CN202995039U - Underwater object detection system based on frequency spectrum cognition and segment frequency hopping modulation - Google Patents

Underwater object detection system based on frequency spectrum cognition and segment frequency hopping modulation Download PDF

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CN202995039U
CN202995039U CN 201220488278 CN201220488278U CN202995039U CN 202995039 U CN202995039 U CN 202995039U CN 201220488278 CN201220488278 CN 201220488278 CN 201220488278 U CN201220488278 U CN 201220488278U CN 202995039 U CN202995039 U CN 202995039U
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frequency
frequency hopping
signal
detection
control subsystem
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韦岗
张琪
杨萃
陈建量
马丽红
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South China University of Technology SCUT
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Abstract

The utility model discloses an underwater object detection system based on frequency spectrum cognition and segment frequency hopping modulation. The system comprises a control center and a detection apparatus. The control center comprises an emission control subsystem and a reception control subsystem. The two subsystems are both connected with the detection apparatus. The system uses a cognitive method of combining active and passive. A frequency spectrum detectaphone passively listens to underwater frequency ranges, and an available frequency range table is obtained. A transmitting terminal generates chirp signals from high to low according to the frequency range in the table, and the chirp signals are transmitted by a transmitting probe. After a receiver receives an echo signal, emission parameters such as transmitting power, modulation parameters, etc. can be adjusted according to quality of the echo signal, so that detection is more accurate. The system enables to adjust the emission parameters in real time according to channel quality conditions, and resists high attenuation and strong multipath interference, thereby realizing accurate and reliable underwater detection. The system can resist high attenuation and strong multipath interference, and adjusts the emission parameters in real time according to the channel quality conditions, thereby realizing accurate underwater detection.

Description

Immersed body detection system based on spectrum cognitive and segmentation frequency hopping frequency modulation
Technical field
The utility model relates to the undersea detection technical field, is specifically related to the closely immersed body detection system based on spectrum cognitive and segmentation frequency hopping frequency modulation.
Background technology
Since entering 21 century; the mankind are research and development of more and more paying attention on economy, military affairs or environmental protection problem the ocean; thereby the detection of submarine target is the problem that we usually run in the process that develops the ocean; it refers to by means such as acoustics, optics and electromagnetics, the process of utilizing the equipment such as sonar, underwater television and magnetic spy instrument that submarine target is surveyed, observes and identified.
With the target detection of land different be, the channel that the undersea detection signal is propagated than the land various wired, wireless channel is more complex, this is mainly reflected in four aspects:
Can produce absorption loss when detectable signal is propagated under water, gradate and be heat energy, be called absorption loss.Absorption loss is relevant with factors such as seawater component, temperature, pressure, signal frequency and circulation ways, is not fixed value;
Figure 320811DEST_PATH_IMAGE002
Channel has the advantages that strong multipath disturbs under water: when the close sea of detecting devices or seabed, can make signal that refraction or reflex occur; Or when having bubble or other impurity in seawater, also the phenomenons such as reflection, scattering can appear;
Figure DEST_PATH_IMAGE003
Complicated marine background noise: in marine environment, the noise that the nature such as sea stormy waves, sea life activity, maritime shipping and human activity produce, can form with generation such as sea, seabed and water body interaction the ground unrest field of a complexity, i.e. ambient sea noise in communication process.Ambient sea noise is complicated and changeable, with the meteorological condition in position, near region and the far field of position, marine site, detecting devices and signal frequency etc., relation is arranged;
Figure 436535DEST_PATH_IMAGE004
Channel is a random time-varying channel under water: the sea of random fluctuation, at random, the factors such as the bubble layer of non-homogeneous, astatic Seawater and distribution thereof, morning and evening tides, stormy waves, internal wave of ocean make under water that channel is the time varying channel of a complexity, therein, the velocity of propagation of detectable signal, decay etc. all can change constantly, and are difficult to obtain its statistical property.
