CN1777072A - Mobile channel andloging method - Google Patents

Abstract

A simulator for mobile channel is setup between baseband processing module and radio frequency module of mobile communication device. In transmitting direction, the simulator does following operations: carrying out digital signal process for signal in base band to be sent from mobile device, or it is equivalent to produce the output of actual mobile channel, and then to generate processed signal in base band; the mobile device modulates the processed signal in base band so as to generate signal in radio frequency, then sending it out. In receiving direction, the simulator does following operations: demodulating the received signal in radio frequency so as to obtain signal in base band; the simulator carries out digital signal process for the signal in base band, or it is equivalent to produce the output of actual mobile channel and then to generate processed signal in base band. Advantages are: reducing amount of calculation, no need of A/D and D/A converters, etc.

Description

A kind of mobile channel analogy method

Technical field

The present invention relates to the mobile channel analogue technique of mobile communication system, specially refer to a kind of mobile channel analogy method.

Background technology

Fig. 1 has shown the basic model of mobile communication system.As shown in Figure 1, at down direction, the baseband signal of the baseband processing module of base station output is formed on the radiofrequency signal of transmitting on the mobile channel through after the modulation of radio-frequency module; The radio-frequency module of travelling carriage receives after the radiofrequency signal of transmitting on the mobile channel, generates baseband signal through demodulation, and then outputs to baseband processing module and handle.Similarly, on up direction, the baseband signal of the baseband processing module of travelling carriage output is formed on the radiofrequency signal of transmitting on the mobile channel through after the modulation of radio-frequency module; The radio-frequency module of base station receives after the radiofrequency signal of transmitting on the mobile channel, generates baseband signal through demodulation, and then outputs to baseband processing module.

Need to prove that above-mentioned mobile channel belongs to wireless channel, and wireless channel have a lot of transmission characteristics different with wire message way.For example, aspect loss, wireless channel is except having common loss, and the electromagnetic wave that also has owing to transmission is subjected to building and massif etc. and stops the slow fading loss that produces, promptly so-called shadow effect on transmission path; And the rapid fading loss that produces owing to the multipath transmisstion effect of signal in wireless environment.In addition, because user's mobility at random in the mobile communication system, mobile channel also will have the far and near different near-far interference that produce apart from the base station owing to different mobile subscribers, and because Doppler effect that mobile subscriber's high-speed mobile is brought or the like.Generally speaking, the transmission characteristic of mobile channel is quite complicated, and be the design basis of mobile communication equipment, many technology in the mobile communication all have direct or indirect getting in touch with the transmission characteristic of mobile channel, thereby have only by the research to the mobile channel propagation characteristic and could provide reliable foundation for the research and development and the optimization of mobile communication system.

Under normal conditions, mobile channel can use following mathematic(al) representation to characterize:

$h_k(\mathrm{\τ},\mathrm{\φ})=\underset{1}{\overset{L}{\mathrm{\Σ}}}{g}_{k,l}\left(t\right){\mathrm{\δ}}_{k,l}(t-{\mathrm{\τ}}_{k,l})a(\mathrm{\φ}-{\mathrm{\φ}}_{k,l}),$

Wherein, h _k(it is the function of signal time delay τ and angle of arrival Φ for τ, φ) k user's of expression mobile channel impulse response, and parameter L is represented total number of path of channel, and l represents Ge Lu multipath label, g _{K, l}(t), τ _{K, l}, φ _{K, l}, α (φ-φ _{K, l}) represent the time varying signal amplitude, relative time delay, arrival angle of k user's l bar multipath and the weights that arrive angle respectively.In addition, can also defined parameters P _{K, l}=E|g _{K, l}(t) | ², the average power of k user's of this parametric representation l bar multipath, ITU and 3GPP have provided the power P of each path l of parameter L under the various environment respectively _{K, l}With time delay τ _{K, l}Value.By above-mentioned formula as can be seen, the response of k user's mobile channel be L paths impulse response and.

Because mobile channel has time variation and characteristics such as bigger affected by environment, in the research and test process of mobile communication system, usually directly do not use real mobile channel, and be to use the mobile channel in the mobile channel simulator analog mobile communication system.Because the mobile channel simulator can utilize technology such as Digital Signal Processing to make its impulse response be equivalent to above-mentioned mobile channel model on statistical significance, thereby the development and testing personnel can directly pass through the mobile channel of mobile channel simulator simulating reality, and to studying and test through the signal of mobile channel simulator processing, and need not in real wireless environment, to test, simplified the complexity of test greatly.

