CN102497238B - Correction Jakes module based on Rayleigh attenuation channel - Google Patents

Abstract

The invention disclose a correction Jakes module based on a Rayleigh attenuation channel, relates to the correction Jakes module and belongs to the field of communication. The module solves the problems of the large number of low frequency oscillators and the high hardware cost of a conventional Jakes module, the correction Jakes module provided is based on the Rayleigh attenuation channel, and the correction Jakes module has the advantages that: the module meets with a real channel environment, has low hardware cost; and the phase angles of the module are uniformly distributed between 0 and 2 pi. The correction Jakes module consists of a group of signal in-phase part receiving modules, a group of signal quadrature-phase part receiving modules, a signal in-phase part summation module, a signal quadrature-phase part summation module, a signal in-phase part load module, a signal output module, a group of low frequency oscillators having different frequencies, a local carrier signal generation module and a phase converter. According to the invention, the channel environment of a real environment is simulated; the hardware complexity and the hardware cost are reduced. The module is used in the field of communication.

Description

A kind of correction type Jakes module based on Rayleigh attenuation channel

Technical field

The present invention relates to a kind of correction type Jakes module, belong to the communications field.

Background technology

It is indispensable that mobile phone can say in modern life, in daily life, bring people very large facility, and this all will give the credit to the development of mechanics of communication, and in urban environment now, because building stands in great numbers, reception antenna is always lower than building, so signal propagation path is the transmission environment that belongs to NLOS (non-line-of-sight).

Jakes is in 1974 according to the EM theory of Clarke, and one of construction adds up the model of (SOS, sum-of-sinusoids) with string ripple; Be to represent doppler shifted frequency with the low-frequency oscillator of a succession of different frequency, first in homophase and the part of quadrature phase, be added separately respectively, finally again two-phase addition is produced to desired signal spectrum.Jakes sets up Rayleigh attenuation model framework by this method, and because framework is simple, can use software emulation, also easily with low-frequency oscillator, realizes its hardware circuit, also considers Doppler shift phenomenon in model simultaneously, is therefore widely used always.

In the theoretical research of multipath attenuation channel, for the statistical property of decay passage is described, there are several channel models to be suggested description multipath attenuation channel, with Clarke model wherein, accepted the most widely and used, Clarke model (Clarke model) be hypothesis in the situation that of radio wave scattering, utilize signal received on action receiving terminal antenna electromagnetic field statistical property and derive; Its hypothesis any point on a physical plane, take action on receiving terminal antenna, can receive by many levels and transmit the electromagnetic field that plane wave forms, these plane wave amplitudes and to the incidence angle of receiving terminal antenna be random and statistics independently, and plane wave is vertically polarized wave, its phase angle is being uniformly distributed of 0 to 2 π; Because its radio wave scattering theory property is highly suitable for the situation of general radio wave propagation, so Jakes model is also usingd, and it carrys out construction in addition as basis.

The envelope of the electric field E (t) of Clarke model is to meet the probability statistical property that Rayleigh distributes, and its phase place presents and is uniformly distributed, so Jakes utilizes this model theory to carry out his simulator of construction.

Jakes model formation is as follows

Y(t)＝X _c(t)cosω _ct+X _s(t)sinω _ct (1)

Wherein

$X_c\left(t\right)=2\underset{n=1}{\overset{M}{\mathrm{\Σ}}}\cos {\mathrm{\β}}_n\cos {\mathrm{\ω}}_{n}t+\sqrt{2}\cos \mathrm{\α}\cos {\mathrm{\ω}}_{m}t---\left(2\right)$

$X_s\left(t\right)=2\underset{n=1}{\overset{M}{\mathrm{\Σ}}}\sin {\mathrm{\β}}_n\cos {\mathrm{\ω}}_{n}t+\sqrt{2}\sin \mathrm{\α}\cos {\mathrm{\ω}}_{m}t---\left(3\right)$

The now selection of parameter is emphasis, because will to make the phase place of Y (t) be random and be evenly distributed on 0 to 2 π, and X _cwith X _smean value is zero, and variance is identical and uncorrelated, that is

$<{\mathrm{<figure-callout\; id="2"\; label="X\; c"\; filenames="HDA0000115094670000011.png,HDA0000115094670000022.png"\; state="\{\{state\}\}">X</figure-callout>}}_c^{}>\&ap;<{\mathrm{<figure-callout\; id="2"\; label="X\; s"\; filenames="HDA0000115094670000011.png,HDA0000115094670000022.png"\; state="\{\{state\}\}">X</figure-callout>}}_s^{}>---\left(4\right)$

<X _cX _s>≈0(5)

Can obtain:

$<{\mathrm{<figure-callout\; id="2"\; label="X\; c"\; filenames="HDA0000115094670000011.png,HDA0000115094670000022.png"\; state="\{\{state\}\}">X</figure-callout>}}_c^{}>=2\underset{n=1}{\overset{\mathrm{<figure-callout\; id="2"\; label="M\; cos"\; filenames="HDA0000115094670000011.png,HDA0000115094670000022.png"\; state="\{\{state\}\}">M</figure-callout>}}{\mathrm{\&Sigma;}}}{\cos }^{}{}^2{\mathrm{\&beta;}}_n+{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000115094670000011.png,HDA0000115094670000022.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2\mathrm{\&alpha;}=M+{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000115094670000011.png,HDA0000115094670000022.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2\mathrm{\&alpha;}+\underset{n=1}{\overset{\mathrm{<figure-callout\; id="2"\; label="M\; cos"\; filenames="HDA0000115094670000011.png,HDA0000115094670000022.png"\; state="\{\{state\}\}">M</figure-callout>}}{\mathrm{\&Sigma;}}}\cos 2{\mathrm{\&beta;}}_{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="HDA0000115094670000011.png,HDA0000115094670000022.png"\; state="\{\{state\}\}">n</figure-callout>}}\frac{1}{2}---\left(6\right)$

$<{\mathrm{<figure-callout\; id="2"\; label="X\; s"\; filenames="HDA0000115094670000011.png,HDA0000115094670000022.png"\; state="\{\{state\}\}">X</figure-callout>}}_s^{}>=2\underset{n=1}{\overset{M}{\mathrm{\&Sigma;}}}{\sin }^2{\mathrm{\&beta;}}_n+{\sin }^2\mathrm{\&alpha;}=M+{\sin }^2\mathrm{\&alpha;}-\underset{n=1}{\overset{M}{\mathrm{\&Sigma;}}}\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000115094670000011.png,HDA0000115094670000022.png"\; state="\{\{state\}\}">cos</figure-callout>}2{\mathrm{\&beta;}}_n---\left(7\right)$

$<X_c{X}_s>=2\underset{n=1}{\overset{M}{\mathrm{\&Sigma;}}}\sin {\mathrm{\&beta;}}_n\cos {\mathrm{\&beta;}}_n+\sin \mathrm{\&alpha;}\cos \mathrm{\&alpha;}---\left(8\right)$

Therefore the suggestion of Jakes is to select α=0, β _n=π n/ (M+1), can obtain

<X _cX _s>≡0(9)

$<{\mathrm{<figure-callout\; id="2"\; label="X\; c"\; filenames="HDA0000115094670000011.png,HDA0000115094670000022.png"\; state="\{\{state\}\}">X</figure-callout>}}_c^{}>=M---\left(10\right)$

$<{\mathrm{<figure-callout\; id="2"\; label="X\; s"\; filenames="HDA0000115094670000011.png,HDA0000115094670000022.png"\; state="\{\{state\}\}">X</figure-callout>}}_s^{}>=M+1---\left(11\right)$

Therefore Y (t) is that a centre frequency is at ω _cnarrow-band signal, have Rayleigh attenuation characteristic.

Hence one can see that, and Jakes attenuation channel simulator is to produce a Y (t), is that a centre frequency is at ω _cnarrow-band signal, its amplitude has Rayleigh attenuation characteristic, phase angle is random and is evenly distributed on 0 to 2 π, to comprise the effect of Doppler shift.Yet, when simulator is during in the selection of doing final parameter, make

x namely _cand X (t) _s(t) variance does not have identically, under condition, could meet completely, when M → ∞ could set up, the statistical property of the probability therefore distributing with previous mathematical expression Rayleigh and not in full conformity with, therefore also will have influence on the part of second-order statistics; In addition, at the part of phase angle, β _n=π n/ (M+1) does not have random being uniformly distributed between 0 to 2 π yet.

Subsequently, Zheng and Xiao have proposed new correction model for traditional Jakes model, and object is to improve the statistical property of high-order, and mathematical expression is as follows:

Y(t)＝x _c(t)+jx _s(t)(12)

$x_c\left(t\right)=\frac{2}{\sqrt{M}}\underset{n=1}{\overset{M}{\mathrm{\&Sigma;}}}\cos \left({\mathrm{\&beta;}}_n\right)\&CenterDot;\cos ({\mathrm{\&omega;}}_{m}t\cos \left({\mathrm{\&alpha;}}_n\right)+\mathrm{\&phi;})---\left(13\right)$

$x_s\left(t\right)=\frac{2}{\sqrt{M}}\underset{n=1}{\overset{M}{\mathrm{\&Sigma;}}}\sin \left({\mathrm{\&beta;}}_n\right)\&CenterDot;\cos ({\mathrm{\&omega;}}_{m}t\cos \left({\mathrm{\&alpha;}}_n\right)+\mathrm{\&phi;})---\left(14\right)$

${\mathrm{\&alpha;}}_n=\frac{2\mathrm{\&pi;n}-\mathrm{\&pi;}+\mathrm{\&theta;}}{4M}$ n＝1，2，…，M (15)

Wherein M low-frequency oscillator number (being subcode number) and M=N/4; N is subcode length; β _nphase angle, ω _mfor maximum Doppler angular frequency, φ is the random phase angle changing with respect to carrier phase, is evenly distributed between [π, π] γ _nequally distributed stochastic variable between [1,1], and and μ _nindependent; μ _nequally distributed stochastic variable between [1,1], and and γ _nindependent; φ is when n path, adds up independence and is evenly distributed on the random phase angle between [π, π], and θ is when n path, adds up independence and is evenly distributed on the random phase angle between [π, π].The concept of this modelling is the Mathematical Modeling of wanting to be loyal to Clarke, has added random parameter, and object is to make it more can meet real reception environment.

