CN1323492C - Realizing method of super-broadband radio communication multi-adress based on othogonal small waveform - Google Patents

Abstract

The present invention discloses a method for realizing ultra-wideband (UWB) wireless communication multiple access on the basis of the waveform of an orthogonal wavelet. On the basis of a wavelet analysis theory, a new UWB multiple access way, namely wavelength division multiple access (WDMA), is provided according to the natural similarity between the waveform of an orthogonal wavelet function and a UWB signal waveform. In the multiple access way, the waveforms of a scale function phi(t) and the wavelet function psi(t) with orthogonality are designed as UWB impulse waveforms, and the two function waveforms are evenly allocated to multiple users according to an M-sequence theory so as to realize multiple access. When two different impulse waveforms of the users collide, multiple access interference is greatly reduced; compared with a time division multiple access (TDMA) and a code division multiple access (CDMA) way, the WDMA way has the advantage of larger user capacity.

Description

A kind of super broad band radio communication multiple access implementation method and device based on the orthogonal wavelet waveform

Technical field

The present invention relates to a kind of super broad band radio communication multiple access implementation method, belong to the communications field based on the orthogonal wavelet waveform.

Background technology

In recent years, ultra broadband (UWB) wireless communication technology becomes the focus of Chinese scholars research.Wireless communication system with 25% or 1.5GHz system bandwidth of surpassing centre frequency is referred to as the UWB communication system.Be different from the legacy wireless communication system of sine wave as carrier wave, UWB adopts extremely short impulse waveform of duration that the data that are transmitted are directly modulated, compare as the legacy wireless communication system of carrier wave with sine wave, aspect the selection of impulse waveform, UWB has its distinctive flexibility.Because modulation bandwidth is extended on several GHz magnitudes, thereby system can be on the basis of occupying utmost point low power spectral density, carry out transfer of data with high speed, simultaneously, UWB has also that anti-multipath disturbs and the narrow band interference ability is strong, the advantage of a series of uniquenesses such as user capacity is huge, hangs down capture rate, and system complexity is low.Thereby the appearance of UWB technology, do not occupying under the close-packed frequency resource situation, a kind of brand-new speech and data communication mode are provided.

It is the main cause of restriction ultra broadband (UWB) Communications System User capacity that multiple access disturbs.At present, realize that the UWB access mode mainly contains following two kinds: one is based on traditional time division multiple access (TDMA) mode, and this mode combines with pulse-position modulation (PPM) and is referred to as TH-PPM UWB (jumping time-pulse-position modulation).Another kind is based on code division multiple access (CDMA) mode, and this mode combines with binary phase shift keying modulation (BPSK), is referred to as DS-BPSKUWB (direct sequence-bipolarity amplitude modulation(PAM)).Because different user adopts identical transmitted pulse, the multiple access of these two kinds of traditional access modes disturbs and can not fundamentally eliminate or reduce, many scholars have proposed the improvement project based on two kinds of traditional multi-access modes, but all do not obtain in itself to improve.

Summary of the invention

In order to overcome the defective of above-mentioned prior art, the purpose of this invention is to provide a kind of super broad band radio communication multiple access implementation method based on the orthogonal wavelet waveform, this method can further improve ultra broadband (UWB) Communications System User capacity.

To achieve these goals, the present invention is by the following technical solutions: a kind of super broad band radio communication multiple access implementation method based on the orthogonal wavelet waveform, scaling function φ (t) with orthogonality and wavelet function ψ (t) waveform are as the UWB impulse waveform, by means of Pseudo-random Sequence Theory, for the M sequence, the probability of occurrence of "+1 " and " 1 " almost equates, therefore, for the definite length M sequence that is Ns, the position of "+1 " and " 1 " is corresponding with scaling function φ (t) and wavelet function ψ (t) respectively, such two different impulse waveforms are just distributed to a user equably, simultaneously, utilize two multiple different integrated modes of pulse, just can realize multiple access.

Described wavelet function ψ (t) each wavelet function for having tight support (waveform limited duration) and regularity (frequency bandwidth is limited).

Described scaling function φ (t) and the uniform distribution of described wavelet function ψ (t) waveform by code word be any pseudo noise code with good auto-correlation and their cross correlation.

Described UWB waveform data modulation system, according to modulating data '+1 ' with ' 1 ' different, can adopt one of switch modulation (OOK), pulse-ampli tude modulation (PAM), pulse position modulation (PPM), bipolarity pulse-ampli tude modulation (BPSK).

