CN101471687B - User terminal for wireless sensing network based on m sequence self correlation - Google Patents

User terminal for wireless sensing network based on m sequence self correlation Download PDF

Info

Publication number
CN101471687B
CN101471687B CN200710173392A CN200710173392A CN101471687B CN 101471687 B CN101471687 B CN 101471687B CN 200710173392 A CN200710173392 A CN 200710173392A CN 200710173392 A CN200710173392 A CN 200710173392A CN 101471687 B CN101471687 B CN 101471687B
Authority
CN
China
Prior art keywords
sequence
signal
information
user
correlation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CN200710173392A
Other languages
Chinese (zh)
Other versions
CN101471687A (en
Inventor
付耀先
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shanghai Institute of Microsystem and Information Technology of CAS
Original Assignee
Shanghai Institute of Microsystem and Information Technology of CAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shanghai Institute of Microsystem and Information Technology of CAS filed Critical Shanghai Institute of Microsystem and Information Technology of CAS
Priority to CN200710173392A priority Critical patent/CN101471687B/en
Publication of CN101471687A publication Critical patent/CN101471687A/en
Application granted granted Critical
Publication of CN101471687B publication Critical patent/CN101471687B/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Mobile Radio Communication Systems (AREA)

Abstract

The invention discloses a user terminal based on self-correlation of m-sequence in a wireless sensor network, which comprises a receiving device and a transmitting device. The receiving device is implemented by correlating a received signal with a local m-sequence pseudo-random code in a matching filter; then judging the relevant peak of a signal exceeding the threshold value by an information dispreading module according to the correlation result to obtain a relevant user information; and further calculating the compensation value required for side lobe removal by a feedback control module according to the relevant peak information. The transmitting device is implemented by determining an initial phase by a pseudo-random code generation controller according to the relevant peak position of the signal in the current wireless sensor network, which is determined by the receiving device; then generating a relevant m-sequence by a pseudo-random code generator according to the initial phase; and finally processing and transmitting the m-sequence and a user information code required for transmission by a spread spectrum signal transmission module. Therefore, the user terminal can identify the individual users according to the difference of the initial phase.