In a word, channel is that an extremely complicated time-space-frequency becomes the random narrow-band channel of ginseng under water, has the characteristics such as height is decayed, strong multipath disturbs, Doppler frequency deviation is serious, available band is narrow.Above-mentioned reason makes under water the accurate detection to the detection of a target become very difficult.Due to the penetration capacity of radiowave under water very a little less than, basically can't propagate in seawater, thereby present Underwater Target Detection technology is main toward optical detection and this both direction development of acoustic sounding.And in fact, the underwater propagation characteristic of light wave is also also not fully up to expectations, and its decay is very fast, and scattering phenomenon is serious, so its detection range is very limited, and detection accuracy is not high yet.
The acoustic sounding technology is divided by working method, can be divided into active probe and passive detection dual mode.Active probe refers to initiatively send one or more detectable signals (sound wave or ultrasound wave) to the detection of a target by detecting devices, the detectable signal arrival detection of a target can produce echoed signal behind the place, receive and analyze so echoed signal by detecting devices, can identify the relevant information such as position, shape, material of the detection of a target.And passive detection does not have special emission coefficient, does not send detectable signal, and it is identified and detection of a target object by the radiated noise of receiving target, determines the state of target and character etc.
The method that traditional active undersea detection system takes usually is:
Figure 338632DEST_PATH_IMAGE001
On transmitter, often adopt the simple signal of preset parameter or linear FM signal conduct to transmit.Although use the square wave of short pulse width can obtain range resolution preferably, but simple signal is subject to the Doppler effect impact in the air, Doppler shift resolution and range resolution can't get both, and autocorrelation is relatively poor, not only easily cause between different detectable signals to interfere with each other, the clutter that also easily other foreign bodies is reflected back receives as echoed signal.Although and the employing linear FM signal can be resisted Doppler effect preferably, considers the strong polytrope of underwater environment, the detectable signal of preset parameter (modulation centre frequency, pulse width etc.) is difficult to keep superperformance.
Tradition undersea detection system considers that seawater is stronger to high-frequency wave absorption ability, for guaranteeing the robustness of system, generally all chooses the transmitted wave of low-frequency range.Yet the ambient sea noise energy relative high frequency section of low-frequency range is much bigger, makes transmitting terminal have to increase considerably transmit signal power and obtains reliable signal to noise ratio (S/N ratio), particularly for the weak wisp of self reflection potential;
Figure 174049DEST_PATH_IMAGE003
On receiver, usually be based upon on desirable optimum receiver theoretical foundation, environmental baseline is done idealized processing.As in signal processing, random signal as ergodic processing, is processed uneven background as homogeneous background, and ignored the uncertain factors such as multipath effect in marine environment, marine background noise and edge effect.Thereby measurement result and the larger gap of actual conditions existence, and the receiver parameters of preset parameter and signal processing method, can't guarantee the optimum in marine environment complicated and changeable at all;
Figure 93464DEST_PATH_IMAGE004
Although the part detection system has been carried out optimization filtering at receiving end to echoed signal, consider that the optimization wave filter need to carry out modeling to the ocean underwater acoustic channel of complexity, calculated amount is huge, can't realize real-time detection.
In order to realize in environment under water accurately, to survey reliably, can carry out real-time cognition to underwater environment in conjunction with cognitive radio technology, the parameters such as the frequency that transmits by adjustment and power obtain reliable result of detection.Specifically:
Figure 787750DEST_PATH_IMAGE001
Can be in conjunction with cognitive radio technology, channel is under water led the passive spectrum cognitive that combines.By spectrum cognitive, the channel of selecting to conform to quality requirements is surveyed.Simultaneously, the spectrum cognitive process is followed whole detection process, therefore can solve well underwater environment complexity and changeable problem;
Figure 337566DEST_PATH_IMAGE002
The linear FM signal of employing centre frequency saltus step is resisted polytrope and the strong Doppler effect of underwater environment.Linear FM signal is a kind of nonlinear phase modulation signal, and it is producing the pulse compression phenomenon through meeting after matched filter, thereby can obtain a burst pulse at output terminal, obtains better range resolution under the prerequisite that guarantees certain signal to noise ratio (S/N ratio).It has the advantage of two aspects: at first, the matched filter of linear FM signal is insensitive to the Doppler shift of echoed signal, even echoed signal has larger Doppler shift, still can play the pulse compression phenomenon through matched filter, make the energy of output signal mostly concentrate on main lobe, this can simplify the echo signal processing system greatly.Secondly, because having good autocorrelation performance, linear FM signal (it is divided subband, have fixing frequency displacement and phase shift relation between each subband waveform), only need that echoed signal is carried out simple correlation analysis and can distinguish objective body echoed signal and undesired signal.