Fig. 2 and Fig. 3 have shown respectively when mobile communication system is tested, the signal processing of its down direction and up direction.As shown in Figure 2, at down direction, the baseband signal S (t) of base station baseband processing module output generates radiofrequency signal RF_BS1 (t) through after the modulation of radio-frequency module, sends to the mobile channel simulator then; After the mobile channel simulator is handled radiofrequency signal, generate radiofrequency signal RF_UE1 (t), send to the radio-frequency module of travelling carriage, radio-frequency module carries out exporting baseband signal after the demodulation.At this moment, the tester then can directly analyze demodulated baseband signal, finishes the test to mobile communication system.

Wherein, make s (t)=s ₁(t)+js ₂(t), through the radiofrequency signal that generates behind the radio frequency unit be:

RF_BS1(t)＝Re[s(t)e ^jωt]＝s ₁(t)coswt-s ₂(t)sinwt；

RF_BS1 (t) arrives travelling carriage through the mobile channel simulator, and handles the convolution that the signal that obtains is RF_BS1 (t) and mobile channel impulse response through band pass filter:

$\mathrm{RF}\_\mathrm{UE}1\left(t\right)=\underset{m=1}{\overset{M}{\mathrm{\Σ}}}\underset{p=1}{\overset{P}{\mathrm{\Σ}}}\mathrm{Re}\left[\sqrt{P\left({\mathrm{\τ}}_p\right)}{g}_p\left(t\right)a\left({\mathrm{\φ}}_{m,p}\right)s(t-{\mathrm{\τ}}_p)e^{\mathrm{j\ω}(t-{\mathrm{\τ}}_p)}\right]+\mathrm{Re}\left[z\left(t\right)e^{\mathrm{jwt}}\right];$

Wherein, M is the bay number, and P is the multipath number, is the white Gaussian noise of base band, Re[z (t) e ^Jwt] be the logical white Gaussian noise of band through band pass filter, α (φ _{M, p}) be the DOA angle weights that the p paths arrives m root antenna, g _p(t) be the decline weights of p paths,

For time-delay is τ _pThe power of p paths.

Make z (t)=z _M1(t)+jz _M2(t), $G_p\left(t\right)e^{{\mathrm{j\ψ}}_{m,p}}=\sqrt{P\left({\mathrm{\τ}}_p\right)}{g}_p\left(t\right)a\left({\mathrm{\φ}}_{m,p}\right),$ Then obtain:

$\mathrm{RF}\_\mathrm{UE}1\left(t\right)=\underset{m=1}{\overset{M}{\mathrm{\Σ}}}\underset{p=1}{\overset{P}{\mathrm{\Σ}}}[G_p\left(t\right)s_1(t-{\mathrm{\τ}}_p)\cos (w(t-{\mathrm{\τ}}_p)+{\mathrm{\ψ}}_{m,p})-G_p\left(t\right)s_2(t-{\mathrm{\τ}}_p)\sin (w(t-{\mathrm{\τ}}_p)+{\mathrm{\ψ}}_{m,p})].$

+z ₁(t)coswt-z ₂(t)sinwt

Above-mentioned expression formula has characterized the radiofrequency signal that obtains by behind baseband signal S (t) the process base station radio frequency module of base station output, the mobile channel simulator.

As shown in Figure 3, on up direction, the baseband signal S (t) of the baseband processing module of travelling carriage output sends to the mobile channel simulator then and handles through generating radiofrequency signal RF_UE2 (t) after the modulation of radio-frequency module, generates RF_BS2 (t); After the radio-frequency module of base station receives the radiofrequency signal of handling through the mobile channel simulator, through generating baseband signal R1 (t) after the radio-frequency module demodulation.