Description

In the wireless sense network based on the user side of m sequence self correlation
Technical field
The present invention relates to wireless communication technology, in particularly a kind of wireless sense network based on the user side of m sequence self correlation.
Background technology
Wireless sensor network (Wireless Sensor Network; WSN) relate to that multidisciplinary height intersects, the hot research field, forward position of 0 one-tenth of knowledge height collection; It combines sensor technology, embedded computing technique, modern network and wireless communication technology, distributed information processing etc.; Can be through the information of all kinds of integrated microsensors cooperation ground monitorings in real time, perception and various environment of collection or monitoring target; These information are sent out through wireless mode, and are sent to user terminal with the network mode of organizing multi-hop certainly, thereby realize physical world, the connection of calculating the world and the human society ternary world.Sensor network has very wide application prospect; At many key areas such as military and national defense, industrial or agricultural, city management, biologic medical, environmental monitoring, rescue and relief work, anti-probably anti-terrorism, deathtrap Long-distance Control potential practical value is arranged all; Cause the great attention of many national academias and industrial quarters, be considered to one of technology of power that 21 century had an immense impact on.
Yet there are four big limited problems in wireless sense network, i.e. energy, communication capacity, calculating and four aspects of storage capacity, and wherein energy constraint is its most basic problem, when designing, need take into full account.Since physical layer mainly be responsible for data modulation, send and receive, so it is the key link that determines node volume, cost and the energy consumption of WSN, also is one of research emphasis of WSN.
Have, wireless sense network is the extensive information aggregation networks that scatters again, and the information transmission of multi-hop is its basic communication mode; When information converges with the multi-hop mode, possibly receive transfer information as the node of transfer, if transit node does not possess when receiving the multinode informational function simultaneously from a plurality of nodes; For the information of uploading simultaneously; Then can only adopt the hysteresis sortord to handle, it is seriously disturbed to occur internal system thus, a large amount of situation about lagging behind of message transmission.Therefore,, need certain multi-user's access capability as wireless sensing net node, and less demanding to the number of users that can insert simultaneously.Because the applied environment of wireless sense network can exist complicated multipath to disturb mostly, and internal interference will be comparatively serious when wireless sense network reaches certain scale, therefore in wireless sense network, the spread spectrum communication system is more common communication system simultaneously.
DS-CDMA system and multiple access disturb (MAI) relevant issues in cellular communication system, to carry out broad research, and the DS-CDMA system adopts spread spectrum (SS) modulation technique, and wherein baseband signal adopts the PN sign indicating number to carry out spread spectrum.The challenging problem of the maximum that the multi-user of DS-CDMA (MAI) environment is introduced promptly is how correct control is disturbed.Consider that (Direct Sequence Spread Spectrum DSSS)/the BPSK system, establishes P to a Direct Sequence Spread Spectrum 0Be the mean receiving power of desired signal, suppose to exist k interference, received power is respectively P 1, P 2..., P k, then effectively the energy noise ratio indicator can be expressed as: μ = E b N 0 Eff = ( 2 Σ i = 1 k P i 3 L P 0 + 1 μ 0 ) - 1 , Wherein L is a processing gain, and when not having interference, μ 0=E b/ N 0Equal E b/ N 0eff, error probability P eUnder the given prerequisite of μ, can be expressed as P e = 1 2 Erfc ( μ ) .
In a honeycomb DS-CDMA system, MAI can be the base station through limiting the active node number and requiring active node its transmitting power of control so that its identical method of power that arrives receiving system is controlled.Then, this principle of identity can not be applied to actual sensing network.Because in the sensing net, adopt the difficulty of DS-CDMA system to be that there is not center base station in the sensing net, cause MAI not controlled.See also Fig. 1, it is R that sensor node A-K is dispersed in communication range RCircle in, wherein, each node all has the neighbor node that is positioned at the different distance place, for example, A has B, E, F, D and G, its each neighbor node that has all have the different distance that arrives node A.If each node all adopts the power of minimum feasible to carry out communication to each other, when node A when neighbor node sends information, the information of its transmission will produce the inconsistent interference of performance number at another neighbor node place.With two information nodes that send simultaneously by A->Node B and by node C->Node D is an example, wherein, and d AB＞＞d AD, the interference power that the information of obviously being sent by node A produces at node D place causes the signal of node C to be difficult to be resumed much larger than being sent to signal from node C.Yet, if signal is from node A->and node E, but not node A-Node B, can ignore to the influence that the reception of node D causes.This shows, in the DS-CDMA sensor-based system, can not adopt power to control the influence that reduces MAI, and MAI will be considered to be in the subject matter of using the DS-CDMA communication standard in the sensing net.
From the above mentioned, the problem that exists in the wireless sense network is following:
Figure S2007101733921D00023
is in wireless sense network; Need transit node to have multi-user's access capability, but less demanding to multi-user's number;
is when DSSS is used in wireless sense network; Because the uniform dispatching of no center base station; And the randomness of transmitting node and target receiving node; Power control can't be implemented, cause MAI not controlled;
In
Figure S2007101733921D00025
wireless sense network, the simplicity of node and energy consumption problem are the problems that needs overriding concern.
Figure S2007101733921D00026
needs to increase spreading factor to improve entire system sensitivity in order to reach transmission range far away.
In addition, see also Fig. 2, the direct sequence modulation is that the pseudo-random code sequence (being produced by the frequency expansion sequence generation module) with two-forty goes to control the phase place (promptly in phase modulator, handling) of carrier wave (the local oscillator generation) and obtain Direct Sequence Spread Spectrum Signal with the information code sequence is carried out mould 2 and back (waveform multiplies each other) in modulo 2 adder compound key sequence; Launch then; And, see also Fig. 3 at receiving system, behind RF Receiving Device reception signal; Pseudo-code generator produces pseudo noise code; And in phase modulator, carry out exporting correlator to after phase modulation is handled with carrier wave that local oscillator produces, carry out relevant back with the signal that receives and obtain intermediate-freuqncy signal, again through the corresponding information of acquisition behind the demodulator; In addition, receiving terminal also is respectively equipped with carrier wave VCO that carrier error is followed the tracks of and the clock VCO that code error is followed the tracks of.
