream transferred from each base station out of first active set to mobile station and of transmission power levels of second data stream which is transferred from each base station out of second active set to mobile station.
EFFECT: enlarged functional capabilities.
80 cl, 21 dwg
FIELD: radio engineering.
SUBSTANCE: proposed method and device designed for fast synchronization of signal in wade-band code-division multiple access (WCDMA) system involve use of accumulations of variable-length samples, testing of decoder estimates for reliability, and concurrent decoding of plurality of sync signals in PERCH channel. Receiver accumulates samples required for reliable estimation of time interval synchronization. As long as time interval synchronization estimates have not passed reliability tests, samples are accumulated for frame synchronization estimates. As long as frame synchronization estimates have not passed reliability tests, samples are analyzed to determine channel pilot signal shift.
EFFECT: reduced time for pulling into synchronism.
13 cl, 9 dwg
FIELD: satellite navigation systems and may be used at construction of imitators of signals of satellite navigational system GLONASS and pseudo-satellites.
SUBSTANCE: for this purpose two oscillators of a lettered frequency and of a fixed frequency are used. Mode includes successive fulfillment of the following operations - generation of a stabilized lettered frequency, its multiplication with an oscillator's fixed frequency and filtration of lateral multipliers with means of filters of L1 and L2 ranges and corresponding option of a fixed and a lettered frequencies.
EFFECT: reduces phase noise and ensures synthesizing of lettered frequencies of L1 and L2 ranges of satellite navigational system from one supporting generator at minimum number of analogous super high frequency units.
3 cl, 1 dwg