CN102904849B - Burst communication system utilizing transient peak energy - Google Patents

Abstract

Disclosed is a burst communication system utilizing transient peak energy. A transmitter adopts a simplified expanded binary phase shift keying modulation mode, a receiver comprises a receiving antenna, the receiving antenna is connected with an analog receiver, the analog receiver is connected with an analog-to-digital converter, the analog-to-digital converter is connected with an EBPSK (expanded binary phase shift keying) digital modulator, and the EBPSK digital modulator is connected with a frame processor; the analog receiver comprises a pre-amplifier, the pre-amplifier is connected with a frequency mixer, and the frequency mixer is connected with an intermediate-frequency amplifier; and the EBPSK digital modulator comprises a digital impacting filter, the digital impacting filter is connected with a preprocessor, the preprocessor is connected with a return-to-zero decision device, the return-to-zero decision device is connected with a delay calculation module, both the delay calculation module and the preprocessor are connected to a variable delayer, the variable delayer is connected with an integration decision device, the return-to-zero decision device is further connected with a clock generator, the clock generator is connected to the integration decision device, and a frequency synthesizer is respectively connected to the frequency mixer and the clock generator.

Description

Burst communication system using transient peak energy

Technical field

The invention belongs to digital communication and wireless sensor network technology field, it is specifically related to one kind and utilizes receipt signal Transient peak energy during setting up transmits the hypervelocity burst communication method of short data or small data packets.

Background technology

1st, Sensor Network and burst communication

Wireless sensor network (WSN：Wireless Sensor Network) be Internet of Things important support, typically The multi-hop data communication network being made up of with self-organizing form the automatons being spatially distributed in a large number, so as to by Monitoring Data It is sent to reception center to be processed.The node of WSN, in addition to being equipped with one or more sensors, also equipped with transceiving letter Machine and microcontroller, size and cost depend on the scale of WSN and the complexity of single sensor node.Generally this WSN section Put minicell to be leaned on to power, its time-to-live is primarily limited to the life-span of battery, therefore energy-conservation makes for extending WSN node Most important with the life-span, also more meet current pursuit energy-saving and emission-reduction, the demand for development of environmental protection.

Because radio transmitter is the main modular of power consumption in WSN node, therefore shorten the work of transmitter by fair means or foul Make the time, can effectively extend the work timing of WSN node, and reduce for other WSN nodes and whole sensing network Interference, thus improve the capacity of whole wireless sensor network.Therefore, WSN wishes that each node can be as short as possible " sudden Send out " complete the transmission of data in the period.

In addition, there being expert analyzing scouting, the impact to antijam communication for the perturbation technique of external high frequency (HF) frequency range After point out：Narrow band signal length is just difficult to be trapped less than 50ms, is just difficult to be directed/position less than 110ms.And to very high Frequently/hyperfrequency (VHF/UHF) frequency range, signal length also should be shorter.Therefore, anti-interference, anti-intercepting and capturing burst communication preferably exists Information transfer is completed, this wishes or require to have in the lasting moment of signal of communication efficiently to adjust as far as possible naturally in 10ms magnitude System/efficiency of transmission.

2nd, the extended binary phase shift keying modulation simplifying

1) availability of frequency spectrum and capacity usage ratio

The broadband wireless services demand of rapid growth proposes higher and higher requirement to radio communication, directly results in sky In radio frequency more and more crowded, compression to greatest extent is wirelessly transferred frequency spectrum and has important practical significance and directly Economic benefit.The availability of frequency spectrum of digital communication system, the numeric code rate that can transmit in available units frequency band is (with bps/Hz table Show, but strictly speaking it should be the information rate after deducting chnnel coding or " net " code check) to examine, depend primarily on two Binary data code stream is modulated into shared bandwidth when sending frequency range analog carrier.

The capacity usage ratio of wireless communication system, can be directly with for reaching required technical specification or being to complete Given task work( Transmission power (W) needed for energy is measuring.But because antenna can introduce extra gain, (either transmitting antenna still receives sky Line) and the species with antenna and form and different, therefore with received signal to noise ratio (SNR) to examine more reasonable with directly.

2) integrated efficiency index

The availability of frequency spectrum and capacity usage ratio be any communication system portion must faced by basic index, but believed by classics The restriction of road capacity, the two be difficult to satisfactory to both parties, therefore can with bps/Hz/SNR as aggregative indicator come more objective, more fully assess. Condition should be compared under identical channel condition, the same bit error rate and equal net code check certainly.Its intension just like Pursue " (Bandwidth-Constrained) steps on the gas (pass high code check) and as far as possible fuel-efficient (saving transmission power) in bicycle road ".For by passing in a large number The wireless sensor network of sensor node self-organizing, even more so.Because it is conceivable that, no matter how remarkable " traffic Rule " (Networking protocol) is it is also difficult to be organized into the old wreck (code speed is low and high energy consumption) of a group low speed excessive fuel consumption efficiently long The traffic and transportation system (sensor network) in longevity.