Because the frequency expansion sequence that in spread spectrum system, has various ways; And binary m sequence is a kind of pseudo random sequence, has good auto-correlation function, is the pseudo noise sequence of narrow sense; And be easy to produce and duplicate, therefore in spread spectrum technique, obtained extensive use.
The m sequence satisfies following three characteristics:
Figure S2007101733921D00031
In each period p=2 nIn-1,0 occurs 2 N-1-1 time, 1 occurs 2 N-1Inferior, 1 to 0 has more at present once.
Figure S2007101733921D00032
In each cycle, have 2 N-1The individual element distance of swimming, wherein 0 the distance of swimming and 1 distance of swimming number respectively account for half the.And, to n＞2, when 1≤k≤n-1, long for the distance of swimming of k account for the distance of swimming total 1/2 k, wherein 0 the distance of swimming and 1 the distance of swimming respectively account for half the.Long have only one for the distance of swimming of n-1, is 0 the distance of swimming; Long also have only one for the distance of swimming of n, is 1 the distance of swimming.
Figure S2007101733921D00033
M sequence { a kAnd its displacement sequence { a K-τ Mould 2 and another displacement sequence { a that is still the m sequence K-τ', promptly
{a k}+{a k-τ}＝{a k-τ′}
Or A k+ A K-τ=A K-τ '
The autocorrelation performance of m sequence satisfies:
R ( τ ) = 1 τ = 0 mod p - 1 p τ ≠ 0 mod p
The diadic autocorrelation performance that it has is as shown in Figure 4; But when carry out information modulation with the m sequence after, if there is information flip (promptly fade to 0 from 1, or fade to 1) from 0; Then carry out relevant result and tangible secondary lobe will occur with original m sequence; As shown in Figure 5, therefore, how to utilize m sequence good autocorrelation to realize that the multi-user in the spread spectrum system distinguishes the real technical task that those skilled in the art need to be resolved hurrily that become.
Summary of the invention
The object of the present invention is to provide in a kind of wireless sense network user side,, avoid the responsive shortcoming of near-far interference that exists in the existing spread spectrum communication to realize the effective differentiation between the wireless sense network user side based on the m sequence self correlation.
In order to achieve the above object; In the wireless sense network provided by the invention based on the user side of m sequence self correlation; It comprises receiving system and emitter, and wherein, said receiving system comprises again: the signal receiving module that is used for receiving the electromagnetic wave signal of propagating in the wireless sense network space; Be used to produce the M sequencer of corresponding local m sequence pseudo noise code; Be used for electromagnetic wave signal that receives and the local m sequence pseudo noise code that is produced are carried out relevant treatment to obtain the matched filter of corresponding correlated results; Be used for confirming the user side number that said electromagnetic wave signal comprises according to the correlated results that is obtained; And set the respective doors limit value and adjudicate to confirm the user profile that comprises in the said electromagnetic wave signal and the correlation peak of record judgement acquisition and the information despreading module of relevant peaks position the signal that surpasses threshold value is carried out relevant peaks; Be used for whether having saltus step according to the correlation peak and the corresponding user profile of relevant peaks position judgment of record; And remove the required offset of secondary lobe when judging when having saltus step to calculate according to said correlation peak, make said matched filter carry out the feedback control module of relevant treatment again again with the user profile that obtains to be flooded by secondary lobe according to said offset; Said emitter comprises again: the signal receiving module that is used for when needs emissions user profile, calling said receiving system receives the electromagnetic wave signal that current wireless sensing net is propagated; And the relevant peaks positional information of the signal that said transmitting terminal promptly will be launched is confirmed in the position of the signal correction peak value that comprises according to the current electromagnetic wave signal that said information despreading module is confirmed; And the m sequence pseudo noise code initial phase bit table that stores in advance according to said relevant peaks place information inquiry to be confirming initial phase, and the poor time delay of initial phase that makes other user sides in said initial phase and the said wireless sense network is much larger than the pseudo noise code generator controller of its maximum multipath time delay that in said wireless sense network, is produced; Be used for producing the pseudo-noise code generator of corresponding m sequence pseudo noise code according to determined initial phase; Be used for frame head, the spread-spectrum signal transmitter module of launching are again caught in the pseudo noise code that the is produced interpolation of relevant back with armed user profile sign indicating number.
Preferable; Said signal receiving module can comprise the input information memory of storing input information; The memory space of said input information memory is set to ping-pong structure, and said matched filter is the filter with dormancy and work two states, and said feedback control module is a basis C i ( m ) = 2 D i ( R i / L i ) ∫ m - τ i T A k - τ i A k The module of offset value calculation, wherein, C i(m) be the offset that i user need carry out, R iBe correlation peak, L iBe local m sequence length, τ iBe spread spectrum initial phase, D iBe information bit, said feedback control module has control and gets into the input information controller of the input information of said matched filter from said input information memory fetch, and the said frame head of catching is complete 1 or complete 0.
In sum; In the wireless sense network of the present invention based on the user side of m sequence self correlation through adopting different time delays can effectively distinguish each user profile at user side, and avoided the responsive shortcoming of near-far interference that exists in the existing spread spectrum communication through overturn point being handled the lower characteristic of back m sequence secondary lobe.
Description of drawings
Fig. 1 is MAI and the near-far interference sketch map of DS-CDMA.
Fig. 2 is DSSS emission block diagram.
Fig. 3 receives block diagram for DSSS.
Fig. 4 is a m sequence auto-correlation function sketch map.
Fig. 5 is the auto-correlation function sketch map that has the m sequence under the information flip situation.
Fig. 6 is the correlated results sketch map of identical m sequence multi-user (initial phase differentiation) and local m sequence.
Fig. 7 is different transmission power multiple user signals and local m sequence correlated results sketch map.
Fig. 8 is different transmission power multiple user signals and local m sequence correlated results sketch map.