The fading channel model that Zheng and Xiao revise, although be that to have implemented phase angle be random equally distributed idea between 0 to 2 π, yet, when the number M of low-frequency oscillator value is large not, phase angle β _nvalue is not to be evenly distributed on very much between 0 to 2 π.

Summary of the invention

The present invention be directed to guarantee phase angle when only having low-frequency oscillator number very large in existing Jakes model is evenly distributed between 0 to 2 π, do not conform to actual channel circumstance, the problem that hardware cost is high, a kind of realistic channel circumstance has been proposed, low hardware cost, phase angle is evenly distributed on a kind of correction type Jakes module based on Rayleigh attenuation channel between 0 to 2 π.

A correction type Jakes module based on Rayleigh attenuation channel, it is comprised of low-frequency oscillator, local carrier signal generation module and the phase converter of one group of signal in orthogonal phase part receiver module, one group of signal in-phase component receiver module, signal in orthogonal phase partial summation module, signal in-phase component summation module, signal in orthogonal phase part load-on module, signal in-phase component load-on module, signal output module, one group of different frequency;

Each output of one group of described signal in orthogonal phase part receiver module connects the input of signal in orthogonal phase partial summation module; The output of signal in orthogonal phase partial summation module connects an input of signal in orthogonal phase part load-on module; Each output of described one group of signal in-phase component receiver module connects the input of signal in-phase component summation module; The output of signal in-phase component summation module connects an input of signal in-phase component load-on module; The output of signal in orthogonal phase part load-on module connects an input of signal output module; The output of signal in-phase component load-on module connects another input of signal output module; An output of each module in the low-frequency oscillator of one group of described different frequency connects respectively the signal input part of one group of respective modules in quadrature phase part receiver module, and another output of each module in the low-frequency oscillator of one group of different frequency connects respectively the signal input part of one group of respective modules in signal in-phase component receiver module; An output in described local carrier signal generation module connects another input of signal in-phase component load-on module, another output in local carrier signal generation module connects the input of phase converter, and the output of described phase converter connects another input of signal in orthogonal phase part load-on module;

One group of described signal in orthogonal phase part receiver module is respectively:

$2\sin (\frac{\mathrm{\&pi;}}{M}+\frac{\mathrm{\&pi;}}{M}{\mathrm{\&gamma;}}_n),......,$ $2\sin (\frac{(2n-1)\mathrm{\&pi;}}{M}+\frac{\mathrm{\&pi;}}{M}{\mathrm{\&gamma;}}_n),$ n＝1，2，...，M，

Each module wherein receives the in-phase component in corresponding frequencies signal in the low-frequency oscillator of one group of different frequency;

One group of described signal in-phase component receiver module is respectively:

$2\cos (\frac{\mathrm{\&pi;}}{M}+\frac{\mathrm{\&pi;}}{M}{\mathrm{\&gamma;}}_n),......,$ $2\cos (\frac{(2n-1)\mathrm{\&pi;}}{M}+\frac{\mathrm{\&pi;}}{M}{\mathrm{\&gamma;}}_n),$ n＝1，2，...，M，

Each module wherein receives the quadrature phase part in corresponding frequencies signal in the low-frequency oscillator of one group of different frequency;

Described signal in orthogonal phase partial summation module, sues for peace for by the quadrature of one group of signal in orthogonal phase part receiver module institute picked up signal, part is cumulative mutually; Wherein one group of signal in orthogonal mutually part and be:

$X_s\left(t\right)=\frac{2}{\sqrt{M}}\underset{n=1}{\overset{M}{\mathrm{\&Sigma;}}}\sin \left({\mathrm{\&beta;}}_n\right)\cos ({\mathrm{\&omega;}}_{m}t\cos {\mathrm{\&alpha;}}_n+\mathrm{\&phi;})$ . formula one;

In formula, M is the number of the low-frequency oscillator of one group of different frequency, i.e. subcode number, and N is subcode length, M=N/4, β _nfor phase angle, ω _mfor maximum Doppler angular frequency; φ is the random phase angle changing with respect to carrier phase, is evenly distributed between [π, π]; β _nfor the phase angle of the correction type Jakes module based on Rayleigh attenuation channel, phase angle β _nat random, be evenly distributed on four quadrants; α _nincident angle for electric wave signal arrival receiving terminal antenna;