The communication physical layer of existing WSN node, using traditional pseudo-random sequence Direct-Spread (DSSS) and classical BPSK/QPSK (binary system/quaternary phase-shift keying (PSK)) modulates, although technically ripe already, power efficiency highest in theory, Because spectrum efficiency is low, thus in same spectral bandwidth, data rate is low, needs short data more frequent for WSN is this The occasion of bursty transmission, may result in communication " shaking hands " slow (at least needing 30ms), data transfer slow (only 250kbps) and Power system capacity low (each receptive WSN nodes of access point institute is far below agreement nominal value), this is accomplished by the transmitting of node Machine and receiver are for longer periods started shooting, and have thus instead resulted in energy consumption increase, because in each functional module of WSN node, send out The machine of penetrating is power consumption " rich and influential family ".

3) the binary phase shift keying modulation extending

In patent of invention " unified Binary orthogonal skew keying modulation and demodulation the method " (patent No.： ZL200710025203.6 in), define the binary phase shift keying (EBPSK of a class extension：Extended Binary Phase Shift Keying) modulation：

s₀(t)=Asin ω_cT, 0≤t ＜ T

$s_1\left(t\right)=\left\{\begin{array}{cc}B\sin ({\mathrm{\&omega;}}_{c}t+\mathrm{\&theta;}),& 0\&le;t<\mathrm{\&tau;},0\&le;\mathrm{\&theta;}\&le;\mathrm{\&pi;}\\ A\sin {\mathrm{\&omega;}}_{c}t,& 0<\mathrm{\&tau;}\&le;t<T\end{array}---\left(1\right)\right.$

Wherein, s₀(t) and s₁T () represents code element " 0 " and the modulation waveform of " 1 ", ω respectively_cFor carrier angular frequencies；Code element week Phase T=2 π N/ ω_cContinue for N >=1 carrier cycle, the modulation time span τ=2 π K/ ω of " 1 " code element_cContinue for the N number of load of K ＜ Period of wave, K and N is integer and is modulated with ensureing complete cycle, and τ: T=K: N can be described as " modulation duty cycle ".

(1) in formula, the phase angle θ of carrier wave keying is less, and EBPSK detection performance is poorer.Therefore in order to ensure demodulation performance and Realize simple, take θ=π, another benefit thus brought is advantageous for receiver by amplitude limit come anti-channel fading and pulse Interference.Now (1) formula is reduced to

s₀(t)=Asin ω_cT, 0≤t ＜ T

$s_1\left(t\right)=\left\{\begin{array}{cc}-B\sin {\mathrm{\&omega;}}_{c}t,& 0\&le;t<\mathrm{\&tau;}\\ A\sin {\mathrm{\&omega;}}_{c}t,& \mathrm{\&tau;}\&le;t<T\end{array}---\left(2\right)\right.$

It can be seen that the section start that EBPSK modulated signal waveform now removes in data " 1 " have in short-term anti-phase and amplitude A+B Outside saltus step, its remaining part is continuous sine wave.

3rd, digital shock filter (Digital Impacting Filters)

For the asymmetric modulation of " 0 ", " 1 " different wave shape very little, the matched filtering for symmetric modulation waveform of classics Device and related detecting method are no longer optimal.In order to improve the demodulation performance for EBPSK modulated signal, the unlimited impulse of a class rings Should (IIR) digital filter, be made up of a pair of conjugation zero point and at least two pairs conjugate poles, signal carrier frequency higher than zero frequency but Less than all pole frequencies, and zero frequency and the close degree of pole frequency, at least to reach the 10 of signal carrier frequency^-3Magnitude. Thus, this wave filter passes through the precipitous trap-selecting frequency characteristic of its bandpass center, can be by EBPSK modulated signal at code element " 1 " place Modulates information (phase hit, cycle disappearance or pulse occur) is changed into obvious and strong parastic modulation impact, exports noise Ratio is significantly improved, or even (SNR ＜ 0) can highlight letter in the form of overshooting in the case of signal is flooded completely by noise Number modulation intelligence, therefore be referred to as digital shock filter or EBPSK signal numeral booster, but in code element " 0 " place then no phase The wave forms impact answered, as shown in Figure 1 (see " for strengthening the impact filtering method of asymmetric binary modulating signal ", patent of invention Publication number：CN101599754).

Using the shock filter of simple zero -3 limit, its transmission function shape is：

$\left(z\right)=\frac{b_0+b_1\&CenterDot;z^{-1}+b_2\&CenterDot;z^{-2}}{1-a_1\&CenterDot;z^{-1}-a_2\&CenterDot;z^{-2}-a_3\&CenterDot;z^{-3}-a_4\&CenterDot;z^{-4}-a_5\&CenterDot;z^{-5}-a_6\&CenterDot;z^{-6}}---\left(3\right)$

Wherein filter coefficient is：

b₀=1, b₁=-1.618092409933249, b₂=0.99990000250000044；

a₁=-4.5620074920961651, a₂=9.5862839416819483, a₃=-11.56698066110164,

a₄=8.4523528839743243, a₅=-3.5467147693005732, a₆=0.6855154433139603.