Fig. 9 is for receiving subscriber signal and local m sequence correlated results sketch map.
Figure 10 is the correlated process sketch map.
Figure 11 is based on the basic framework sketch map of the user side of m sequence self correlation in the wireless sense network of the present invention.
Figure 12 is the frame structure sketch map that adopts based on the emitter of the user side of m sequence self correlation in the wireless sense network of the present invention.
Figure 13 is based on the receiving system signal flow graph of the user side of m sequence self correlation in the wireless sense network of the present invention.
Figure 14 is based on the receiving system structural representation of the user side of m sequence self correlation in the wireless sense network of the present invention.
Figure 15 is for being respectively 1, the 0.01 correlated results sketch map relevant with local m sequence with 0.001 multiple user signals based on the signal amplitude of the user side of m sequence self correlation in the wireless sense network of the present invention.
Figure 16 adopts the sketch map as a result that goes after the secondary lobe processing for being respectively 1,0.01 and 0.001 multiple user signals and local m sequence based on the signal amplitude of the user side of m sequence self correlation in the wireless sense network of the present invention.
Figure 17 is that Figure 16 is near near the signal enlarged diagram 0 value.
Be respectively 1 and 0.001 multiple user signals and local m sequence correlated results sketch map in Figure 18 wireless sense network of the present invention based on the signal amplitude of the user side of m sequence self correlation.
Embodiment
Basic thought based on the design of the user side of m sequence self correlation in the wireless sense network of the present invention is: each user side in wireless sense network utilizes the different initial phases of identical m sequence as the sign of distinguishing; It is inconsistent that different user brings out the start-phase of existing signal, utilizes the autocorrelation performance of m to carry out correlation capturing.Compensate to m sequence bigger secondary lobe problem on the information trip point simultaneously, obtain lower secondary lobe, to reduce requirement power control.
Each user side in the wireless sense network all adopts identical m sequence, but the initial phase of each user side is inconsistent, and the poor time delay of each initial phase utilizes initial phase to carry out multi-user's differentiation much larger than the maximum multipath time delay that the wireless sense network environment is produced.Each user's the frame head of catching all adopts complete 1 (or complete 0), is used to catch judgement.Receiving system frame head acquisition phase is searched for m sequence correlation peak; And whether the principal phase of judgement correlation peak and the generation of a last user side closes the peak phase difference much larger than multidiameter delay; As denying; Then with it as the new multipath of a last user side information, in this way, then think to detect new user and with the detected phase of this phase place as user profile.In the demodulates information stage; The strong and weak degree of subscriber signal that obtains according to detection-phase detects respectively; The strongest signal at first detects; The adjustment foundation of whether overturning and detecting as next user according to its information is then removed this user through the method for estimating because the secondary lobe influence that information flip causes in next user detects, till detecting weak signal.
If total N user side in the wireless sense network, first user side adopts the m sequence A k, second user side adopts the m sequence A K-τ 1, the third party end adopts the m sequence A K-τ 2By that analogy.It should be noted that when the time of delay of setting between the different user end, require min (τ 1, and τ 2 ...)＞τ, wherein τ be that maximum multipath under this applied environment is delayed time.If the information that the different user end carries is respectively D 1, D 2..., D N, the information that then arrives receiving system is: S= Σ i = 1 N D i , LT A k - τ i , Wherein, T is the information code element duration, continues the cycle at this for the m sequence, and L is the information code element number.When information that receives and local m sequence are carried out relevant treatment, will correlation peak occur at corresponding delay phase place place respectively, work as D especially i≡ 1 or D iDuring ≡ 0, secondary lobe is quite little in the correlated results.See also Fig. 6; It is the multi-user's end signal of different initial phases and the correlated results sketch map of local m sequence, this shows that a plurality of user sides can be distinguished easily; And it is insensitive to near-far interference; Even 1000 times of the power difference between user side still can be told the information of different user, clearly like Fig. 7 and shown in Figure 8.It is thus clear that, utilizing the autocorrelation performance of m sequence can distinguish different user sides, and can reduce near-far interference preferably, the application in the sensing net has special significance to spread spectrum system.But also introduced simultaneously a problem, when information that the user carries is for complete 1 or complete 0, i.e. D iWhen being 0,1 staggered sequence, the m sequence has bigger secondary lobe.The main cause that this secondary lobe occurs is that variation has taken place for m sequence 0 in the one-period and 1 number, thereby the binary feature of m sequence has not been existed owing to carry the upset of information.As shown in Figure 9, at this moment, can adopt the mode of compensation to proofread and correct.
For ease of explanation; See also relevant sketch map shown in Figure 10; Shadow representation information is-1 o'clock spread spectrum information among the figure; White expression information is 1 o'clock spread spectrum information, the correlated process of local m sequence and input spread spectrum information be local m sequence do not stop to be shifted and with the corresponding input spread spectrum information result of multiply accumulating mutually, on the left of this result is illustrated among the figure.
In the moment 1, local m sequence is corresponding fully with the input m sequence that spread spectrum information comprised, and exports relevant main peak this moment.
Constantly 2, input spread spectrum information and local m sequence counterpart be equivalent to local m sequence displacement and local m sequence mould two with still be the m sequence, the secondary lobe of being correlated with at this moment is-1/p.
In the moment 3; There are the saltus step of information bit from 1 to-1 in input spread spectrum information and local m sequence counterpart; 1 and-1 number no longer only differs 1 at this moment, and the spread spectrum information of input no longer has the mould two of m sequence characteristic and local m sequence and also is not the m sequence; So the time secondary lobe no longer be-1/p, this moment secondary lobe higher.
Constantly 4, the input spread spectrum information be complete-1, and differ 1 with-1 number this moment 1, but just opposite with the m sequence, at this moment and the mould two and the gained secondary lobe of local m sequence be 1/p.