Figure 445199DEST_PATH_IMAGE003
Adopt the frequency hopping modulation technique, with the cognitive ultrasonic carrier that obtains to the LMF(linear frequency modulation) signal modulates, and carries out the transmission of detectable signal on reliable frequency range.Frequency hopping pattern is cognitive resulting available frequency band, realizes simply guaranteeing the real-time of system.
The utility model content
The purpose of this utility model is for the generally consideration of shortage to actual underwater environment in realization of prior art, but by experiment or the method for emulation obtain under water that channel model designs the immersed body detection method, make result of detection and actual conditions have larger difference, the immersed body detection system based on spectrum cognitive and segmentation frequency hopping frequency modulation is provided.The utility model is taked the main passive cognitive approach that combines, and to frequency range passive listening under water, obtains an available frequency band table (frequency is order from high to low) by the spectrum sensing device.Transmitting terminal produces successively from high to low linear FM signal according to the table Mid Frequency and sends by sending probe.Receiver can be surveyed with realization more accurately according to the emission parameters such as emissive power and modulation parameter of quality adjustment of echoed signal after receiving echoed signal.This undersea detection method can be adjusted the transmission parameter in real time according to channel quality status, can resist high the decay and disturb with strong multipath, thereby realize accurate, reliable undersea detection.
The purpose of this utility model is achieved through the following technical solutions.
Immersed body detection system based on spectrum cognitive and segmentation frequency hopping frequency modulation, comprise control center and sniffer, described control center comprises Launch Control Subsystem and reception control subsystem, and Launch Control Subsystem all is connected with sniffer with the reception control subsystem.
described Launch Control Subsystem comprises the spectrum sensing device, several bandpass filter (BPF), parallel/serial converter, squarer, integrator, decision device, signal generator, the LFM modulator, the frequency hopping modulator, frequency hopping frequency meter and frequency synthesizer, wherein, the spectrum sensing device is connected with several bandpass filter, each bandpass filter all is connected on parallel/serial converter, parallel/serial converter, squarer, integrator, decision device, signal generator, the LFM modulator is connected with the frequency hopping modulator and is connected, the frequency hopping frequency meter is connected with decision device, frequency synthesizer is connected with the frequency hopping frequency meter and is connected to the frequency hopping modulator,
Described reception control subsystem comprises filtering detecting device, frequency hopping detuner, frequency hopping frequency meter, frequency synthesizer and signal processor, wherein, the filtering detecting device is connected with the frequency hopping detuner, the frequency hopping frequency meter is connected with the frequency hopping frequency meter of above-mentioned Launch Control Subsystem, frequency synthesizer is connected with the frequency hopping frequency meter, and being connected to the frequency hopping detuner, the frequency hopping detuner connects signal processor;
Described sniffer comprises several probes, and these probes are transmission probe or the receiving transducers with simplex mode work, or pops one's head in the sending/receiving of duplex mode work.
This detection system is mainly used in the lake, shallow sea, and the wisp in hundred meters is accurately surveyed, and can be used for the salvaging of wisp under water, also can use on the water or in submarine navigation device, clash into wisp under water to prevent aircraft.