A kind of transmitter that is adopted based on the super broad band radio communication multiple access implementation of orthogonal wavelet waveform, its structure mainly are made up of PN sign indicating number generator, frame sequence generator, pulse generator and four parts of multiplier; PN sign indicating number generator output length is the PN sign indicating number c of Ns ^(k), its chip lengths is T _f, period T s=NsT _f, this PN sign indicating number is the basic foundation that each user is given in scaling function waveform φ (t) and wavelet function waveform ψ (t) uniform distribution; Sequence generator is according to k user's of PN sign indicating number generator output PN sign indicating number c ^(k), produce periodic sampling pulse s ^(k)(t), the pulse spacing equals PN sign indicating number chip width T _f, each pulse polarity depends on PN sign indicating number chip data, that is: $s^{\left(k\right)}\left(t\right)=\underset{j=-\∞}{\overset{-\∞}{\mathrm{\Σ}}}{a_j}^{\left(k\right)}(t-{\mathrm{jT}}_f);$ Pulse generator mainly is responsible for producing scaling function waveform φ (t) and wavelet function waveform ψ (t), and distributes according to the polarity of each sampling pulse δ (t) among the frame sequence s (t), and then obtains k user's the basic modulated pulse trains of WDMA UWB: ${\mathrm{\η}}^{\left(k\right)}\left(t\right)=s^{\left(k\right)}\left(t\right)*w_j^{\left(k\right)}\left(t\right)=\underset{j=-\∞}{\overset{+\∞}{\mathrm{\Σ}}}{w}_j^{\left(k\right)}(t-{\mathrm{jT}}_f).$

A kind of receiver that is adopted based on the super broad band radio communication multiple access implementation of orthogonal wavelet waveform, its structure mainly selects control module, pulse generator, multiplier and six parts of pip integrator to form by synchronization control module, frame clock generator, waveform, adopts the correlation demodulation method; Synchronization control module control frame clock generator, make local clock and k user's WDMA UWB transmitter clock keep good synchronously, select control module for waveform simultaneously timing information be provided; The frame clock generator is exported periodic sampling pulse $s^{\left(k\right)}\left(t\right)=\underset{j=-\∞}{\overset{+\∞}{\mathrm{\Σ}}}\mathrm{\δ}(t-{\mathrm{jT}}_f-{\mathrm{\τ}}_k)$ , the pulse spacing equals PN sign indicating number chip width T _f, τ _kFor compare the delay of k subscriber signal with receiver clock; Waveform is selected the waveform allocation rule of control module according to k user, selects information for pulse generator provides the generation of scaling function waveform φ (t) and wavelet function waveform ψ (t); Pulse generator mainly is responsible for producing the basic modulated pulse trains of WDMA UWB: ${\mathrm{\η}}^{\left(k\right)}\left(t\right)=s^{\left(k\right)}\left(t\right)*w_j^{\left(k\right)}\left(t\right)=\underset{j=-\∞}{\overset{+\∞}{\mathrm{\Σ}}}{w}_j^{\left(k\right)}(t-{\mathrm{jT}}_f)$ Received signal r (t) and template signal η ^(k)(t) multiply each other, send into pip integrator, and at t=jT _f-τ _kConstantly sample, obtain sample value y _j, according to y _jThe polarity difference recover modulated binary data stream $d_i^{\left(k\right)}\∈\{\±1\}.$

Because the present invention has adopted above technical scheme, so have the following advantages:

The present invention proposes the UWB access mode of a kind of wavelength division multiple access (WDMA), in this access mode, scaling function φ (t) with orthogonality is designed the impulse waveform as UWB with wavelet function ψ (t) waveform, for the definite length M sequence that is Ns, the position of "+1 " and " 1 " is corresponding with scaling function φ (t) and wavelet function ψ (t) respectively, such two different impulse waveforms are just distributed to a user equably, simultaneously, utilize two multiple different integrated modes of pulse, just can realize multiple access.When two users' different pulse shape bumped, multiple access disturbed and will be reduced greatly, compares with TDMA and CDMA multi-access mode, and the WDMA implementation has bigger user capacity.