Obviously; The secondary lobe problem occurs in the moment 3; The main cause that causes secondary lobe is because the m sequence that is comprised in the input spread spectrum information by the part anti-phase, makes the spreading code of corresponding local m sequence part no longer have the m sequence characteristic, if can be according to the initial phase of m sequence and the estimation of amplitude are compensated; It is reverted to the m sequence, then can realize lower secondary lobe.The concrete grammar of compensation is following:
If detecting i user's correlation peak is R i, the m sequence length is L i, the spread spectrum initial phase is τ i, information bit is D iThen the unique user offset that need carry out is:
C i ( m ) = 2 D i ( R i / L i ) ∫ m - τ i T A k - τ i A k
As far as a plurality of users, the offset that need carry out is:
C ( m ) = Σ i = 1 N C i ( m )
Wherein, T is the information code element duration, and m is current correlation displacement value.
According to above-mentioned design philosophy, see also Figure 11, the user side based on the m sequence self correlation in the wireless sense network of the present invention comprises receiving system and emitter.
Said emitter comprises: pseudo noise code generator controller, pseudo-noise code generator, and spread-spectrum signal transmitter module.Wherein, The signal receiving module (please hold the back explanation) that said pseudo noise code generator controller is used for when needs are launched user profile, calling said receiving system receives the electromagnetic wave signal that current wireless sensing net is propagated; And the relevant peaks positional information of the signal that said transmitting terminal promptly will be launched is confirmed in the position of the signal correction peak value that comprises of the current electromagnetic wave signal of confirming according to the said information despreading module of said receiving system (please hold the back explanation); And the m sequence pseudo noise code initial phase bit table that stores in advance according to said relevant peaks place information inquiry to be confirming initial phase, and the poor time delay of initial phase that makes other user sides in said initial phase and the said wireless sense network is much larger than its maximum multipath time delay that in said wireless sense network, is produced; Said pseudo-noise code generator is used for producing corresponding m sequence pseudo noise code (PN sign indicating number) according to determined initial phase; The electromagnetic wave signal of propagating in PN sign indicating number that produces through this mode and the current wireless sensing net has certain phase difference to the PN sign indicating number of signal; This phase difference is N chip and adds certain error; And with regard to whole system, as long as phase difference within the specific limits; Said spread-spectrum signal transmitter module is used for frame head is caught in the pseudo noise code that the is produced interpolation of relevant back with armed user profile sign indicating number; Launch, the said frame head of catching is complete 1 or complete 0 again, and the frame structure that forms thus is shown in figure 12; Owing to catch frame head and adopt complete 1 or complete 0; Prize judgment can be better carried out,, a plurality of users' relevant information can be distinguished because the secondary lobe of signal is quite little at this moment.
See also Figure 13, said receiving system comprises: signal receiving module, M sequencer, information despreading module, and feedback control module.Wherein, Said signal receiving module is used for receiving the electromagnetic wave signal that propagate in the wireless sense network space; It further comprises the input information memory of storing input information again; After the information input, it is stored in the input information memory by piece, and the memory space of said input information memory is set to ping-pong structure; Said M sequencer is used to produce corresponding local m sequence pseudo noise code; Said matched filter is used for electromagnetic wave signal that receives and the local m sequence pseudo noise code that is produced are carried out relevant treatment to obtain corresponding correlated results; In the present embodiment; Said matched filter has dormancy and work two states; Its input comprises by the pending information of input information memory input, matched filter dormancy control indication, reaches the m sequence that the m sequencer produces, and it is output as correlated results, and the work that matched filter is done promptly is under clock control; With input information delay time in order and with the multiply each other back summation of m sequence, and its output result deposits in relevant position in the correlated results memory successively.Then expression of dormancy control indication; At acquisition phase, matched filter is in running order all the time, and in the information processing stage; Only need pay close attention near the corresponding initial phase position the result and with its relevant position of inserting the correlated results memory, Duan Junke is in resting state at other times.Adopt this mode can save the energy consumption of whole system preferably; Said information despreading module is used for confirming the user side number that said electromagnetic wave signal comprises according to the correlated results that is obtained; And set the respective doors limit value and adjudicate to confirm the user profile that comprises in the said electromagnetic wave signal the signal that surpasses threshold value is carried out relevant peaks; And the correlation peak and the relevant peaks position of record judgement acquisition; Said information despreading module promptly is to judge and obtain the information of different user according to the value in the correlated results memory, and it at first sets thresholding according to correlated results, then the signal that surpasses thresholding is carried out the relevant peaks judgement; Confirm user profile, divide the user to carry out information output.For the multipath of same subscriber, can adopt the Rake technology to merge output; Said feedback control module is used for whether having saltus step according to the correlation peak and the corresponding user profile of relevant peaks position judgment of record; And remove the required offset of secondary lobe when judging when having saltus step to calculate according to said correlation peak; Make said matched filter carry out the user profile of relevant treatment again again to obtain to be flooded by secondary lobe according to said offset; It has control gets into the input information of said matched filter from said input information memory fetch input controller; Said input controller is main according to whether needs go the indication of secondary lobe processing to control; If need remove secondary lobe, then the lastblock input information is imported matched filter (can call the work and the dormancy of matched filter according to circumstances) once more; Otherwise; Then begin to call in the new input data of storing in the said input information memory; What this need guarantee be, the time of these information-storing device data of subsequent treatment is shorter than the time that input information fills up the same memory of ping-pong structure, could requirement of real time.Said feedback control module is for removing the main enforcement control section of m sequence secondary lobe; Its input is mainly in the number of users of acquisition phase affirmation and present user's correlation peak situation, and its output is mainly required instant offset of matched filter and the control information signal that matches.Correlation peak situation according to said information despreading module acquisition; Said matched filter extracts the positive and negative situation that the relevant peaks amplitude is big or small, position and relevant peaks appear in relevant peaks; The complete situation of position judgment number of users and output information occurs according to relevant peaks, and confirm according to the number of users of acquisition phase whether needs carry out secondary lobe and remove.The judgement mode of number of users is following:
If it is P=[P that location sets appears in correlation peak 1, P 2, P 3..., P P], spreading code length is L, maximum multipath time delay is μ.
When searching correlation peak P iThe time, if (P i+ kL) ∈ P, wherein k is an integer, k=0,1,2 ..., judge that then this information is same user's correlation peak, is designated as user one.
Belong to interval [(P in the set of records ends family i+ kL)～(P i+ (k+1) L)] value, each value record in this set is P I, k'.Next user is searched in beginning in this interval, search for this interval correlation peak location, if
P I, k'-U p＞μ and P I, k'+kL ∈ P,
Wherein, U pCorrelation peak location for next user of searching in this interval.
Then think this signal for another user, think and a last user between correlation peak be a last user's multipath, and set U p=P I, k'.
This process continues always, till last value that searches this interval.
Equal the number of users that acquisition phase is confirmed if surpass the number of users of threshold value, then need not carry out the secondary lobe removal this moment and can obtain last result.But if in whole process, can carry out user's access at any time, promptly in whole process, all catch, then the secondary lobe removal is necessary.But secondary lobe is removed and is occurred over just under the situation of information flip, when not having information flip, adds that instead offset can lead to errors, and whether fibrous root according to same user profile in the correlated results upset takes place determines whether carrying out the secondary lobe removal.
After confirming number of users and corresponding correlation peak location and amplitude, can calculate based on correlation circumstance value of compensating of current m sequence and matched filter.Compensation mainly comprises the m sequence two-value property inefficacy that information flip causes through the simulation of raw information is removed in the original signal.
If press the numerical value entering matched filter that clock drives current storage, the current d position that has been displaced to, total N user, the position of the up-to-date acquisition correlation peak of different user is respectively U=[U 1, U 2..., U N], be M=[d-U then with the corresponding m sequence that input information comprised (comparing) start bit of the m sequence of current matched filter with local m sequence 1, d-U 2..., d-U N], get corresponding m sequence and local m sequence and carry out mould two and processing, and with its amplitude A=[A 1, A 2..., A N] and the positive and negative D=[D of information bit 1, D 2..., D N] take into account in the lump, multiply each other, acquisition be the array of N similar m sequence
R n = A n D n mm d - U n
Wherein m is local m sequence, is a fixed value;
m D-UnThen represent d-U from m nThe displacement m sequence of position beginning.
And the offset that should get this moment is R nBack M=[d-U 1, d-U 2..., d-U N] the adding up of position, and in final result, adding offset, the computational methods of offset no longer repeat at this as previously mentioned.
See also Figure 14; It is said receiving system handling process sketch map; Said receiving system carries out relevant treatment with said m sequencer local m sequence that produces and the input information that the input information memory provides, when said signal despreading module conducting frame head is caught, owing to the existence of not having secondary lobe basically; Can judge the number of users of existence in view of the above, and be to follow the tracks of thresholding (it can be set to higher relatively value) according to signalization with the highest correlation peak.Get into information trace after the stage, setting according to thresholding and carry out the despreading processing, keeping correlation peak and correlation peak location correspondence table simultaneously; Judge according to the despreading result whether the user's despread signal value that surpasses thresholding saltus step takes place again, if 0,1 saltus step appears in information bit; Then consult correlation peak H and correlation peak location P that this place occurs, positive and negative according to said correlation peak signal calculated amplitude (being H/ spread spectrum code length) and signal again, and then carry out relevant treatment; And the increase and decrease amount (being offset) that need carry out of calculating simultaneously, then in relevant treatment once more, carry out the correlation increase and decrease, and the output correlated results; Then judge whether to still have signal to be submerged in the secondary lobe again,, continue the information that surpasses thresholding is carried out processing such as despreading if having; If do not have, then finish.
Below will further specify in the wireless sense network of the present invention relevant treatment effect through emulation based on the user side of m sequence self correlation.3 users are example with emulation, and each subscriber signal amplitude is respectively 1,0.01 and 0.001.
See also Figure 15, it is a subscriber signal and result sketch map after local m sequence is directly related, and is visible by figure; In this case; When signal overturns, can be observed a plurality of signals, but when upset takes place signal; Small-signal will be submerged in the secondary lobe of large-signal, thereby can't right demodulation.
See also Figure 16, it is the result sketch map that adopts after secondary lobe is handled, and visible by figure, no matter signal has or not upset, but equal right demodulation small-signal.Figure 17 is that Figure 16 is near near the signal enlarged diagram 0 value; It is thus clear that; Signal amplitude is that 0.01 signal all can be recognized fully, and owing to 0.01 signal is not carried out secondary lobe remove, so the secondary lobe when this signal message overturns is that 0.001 signal exerts a certain influence to amplitude.Therefore, after to detect signal amplitude be 0.01 signal, carry out secondary lobe once more and remove, can be that 0.001 signal recovers fully with signal amplitude then.
See also Figure 18, it is the secondary lobe processing scheme result of 1 and 0.001 signal for signal amplitude, and is visible by figure, and to detected signal, it is removed precision and satisfies the requirement that the recovery amplitude is 0.001 signal.
In sum; In the wireless sense network of the present invention based on the user side of m sequence self correlation through adopting different time delays can effectively distinguish each user profile at user side, and avoided the responsive shortcoming of near-far interference that exists in the existing spread spectrum communication through overturn point being handled the lower characteristic of back m sequence secondary lobe.