4th, sudden transmission

According to early-stage Study, if EBPSK is receiver signal to noise ratio snr ＞ 0dB, adjusted using EBPSK defined in (2) formula Transmission code rate processed is up to the 1/10 of communication carrier frequency.Therefore, if taking 10MHz as carrier frequency (HF frequency range) or intermediate frequency (VHF/UHF frequency Section), then can transmit 10000 data in 10ms burst-length, or 625 Chinese characters (each Chinese character 16).But this simply manages Think situation, because on the one hand, the data bit shared by synchronous head also to be deducted, chnnel coding etc.；On the other hand, receiver for The capture of burst of data string signal is progressively set up from scratch with synchronously, the synchronous or synchronous data bit not reached during stable state It is difficult correctly to detect, error is many.

For example, the phase-locked receive for 400MHz frequency range as shown in Figure 2 and 20MHz intermediate frequency are based on digital impact filtering EBPSK demodulator, take EBPSK signal waveform modulation duty cycle be K: N=2: 20, then can obtain 1Mbps code in 20MHz intermediate frequency Rate.Setting EBPSK demodulator analog-digital converter (ADC) sample frequency be 80MHz, that is, each intermediate frequency cycle can adopt at 4 points.Due to connecing Automatic growth control (AGC) circuit of receipts machine, the loop filter (LF) of phaselocked loop and narrow-band digital shock filter portion can Can there is larger time constant so that each sudden transmission, receipt signal portion has one (to scheme from foundation to stable transit time 3 is measured waveform), error will be adjudicated in not up to certain thresholding height, therefore transitional code element must be given up.Through reality Survey this transit time under above-mentioned waveform parameter and code check is 3.4ms, therefore in order to be properly received judgement, has abandoned the number of front 4ms According to.This code check (or transmission time) and the waste of emitted energy, just account for 40% in the length only packet of 10ms, and For shorter packet, then this Section Overhead will be more notable.Especially for typical application of higher wireless sensor network, Even if taking sufficiently high 16 ADC of precision, collection one secondary data is also only equivalent to 1 Chinese character；Once monitor 5 sensing amounts (as temperature, humidity, pressure, vibrations, displacement etc.), also only 80 net amount evidences, according to 1Mbps code check, 80 μ s can pass.But In order to ensure shock filter stable output signal, just need to wait for 4ms, cause the huge waste of resource.Therefore, for EBPSK The quick detection of burst signal of modulation and synchronization, are the keys effectively improving EBPSK burst communication performance.

5th, quick bit synchronization

In order to reduce the transit time of EBPSK receiver, we have disclosed a kind of " binary phase shift keying modulation of extension Burst communication fast synchronization method " (patent of invention publication number：CN101895387A), the method has got rid of the simulation in receiver Impact envelope directly is respectively fed to after threshold detector and variable delay quickly adjust by phaselocked loop and digital phase-locked loop, Accurate bit synchronization can be set up in 30 code elements.EBPSK receiver overall block-diagram based on this quick bit synchronization method is such as Shown in Fig. 4.

Compared with Fig. 2, because Fig. 4 eliminates the slower phaselocked loop of the process of foundation, thus the transient process of Fig. 5 shortens very Many.However, due to occurring in that signal amplitude again very after signal amplitude rises to peak value (near " A " point) in Fig. 5 Low valley point (near " B " point), signal to noise ratio here is minimum, bunchiness error code easily, thus in order to safe, generally work After point is selected in entrance stable state (after " C " point.And start just to actually enter stable state from " D " point), continuous in particular for transmission When code stream or big data bag.

Content of the invention

For realizing, object of the present invention is to provide a kind of sudden transmission time of complete data packet shortens to sub- millisecond The burst communication system of the utilization transient peak energy of level.

For solving above-mentioned technical problem, the present invention is achieved through the following technical solutions：

Using the burst communication system of transient peak energy, including transmitter and receiver, described transmitter is using simplification Extended binary phase shift keying modulation, modulation data expression formula is one of following 3 kinds of reduced forms of (2) formula：

1) anti-phase modulation (PRM：Phase Reversal Modulation)：

s₀(t)=sin ω_cT, 0≤t ＜ T

$s_1\left(t\right)=\left\{\begin{array}{cc}-\sin {\mathrm{\&omega;}}_{c}t,& 0\&le;t<\mathrm{\&tau;}\\ \sin {\mathrm{\&omega;}}_{c}t,& \mathrm{\&tau;}\&le;t<T\end{array}---\left(4a\right)\right.$

2) lack periodic modulation (MCM：Missing Cycle Modulation)：

s₀(t)=sin ω_cT, 0≤t ＜ T

$s_1\left(t\right)=\left\{\begin{array}{cc}0,& 0\&le;t<\mathrm{\&tau;}\\ \sin {\mathrm{\&omega;}}_{c}t,& \mathrm{\&tau;}\&le;t<T\end{array}---\left(4b\right)\right.$