Description of drawings

Fig. 1 is the WDMA UWB modulation waveform of single user (k user) among the present invention

Fig. 2 is the transmitter block diagram of the WDMA UWB of single user (k user) among the present invention

Fig. 3 is the receiver block diagram of single user's of the present invention (k user) WDMA UWB

Embodiment

The present invention according to the natural similitude of orthogonal wavelet function waveform with the UWB signal waveform, has proposed a kind of new UWB access mode---wavelength division multiple access (WDMA) on the Wavelet Analysis Theory basis.In this access mode, scaling function φ (t) with orthogonality is designed the impulse waveform as UWB with wavelet function ψ (t) waveform, by the M sequencing theory, because the probability of occurrence of "+1 " and " 1 " almost equates, therefore the M sequence that is Ns for a definite length, the position of "+1 " and " 1 " is corresponding with scaling function φ (t) and wavelet function ψ (t) respectively, and such two different impulse waveforms are just distributed to a user equably.Simultaneously, utilize two multiple different integrated modes of pulse, just can realize multiple access.

When two users' different pulse shape bumped, multiple access disturbed and will be reduced greatly, compares with TDMA and CDMA multi-access mode, and the WDMA implementation has bigger user capacity.

If ψ (t) is a quadractically integrable function, also be ψ (t) ∈ L ²(R), if its Fourier transform ψ (w) satisfies condition:

${\&Integral;}_R\frac{{\left|\mathrm{\&psi;}\left(\mathrm{\&omega;}\right)\right|}^2}{\mathrm{\&omega;}}\mathrm{dt}<\&infin;---\left(1\right)$

Claim that then ψ (t) is a wavelet mother function, and title formula (1) is the admissibility condition of wavelet function.

When wavelet function satisfies time domain limited duration (promptly satisfying tight support characteristic) and during the condition of frequency domain bandwidth limited (that is: satisfy regularity condition), just can be used as the UWB impulse waveform.

Supposing to exist in the UWB system number of users is N _nThe data-modulated mode can adopt switch modulation (OOK), pulse-ampli tude modulation (PAM), pulse position modulation (PPM) or bipolarity pulse-ampli tude modulation (BPSK), this sentences BPSK and is modulated to example, and then wavelength division multiple access (WDMA) the UWB signal definition based on orthogonal wavelet is: $S^{\left(k\right)}=\underset{j=-\&infin;}{\overset{+\&infin;}{\mathrm{\&Sigma;}}}{d}_{\left[j/\mathrm{Ns}\right]}^{\left(k\right)}{w}_j^{\left(k\right)}(t-{\mathrm{jT}}_f)$ 。

As shown in Figure 3, k the pairing WDMA UWB of user signal, wherein, w _j ^(k)(t) k user's of expression j impulse waveform (φ (t) or ψ (t)), and satisfy $w_j^{\left(k\right)}\left(t\right)=0\left(\right|t|>T_m/2,T_m<<T_f)$ 。T _mBe the pulse duration, T _fBe pulse-recurrence time, also be referred to as frame length, $d_{[j/\mathrm{Ns}]}^{\left(k\right)}\&Element;\{\&PlusMinus;1\}$ It is k user's modulating data.Because every Ns pulse is used to transmit a modulating data, thereby j impulse waveform carrying [j/Ns] bit data ([x] expression rounds x) of a certain user.

In order to guarantee that each user has identical channel capacity in the UWB system, scaling function φ (t) and wavelet function ψ (t) must be distributed in each user's the different frame equably.By means of Pseudo-random Sequence Theory, for the M sequence, the probability of occurrence of "+1 " and " 1 " almost equates.Therefore, for the M sequence that a definite length is Ns that the position of "+1 " and " 1 " is corresponding with scaling function φ (t) and wavelet function ψ (t) respectively, such two different impulse waveforms are just distributed to a user equably.Simultaneously, utilize two multiple different integrated modes of pulse, just can realize multiple access.

K user's WDMA ultra broadband multi-address system transmitter model as shown in Figure 2, WDMA UWB transmitter mainly is made up of PN sign indicating number generator, frame sequence generator, pulse generator and four major parts of multiplier.The length of PN sign indicating number generator output is N _sPN sign indicating number (for example: M sequence or GOLD sign indicating number etc.) c ^(k), its chip lengths is T _f, period T _s=N _sT _f, this PN sign indicating number is the basic foundation that each user is given in scaling function waveform φ (t) and wavelet function waveform ψ (t) uniform distribution.The frame sequence generator is according to k user's of PN sign indicating number generator output PN sign indicating number c ^(k), produce periodic sampling pulse s ^(k)(t), the pulse spacing equals PN sign indicating number chip width T _f, each pulse polarity depends on PN sign indicating number chip data, that is: $s^{\left(k\right)}\left(t\right)=\underset{j=-\&infin;}{\overset{+\&infin;}{\mathrm{\&Sigma;}}}{a}_j^{\left(k\right)}(t-{\mathrm{jT}}_f)$ 。Pulse generator is the critical component of WDMA UWB system, this part mainly is responsible for producing scaling function waveform φ (t) and wavelet function waveform ψ (t), and distribute according to the polarity of each sampling pulse δ (t) among the frame sequence s (t), and then obtain k user's the basic modulated pulse trains of WDMA UWB:

${\mathrm{\&eta;}}^{\left(k\right)}\left(t\right)=s^{\left(k\right)}\left(t\right)*w_j^{\left(k\right)}\left(t\right)=\underset{j=-\&infin;}{\overset{+\&infin;}{\mathrm{\&Sigma;}}}{w}_j^{\left(k\right)}(t-{\mathrm{jT}}_f).$

K user's binary message stream d _i ^(k)∈ ± 1}, by with the basic modulated pulse trains η of WDMA UWB ^(k)(t) multiply each other, can obtain transmitting of WDMA UWB system: $S^{\left(k\right)}=\underset{j=-\&infin;}{\overset{+\&infin;}{\mathrm{\&Sigma;}}}{d}_{[j/\mathrm{Ns}]}^{\left(k\right)}{w}_j^{\left(k\right)}(t-{\mathrm{jT}}_f)$ 。

K user's WDMA ultra broadband multi-address system receiver module as shown in Figure 3, WDMA UWB receiver mainly selects control module, pulse generator, multiplier and six major parts of pip integrator to form by synchronization control module, frame clock generator, waveform.Receiver adopts the correlation demodulation method, and synchronization control module control frame clock generator makes local clock and k user's WDMA UWB transmitter clock keep good synchronous, provides timing information for waveform selection control module simultaneously.The frame clock generator is exported periodic sampling pulse $S^{\left(k\right)}\left(t\right)=\underset{j=-\&infin;}{\overset{+\&infin;}{\mathrm{\&Sigma;}}}\mathrm{\&delta;}(t-{\mathrm{jT}}_f-{\mathrm{\&tau;}}_k)$ , the pulse spacing equals PN sign indicating number chip width T _f, τ _kFor compare the delay of k subscriber signal with receiver clock.Waveform is selected the waveform allocation rule of control module according to k user, selects information for pulse generator provides the generation of scaling function waveform φ (t) and wavelet function waveform ψ (t).Identical in the effect of pulse generator and the emitter block diagram, produce the basic modulated pulse trains of WDMA UWB: ${\mathrm{\&eta;}}^{\left(k\right)}\left(t\right)=s^{\left(k\right)}\left(t\right)*w_j^{\left(k\right)}\left(t\right)=\underset{j=-\&infin;}{\overset{+\&infin;}{\mathrm{\&Sigma;}}}{w}_j^{\left(k\right)}(t-j{T}_f)$ , but at the template signal of this signal of receiver end as correlation demodulation.Received signal r (t) and template signal η ^(k)(t) multiply each other, send into pip integrator, and at t=jT _f-τ _kConstantly sample, obtain sample value y _j, according to y _jThe polarity difference recover modulated binary data stream $d_i^{\left(k\right)}\&Element;\{\&PlusMinus;1\}$ 。

The above is preferred embodiment of the present invention only, and protection scope of the present invention is not limited thereto.Anyly all belong within protection scope of the present invention based on the equivalent transformation on the technical solution of the present invention.

Claims (6)

1, a kind of super broad band radio communication multiple access implementation method based on the orthogonal wavelet waveform, it is characterized in that: the scaling function φ (t) with orthogonality and wavelet function ψ (t) waveform are as the UWB impulse waveform, by means of Pseudo-random Sequence Theory, for the M sequence, the probability of occurrence of "+1 " and " 1 " almost equates, therefore, for the definite length M sequence that is Ns, the position of "+1 " and " 1 " is corresponding with scaling function φ (t) and wavelet function ψ (t) respectively, such two different impulse waveforms are just distributed to a user equably, simultaneously, utilize two multiple different integrated modes of pulse, just can realize multiple access.