Described signal in-phase component summation module, for the cumulative summation of in-phase component of signal that signal in-phase component receiver module is a group by a group obtained, wherein the in-phase component of one group of signal and be:

$X_c\left(t\right)=\frac{2}{\sqrt{M}}\underset{n=1}{\overset{M}{\mathrm{\&Sigma;}}}\cos \left({\mathrm{\&beta;}}_n\right)\cos ({\mathrm{\&omega;}}_{m}t\cos {\mathrm{\&alpha;}}_n+\mathrm{\&phi;})$ . formula two;

Described signal in orthogonal phase part load-on module, for the quadrature phase part sin ω of local carrier signal generation module _ct is loaded in the cumulative sum of signal in orthogonal phase part, that is: X _s(t) sin ω _ct, wherein, ω _cfor local carrier signal frequency;

Described signal in-phase component load-on module, for the in-phase component cos ω of local carrier that local carrier signal generation module is produced _ct is loaded in the cumulative sum of signal in-phase component, that is: X _c(t) cos ω _ct;

Described signal output module, the cumulative summation of the signal that signal in-phase component load-on module and signal in orthogonal phase part load-on module are exported respectively, that is: Y (t)=X _c(t) cos ω _ct+X _s(t) sin ω _ct, Y (t) is that a centre frequency is at ω _cnarrow-band signal, have Rayleigh attenuation characteristic;

The low-frequency oscillator of described different frequency, produces the signal of a plurality of different frequencies;

Described local carrier signal generation module, produces local carrier signal;

Described phase converter, by the phase place adjustment in the signal in local carrier

Good effect of the present invention:

A kind of correction type Jakes module based on Rayleigh attenuation channel of the present invention, when low-frequency oscillator number is little, phase angle also can be evenly distributed between 0 to 2 π at random, the distortion of signal has been lacked like this, the channel circumstance of simulation more approaches real environment, reduce the complexity that realizes hardware, and then reduced the cost of hardware.

Accompanying drawing explanation

Fig. 1 is the original Jakes model emulation device Organization Chart based on Rayleigh attenuation channel.

Fig. 2 is the angular distribution method of the correction type Jakes module based on Rayleigh attenuation channel.

Fig. 3 is the namely number of outside a plurality of different frequency signals of low-frequency oscillator number, i.e. subcode number M=14, and the electric wave of Jakes model arrives the angular distribution method of receiving terminal.

The angular distribution method of low-frequency oscillator number (being subcode number) the M=16 electric wave arrival receiving terminal that Fig. 4 is the correction type Jakes module based on Rayleigh attenuation channel, wherein electric wave arrives the incident angle α of receiving terminal antenna _nto drop at random on the camber line of black thick line, therefore work as α _nin the time of=0 °, will there will be maximum Doppler skew.

Fig. 5 is that the envelope oscillator intensity that simulator produces distributes, and the envelope probability density function of simulation Rayleigh fading, for improved model, Jakes model and Zheng & Xiao model compare when the M=4; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is the probability density function that Rayleigh distributes.

Fig. 6 is that the envelope oscillator intensity that simulator produces distributes, for improved model, Jakes model and Zheng & Xiao model compare when the M=8; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is the probability density function that Rayleigh distributes.

Fig. 7 is that the envelope oscillator intensity that simulator produces distributes, for improved model, Jakes model and Zheng & Xiao model compare when the M=12; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is the probability density function that Rayleigh distributes.Visible, when M value is little, still can obtain the effect close with theoretical value.

Fig. 8 is that the envelope oscillator intensity that simulator produces distributes, for improved model, Jakes model and Zheng & Xiao model compare when the M=16; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is the probability density function that Rayleigh distributes.Visible, when M value is little, still can obtain the effect close with theoretical value.

Fig. 9 is the PHASE DISTRIBUTION that simulator produces, for improved model, Jakes model and Zheng & Xiao model compare when the M=4; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is equally distributed probability density function.

Figure 10 is the PHASE DISTRIBUTION that simulator produces, for improved model, Jakes model and Zheng & Xiao model compare when the M=8; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is equally distributed probability density function.

Figure 11 is the PHASE DISTRIBUTION that simulator produces, for improved model, Jakes model and Zheng & Xiao model compare when the M=12; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value is wherein equally distributed probability density function.Visible, improved model still can obtain the effect close with theoretical value when M value is little.

Figure 12 is the PHASE DISTRIBUTION that simulator produces, for improved model, Jakes model and Zheng & Xiao model compare when the M=16; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value is wherein equally distributed probability density function.Visible, improved model still can obtain the effect close with theoretical value when M value is little.

Figure 13 is the in-phase component x that simulator produces _c(t) auto-correlation function, for improved model, Jakes model and Zheng & Xiao model compare when the M=4; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is the bessel function curve of first kind zeroth order.