3) burst pulse modulation (NPM：Narrow Pulse Modulation), similar to traditional pulsed radar signal：

s₀(t)=0,0≤t ＜ T

$s_1\left(t\right)=\left\{\begin{array}{cc}-\sin {\mathrm{\&omega;}}_{c}t,& 0\&le;t<\mathrm{\&tau;}\\ 0,& \mathrm{\&tau;}\&le;t<T\end{array}---\left(4c\right)\right.$

Described receiver includes one for receiving the reception antenna of modulated signal, and described reception antenna connects a simulation and receives Machine, described analog receiver connects an analog-digital converter, and described analog-digital converter connects an EBPSK digital demodulator, described EBPSK digital demodulator connects a Frame Handler；

Described analog receiver includes the preamplifier of the described reception antenna of a connection, and described preamplifier connects one Frequency mixer, described frequency mixer connects one and is used for connecting the intermediate frequency amplifier of described analog-digital converter, also includes a frequency synthesizer, Described frequency synthesizer connects described frequency mixer；

Described EBPSK digital demodulator includes one for connecting the digital shock filter of described analog-digital converter, described Digital shock filter connects a preprocessor, and described preprocessor connects a NRZ decision device, described NRZ decision device Connect a time delay computing module, described time-delay calculation module and described preprocessor are all connected to a variable delay, described can Become chronotron and connect one for connecting the integration decision device of described Frame Handler, in addition, described NRZ decision device is also connected with one Clock generator, described clock generator is also connected to described integration decision device, and meanwhile, described frequency synthesizer is also connected to institute State clock generator.

Further, described numeral shock filter is infinite-duration impulse response structure, by a pair of conjugation zero point and at least two Conjugate pole is constituted, signal carrier frequency is higher than zero frequency but is less than all pole frequencies, and zero frequency and pole frequency Near degree, the 10 of signal carrier frequency at least to be reached^-3Magnitude；

Further, described preprocessor is to take envelope to parastic modulation waveform produced by described numeral shock filter Absolute value；

Further, described NRZ decision device is carried out to the impact envelope that described preprocessor exports by threshold judgement Shaping, after obtaining NRZ, is simultaneously fed into described bit clock generator and described time-delay calculation module；

Further, when NRZ " 1 ", described time-delay calculation module measures its high level lasting time, according to Impact envelope highest point and the relative position relation of NRZ " 1 " trailing edge, obtain impacting the amount of delay of envelope；

Further, the initial time of described bit clock generator is alignd with the trailing edge of NRZ " 1 ", produces and transmission The corresponding bit synchronization clock of code check；

Further, amount of delay according to measured by described time-delay calculation module for the described variable delay dynamically adjusts punching Hitting the time delay of envelope, so that the rising edge of bit synchronization clock is alignd with the highest point of impact envelope, thus reaching bit synchronous mesh 's；

Further, the bit synchronization pulse that described integration decision device is exported using described bit clock generator is as time base Standard, makes decisions to after the envelope-sampling value integration in code element, that is, demodulates received data sequence；

Further, the bit synchronous code stream of bursting to described integration decision device output for the described Frame Handler, utilizes 11 Barker codes carry out coherent detection therewith, are just had after 11 Barker code frame heads " 11100010010 " is only detected The extraction of effect data message, this preamble detecting process completes discarding and initial the sentencing of valid data of invalid data simultaneously Disconnected it is achieved that frame synchronization.

The invention has the advantages that：

1. the phase of bursting is short, anti-intercepting and capturing is strong.Because receiver used is without analog phase-locked look and digital phase-locked loop, only utilize The impact filtering envelope of EBPSK modulated signal can set up accurate bit synchronization in 30 code elements, thus system work of originally bursting Make to respond the envelope oscillations phase in initial segment 0.2ms in EBPSK signal impact filtering, the therefore sudden transmission of short data can be in Asia The moment of Millisecond (or even shorter, if code check is higher) completes, and such miniature packet is more difficult to be trapped or disturb.

2. system energy efficiency height, more environmental protection.

1) design of Frame of the present invention ensure that described system makes full use of at the beginning of receiver shock filter transient response The moment high-amplitude overshoot period of beginning section carries out bursting of valid data, and now received signal to noise ratio is higher than meansigma methodss during stable state, no The transmission of only valid data is more reliable (or transmission power can be lower), and the available machine time of transmitter can shorten dramatically, special Be not conducive to the energy-saving of miniature data collection station and wireless sensor network node etc.；

2) EBPSK is single sine-shaped simple binary constant enveloped modulation, particularly MCM and NPM more on-line operation In the on off state of sine pulse, the linearity for last stage of transmitter power amplifier is greatly lowered, peak power (transient state " electricity Magnetic field impulse " communicate) and work efficiency higher；

3) no matter whether wireless sensor network node itself or its battery reclaim, and all can affect environment, and the present invention Be conducive to extending the service life of similar battery, thus help in minimizing battery level, and reduce carbon emission amount (low in energy consumption, send out Heat is necessarily low, and can suitably reduce battery production).

3. receiver is simpler, general, can be totally digitilized integrated.The receiver of the present invention is due to eliminating simulation lock phase Ring, the local oscillator that available common crystal produces replaces the RF Voltage-Controlled Oscillator compared with complex and expensive, without carrier synchronization And sample-synchronous, thus not only totally digitilized integrated demodulator is realized simpler inexpensive, and can be placed directly within any communication The intermediate frequency amplifier outfan of receiver, versatility is very strong.

