The method of suppressing narrowband interference in a broadband system
The invention relates to radio engineering. The technical result is to increase the coefficient of suppression of narrowband interference. The invention consists in that in the transmitting tract form a broadband noise signal in the frequency band (F0, F1), modulate the broadband noise signal according to a given modulation, pass the received signal through the distribution environment, take it imposed on him a narrow-band interference filter in the frequency band (F0, F1), generate two signals, one of which is a result of amplification of the filtered signal and limiting its amplitude, as well as a second signal using the aforementioned filtered signal or linearly amplified without changing the shape of the filtered signal, Peremohy received two signals, the resulting signal is filtered in the frequency band [Fut(F1-F0), distinguish the envelope of the received signal and demodulator to receive the information signal, whereut- frequency band of the spectrum change of the square of the amplitude of the voltage noise. 6 Il.The invention relates to electrical engineering and can be used in communications technology, such as the broadband is delirous the amplitude of the signal, phase, frequency, or both. In all these systems the main type of interference are narrowband interference, i.e. interference, in which all the energy is concentrated in a narrow band of frequencies. Therefore, the task of filtering the complex signal with a simultaneous impact on the receiver fluctuation noise and powerful narrowband interference in the spectrum of the useful signal, is very topical. This is due to the fact that powerful narrowband station can completely disrupt communication in broadband systems, as in the multiplier correlator narrowband interference is converted into fotoemulsii signal having a linear spectrum with envelope proportional to sin(x)/x, and if powerful enough interference noise at the output of the correlator can exceed the collapsed level of the useful signal.There are many ways to eliminate this phenomenon, for example quasi-optimal linear filtering, the rejection of part of the spectrum, compensation methods, and so on (1).A disadvantage of known methods is their complexity.The closest to this invention is a method of suppressing narrowband interference in a broadband system, wherein in the transmitting tract form provided by pressinformation, form a digital phase noise signal with a center frequency F0logically summed with previously obtained digital pseudo-random signal, amplify the received signal in the receiving device, accept the transmitted signal overlaid in the distribution environment narrowband signal with frequency Fut&;&;FSRPfilter the received signal by passing through the high-frequency band-pass filter with a bandwidth of 2 FSRPand the Central frequency F0transform the input signal into a voltage proportional to the power received signal is filtered in the frequency band (Fut-FSRP), increase, limit the received signal, and then the correlation method of processing the receive signal to the mismatch between the clock frequency FSRPthe transmitted signal and the corresponding clock frequency of the receiving device (2).The disadvantage of this method is the low coefficient of suppression of interference from powerful narrowband stations.The technical result of the present invention is to increase the ratio of suppression of the bellows or group of narrowband interference in a limited frequency band, including frequency modulation and scanning interference that will improve the quality of communication at the expense of increasing the noise immunity of the useful signal.This technical result is achieved in that in the method of suppressing narrowband interference in a broadband system in the transmitting tract form a broadband noise signal in the frequency band (F0F1), modulate the broadband noise signal according to a given modulation to modulate power with modulation frequency Fmod&;&;(F1-F0), pass the received signal through the distribution environment, take it in the receiving device overlaid with the distribution environment narrowband interference filter in the frequency band (F0F1), generate two signals, one of which receives the gain filtered in the frequency band (F0F1signal limiting its amplitude, as well as a second signal using the aforementioned filtered signal or linearly amplified without changing the shape of the filtered signal, Peremohy received two signals, the resulting signal is signal and scientists demodulator to receive the information signal, whereFut- frequency band of the spectrum change of the square of the voltage amplitude narrowband interference.In Fig.1 presents a block diagram of a device implementing the method of suppressing narrowband interference in a broadband system;in Fig.2 is a block diagram of the propagation medium;in Fig.3 - form filtered in the frequency band (F0F1the signal obtained after amplification and restriction;in Fig.4 - shape filtered in the frequency band (F0F1) signal or linearly amplified filtered in the frequency band (F0F1signal; andin Fig.5 spectrum of the resulting signal obtained after multiplication of these two signals;in Fig.6 - range filtered in the frequency band [Fut, ((F1-F0)] the resulting signal.A device that implements the method