Figure 14 is the quadrature phase component x that simulator produces _s(t) auto-correlation function, for improved model, Jakes model and Zheng & Xiao model compare when the M=8; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is the bessel function curve of first kind zeroth order.

Figure 15 is the in-phase component x that simulator produces _c(t) auto-correlation function, for improved model, Jakes model and Zheng & Xiao model compare when the M=12; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is the bessel function curve of first kind zeroth order.Visible, improved model still can obtain the effect close with theoretical value when M value is little.

Figure 16 is the quadrature phase component x that simulator produces _s(t) auto-correlation function, improved model, Jakes model and Zheng & Xiao model compare when M=16; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is the bessel function curve of first kind zeroth order.Visible, when M value is little, still can obtain the effect close with theoretical value.

Figure 17 is the quadrature phase component x that simulator produces _s(t) auto-correlation function, for improved model, Jakes model and Zheng & Xiao model compare when M=4 and the M=8; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is the bessel function curve of first kind zeroth order.

Figure 18 is the quadrature phase component x that simulator produces _s(t) auto-correlation function, for improved model, Jakes model and Zheng & Xiao model compare when M=4 and the M=8; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is the bessel function curve of first kind zeroth order.

Figure 19 is the quadrature phase component x that simulator produces _s(t) auto-correlation function, for improved model, Jakes model and Zheng & Xiao model compare when the M=12; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is the bessel function curve of first kind zeroth order.Visible, the present invention still can obtain the effect close with theoretical value when M value is little.

Figure 20 is the quadrature phase component x that simulator produces _s(t) auto-correlation function, for improved model, Jakes model and Zheng & Xiao model compare when the M=16; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is the bessel function curve of first kind zeroth order.Visible, the present invention still can obtain the effect close with theoretical value when M value is little.

Figure 21 is quadrature phase component y (t) auto-correlation function that simulator produces, for improved model, Jakes model and Zheng & Xiao model compare when the M=4; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is the bessel function curve of first kind zeroth order.Visible, the present invention still can obtain the effect close with theoretical value when M value is little.

Figure 22 is quadrature phase component y (t) auto-correlation function that simulator produces, for improved model, Jakes model and Zheng & Xiao model compare when the M=8; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is the bessel function curve of first kind zeroth order.Visible, the present invention still can obtain the effect close with theoretical value when M value is little.

Figure 23 is plural y (t) auto-correlation function that simulator produces, for improved model, Jakes model and Zheng & Xiao model compare when the M=12; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is the bessel function curve of first kind zeroth order.Visible, this patent still can obtain the effect close with theoretical value when M value is little.

Figure 24 is plural y (t) auto-correlation function that simulator produces, for improved model, Jakes model and Zheng & Xiao model compare when the M=16; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is the bessel function curve of first kind zeroth order.Visible, this patent still can obtain the effect close with theoretical value when M value is little.

Figure 25 is the in-phase component x that simulator produces _c(t) with quadrature phase component x _s(t) cross-correlation function, for improved model, Jakes model and Zheng & Xiao model compare when the M=4; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is zero.Visible, this patent still can obtain the effect close with theoretical value when M value is little.

Figure 26 is the in-phase component x that simulator produces _c(t) with quadrature phase component x _s(t) cross-correlation function, for improved model, Jakes model and Zheng & Xiao model compare when the M=8; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is zero.Visible, this patent still can obtain the effect close with theoretical value when M value is little.

Figure 27 is the in-phase component x of simulator generation _c(t) with quadrature phase component x _s(t) hand over correlation function, for improved model, Jakes model and Zheng & Xiao model compare when the M=12; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is zero.Visible, this patent still can obtain the effect close with theoretical value when M value is little.

Figure 28 is the in-phase component x of simulator generation _c(t) with quadrature phase component x _s(t) hand over correlation function, for improved model, Jakes model and Zheng & Xiao model compare when the M=16; Centre carrier frequency is 2000MHz, and the speed of a motor vehicle is 50km/hr, and Doppler's peak excursion is 92.59Hz.Theoretical value in this figure is zero.Visible, this patent still can obtain the effect close with theoretical value when M value is little.

In figure in Fig. 5 to Figure 28, the implication of symbol is respectively:

represent result of the present invention;

the result that represents traditional Jakes module;

the result that represents Zheng and Xiao;---representation theory value.

Figure 29 is structural representation of the present invention.

Figure 30 is cdma system running block diagram.

Figure 31 is main program flow chart.

Figure 32 is subprogram Jakes_mod flow chart.

Figure 33 is subprogram BVS flow chart.

Figure 34 is subprogram CH flow chart.

Figure 35 is subprogram MPPC flow chart.