The detection method of described closely immersed body detection system based on spectrum cognitive and segmentation frequency hopping frequency hopping comprises following steps:
Step 1, by the spectrum sensing device in Launch Control Subsystem, whole undersea detection frequency range is intercepted, and the signal that receives is delivered to several bandpass filter (frequency spectrum is divided into N frequency range, the centre frequency of bandpass filter is the centre frequency of each frequency range), then carry out parallel/serial conversion;
Step 2 successively by the squarer sum-product intergrator, is calculated the energy of the reception signal of each frequency sub-band through the serial signal after parallel/serial conversion, and squarer is all identical with the work period of spectrum sensing device with the work period of integrator;
Step 3, the energy of each frequency sub-band reception signal that calculates is sent into successively decision device and is adjudicated, and the frequency sub-band centre frequency that will satisfy detection condition (energy is lower than certain threshold value) is recorded in the frequency hopping frequency meter, and wherein Launch Control Subsystem is synchronizeed renewal with the frequency hopping frequency meter that receives control subsystem;
Step 4 is carried out the base band linear frequency modulation by the raw digital signal that signal generator produces through the LFM modulator;
The M.U.F. that step 5, frequency synthesizer are selected to record in the frequency hopping frequency meter is synthesized local oscillation signal, controls the frequency hopping modulator base band linear FM signal of LFM modulator output is carried out the frequency hopping modulation.After the transmission of completing a detectable signal, continuing frequency hopping modulation and signal transmission every an interval time---the frequency of frequency hopping modulation this moment is just selected inferior high frequency in the frequency hopping frequency meter, so continue, until receive the echo that is reflected by the detection of a target;
Step 6 in receiving control subsystem, is delivered to the filtering detecting device by the information that receiving transducer receives, and carries out to received signal filtering, and the signal demodulation after then by the frequency hopping detuner, filtering being processed is sent at last and carried out echo analysis in signal processor.If not satisfying to survey, the echoed signal that receives do not require (indistinguishable that causes as too low in received signal power goes out to expect echoed signal and ground unrest etc.), receive control subsystem and can transmit corresponding signal to Launch Control Subsystem, require to adjust transmission parameter (as emissive power, chirp slope etc.) and re-start detection, to guarantee accurately to survey purpose.
In step 5, consider the uncertainty of underwater environment, in order to improve the work efficiency of system, do not wait for that receive this echoed signal just begins later on to send next time in the process that sends detectable signal, but send incessantly detectable signal (with Fixed Time Interval) at transmitting terminal, until till receiving echoed signal.
In step 6, described requirement to the echoed signal quality is to be determined by the actual detection demand, can be the isoparametric requirement of signal to noise ratio (S/N ratio), resolution to echoed signal.
The utility model compared with prior art has the following advantages:
1. undersea detection method described in the utility model, in transmitting terminal adaptively modifying detectable signal parameter, do not need the underwater acoustic channel of complexity is carried out modeling, avoided numerous and diverse computing, and real-time is high, guarantees the quality of each detectable signal, realizes accurately surveying;
2. undersea detection method described in the utility model, take to lead the method that passive cognition combines when channel quality is detected, and can greatly improve the work efficiency of system under the prerequisite that guarantees channel quality;
3. undersea detection method described in the utility model, select successively the high band in usable frequency to survey, to reduce the impact (because ambient sea noise mainly concentrates on low frequency range) of ground unrest, improve the resolution of robustness and echoed signal, especially for the weak wisp under water of self reflection potential.In addition, because the utility model is for proximity detection under water, in the detection range scope, the attenuation degree almost not impact of frequency height on underwater sound signal;
4. undersea detection method described in the utility model, for the characteristics of underwater acoustic channel, adopted special frequency-hopping method, utilizes the result of spectrum cognitive, selects from high to low carrier frequency, greatly simplified the implementation procedure of traditional frequency-hopping system;
5. undersea detection method described in the utility model adopts chirped modulator approach to detectable signal, makes detectable signal have the characteristics of permanent envelope, can resist the problem of high decay and strong Doppler shift in channel under water.
Description of drawings
Fig. 1 is the structural representation of detection system in embodiment.
Fig. 2 is the groundwork schematic flow sheet of detection system in embodiment.
Fig. 3 is the detailed operation process flow diagram of detection system in embodiment.