of suppressing narrowband interference in a broadband system contains the transmit path, which includes connected in series generator 1 broadband noise signal, the modulator 2 and the transmitting antenna 3 (Fig.1), the signal from which is through the distribution environment (Fig.2) is fed to the receiving antenna 3’ prinimaya , F1), the output of which is connected to the input of the amplifier 6. The output of the amplifier 6 is connected to the input of the linear amplifier 7 and the amplifier 8 with the constraint that the outputs are connected to the inputs of block multiplication 9 connected to the output to the input of bandpass filter 10 bandwidth [Fut, (F1-F0)]. From the output of bandpass filter 10, the signal is supplied to the input unit 11 allocation of the envelope of the signal filtered in the frequency band [Fut(F1-F0)]. The received signal at the demodulator 12 to highlight the information signal.The considered method of suppressing narrowband interference in a broadband system is as follows.In the transmitting tract of the generator 1 form a broadband noise signal in the frequency band (F0F1), which modulate power (modulator 2) according to a given modulation with a modulation frequency Fmod&;&;(F1-F0). The received signal is transmitted in the distribution environment, such as radio waves (Fig.2), where it is superimposed narrowband interference. Usado-modulated, frequency-modulated, scanning and so on, but must satisfy the following conditions: frequency narrowband interference Futsatises F0<F<Fand the frequency band of the spectrum change of the square of the amplitude of the voltage noise (Futmust be much less than the frequency band of the spectrum change of the square of the voltage amplitude modulated broadband noise signal at the point of reception. Thus, the input of the receiving device receives the signal, equal to the vector sum of the voltages of the useful signaland narrowband interferenceThis mixed signal is fed to the input of bandpass filter 5 with a bandwidth of frequencies (F0F1). Then the filtered signal is pre-amplified by the amplifier 6, is divided into two signals. The first receive signal after amplification filtered in a specified frequency band signal and limiting its amplitude in the amplifier 8. When a signal with interference through the amplifier-limiter interference suppress the useful signal and its output signal is formed of the normalized values ofIn the linear amplifier 7. Linear amplifier 7 does not alter the shape of the filtered signal and it will beThe form of these two signals is shown in Fig.3, 4, respectively. Received two signals received at the respective inputs of block multiplication that multiplies them, providing output the resulting signal, whose spectrum is shown in Fig.5. Then the resulting signal is filtered bandpass filter 10 bandwidth [Fut(F1-F0)]. When narrowband interference is a local oscillator for the useful signal and in the condition in which the frequency band of the spectrumFutmuch less than the frequency band of the spectrum change of the square of the voltage amplitude modulated broadband noise signal, after transmission of the resulting signal multiplication through the band-pass filter with a bandwidth of frequencies [Fut(F1-F0)] is excluded itself narrowband interference Fig.6. Highlighting the next envelope of the filtered signal, the received useful signal, modulated power, which is further processed by known laws of tvline in a variety of ways, for example, using the amplitude-frequency modulation or pulse modulation using any of the methods of coding and pseudo-random sequences.Thus, the information is then stored in the power change signal and transmitted across the frequency band (F0F1), and when the transfer range during processing in the receiver is moved together with the spectrum.From this it follows that the limiting factor for this method of suppressing narrowband interference is a band of the spectrum of changes in the power of interference, and not the frequency band occupied by the disturbance in the air that can suppress and even scanning a hindrance, not knowing the real location it in the air.Sources of information1. Address, control and communications systems. /Edited TUZOVA, I. M.: Radio and communication, 1993, S. 256-259, 261-264.2. EN 2127021 C1 (KALUGIN centuries and others), 27.02.1999.
ClaimsThe method of suppressing narrowband interference in a broadband system, wherein in the transmitting tract form a broadband noise signal in the frequency band (F0F1), modulate the broadband noise signal according to a given modulation to modulate power frequency seize him in the receiving device overlaid with the distribution environment narrowband interference, filtered in the frequency band (F0F1), generate two signals, one of which receives the gain filtered in the frequency band (F0F1signal limiting its amplitude, as well as a second signal using the aforementioned filtered signal or linearly amplified without changing the shape of the filtered signal, Peremohy received two signals, the resulting signal is filtered in the frequency band [Fut, (F1-F0) allocate envelope of the received signal and demodulator to receive the information signal, whereFut- frequency band of the spectrum change of the square of the amplitude of the voltage noise.
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