Embodiment

Embodiment one: below in conjunction with Figure 29, present embodiment is described,

A correction type Jakes module based on Rayleigh attenuation channel, it is by signal in orthogonal phase part receiver module 1 a group by a group, low-frequency oscillator 8, local carrier signal generation module 9 and the phase converter 10 of signal in-phase component receiver module 2, signal in orthogonal phase partial summation module 3, signal in-phase component summation module 4, signal in orthogonal phase part load-on module 5, signal in-phase component load-on module 6, signal output module 7, one group of different frequency form a group by a group;

Each output of one group of described signal in orthogonal phase part receiver module 1 connects the input of signal in orthogonal phase partial summation module 3; The output of signal in orthogonal phase partial summation module 3 connects an input of signal in orthogonal phase part load-on module 5; Each output of described one group of signal in-phase component receiver module 2 connects the input of signal in-phase component summation module 4; The output of signal in-phase component summation module 4 connects an input of signal in-phase component load-on module 6; The output of signal in orthogonal phase part load-on module 5 connects an input of signal output module 7; The output of signal in-phase component load-on module 6 connects another input of signal output module 7; An output of each module in the low-frequency oscillator 8 of one group of described different frequency connects respectively the signal input part of one group of respective modules in quadrature phase part receiver module 1, and another output of each module in the low-frequency oscillator 8 of one group of different frequency connects respectively the signal input part of one group of respective modules in signal in-phase component receiver module 2; An output in described local carrier signal generation module 9 connects another input of signal in-phase component load-on module 6, another output in local carrier signal generation module 9 connects the input of phase converter 10, and the output of described phase converter 10 connects another input of signal in orthogonal phase part load-on module 5;

One group of described signal in orthogonal phase part receiver module 1 is respectively:

$2\sin (\frac{\mathrm{\&pi;}}{M}+\frac{\mathrm{\&pi;}}{M}{\mathrm{\&gamma;}}_n),......,$ $2\sin (\frac{(2n-1)\mathrm{\&pi;}}{M}+\frac{\mathrm{\&pi;}}{M}{\mathrm{\&gamma;}}_n),$ n＝1，2，...，M，

Each module wherein receives the in-phase component in corresponding frequencies signal in the low-frequency oscillator 8 of one group of different frequency;

One group of described signal in-phase component receiver module 2 is respectively:

$2\cos (\frac{\mathrm{\&pi;}}{M}+\frac{\mathrm{\&pi;}}{M}{\mathrm{\&gamma;}}_n),......,$ $2\cos (\frac{(2n-1)\mathrm{\&pi;}}{M}+\frac{\mathrm{\&pi;}}{M}{\mathrm{\&gamma;}}_n),$ n＝1，2，...，M，

Each module wherein receives the quadrature phase part in corresponding frequencies signal in the low-frequency oscillator 8 of one group of different frequency;

Described signal in orthogonal phase partial summation module 3, sues for peace for by the quadrature of 1 picked up signal of one group of signal in orthogonal phase part receiver module, part is cumulative mutually; Wherein one group of signal in orthogonal mutually part and be:

$X_s\left(t\right)=\frac{2}{\sqrt{M}}\underset{n=1}{\overset{M}{\mathrm{\&Sigma;}}}\sin \left({\mathrm{\&beta;}}_n\right)\cos ({\mathrm{\&omega;}}_{m}t\cos {\mathrm{\&alpha;}}_n+\mathrm{\&phi;})$ . formula one;

In formula, M is the number of the low-frequency oscillator 8 of one group of different frequency, i.e. subcode number, and N is subcode length, M=N/4, β _nfor phase angle, ω _mfor maximum Doppler angular frequency; φ is the random phase angle changing with respect to carrier phase, is evenly distributed between [π, π]; β _nfor the phase angle of the correction type Jakes module based on Rayleigh attenuation channel, phase angle β _nat random, be evenly distributed on four quadrants; α _nincident angle for electric wave signal arrival receiving terminal antenna;

Described signal in-phase component summation module 4, for the cumulative summation of in-phase component of signal that one group of signal in-phase component receiver module 2 is obtained, wherein the in-phase component of one group of signal and be:

$X_s\left(t\right)=\frac{2}{\sqrt{M}}\underset{n=1}{\overset{M}{\mathrm{\&Sigma;}}}\sin \left({\mathrm{\&beta;}}_n\right)\cos ({\mathrm{\&omega;}}_{m}t\cos {\mathrm{\&alpha;}}_n+\mathrm{\&phi;})$ . formula two;

Described signal in orthogonal phase part load-on module 5, for the quadrature phase part sin ω of local carrier signal generation module 9 _ct is loaded in the cumulative sum of signal in orthogonal phase part, that is: X _s(t) sin ω _ct, wherein, ω _cfor local carrier signal frequency;

Described signal in-phase component load-on module 6, for the in-phase component cos ω of local carrier that local carrier signal generation module 9 is produced _ct is loaded in the cumulative sum of signal in-phase component, that is: X _c(t) cos ω _ct;