Claims (6)

  1. In the wireless sense network based on the user side of m sequence self correlation, it is characterized in that comprising receiving system and emitter, wherein, said receiving system comprises:
    Signal receiving module is used for receiving the electromagnetic wave signal that propagate in the wireless sense network space;
    The M sequencer is used to produce local m sequence pseudo noise code;
    Matched filter is used for electromagnetic wave signal that receives and the local m sequence pseudo noise code that is produced are carried out relevant treatment to obtain corresponding correlated results;
    Information despreading module; Be used for confirming the user side number that said electromagnetic wave signal comprises according to the correlated results that is obtained; And set the respective doors limit value and adjudicate to confirm the user profile that comprises in the said electromagnetic wave signal and the correlation peak and the relevant peaks position of record judgement acquisition the signal that surpasses threshold value is carried out relevant peaks;
    Feedback control module; Be used for whether having saltus step according to the correlation peak and the corresponding user profile of relevant peaks position judgment of record; And remove the required offset of secondary lobe when judging when having saltus step to calculate according to said correlation peak, make said matched filter carry out the user profile of relevant treatment again again to obtain to be flooded by secondary lobe according to said offset; Particularly, said feedback control module is a basis
    Figure FSB00000755324100011
    The module of offset value calculation, wherein, C i(m) be the offset that i user need carry out, R iBe correlation peak, L iBe local m sequence length, τ iBe spread spectrum initial phase, D iBe information bit, T is the information code element duration, and m is current correlation displacement value, A kBe the m sequence of first user side employing,
    Figure FSB00000755324100012
    It is the m sequence that (i+1) individual user side adopts;
    Said emitter comprises:
    The pseudo noise code generator controller; The signal receiving module that is used for when needs emissions user profile, calling said receiving system receives the electromagnetic wave signal that current wireless sensing net is propagated; And the position of the relevant peaks of the signal that said transmitting terminal promptly will be launched is confirmed in the position of the signal correction peak value that comprises according to the current electromagnetic wave signal that said information despreading module is confirmed; And the position of the relevant peaks of the signal that promptly will launch according to said transmitting terminal inquires about the m sequence pseudo noise code initial phase bit table that stores in advance confirming initial phase, and the maximum multipath time delay that the poor time delay of the initial phase of other user sides in said initial phase and the said wireless sense network is produced in said wireless sense network much larger than said initial phase;
    Pseudo-noise code generator is used for producing corresponding m sequence pseudo noise code according to determined initial phase;
    The spread-spectrum signal transmitter module is used for frame head is caught in the pseudo noise code that the is produced interpolation of relevant back with armed user profile sign indicating number, launches again.
  2. 2. based on the user side of m sequence self correlation, it is characterized in that in the wireless sense network as claimed in claim 1: said signal receiving module comprises the input information memory of storing input information.
  3. 3. based on the user side of m sequence self correlation, it is characterized in that in the wireless sense network as claimed in claim 2: the memory space of said input information memory is set to ping-pong structure.
  4. 4. based on the user side of m sequence self correlation, it is characterized in that in the wireless sense network as claimed in claim 1: said matched filter is the filter with dormancy and work two states.
  5. 5. based on the user side of m sequence self correlation, it is characterized in that in the wireless sense network as claimed in claim 2: said feedback control module has control gets into the input information of said matched filter from said input information memory fetch input information controller.
  6. 6. based on the user side of m sequence self correlation, it is characterized in that in the wireless sense network as claimed in claim 1: the said frame head of catching is complete 1 or complete 0.
CN200710173392A 2007-12-27 2007-12-27 User terminal for wireless sensing network based on m sequence self correlation Expired - Fee Related CN101471687B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN200710173392A CN101471687B (en) 2007-12-27 2007-12-27 User terminal for wireless sensing network based on m sequence self correlation