Wherein, make s (t)=s ₁(t)+js ₂(t), the radiofrequency signal that generates through the travelling carriage radio-frequency module is:

RF_UE2(t)＝Re[s(t)e ^jωt]＝s ₁(t)coswt+s ₂(t)sinwt；

Above-mentioned radiofrequency signal RF_UE2 (t) arrives the base station through the mobile channel simulator, and the signal that processing obtains through band pass filter is the convolution of RF_UE2 (t) mobile channel impulse response:

$\mathrm{RF}\_\mathrm{BS}2{\left(t\right)}^m=\mathrm{Re}\left\{\underset{p=1}{\overset{P}{\mathrm{\Σ}}}\right[\sqrt{P\left({\mathrm{\τ}}_p\right)}{g}_p\left(t\right)a\left({\mathrm{\φ}}_{m,p}\right)s(t-{\mathrm{\τ}}_p)e^{\mathrm{j\ω}(t-{\mathrm{\τ}}_p)}]+z_m\left(t\right)e^{\mathrm{jwt}}\};$

Wherein, P is the multipath number, z _m(t) be the low pass white Gaussian noise behind the logical white Gaussian noise process of the band radio demodulating on the m root antenna, Re[z _m(t) e ^Jwt] be that the band through band pass filter leads to white Gaussian noise on the m root antenna.

Make Z _m(t)=z _M1(t)+jz _M2(t), $G_p\left(t\right)e^{{\mathrm{j\ψ}}_{m,p}}=\sqrt{P\left({\mathrm{\τ}}_p\right)}{g}_p\left(t\right)a\left({\mathrm{\φ}}_{m,p}\right),$ Then obtain:

$\mathrm{RF}\_\mathrm{BS}2{\left(t\right)}^m=\underset{p=1}{\overset{P}{\mathrm{\Σ}}}[G_p\left(t\right)s_1(t-{\mathrm{\τ}}_p)\cos (w(t-{\mathrm{\τ}}_p)+{\mathrm{\ψ}}_{m,p})-G_p\left(t\right)s_2(t-{\mathrm{\τ}}_p)\sin (w(t-{\mathrm{\τ}}_p)+{\mathrm{\ψ}}_{m,p})];$

+z _m1(t)coswt-z _m2(t)sinwt

RF_BS2 (t) ^mThrough the baseband signal after the radio-frequency module demodulation be:

R1(t)＝Re[RF_BS2(t) ^me ^-jwt]；

Its I road: $I\left[R1{\left(t\right)}^m\right]=\underset{p=1}{\overset{P}{\mathrm{\Σ}}}\left[G_p{s}_1(t-{\mathrm{\τ}}_p)\cos ({-\mathrm{w\τ}}_p+{\mathrm{\ψ}}_{m,p})\right]+z_{m1}\left(t\right);$

The Q road: $Q\left[R1{\left(t\right)}^m\right]=\underset{p=1}{\overset{P}{\mathrm{\Σ}}}\left[G_p{s}_2(t-{\mathrm{\τ}}_p)\sin ({-\mathrm{w\τ}}_p+{\mathrm{\ψ}}_{m,p})\right]+z_{m2}\left(t\right).$

Above-mentioned expression formula has characterized the baseband signal that obtains after the radio-frequency module demodulation of baseband signal S (t) through the modulation of travelling carriage radio-frequency module, mobile channel simulator and base station of being exported by travelling carriage.

In above-mentioned mobile channel analogy method, the mobile channel simulator need receive the radiofrequency signal of base station or travelling carriage output, and the radiofrequency signal that receives handled, make the signal of its output be equivalent to the signal of real mobile channel output, and then export to travelling carriage or base station.In above-mentioned processing procedure, because radiofrequency signal is an analog signal, it is the Digital Signal Processing operation that digital signal just can be simulated true mobile channel then accordingly with the analog signal conversion of importing at first that the mobile channel simulator needs, and the digital signal that processing need be obtained is converted to analog signal output.In addition, the frequency of above-mentioned radiofrequency signal is very high under normal conditions, generally all more than the GHz rank, therefore, the mobile channel simulator needs mould/number conversion and D/A switch device at a high speed to carry out mould/number, D/A switch on the one hand, when above-mentioned high speed signal was carried out Digital Signal Processing, the amount of calculation of its multiplication, add operation was very big on the other hand, was difficult to realize.

In addition, when the speed of radiofrequency signal is very high, the mobile channel simulation requires also very high to the control precision that radiofrequency signal arrives angle, but, because prior art in practice is very limited to the arrival angle analog capability of high speed analog signal, especially in the simulation process to 3-G (Generation Three mobile communication system), thereby be difficult to realize radiofrequency signal is arrived the accurate control of angle.

In sum, can test mobile communication system, in the application of reality, significant limitation be arranged though use above-mentioned mobile channel analogy method.