4. power system capacity is big, and electromagnetic interference is low.The sudden transmission time due to single packet shortens dramatically, thus with when The capacity of the multi-user system that point multiple access (TDMA) mode is organized greatly increases, or vice versa, the electromagnetism between multi-user in system Interference can be greatly reduced.

Described above is only the general introduction of technical solution of the present invention, in order to better understand the technological means of the present invention, And can be practiced according to the content of description, below with presently preferred embodiments of the present invention and coordinate accompanying drawing describe in detail as after. The specific embodiment of the present invention is shown in detail in by following examples and its accompanying drawing.

Brief description

Accompanying drawing described herein is used for providing a further understanding of the present invention, constitutes the part of the application, this Bright schematic description and description is used for explaining the present invention, does not constitute inappropriate limitation of the present invention.In the accompanying drawings：

Fig. 1 be (4) formula 3 kinds of EBPSK modulated signals exported after (3) formula shock filter response envelope absolute Value.

Fig. 2 is the EBPSK receiver block diagram that 400MHz frequency range 20MHz intermediate frequency is realized.

Fig. 3 is defeated for the signal data frame shock filter of 10ms sudden transmission actual measurement using the EBPSK receiver of Fig. 2 Go out envelope initial fluctuating (on) and testing result (under).

Fig. 4 is the overall block-diagram of the receiver of the present invention.

Fig. 5 is the envelope absolute value of the output waveform of receiver shock filter shown in Fig. 4, and in figure abscissa is the time, indulges Coordinate is amplitude.

Fig. 6 be EBPSK manipulator realize block diagram：Fig. 6 (a) is anti-phase manipulator, and Fig. 6 (b) is to lack periodic modulator, figure 6 (c) is narrow pulse modulator.

Fig. 7 is K: 3 kinds of time domain waveforms simplifying EBPSK modulation when N=2: 20.

Fig. 8 is K: 3 kinds of power spectrum emulation simplifying EBPSK modulation when N=2: 20.

Fig. 9 is that the demodulation performance that 3 kinds of simplification EBPSK are modulated at additive white Gaussian noise channel compares：Fig. 9 (a) is K=2 When ber curve；Fig. 9 (b) is ber curve during K=3 and K=4.

Figure 10 is sudden transmission frame structure, totally 240.

Figure 11 is the auto-correlation function of 11 Barker codes as frame head.

Figure 12 is the receiver implementation result figure shown in Fig. 7, and wherein, Figure 12 (a) is that impact filtering output waveform is taken absolutely Output to value；Figure 12 (b) is to the impact envelope waveform obtaining after Figure 12 (a) signal waveform low-pass filtering；Figure 12 (c) is right The NRZ obtaining after Figure 12 (b) shaping；Figure 12 (d) is the amount of delay measured by time-delay calculation device；When Figure 12 (e) is bit synchronization Clock waveform；Figure 12 (f) is the waveform after impact envelope adjusts through variable delay is dynamic.

Figure 13 is the envelope absolute value of EBPSK receiver shock filter output waveform when transient state is burst.

Figure 14 is impact envelope and the effective information comparison diagram demodulating when transient state is burst, and wherein Figure 14 (a) is Figure 13 Partial enlargement, Figure 14 (b) is demodulated judgement, after preamble detecting output code element.

Effective code element before and after Figure 15 is preamble detecting contrasts, and wherein Figure 15 (a) is to remove most of position that abandons (only to retain Last " 101010 ") after effective output symbol, Figure 15 (b) is then to detect and eliminate 11 Barker code frame heads Actually active data output after " 11100010010 ".

Figure 16 is the anti-frequency deviation performance test result of the present invention.

Specific embodiment

Shown in Figure 5, because " A " point is nearby the peak value of impact envelope amplitude during whole signal transition, therefore Secured transmission of payload data near this, not only reliable, and receiver impact filtering transient process can be waited to terminate, thus Also quicker.For example, in Figure 5 although after having crossed " D " point the envelope range value of signal stable 14 about, but in " E " point Between " F " point, the envelope range value of signal is but all not less than 20, and the ratio of the signal power at two is (20/14)²≈ 2, is equivalent to Signal transmission power is at least doubled (transmission power of signal at least can save half in other words), power efficiency is big For improving, energy-saving effect is notable.And just start, than in " C " point, the transmitter work that valid data also at least can save half Time with channel occupancy.

Using the receiver of Fig. 4, and match with EBPSK transmission code rate, the efficient Frame of design (or independent data Bag) structure so that valid data occur in receipt signal impact filtering response highest transient peak near, thus achieve Short packages carry out burst communication using the transient peak energy of signal.Thus, meet the signal transmission frame of described technical requirements Following 3 part substances at least will be included in structure：

1) abandon position.Shown in Figure 5, the sample of signal amplitude due to Frame the initial segment (before " G " point) not yet reaches To the amplitude average value of (after " D " point) during stable state, thus signal to noise ratio is relatively low, and data transfer is less reliable, gives it up.