Embodiment
Describe the utility model in detail below in conjunction with accompanying drawing, but protection domain of the present utility model and embodiment are not limited to this.
based on the immersed body detection system structural representation of spectrum cognitive and segmentation frequency hopping frequency modulation as shown in Figure 1, comprise following four parts: control center's (comprise emission control and receive and control two parts), sniffer, channel model and the detection of a target, the annexation of each several part and signal transitive relation are as shown in the figure, wherein 10 is control center, 110 are emission control, 1101 is the spectrum sensing device, 1102 is bandpass filter (BPF), 1103 is parallel/serial converter, 1104 is squarer, 1105 is integrator, 1106 is decision device, 1107 is signal generator, 1108 is the LFM modulator, 1109 is the frequency hopping modulator, 1110 is the frequency hopping frequency meter, 1111 is frequency synthesizer, 120 control for receiving, 121 is signal processor, 122 is the frequency hopping detuner, 123 are the filtering detection, 20 is sniffer, 30 is channel model, 31 is fading channel, 32 is noise, 33 is scatterer, 40 is the detection of a target.
during work, at first intercepted by 111 pairs of whole frequency ranges of spectrum sensing device, this spectrum sensing device should be that (the reception bandwidth of existing nautical receiving set can satisfy the demand of native system to a wideband receiver substantially, the receiving belt wide region all can reach the hundreds of hertz---tens megahertzes), can be better and truly and delicately receive the signal s (t) of whole frequency range, next s (t) sends into N bandpass filter 1102(BPF1-BPFN), the centre frequency of this N bandpass filter is respectively the centre frequency of N sub-frequency bands, bandwidth is the bandwidth F of sub-band.As representing total bandwidth (frequency range is [B_1-B_2]) take B, N represents the sub-band sum divided, and f represents the space of adjacent two intersubbands, F represent sub-band bandwidth (sub-band bandwidth with modulate after the signal bandwidth of detectable signal identical).B=(N-1 is arranged) * (F+ f)+F, the centre frequency of i bandpass filter is B_1+(i-1) * (F+f)+F/2.Obtain N bandpass signal after N bandpass filter of s (t) process:
Figure DEST_PATH_IMAGE005
,
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,
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...,
Figure 513835DEST_PATH_IMAGE008
The bandwidth of this N bandpass signal is F, and the duration is the time of reception T of spectrum sensing device 111.N parallel bandpass signal
Figure 664194DEST_PATH_IMAGE005
, ,
Figure 192444DEST_PATH_IMAGE007
..., Through the parallel/serial serial signal that is converted to
Figure 917004DEST_PATH_IMAGE010
Figure DEST_PATH_IMAGE011
Pass through successively squarer 1104 sum-product intergrators 1105, and the work period of squarer sum-product intergrator be T, therefore successively will can think
Figure 733650DEST_PATH_IMAGE005
, ,
Figure 118681DEST_PATH_IMAGE007
...,
Figure 610842DEST_PATH_IMAGE008
This N signal is sent into the squarer sum-product intergrator and is carried out the quadratic sum Integral Processing.Obtain energy signal:
Figure 586888DEST_PATH_IMAGE012
The energy signal E (t) that obtains sends into decision device 1106 and adjudicates, and the work period of decision device is also T, and the result of judgement comprises
Figure DEST_PATH_IMAGE013
,
Figure 189908DEST_PATH_IMAGE014
These two states:
Figure 895696DEST_PATH_IMAGE016
Wherein
Figure DEST_PATH_IMAGE017
Be decision threshold, be pre-determined according to surveying purpose (as, if whether only need to differentiate target exists, and do not need the information such as shape, material of the detection of a target, threshold settings can be got so relatively low, must be higher with threshold settings if need the details of target to need.And threshold value itself can be done corresponding adjustment in follow-up adjustment process).When intercepting received signal energy of period lower than this threshold value, represent that the noise energy in this sub-band is lower, this detection can be used this frequency range; When intercepting received signal energy of period higher than this threshold value, represent that the noise energy in this sub-band is too high, this frequency range can not be used.The court verdict of decision device is sent in frequency hopping frequency meter 1110 and is recorded.