Summary of the invention

In order to solve the problems of the technologies described above, the invention provides a kind of analogy method of the mobile channel of being convenient to realize, can be applied to the channel simulation of high-speed mobile communication system.

Mobile channel analogy method of the present invention is applied to comprise the mobile communication system of mobile communication equipment, it is characterized in that, between the baseband processing module of mobile communication equipment and radio-frequency module a mobile channel simulator is set;

At sending direction, may further comprise the steps:

A, mobile channel simulator carry out Digital Signal Processing to mobile communication equipment baseband signal to be sent, are equivalent to true mobile channel output, generate treated baseband signal;

B, this mobile communication equipment are modulated treated baseband signal, generate radiofrequency signal, send then;

At receive direction, may further comprise the steps:

A, mobile communication equipment carry out demodulation to the radiofrequency signal that receives, and obtain baseband signal;

Mobile channel simulator in b, the mobile communication equipment carries out Digital Signal Processing to this baseband signal, is equivalent to true mobile channel output, generates treated baseband signal, makes Base-Band Processing for this mobile communication equipment.

Method of the present invention with base station or travelling carriage as described mobile communication equipment.

Steps A is described to be equivalent to baseband signal to be sent and to be specially through true mobile channel output: the impulse response of baseband signal to be sent and mobile channel is carried out convolution, export convolution results;

Described this baseband signal that is equivalent to of step b is specially through true mobile channel output: the impulse response of this baseband signal and mobile channel is carried out convolution, the output convolution results.

The impulse response of mobile channel of the present invention is each path impulse response sum on the mobile channel.

The product of the impulse function of the time varying signal amplitude that each path impulse response of the present invention is this path, arrival angle weighted value and process τ in relative time delay time-delay.

This shows, use mobile channel analogy method of the present invention and can obtain following beneficial effect: since method of the present invention with the equivalence of mobile channel simulator on base band, make its input and output signal be the digital signal of base band, therefore can reduce the amount of calculation of mobile channel simulator multiplication and add operation greatly, and do not need at a high speed analog/digital conversion and digital/analog converter spare, it is good to have controllability, is convenient to advantages such as realization.

Description of drawings

Fig. 1 is the system model of general mobile communication system;

Fig. 2 is the signal processing of down direction mobile communication system in the existing test process;

Fig. 3 is the signal processing of up direction mobile communication system in the existing test process;

Fig. 4 is the signal processing of the method for the invention on down direction;

Fig. 5 is the signal processing of the method for the invention on up direction.

Embodiment

For the purpose, technical scheme and the advantage that make invention is clearer, below with reference to the accompanying drawing embodiment that develops simultaneously, the present invention is described in further detail.

In order to realize the channel simulation of high-speed mobile communication system, the invention provides a kind of analogy method of mobile channel.Fig. 4 and Fig. 5 have shown the signal processing flow of mobile communication system on down direction and up direction of using the method for the invention respectively.

As shown in Figure 4, at down direction, the baseband processing module of base station at first is input to the mobile channel simulator with baseband signal S (t) and handles, mobile channel simulator output baseband signal BB_BS1 (t) modulates to the radio-frequency module of base station then, and export radiofrequency signal RF_UE1 ' (t) to travelling carriage, the radio-frequency module of travelling carriage carries out will exporting baseband signal after the demodulation to the radiofrequency signal of input.

After the processing of above-mentioned baseband signal S (t) through the mobile channel simulator, the baseband signal BB_BS1 of output (t) is the convolution of S (t) and mobile channel impulse response:

$\mathrm{BB}\_\mathrm{BS}1\left(t\right)=\underset{m=1}{\overset{M}{\mathrm{\Σ}}}\underset{p=1}{\overset{P}{\mathrm{\Σ}}}\left[\sqrt{P\left({\mathrm{\τ}}_p\right)}{g}_p\left(t\right)a^{\′}\left({\mathrm{\φ}}_{m,p}\right)s(t-{\mathrm{\τ}}_p)\right]+z^{\′}\left(t\right);$

Wherein, M is the bay number, and P is the multipath number, and z ' is the low pass additive white Gaussian noise (t).