2) frame head.For frame synchronization, and indicate the initial of valid data.

3) valid data.The data message of actual transmissions.

It is related to thinking according to above-mentioned, below with reference to the accompanying drawings and in conjunction with the embodiments, to describe the present invention in detail.

1.EBPSK manipulator

The modulation system expression formula of described PRM, MCM and NPM respectively as shown in (4a), (4b) and (4c) formula, its manipulator Realize block diagram respectively as shown in Fig. 6 (a)～(c).

1) the PRM manipulator of EBPSK

As Fig. 6 (a), including sine-wave oscillator, phase inverter and electrical switch S.Wherein sine-wave oscillator output frequency For f_cSine wave, be divided into upper and lower two-way, above branch road directly export, below branch road inverted device anti-phase output；Two branch roads are even Connect two inputs of electrical switch S, in electrical switch S selection two branch roads, either signal is as the PRM signal of output；Original sends out Information sequence is sent to be converted to corresponding train of pulse, for the selection of described control electrical switch S.For described train of pulse, only exist The initial time of data " 1 " is high level, and the persistent period is τ；In other moment, train of pulse portion keeps low level.And pulse In low level, upper tributary signal is output signal to string, conversely, lower tributary signal is output signal.

2) the MCM manipulator of EBPSK

As Fig. 6 (b), in addition to phase inverter and electrical switch are reduced to a strangler, remaining and PRM manipulator phase With.And in addition to strangler blocks when the high level in data pulse string, remaining time is straight-through.

3) the NPM manipulator of EBPSK

As Fig. 6 (c), in addition to negating information sequence, NPM manipulator is identical with MCM manipulator.Strangler except Block outer in the high level of data pulse string, remaining time is straight-through.

As seen from Figure 7, the time domain ripple of the simple special case code element " 1 " of 3 kinds of EBPSK modulation of this represented by (4) formula and " 0 " Shape portion is very simple；As seen from Figure 8, after code-element period T (or N) and modulating range τ (or K) gives, this 3 kinds of EBPSK special cases There is identical power spectrum structure and shape, simply the ratio of carrier amplitude and sidebands levels is different, and theory analysis Show with Computer Simulation portion：For identical code-element period, modulating range is bigger, and power spectrum main lobe and secondary lobe portion are narrower, but Corresponding amplitude is also higher, and demodulation performance is also more preferable (referring to Fig. 9) under certain condition simultaneously.Thus also show EBPSK to adjust Motility in terms of adjusting or take into account the availability of frequency spectrum and capacity usage ratio for the system.

Select 400MHz working frequency range, 120 μ s burst duration.For EBPSK modulation system anti-phase defined in (4a) formula, Take τ: T=3: 15, IF-FRE f_c=30MHz, then corresponding code check is 2Mbps.

2. sudden transmission frame structure

Burst 120 μ s with 2Mbps code check, 120 μ s × 2Mbps=240bit can be transmitted, design transmission frame-form such as Figure 10 Shown, wherein front 101 are only intended to receipt signal impact filtering output envelope and bit synchronous foundation, without valid data, Give up after demodulation；Using 11 Barker codes " 11100010010 " as frame head, its auto-correlation function has as Figure 11 institute for centre The sharp single-peak response showing is it is easy to distinguish with information code；Last 128 data messages being used for sudden transmission.It can be seen that this is System can transmit 16 bytes or effective information (8 16 sensings of 8 Chinese characters (2 bytes/every Chinese character) in 120 μ s burst times The once uncompressed sampled value of amount), the waveform of Figure 12 high order end, peace are shown in the sudden transmission impact filtering response of the whole frame data of one Arrange 128 valid data information therein and be located near its envelope peak, with the transient peak energy of effectively utilizes signal.And scheme 13 (a) is then the partial enlargement corresponding to frame signal of bursting in Figure 12.

3. receiver structure

Shown in Figure 4, no matter using any EBPSK modulation, the receiver of available transient peak energy is by simulating Receiver 10, analog-digital converter 11, EBPSK digital demodulator 12 and Frame Handler 8 are constituted.Wherein analog receiver is by front storing Big device 1001, frequency mixer 1002, intermediate frequency amplifier 1003 are constituted with frequency synthesizer 1004, by from reception antenna 9 The high-frequency signal of 400MHz frequency range EBPSK modulation is changed into the intermediate-freuqncy signal of 30MHz, the analog-digital converter 11 through 14 precision according to 90MHz sample frequency gives EBPSK digital demodulator after being converted to digital medium-frequency signal.