2, the super broad band radio communication multiple access implementation based on the orthogonal wavelet waveform as claimed in claim 1 is characterized in that: described wavelet function ψ (t) each wavelet function for having tight support and regularity.

3, the super broad band radio communication multiple access implementation based on the orthogonal wavelet waveform as claimed in claim 1 is characterized in that: described scaling function φ (t) and the uniform distribution of described wavelet function ψ (t) waveform by code word be any pseudo noise code with good auto-correlation and their cross correlation.

4, the super broad band radio communication multiple access implementation based on the orthogonal wavelet waveform as claimed in claim 1, it is characterized in that: described UWB waveform data modulation system, different according to modulating data "+1 " and " 1 " can be adopted the bipolarity pulse-ampli tude modulation.

5, a kind of transmitter that is adopted based on the super broad band radio communication multiple access implementation of orthogonal wavelet waveform is characterized in that: its structure mainly is made up of PN sign indicating number generator, frame sequence generator, pulse generator and four parts of multiplier; PN sign indicating number generator output length is the PN sign indicating number c of Ns ^(k), its chip lengths is T _f, period T s=NsT _f, this PN sign indicating number is the basic foundation that each user is given in scaling function waveform φ (t) and wavelet function waveform ψ (t) uniform distribution; Sequence generator is according to k user's of PN sign indicating number generator output PN sign indicating number c ^(k), produce periodic sampling pulse s ^(k)(t), the pulse spacing equals PN sign indicating number chip width T _f, each pulse polarity depends on PN sign indicating number chip data, that is:

$s^{\left(k\right)}\left(t\right)=\underset{j=-\&infin;}{\overset{+\&infin;}{\mathrm{\&Sigma;}}}{\mathrm{\&alpha;}}_j^{\left(k\right)}(t-{\mathrm{jT}}_f);$ Pulse generator mainly is responsible for producing scaling function waveform φ (t) and wavelet function waveform ψ (t), and distributes according to the polarity of each sampling pulse δ (t) among the frame sequence s (t), and then obtains k user's the basic modulated pulse trains of WDMAUWB: ${\mathrm{\&eta;}}^{\left(k\right)}\left(t\right)=s^{\left(k\right)}\left(t\right)*w_j^{\left(k\right)}\left(t\right)=\underset{j=-\&infin;}{\overset{+\&infin;}{\mathrm{\&Sigma;}}}{w}_j^{\left(k\right)}(t-{\mathrm{jT}}_f),$ Here, α _j ^(k)Be k user's j PN sign indicating number, w _j ^(k)(t) be k user's j impulse waveform.

6, a kind of receiver that is adopted based on the super broad band radio communication multiple access implementation of orthogonal wavelet waveform, it is characterized in that: its structure mainly selects control module, pulse generator, multiplier and six parts of pip integrator to form by synchronization control module, frame clock generator, waveform, adopts the correlation demodulation method; Synchronization control module control frame clock generator, make local clock and k user's WDMAUWB transmitter clock keep good synchronously, select control module for waveform simultaneously timing information be provided; The frame clock generator is exported periodic sampling pulse $s^{\left(k\right)}\left(t\right)=\underset{j=-\&infin;}{\overset{+\&infin;}{\mathrm{\&Sigma;}}}\mathrm{\&delta;}(t-{\mathrm{jT}}_f-{\mathrm{\&tau;}}_k),$ Pulse spacing equals PN sign indicating number chip width T _f, τ _kFor compare the delay of k subscriber signal with receiver clock; Waveform is selected the waveform allocation rule of control module according to k user, selects information for pulse generator provides the generation of scaling function waveform φ (t) wavelet function waveform ψ (t); Pulse generator mainly is responsible for producing the basic modulated pulse trains of WDMAUWB: ${\mathrm{\&eta;}}^{\left(k\right)}\left(t\right)=s^{\left(k\right)}\left(t\right)*w_j^{\left(k\right)}\left(t\right)=\underset{j=-\&infin;}{\overset{+\&infin;}{\mathrm{\&Sigma;}}}{w}_j^{\left(k\right)}(t-{\mathrm{jT}}_f);$ Received signal r (t) and template signal η ^(k)(t) multiply each other, send into pip integrator, and at t=jT _f-τ _kConstantly sample, obtain sample value y _j, according to y _jThe polarity difference recover modulated binary data stream d _i ^(k){ ± 1}, here, δ (t) is sampling pulse to ε, w _j ^(k)(t) be k user's j impulse waveform.

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