Baseband signal BB_BS1 (t) is through the radio frequency unit of base station, and the logical signal of exporting the back of handling of process band is: $\mathrm{RF}\_{\mathrm{UE}1}^{\′}\left(t\right)=\mathrm{Re}\left\{\right[\underset{m=1}{\overset{M}{\mathrm{\Σ}}}\underset{p=1}{\overset{P}{\mathrm{\Σ}}}\left[\sqrt{P\left({\mathrm{\τ}}_p\right)}{g}_p\left(t\right)a^{\′}\left({\mathrm{\φ}}_{m,p}\right)s(t-{\mathrm{\τ}}_p)\right]+z^{\′}\left(t\right)\left]e^{\mathrm{j\ωt}}\right\}.$

S (t)=s is set ₁(t)+js ₂(t), $G_p\left(t\right)e^{{{\mathrm{j\ψ}}_{m,p}}^{\′}}=\sqrt{P\left({\mathrm{\τ}}_p\right)}{g}_p\left(t\right)a^{\′}\left({\mathrm{\φ}}_{m,p}\right),$ Then

$\mathrm{RF}\_\mathrm{UE}{1}^{\′}\left(t\right)=\underset{m=1}{\overset{M}{\mathrm{\Σ}}}\underset{p=1}{\overset{P}{\mathrm{\Σ}}}[G_p\left(t\right)s_1(t-{\mathrm{\τ}}_p)\cos (\mathrm{wt}+{{\mathrm{\ψ}}_{m,p}}^{\′})-G_p\left(t\right)s_2(t-{\mathrm{\τ}}_p)\sin (\mathrm{wt}+{{\mathrm{\ψ}}_{m,p}}^{\′})];$

+z ₁′(t)coswt-z ₂′(t)sinwt

And in existing test model shown in Figure 2,

$\mathrm{RF}\_\mathrm{UE}1\left(t\right)=\underset{m=1}{\overset{M}{\mathrm{\Σ}}}\underset{p=1}{\overset{P}{\mathrm{\Σ}}}[G_p\left(t\right)s_1(t-{\mathrm{\τ}}_p)\cos (w(t-{\mathrm{\τ}}_p)+{\mathrm{\ψ}}_{m,p})-G_p\left(t\right)s_2(t-{\mathrm{\τ}}_p)\sin (w(t-{\mathrm{\τ}}_p)+{\mathrm{\ψ}}_{m,p})];$

+z ₁(t)coswt-z ₂(t)sinwt

If order $a^{\′}\left({\mathrm{\φ}}_{m,p}\right)=a\left({\mathrm{\φ}}_{m,p}\right)e^{{-\mathrm{j\ω\τ}}_p},$ And z ' (t)=z (t), then

$\mathrm{RF}\_{\mathrm{UE}1}^{\′}\left(t\right)=\mathrm{Re}\left\{\right[\underset{m=1}{\overset{M}{\mathrm{\Σ}}}\underset{p=1}{\overset{P}{\mathrm{\Σ}}}\left[\sqrt{P\left({\mathrm{\τ}}_p\right)}{g}_p\left(t\right)a\left({\mathrm{\φ}}_{m,p}\right)e^{{-\mathrm{j\ω\τ}}_p}s(t-{\mathrm{\τ}}_p)\right]+z\left(t\right)\left]e^{\mathrm{j\ωt}}\right\};$

$=\underset{m=1}{\overset{M}{\mathrm{\Σ}}}\underset{p=1}{\overset{P}{\mathrm{\Σ}}}[G_p\left(t\right)s_1(t-{\mathrm{\τ}}_p)\cos (w(t-{\mathrm{\τ}}_p)+{\mathrm{\ψ}}_{m,p})-G_p\left(t\right)s_2(t-{\mathrm{\τ}}_p)\sin (w(t-{\mathrm{\τ}}_p)+{\mathrm{\ψ}}_{m,p})]+z_1\left(t\right)\cos \mathrm{wt}-z_2\left(t\right)\sin \mathrm{wt}$

Obtain RF_UE1 ' (t)=RF_UE1 (t).Promptly work as $a^{\′}\left({\mathrm{\φ}}_{m,p}\right)=a\left({\mathrm{\φ}}_{m,p}\right)e^{{-\mathrm{j\ω\τ}}_p}$ , z ' (t)=when two conditions of z (t) were set up, on down direction, it was consistent to use the received signal that mobile channel analogy method general in received signal that mobile channel analogy method of the present invention obtains and the application prior art obtains.