Described signal output module 7, the cumulative summation of the signal that signal in-phase component load-on module 6 and signal in orthogonal phase part load-on module 5 are exported respectively, that is: Y (t)=X _c(t) cos ω _ct+X _s(t) sin ω _ct, Y (t) is that a centre frequency is at ω _cnarrow-band signal, have Rayleigh attenuation characteristic;

The low-frequency oscillator 8 of described different frequency, produces the signal of a plurality of different frequencies;

Described local carrier signal generation module 9, produces local carrier signal;

Described phase converter 10, by the phase place adjustment in the signal in local carrier

Embodiment two: below in conjunction with Figure 29, present embodiment is described, present embodiment is for to the further illustrating of execution mode one,

Described a kind of correction type Jakes module based on Rayleigh attenuation channel, is characterized in that the phase angle β in formula one or formula two _nfor:

n=1,2 ..., M .... formula three, wherein, γ _nequally distributed stochastic variable between [1,1], and and μ _nindependent.

Embodiment three: below in conjunction with Figure 29, present embodiment is described, present embodiment is for to the further illustrating of execution mode one,

Described a kind of correction type Jakes module based on Rayleigh attenuation channel, is characterized in that the incident angle α of the receiving terminal antenna in formula one or formula two _nfor:

${\mathrm{\&alpha;}}_n=\frac{(2n-1)\mathrm{\&pi;}}{N}+\frac{\mathrm{\&pi;}}{N}{\mathrm{\&mu;}}_n,$ N=1,2 ..., M .... formula four,

In formula, μ _nequally distributed stochastic variable between [1,1], and and γ _nindependent.

Embodiment four: below in conjunction with Figure 29, present embodiment is described, present embodiment is to execution mode one, and the further illustrating of execution mode two,

Phase angle β _nrandom distribution, and be evenly distributed on four methods above quadrant and be:

Allow phase angle β _ndivide equally on circle, each angle all branching away has random scope separately, recycling γ _nallow each angle random value separately allow phase angle β _nrandom value.

The present invention is not limited to above-mentioned execution mode, can also be the reasonable combination of technical characterictic described in the respective embodiments described above.

Embodiment

In conjunction with Figure 30 to Figure 35, the present embodiment is described

Take cdma system as example, and modified form Jakes model module is wherein just this patent summary of the invention, and from operating the just flow process of known system of block diagram, then matching program flow chart just can be understood running and the implementation of whole program.

First be main program, main program with bit error rate (bit error rate) as a result of, for the relatively variation of system effectiveness under different parameters, write the part of mistake in computation rate as subprogram, as long as do a little changes in the place of parameter, just can obtain the bit error rate under different parameters simultaneously, also more efficient on carrying out.Main program can be introduced into subprogram jakes_mod, i.e. content of the present invention, and this is the Rayleigh passage becoming in order to produce time, the form that it is saved as to matrix returns.Next enter subprogram BVS, it is for calculating bit error rate, according to the difference of SNR (dB), there is the row the inside of matrix B ER, the value of error rate that BER the first row is deposited when being exactly SNR=1 (dB), the row of BER are for setting level equal number of times, that is to say, if run n time, BER just has n row, this n time addition, divided by n, has been finally mean value again.Obtain needing only and sequentially just can draw the curve chart of bit error rate afterwards of different parameters.

Subprogram BVS starts first to call out subprogram RANDOM, produces bit random order, and in the process producing, does BPSK coding, the matrix that total number of users is user; Then call out subprogram NCEC, all users' data are done to exhibition action frequently; Then the complete data of exhibition frequency are delivered in channel.Subprogram CH namely, it is by the channel in emulation Mobile Communications, and running will illustrate in addition when program flow diagram in detail; Then receive after the data of channel, produce an additive property noise and be added, then enter subprogram NCDC, all customer data is multiplied by the spreading codes of wanting to ask user, has taken advantage of again the correlation function after all calculating is added, then judgement, if bit is greater than 0 and is judged to 1, be less than 0 and sentence-1; Finally data and former data after judgement are subtracted each other, if the data of subtracting each other are not 0, this mistake in judgment, is bit error rate vicious figure place divided by total bit again, then by the error rate values passback main program obtaining.

Subprogram CH is the part for emulation passage, comprising can multiplicative noise, asynchronous and multi-path between user, and the action of carrying out is to be completed by subprogram MPPC, utilize two for circulations that whole subcodes of all users are all thrown into, the all customer data that just can obtain being interfered after computing, now more all users' data are added to the data of wanting to ask user, just sub-routine ends CH.

Subprogram MPPC is synchronous problem whether between computing user first, by d chips of data displacement, then produce the multipath matrix that comprises d chips displacement, and channel response is taken on corresponding delay path matrix, finally again these are had to inter-user delay, multipath delay simultaneously and to the matrix affecting, be added by then accommodation, just return data and go back.