4.EBPSK digital demodulator

Shown in Figure 4, described EBPSK digital demodulator 12 includes a digital shock filter 1, described numeral impact filter Ripple device 1 connects a preprocessor 2, and described preprocessor 2 connects a NRZ decision device 3, and described NRZ decision device 3 connects one Time-delay calculation module 4, described time-delay calculation module 4 and described preprocessor 2 are all connected to a variable delay 5, described variable Chronotron 5 connects an integration decision device 6.In addition, described NRZ decision device 3 is also connected with a clock generator 7, described clock is sent out Raw device 7 is also connected to described integration decision device 6.Meanwhile, when the frequency synthesizer in described analog receiver is also connected to described Clock generator 7.It realizes principle and functions of modules is as follows：

1) described numeral shock filter 1 is realized using simple zero -3 limit iir filter given by (4) formula, will The modulation intelligence at EBPSK modulated signal code element " 1 " place projects as parastic modulation impact.

2) described preprocessor 2 is that parastic modulation impact produced by described numeral shock filter 1 is first taken absolute value (waveform as shown in Figure 14 (a)) carries out low-pass filtering again, is rung with the EBPSK signal impact filtering extracting as shown in Figure 14 (b) The envelope answered.In the present embodiment, described low-pass filtering adopts finite impulse response (FIR) digital filter, and below 4MHz is Passband, more than 10MHz is stopband.

3) described NRZ decision device 3 carries out shaping using the impact envelope that threshold judgement exports to described preprocessor 2, After obtaining the NRZ as shown in Figure 14 (c), it is simultaneously fed into described bit clock generator 7 and described time-delay calculation module 4.Detection The arithmetic average of thresholding generally desirable impact envelope peak and its reference level value (i.e. the horizontal line of in figure) as shown in Figure 14 (b) Value.When NRZ " 1 " occurs：

1. (the present embodiment directly continues described time-delay calculation module 4 its high level lasting time of measurement to its high level Sampling number in phase is counted), according to impact envelope highest point and the relative position relation of NRZ " 1 " trailing edge, obtain To the amount of delay of impact envelope, such as shown in Figure 14 (d)；

2. trailing edge in NRZ " 1 " resets described bit clock generator 7 so as to initial time and NRZ " 1 " Trailing edge aligns, and produces the bit synchronization clock corresponding with 2Mbps code check, such as shown in Figure 14 (e).

4) described variable delay 5 dynamically adjusts impact envelope according to the amount of delay that described time-delay calculation module 4 is measured Time delay, makes bit synchronization rising edge clock align with impact envelope highest point, such as shown in Figure 14 (f), thus reaching bit synchronous mesh 's.This example realizes variable delay using addressable shift register, and the address of shift register is exactly to impact prolonging of envelope Shi Liang, the output of shift register is then the content in the depositor pointed by this address.

5) the bit synchronization pulse that described integration decision device 6 is exported using described bit clock generator 7 is as time reference, to code Make decisions after envelope-sampling value integration in unit, that is, demodulate received data sequence.After being set up due to bit synchronization, punching The peak value hitting envelope corresponds to bit synchronization rising edge of a pulse, and relatively low range value then corresponds to bit synchronization pulse falling edge, is The rising edge of synchronised clock in place and trailing edge take multiple sampled points to add up respectively to this described integration decision device 6 respectively, if 2 tired Value added it is closer to, you can judge this code element for " 0 ", otherwise is " 1 ", so can make full use of shock filter can make EBPSK adjust The phase hit of system is transformed into the feature of high-amplitude pulse, makes court verdict more excellent.

5. Frame Handler

Abandon position, frame head sum referring to, Figure 13 (a) Suo Shi, containing in the output code flow of described EBPSK digital demodulator It is believed that breath, also need to for this carry out frame process.Thus as shown in figure 4, described integration decision device 6 connects a Frame Handler 8, described The bit synchronous code stream of bursting to described integration decision device 6 output for the Frame Handler 8, using 11 Barker codes " 11100010010 " carry out coherent detection therewith, just carry out valid data information after this 11 Barker code frame heads is only detected Extraction, be the final valid data extracting output shown in Figure 13 (b).This preamble detecting process completes Figure 10 number simultaneously The judgement that initiates according to the discarding of invalid data in frame and valid data is it is achieved that frame synchronization.Effective code element before and after preamble detecting Contrast is shown in that Figure 15, wherein Figure 15 (a) are the effective output after removing most of discarding position (only remaining last " 101010 ") Code element, and Figure 15 (b) to be then actually active data after detecting and eliminate 11 Barker code frame heads " 11100010010 " defeated Go out.From Figure 12 and Figure 13, abandon the effect of position in the present invention constructed data burst frame it is simply that avoiding EBPSK impact filter Ripple responds the unreliable of the initial segment low signal-to-noise ratio transition region demodulating data, and valid data are tried one's best the signal wink arranging behind Near state peak value, i.e. signal to noise ratio highest region.