As shown in Figure 5, on up direction, the baseband signal S (t) of travelling carriage baseband processing module output generates radiofrequency signal RF_UE2 (t) through radio-frequency module modulation back, and the radio-frequency module that sends to the base station then carries out demodulation, obtains baseband signal BB_BS2 (t).And then the baseband signal BB_BS2 (t) that obtains is sent to the mobile channel simulator handle, generate the baseband signal R2 (t) that receives.

Make s (t)=s ₁(t)+js ₂(t), the radiofrequency signal of the generation of process radio-frequency module is:

RF_UE2(t)＝Re[s(t)e jωt]＝s ₁(t)coswt+s ₂(t)sinwt；

Radiofrequency signal RF_UE2 (t) through the baseband signal of exporting after the demodulation of base station radio frequency module is: BB_BS2 (t) ^m=s (t) e ^Jwte ^-jwt=s (t); The i.e. baseband signal s (t) that still sends for travelling carriage.

After the processing of baseband signal BB_BS2 (t) through the mobile channel simulator, the baseband signal of output is the convolution of BB_BS2 (t) and mobile channel impulse response:

$R2{\left(t\right)}^m=\underset{p=1}{\overset{P}{\mathrm{\Σ}}}\left[\sqrt{P\left({\mathrm{\τ}}_p\right)}{g}_p\left(t\right)a^{\′}\left({\mathrm{\φ}}_{m,p}\right)s(t-{\mathrm{\τ}}_p)\right]+{z_m}^{\′}\left(t\right);$

Wherein, P is the multipath number, z _m' (t) be low pass additive white Gaussian noise on the m root antenna

Make z _m' (t)=z _M1' (t)+jz _M2' (t), $G_p\left(t\right)e^{{{\mathrm{j\ψ}}_{m,p}}^{\′}}=\sqrt{P\left({\mathrm{\τ}}_p\right)}{g}_p\left(t\right)a^{\′}\left({\mathrm{\φ}}_{m,p}\right),$ Then:

The I road: $I\left[R2{\left(t\right)}^m\right]=\underset{p=1}{\overset{P}{\mathrm{\Σ}}}\left[G_p{s}_1(t-{\mathrm{\τ}}_p)\cos \left({{\mathrm{\ψ}}_{m,p}}^{\′}\right)\right]+{z_{m1}}^{\′}\left(t\right);$

The Q road: $Q\left[R2{\left(t\right)}^m\right]=\underset{p=1}{\overset{P}{\mathrm{\Σ}}}\left[G_p{s}_2(t-{\mathrm{\τ}}_p)\sin \left({{\mathrm{\ψ}}_{m,p}}^{\′}\right)\right]+{z_{m2}}^{\′}\left(t\right).$

And in existing test model shown in Figure 3, have:

The I road: $I\left[R1{\left(t\right)}^m\right]=\underset{p=1}{\overset{P}{\mathrm{\Σ}}}\left[G_p{s}_1(t-{\mathrm{\τ}}_p)\cos ({-\mathrm{w\τ}}_p+{\mathrm{\ψ}}_{m,p})\right]+z_{m1}\left(t\right);$

The Q road: $Q\left[R1{\left(t\right)}^m\right]=\underset{p=1}{\overset{P}{\mathrm{\Σ}}}\left[G_p{s}_2(t-{\mathrm{\τ}}_p)\sin ({-\mathrm{w\τ}}_p+{\mathrm{\ψ}}_{m,p})\right]+z_{m2}\left(t\right).$

If order: $a^{\′}\left({\mathrm{\φ}}_{m,p}\right)=a\left({\mathrm{\φ}}_{m,p}\right)e^{{-\mathrm{j\ω\τ}}_p},$ And z _m' (t)=z _m(t), then have:

$R2{\left(t\right)}^m=\underset{p=1}{\overset{P}{\mathrm{\Σ}}}\left[\sqrt{P\left({\mathrm{\τ}}_p\right)}{g}_p\left(t\right)a\left({\mathrm{\φ}}_{m,p}\right)e^{{-\mathrm{jw\τ}}_p}s(t-{\mathrm{\τ}}_p)\right]+z_m\left(t\right);$

Its I road: $I\left[R2{\left(t\right)}^m\right]=\underset{p=1}{\overset{P}{\mathrm{\Σ}}}\left[G_p{s}_1(t-{\mathrm{\τ}}_p)\cos ({-\mathrm{w\τ}}_p+{\mathrm{\ψ}}_{m,p})\right]+z_{m1}\left(t\right);$