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN200710173392A CN101471687B (en) 2007-12-27 2007-12-27 User terminal for wireless sensing network based on m sequence self correlation

Publications (2)

Publication Number Publication Date
CN101471687A CN101471687A (en) 2009-07-01
CN101471687B true CN101471687B (en) 2012-10-10

Family

ID=40828846

Family Applications (1)

Application Number Title Priority Date Filing Date
CN200710173392A Expired - Fee Related CN101471687B (en) 2007-12-27 2007-12-27 User terminal for wireless sensing network based on m sequence self correlation

Country Status (1)

Country Link
CN (1) CN101471687B (en)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8385389B2 (en) * 2010-11-03 2013-02-26 Empire Technology Development Llc Collaborative data sharing for CDMA interference subtraction
CN102136849A (en) * 2011-04-25 2011-07-27 中国科学院自动化研究所 Wireless communication star network system with code division multiple access (CDMA) inward link and realization method thereof
CN102932912A (en) * 2012-10-08 2013-02-13 中国电子科技集团公司第五十四研究所 WSN (wireless sensor network) based electromagnetic spectrum signal positioning method
DE102012221121A1 (en) * 2012-11-20 2014-06-05 Zf Friedrichshafen Ag Concept for sending and receiving an information symbol
CN103826218B (en) * 2014-03-06 2016-10-19 湖南大学 The pseudo random sequence generation method of wireless sensor network node and application process thereof
CN105680976B (en) * 2016-03-29 2018-08-14 中国电子科技集团公司第二十九研究所 A kind of distributed network method for synchronizing time
CN107144817A (en) * 2017-04-28 2017-09-08 南京邮电大学 A kind of indoor visible light localization method based on PN spreading codes
CN108718212A (en) * 2018-05-09 2018-10-30 马林华 A method of the light spatial multiple-access wireless communication based on video
CN111580110B (en) * 2020-04-30 2022-08-19 天津大学 Composite code underwater acoustic ranging method based on shallow sea multipath time delay
CN117811596B (en) * 2024-02-29 2024-05-03 成都天传科技有限公司 Passive wireless signal coherence judging and transmitting method and system

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1719741A (en) * 2005-07-28 2006-01-11 上海大学 Spread spectrum communicatoion system and non-centre wireless network for implementing CDMA by single different phase sequence of spread spectrum code

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1719741A (en) * 2005-07-28 2006-01-11 上海大学 Spread spectrum communicatoion system and non-centre wireless network for implementing CDMA by single different phase sequence of spread spectrum code

Also Published As

Publication number Publication date
CN101471687A (en) 2009-07-01

Similar Documents

Publication Publication Date Title
CN101471687B (en) User terminal for wireless sensing network based on m sequence self correlation
JP3373746B2 (en) Initial synchronization method and receiver in asynchronous cellular system between DS-CDMA base stations
CN102332933B (en) Short-term burst spread spectrum signal transmitting and receiving method
US6768768B2 (en) Method and apparatus for step two W-CDMA searching
KR100869465B1 (en) Method and apparatus for searching a gated pilot
CN101171759B (en) Detection signal generation method and receiver
CN105791184B (en) Aperiodic long code direct sequence signal frequency expansion sequence blind estimating method based on similarity
CN1354916A (en) Programmable matched filter searcher
AU748658B2 (en) Device and method for communicating reverse pilot signal in mobile communication system
CN106788470B (en) High data rate bursts communication quick capturing method and device based on spread spectrum
JP2856249B2 (en) CDMA synchronization acquisition circuit
EP1109325B1 (en) Apparatuses and method for acquisition of asynchronous wideband CDMA signals
Sriram et al. Cyclically permutable codes for rapid acquisition in DS-CDMA systems with asynchronous base stations
CN102185628A (en) Spread spectrum code phase capture equipment based on adaptive power accumulation and capture method thereof
CN105049079A (en) Spreading code synchronization method based on square correlation
US20060093021A1 (en) Code acquisition device and method using two-step search process in DS-CDMA UWB modem
CN115189714A (en) Spread spectrum communication pseudo code tracking method based on FPGA
CN101193436A (en) Device for acquiring pilot detection threshold of random access channel at physical layer of the base station Node B
CN101005294A (en) Matched filter, judging device and search method
CN103163535A (en) P code direct capturing method based on digital signal processor (DSP)
CN101193435B (en) Method for acquiring pilot detection threshold of random access channel at physical layer
CN101174852A (en) WCDMA subdistrict searching time slot synchronization method and system
US7193984B2 (en) Method for determining a time offset of a CDMA signal
WO1999067895A1 (en) Method and apparatus for storing and accessing different chip sequences
Kim et al. Robust noncoherent PN-code acquisition for CDMA communication systems

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20121010

Termination date: 20191227