Signal generator 1107 produces raw digital signal x (t), and (be assumed to rectangular pulse signal here, pulse height is A, and width is
Figure 293179DEST_PATH_IMAGE018
):
Figure 84418DEST_PATH_IMAGE020
X (t) sends into LFM modulator 1108 and carries out linear frequency modulation, obtains linear FM signal y (t):
Wherein
Figure DEST_PATH_IMAGE023
The instantaneous frequency of expression linear FM signal y (t) changes slope.Frequency synthesizer 1111 produces local oscillation signal according to the highest frequency in usable frequency in the frequency hopping frequency meter and (supposes that herein frequency is as ultrasonic carrier
Figure 785843DEST_PATH_IMAGE024
), linear FM signal y (t) is carried out the frequency hopping modulation, obtain Frequency Hopping Signal z (t):
Figure 291911DEST_PATH_IMAGE026
Frequency Hopping Signal z (t) sends into sniffer, is carried out the transmission of detectable signal by transmitting probe.The probe that control center can select to be in idle condition arbitrarily from n transmitting probe carries out the transmission of detectable signal.
The detectable signal that sends through transmitting probe transmits in underwater acoustic channel, and because the absorption of seawater can produce decay, the signal after decay produces echoed signal v (t) after arriving the detection of a target; In addition, when detectable signal transmits in underwater acoustic channel, except meeting produces decay, also can produce multipath effect due to scatterers 33 such as running into bubble or impurity---reverberation u (t), reverberation u (t) and echoed signal v (t) are superimposed, experience again the decay of underwater acoustic channel, and with the ocean in neighbourhood noise and be superimposed from the interference (being referred to as noise 32) of the signal of other detections or communication facilities, obtain signal r (t).
The received probe of signal r (t) receives.Due in the emission control part, detectable signal is to send continuously, and due to the complicacy of channel under water, and the signal that receiving transducer receives may be without any rule on frequency range, so n receiving transducer also must possess the ability of broadband reception.And, select all should to remain on the duty of reception as other several probe of transmitting probe not being launched control section.
suppose that receiving transducer can carry out the reception of signal undistortedly, be also, the signal of being passed to control center 10 by receiving transducer still is r (t), filtering detecting unit 123 to received signal r (t) carry out filtering (can utilize herein a bandpass filter such as Butterworth bandpass filter to received signal r (t) carry out bandpass filtering, filter bandwidht is the subband bandwidth, the filtering broadband noise), the signal that obtains after filtering is sent into successively frequency hopping detuner 122 and is carried out the frequency hopping demodulation, the frequency hopping frequency meter of wherein controlling the frequency hopping detuner is identical (the synchronous renewal) with emission control part 110.At last, the signal after demodulation is sent into the operation of carrying out echo analysis in signal processor 121.For narrow band signal, all useful informations that namely comprised signal in its complex envelope, therefore can get envelope operation to conciliating the signal of jumping through filtering herein---can utilize the Hilbert method to obtain signal envelope, next signal be sent into low-pass filter and carried out smoothing processing.At last, envelope waveform is carried out the spectrogram that Fourier transform (FFT) can obtain envelope.Analysis spectrum figure, can judge whether the detection of a target exists, and can pass through repeatedly and the detection of different azimuth, the echoed signal that the different target bright spot that receives by analysis is returned, obtain the target strength information of the relevant detection of a target, can be used for the shape of the detection of a target, material etc. are carried out modeling analysis.
If through echo analysis, the requirement that the quality of finding echoed signal can't reach accurate detection (for example, the frequency resolution that obtains in aforesaid operations is too low etc.), inner in control center so, receive to control to send and adjust signal to emission control, correspondingly adjust emissive power (keeping existing transmission frequency, i.e. the frequency hopping frequency).