6. anti-frequency deviation performance

Already mentioned before, we require described shock filter 1 by a pair of conjugation zero point and at least two pairs conjugate pole structures Become, and signal carrier frequency is higher than zero frequency but is less than all pole frequencies, and the close degree of zero frequency and pole frequency, extremely The 10 of signal carrier frequency will be reached less^-3Magnitude.Therefore, the precipitous trap-selecting frequency characteristic in this filter passband center, cannot be only used for The demodulation of EBPSK modulated signal, and have certain frequency locking ability：As long as transmitting-receiving frequency offsets without departing from this trap-frequency-selecting model Enclose, the system can in the case of there is no phaselocked loop normal work.For this reason, we are respectively in EBPSK signal(-) carrier frequency f_c Different relative frequency deviation Δ f/f have been carried out when being respectively 1MHz, 10MHz and 50MHz_cTest, result is shown in Figure 16.By Figure 16 Understand, for different carrier frequency, as relative frequency deviation Δ f/f_c10^-3During magnitude, the system at least can ensure to continuously transmit 10,000 Code element (the present embodiment only need to transmit 240 code elements) just the error code once causing because of transmitting-receiving frequency difference.Due to common crystal Oscillator precision is at least 10^-5More than, even if therefore there is certain transmitting-receiving frequency difference in this burst communication, at least remain to reliable enter The static communication of row, can save phaselocked loop completely.

The foregoing is only the preferred embodiments of the present invention, be not limited to the present invention, for the skill of this area For art personnel, the present invention can have various modifications and variations.All within the spirit and principles in the present invention, made any repair Change, equivalent, improvement etc., should be included within the scope of the present invention.

Claims (1)

1. utilize the burst communication system of transient peak energy, including transmitter and receiver, described transmitter is using simplification Extended binary phase shift keying is modulated, and modulation data expression formula is one of following 3 kinds of forms：

1）Anti-phase modulation

s₀(t)=sin ω_cT, 0≤t ＜ T

2）Scarce periodic modulation

s₀(t)=sin ω_cT, 0≤t ＜ T

3）Burst pulse is modulated

s₀(t)=0,0≤t ＜ T

Wherein, s₀(t) and s₁T () represents code element " 0 " and the modulation waveform of " 1 " respectively, T is code-element period, when τ is keying modulation Section, ω_cFor modulating the angular frequency of carrier wave；

Described receiver includes one for receiving the reception antenna (9) of modulated signal, and described reception antenna (9) connects a simulation and connects Receipts machine (10), described analog receiver (10) connects an analog-digital converter (11), and described analog-digital converter (11) connects an EBPSK Digital demodulator (12), described EBPSK digital demodulator (12) connects a Frame Handler (8)；

Described analog receiver (10) includes a preamplifier (1001) connecting described reception antenna (9), described front storing Big device (1001) connects a frequency mixer (1002), and described frequency mixer (1002) connects one and is used for connecting described analog-digital converter (11) Intermediate frequency amplifier (103), also include a frequency synthesizer (1004), described frequency synthesizer (1004) connects described frequency mixer (1002)；

Described EBPSK digital demodulator (12) includes one and is used for connecting the digital shock filter of described analog-digital converter (11) (1), described numeral shock filter (1) connects a preprocessor (2), and described preprocessor (2) connects a NRZ decision device (3), described NRZ decision device (3) connects a time delay computing module (4), described time-delay calculation module (4) and described pretreatment Device (2) is all connected to a variable delay (5), and described variable delay (5) connects one and is used for connecting described Frame Handler (8) Integration decision device (6), in addition, described NRZ decision device (3) is also connected with a clock generator (7), described clock generator (7) It is also connected to described integration decision device (6), meanwhile, described frequency synthesizer (1004) is also connected to described clock generator (7)；

It is characterized in that：

Described numeral shock filter (1) is infinite-duration impulse response structure, by a pair of conjugation zero point and at least two pairs conjugate poles Constitute, signal carrier frequency is higher than zero frequency but is less than all pole frequencies, and the close degree of zero frequency and pole frequency, extremely The 10 of signal carrier frequency will be reached less^-3Magnitude；

Described preprocessor (2) is to take envelope absolute value to parastic modulation waveform produced by described numeral shock filter (1)；

Described NRZ decision device (3) carries out shaping by the impact envelope that threshold judgement exports to described preprocessor (2), obtains To after NRZ, it is simultaneously fed into described bit clock generator (7) and described time-delay calculation module (4)；

When NRZ " 1 ", described time-delay calculation module (4) measures its high level lasting time, according to impact envelope Eminence and the relative position relation of NRZ " 1 " trailing edge, obtain impacting the amount of delay of envelope；

The initial time of described bit clock generator (7) is alignd with the trailing edge of NRZ " 1 ", produces corresponding with transmission code rate Bit synchronization clock；

Amount of delay according to measured by described time-delay calculation module (4) for the described variable delay (5) dynamically adjusts impact envelope Time delay, makes the rising edge of bit synchronization clock align with the highest point of impact envelope, thus reaching bit synchronous purpose；

The bit synchronization pulse that described integration decision device (6) is exported using described bit clock generator (7) as time reference, to code element Make decisions after interior envelope-sampling value integration, that is, demodulate received data sequence；

The bit synchronous code stream of bursting that described Frame Handler (8) exports to described integration decision device (6), using 11 Barks Code carry out coherent detection therewith, just carry out significant figure after 11 Barker code frame heads " 11100010010 " is only detected it is believed that The extraction of breath, the judgement that this preamble detecting process completes the discarding of invalid data simultaneously and valid data initiate it is achieved that Frame synchronization.