The Q road: $Q\left[R2{\left(t\right)}^m\right]=\underset{p=1}{\overset{P}{\mathrm{\Σ}}}\left[G_p{s}_2(t-{\mathrm{\τ}}_p)\sin ({-\mathrm{w\τ}}_p+{\mathrm{\ψ}}_{m,p})\right]+z_{m2}\left(t\right).$

Thereby obtain: I[R2 (t) ^m]=I[R1 (t) ^m], Q[R2 (t) ^m]=Q[R1 (t) ^m], i.e. R2 (t)=R1 (t).

This shows, if order $a^{\′}\left({\mathrm{\φ}}_{m,p}\right)=a\left({\mathrm{\φ}}_{m,p}\right)e^{{-\mathrm{j\ω\τ}}_p}$ , and z ' (t)=z (t), on up direction, the received signal that general mobile channel analogy method obtains in using received signal that mobile channel analogy method of the present invention obtains and using prior art is consistent.

The mobile channel analogy method of complex chart 4 and Fig. 5 as can be seen, the method that generally adopts in mobile channel analogy method of the present invention and the prior art is equivalent.Therefore, the analogy method of mobile channel of the present invention can be applied in the research or test process of mobile communication system.

From the analogy method of above-mentioned mobile channel as can be seen, method of the present invention has arrived base band domain with the equivalence of mobile channel simulator, be digital signal owing to use the input and the output signal of the mobile channel simulator of said method, and its signal rate is relatively low, above-mentioned mobile channel simulator does not need analog/digital conversion and digital/analog converter spare at a high speed, and the amount of calculation of multiplication and add operation is also reduced significantly in processing procedure, thereby, it is good that mobile channel analogy method of the present invention has controllability, the advantage of being convenient to realize.

Need to prove in addition, in the preferred embodiment of the invention described above, with the mobile channel simulator between the radio-frequency module of base station and travelling carriage the equivalence to the baseband processing module and radio-frequency module of base station, promptly equivalence is to base band domain, it is good to make that the mobile channel simulator has controllability, the advantage of being convenient to realize.Equally, mobile channel simulator equivalence also can be realized purpose of the present invention between the baseband processing module of travelling carriage and radio-frequency module, and can not exceed the spirit and scope of the present invention.

More than lift preferred embodiment; the purpose, technical solutions and advantages of the present invention have been carried out further detailed description; institute is understood that; the above is the preferred embodiments of the present invention; not in order to show the present invention; within the spirit and principles in the present invention all, any modification of being done, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (5)

1, a kind of mobile channel analogy method is applied to comprise the mobile communication system of mobile communication equipment, it is characterized in that, between the baseband processing module of mobile communication equipment and radio-frequency module a mobile channel simulator is set;

At sending direction, may further comprise the steps:

A, mobile channel simulator carry out Digital Signal Processing to mobile communication equipment baseband signal to be sent, are equivalent to true mobile channel output, generate treated baseband signal;

B, this mobile communication equipment are modulated treated baseband signal, generate radiofrequency signal, send then;

At receive direction, may further comprise the steps:

A, mobile communication equipment carry out demodulation to the radiofrequency signal that receives, and obtain baseband signal;

Mobile channel simulator in b, the mobile communication equipment carries out Digital Signal Processing to this baseband signal, is equivalent to true mobile channel output, generates treated baseband signal, makes Base-Band Processing for this mobile communication equipment.

2, the method for claim 1 is characterized in that, with base station or travelling carriage as described mobile communication equipment.

3, the method for claim 1 is characterized in that, steps A is described to be equivalent to baseband signal to be sent and to be specially through true mobile channel output: the impulse response of baseband signal to be sent and mobile channel is carried out convolution, export convolution results;

Described this baseband signal that is equivalent to of step b is specially through true mobile channel output: the impulse response of this baseband signal and mobile channel is carried out convolution, the output convolution results.

4, method as claimed in claim 3 is characterized in that, the impulse response of described mobile channel is each path impulse response sum on the mobile channel.

5, method as claimed in claim 4 is characterized in that, the product of the impulse function of the time varying signal amplitude that described each path impulse response is this path, arrival angle weighted value and process τ in relative time delay time-delay.

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