In present embodiment, what take is first to carry out passive listening before each the detection, judges available frequency range, and then is tried out by the detectable signal that the detecting devices transmission modulates.The resource utilization of the method mode is high---and detecting devices need not to continue to intercept channel status, is fit to this mode when the frequency of utilization of detecting devices is hanged down.When if the frequency of utilization of detecting devices is higher, can with regular time the interval as
Figure DEST_PATH_IMAGE027
Each subchannel is intercepted, utilize the result of energy measuring and decision unit to refresh available band table, and intercept again after not needing to wait for the detection process startup.When actual the detection, the highest available frequency band in the available frequency band table after only the needs employing refreshes carries out the frequency hopping modulation to detectable signal and gets final product so.
The above; it is only the better embodiment of the utility model; but protection domain of the present utility model is not limited to this; anyly be familiar with those skilled in the art in the technical scope that the utility model discloses; the variation that can expect easily or replacement are within all should being encompassed in protection domain of the present utility model.Therefore, protection domain of the present utility model should be as the criterion with the protection domain of claim.

Claims (3)

1. based on the immersed body detection system of spectrum cognitive and segmentation frequency hopping frequency modulation, comprise control center and sniffer, it is characterized in that: described control center comprises Launch Control Subsystem and reception control subsystem, and Launch Control Subsystem all is connected with sniffer with the reception control subsystem;
described Launch Control Subsystem comprises the spectrum sensing device, several bandpass filter, parallel/serial converter, squarer, integrator, decision device, signal generator, the LFM modulator, the frequency hopping modulator, frequency hopping frequency meter and frequency synthesizer, wherein, the spectrum sensing device is connected with several bandpass filter, each bandpass filter all is connected on parallel/serial converter, parallel/serial converter, squarer, integrator, decision device, signal generator, the LFM modulator is connected with the frequency hopping modulator and is connected, the frequency hopping frequency meter is connected with decision device, frequency synthesizer is connected with the frequency hopping frequency meter and is connected to the frequency hopping modulator.
2. the immersed body detection system based on spectrum cognitive and segmentation frequency hopping frequency modulation according to claim 1, it is characterized in that: described reception control subsystem comprises filtering detecting device, frequency hopping detuner, frequency hopping frequency meter, frequency synthesizer and signal processor, wherein, the filtering detecting device is connected with the frequency hopping detuner, the frequency hopping frequency meter is connected with the frequency hopping frequency meter of above-mentioned Launch Control Subsystem, frequency synthesizer is connected with the frequency hopping frequency meter, and being connected to the frequency hopping detuner, the frequency hopping detuner connects signal processor.
3. the immersed body detection system based on spectrum cognitive and segmentation frequency hopping frequency modulation according to claim 1, it is characterized in that: described sniffer comprises several probes, these probes are transmission probe or the receiving transducers with simplex mode work, or pop one's head in the sending/receiving of duplex mode work.
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CN105022033A (en) * 2015-06-26 2015-11-04 李广柱 Radar device and control method
CN108318882A (en) * 2017-12-28 2018-07-24 中国船舶重工集团公司第七0研究所 A kind of self-conductance canister shell side cooler echo detecting and direction-finding method
CN108882247A (en) * 2018-07-04 2018-11-23 西北工业大学 A kind of cognitive radio networks resource allocation methods based on Contract Theory
CN109459731A (en) * 2018-12-13 2019-03-12 广州极飞科技有限公司 Signal processing method and device, millimetre-wave radar

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105022033A (en) * 2015-06-26 2015-11-04 李广柱 Radar device and control method
CN105022033B (en) * 2015-06-26 2018-01-05 李广柱 Radar installations and control method
CN108318882A (en) * 2017-12-28 2018-07-24 中国船舶重工集团公司第七0研究所 A kind of self-conductance canister shell side cooler echo detecting and direction-finding method
CN108882247A (en) * 2018-07-04 2018-11-23 西北工业大学 A kind of cognitive radio networks resource allocation methods based on Contract Theory
CN108882247B (en) * 2018-07-04 2019-07-30 西北工业大学 A kind of cognitive radio networks resource allocation methods based on Contract Theory
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