Claims (4)

1. the correction type Jakes module based on Rayleigh attenuation channel, is characterized in that it is comprised of low-frequency oscillator (8), local carrier signal generation module (9) and the phase converter (10) of one group of signal in orthogonal phase part receiver module (1), one group of signal in-phase component receiver module (2), signal in orthogonal phase partial summation module (3), signal in-phase component summation module (4), signal in orthogonal phase part load-on module (5), signal in-phase component load-on module (6), signal output module (7), one group of different frequency;

Each output of described one group of signal in orthogonal phase part receiver module (1) connects the input of signal in orthogonal phase partial summation module (3); The output of signal in orthogonal phase partial summation module (3) connects an input of signal in orthogonal phase part load-on module (5); Each output of described one group of signal in-phase component receiver module (2) connects the input of signal in-phase component summation module (4); The output of signal in-phase component summation module (4) connects an input of signal in-phase component load-on module (6); The output of signal in orthogonal phase part load-on module (5) connects an input of signal output module (7); The output of signal in-phase component load-on module (6) connects another input of signal output module (7); An output of each module in the low-frequency oscillator (8) of one group of described different frequency connects respectively the signal input part of the respective modules in one group of quadrature phase part receiver module (1), and another output of each module in the low-frequency oscillator of one group of different frequency (8) connects respectively the signal input part of the respective modules in one group of signal in-phase component receiver module (2); An output in described local carrier signal generation module (9) connects another input of signal in-phase component load-on module (6), another output in local carrier signal generation module (9) connects the input of phase converter (10), and the output of described phase converter (10) connects another input of signal in orthogonal phase part load-on module (5);

Described one group of signal in orthogonal phase part receiver module (1) is respectively:

Each module wherein receives the in-phase component in corresponding frequencies signal in the low-frequency oscillator (8) of one group of different frequency;

Described one group of signal in-phase component receiver module (2) is respectively:

Each module wherein receives the quadrature phase part in corresponding frequencies signal in the low-frequency oscillator (8) of one group of different frequency;

Described signal in orthogonal phase partial summation module (3), sues for peace for by the quadrature of one group of signal in orthogonal phase part receiver module (1) institute picked up signal, part is cumulative mutually; Wherein one group of signal in orthogonal mutually part and be:

formula one;

In formula, M is the number of the low-frequency oscillator (8) of one group of different frequency, i.e. subcode number, and N is subcode length, M=N/4, β _nfor phase angle, ω _mfor maximum Doppler angular frequency; φ is the random phase angle changing with respect to carrier phase, is evenly distributed between [π, π]; β _nfor the phase angle of the correction type Jakes module based on Rayleigh attenuation channel, phase angle β _nat random, be evenly distributed on four quadrants; α _nincident angle for electric wave signal arrival receiving terminal antenna;

Described signal in-phase component summation module (4), for the cumulative summation of in-phase component of signal that one group of signal in-phase component receiver module (2) is obtained, wherein the in-phase component of one group of signal and be:

formula two;

Described signal in orthogonal phase part load-on module (5), for the quadrature phase part sin ω of local carrier signal generation module (9) _ct is loaded in the cumulative sum of signal in orthogonal phase part, that is: X _s(t) sin ω _ct, wherein, ω _cfor local carrier signal frequency;

Described signal in-phase component load-on module (6), for the in-phase component cos ω of local carrier that local carrier signal generation module (9) is produced _ct is loaded in the cumulative sum of signal in-phase component, that is: X _c(t) cos ω _ct;

Described signal output module (7), the cumulative summation of the signal that signal in-phase component load-on module (6) and signal in orthogonal phase part load-on module (5) are exported respectively,

That is: Y (t)=X _c(t) cos ω _ct+X _s(t) sin ω _ct,

Y (t) is that a centre frequency is at ω _cnarrow-band signal, have Rayleigh attenuation characteristic;

The low-frequency oscillator of described different frequency (8), produces the signal of a plurality of different frequencies;

Described local carrier signal generation module (9), produces local carrier signal;

Described phase converter (10), by the phase place adjustment in the signal in local carrier

2. a kind of correction type Jakes module based on Rayleigh attenuation channel according to claim 1, is characterized in that the phase angle β in formula 1 or formula 2 _nfor:

formula three, in formula, γ _nequally distributed stochastic variable between [1,1], and and μ _nindependent, μ _nit is equally distributed stochastic variable between [1,1].

3. a kind of correction type Jakes module based on Rayleigh attenuation channel according to claim 1, is characterized in that the incident angle α of the receiving terminal antenna in formula one or formula two _nfor:

formula four, in formula, μ _nequally distributed stochastic variable between [1,1], and and γ _nindependent.

4. a kind of correction type Jakes module based on Rayleigh attenuation channel according to claim 1 and 2, is characterized in that phase angle β in formula _nrandom distribution, and be evenly distributed on four methods above quadrant and be:

Allow phase angle β _ndivide equally on circle, each angle all branching away has random scope separately, recycling γ _nallow each angle random value separately allow phase angle β _nrandom value.

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