Hi everybody,
I would like to model a finite scattering flat fading channel model:
the channel vector of the ith user to BS is denoted by:
hi=(1/P1/2)*sum(alphaqi *a(phiq) from q=1 to P)
-where alphaqi is the path gain of the qth path to the ith user CN(0,1).
-a is the steering vector.
-P the number of scatterers
-K the number of users
We have H=A*G where H is the channel matrix, A is the steering vector, and G is the matrix gain.
1-Concerning the matrix gain G(P*K)), shall I consider the distance between user and the BS in this model or just :
G=sqrt(1/2)*(randn(P,K)+1j*randn(P,K)) ?
2-How can I model flat channel in matlab?
Best regards,
Wafa HAJ HMIDA
Dear Wafa,
welcome,
The gain of the channel depends on the distance of the user from the base station. So, you have to add a channel gain depending on the distance and the nature of the scatters. This is the so-called average or long term path loss. As for the effect of the scatterers, every one partially attenuate the signal. Because of the random nature of the scattering and as the number of the scatterers tends to large values the attenuation in decible will have normal distribution. If you want to study only the effect of the scattering on the transmission process you can discard the average value of the channel attenuation.
For more information please follow the link: http://wits.ice.nsysu.edu.tw/course/pdfdownload/95ADV/lect3-Wireless%20Fading%20Channels.pdf
Best wishes
Dear Wafa,
Hopefully you have already solved your questions, but just in case...
Correct me if I'm wrong or I missunderstood your point, but, as far as I know, a channel will be frequency-FLAT fading as long as there is a single path within the channel. If there are several paths or scatterers you will get a frequency-SELECTIVE (not flat) fading channel. For what I understand, you are modeling a multi-path channel.
As for your first question, I couldn't give you a better answer than the one you already got.
Regarding the second question, in your equation, assuming P=1 should give you single tap channels with flat frequency response. Otherwise, you could employ the Matlab system object from the Communications System Toolbox comm.MIMOChannel (https://fr.mathworks.com/help/comm/ref/comm.mimochannel-system-object.html?s_tid=gn_loc_drop).
You also have comm.RicianChannel and comm.RayleighChannel for SISO models (https://fr.mathworks.com/help/comm/ug/fading-channels.html#a1070375923).
Best regards,
Thanks a lot for your response.
In fact, I would like to implement the model in this paper 2.2 finite scattering model.
If you have any suggestion please let me know.
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