Discover MakerZone

MATLAB and Simulink resources for Arduino, LEGO, and Raspberry Pi

Learn more

Discover what MATLAB® can do for your career.

Opportunities for recent engineering grads.

Apply Today

Thread Subject:
Channel State Information with a Rayleigh channel

Subject: Channel State Information with a Rayleigh channel

From: C?sar Ghali

Date: 9 Jan, 2009 15:11:02

Message: 1 of 8

Dear friends,

I am using a Rayleigh channel with convolutional encoder and Viterbi decoder, but how can I use CSI with Viterbi decoder in matlab?


Thanks in advance for your help.


Cesar Ghali

Subject: Channel State Information with a Rayleigh channel

From: Idin Motedayen-Aval

Date: 9 Jan, 2009 15:27:59

Message: 2 of 8

C?sar Ghali wrote:
> Dear friends,
>
> I am using a Rayleigh channel with convolutional encoder and Viterbi decoder, but how can I use CSI with Viterbi decoder in matlab?
>
>
> Thanks in advance for your help.
>
>
> Cesar Ghali

The Viterbi Decoder doesn't have the ability to take advantage of CSI.
You should use the CSI before the decoder to remove its effect (for a
flat-fading channel, divide your received signal by the complex channel
gain). For a frequency-selective fading channel, you will have to use
an equalizer (inverse of the channel filter) to achieve the same thing.

HTH,
Idin

--
Idin Motedayen-Aval
The MathWorks, Inc.
zq=[4 2 5 -15 -1 -3 24 -57 45 -12 19 -12 15 -8 3 -7 8 -69 53 12 -2];
char(filter(1,[1,-1],[105 zq])), clear zq

Subject: Channel State Information with a Rayleigh channel

From: C?sar Ghali

Date: 9 Jan, 2009 15:54:02

Message: 3 of 8

Do you mean by "the complex channel gain" the "PathGains" property of the channel? Or something else.

Subject: Channel State Information with a Rayleigh channel

From: Idin Motedayen-Aval

Date: 9 Jan, 2009 16:12:50

Message: 4 of 8

C?sar Ghali wrote:
> Do you mean by "the complex channel gain" the "PathGains" property of the channel? Or something else.

Yes, the PathGains. If it's flat fading, you only have one path gain,
so everything is easy; it's just a complex gain factor.
Frequency-selective fading is harder to deal with.

--
Idin Motedayen-Aval
The MathWorks, Inc.
zq=[4 2 5 -15 -1 -3 24 -57 45 -12 19 -12 15 -8 3 -7 8 -69 53 12 -2];
char(filter(1,[1,-1],[105 zq])), clear zq

Subject: Channel State Information with a Rayleigh channel

From: C?sar Ghali

Date: 11 Jan, 2009 15:32:01

Message: 5 of 8

Thanks Idin Motedayen-Ava for your help.

Can I take your email please.

Subject: Channel State Information with a Rayleigh channel

From: Ali Fakoorian

Date: 18 Jan, 2009 09:04:45

Message: 6 of 8

Dear Idin,

I need to know how the receiver can obtain full channel state information.

I would be grateful if you could help me and answer the above question or cite some relevant references.

Best regards,
Ali Fakoorian.

Subject: Channel State Information with a Rayleigh channel

From: Idin Motedayen-Aval

Date: 18 Jan, 2009 22:33:55

Message: 7 of 8

Ali Fakoorian wrote:
> Dear Idin,
>
> I need to know how the receiver can obtain full channel state information.
>
> I would be grateful if you could help me and answer the above question or cite some relevant references.
>
> Best regards,
> Ali Fakoorian.

Hi Ali,
In a real system, the receiver can't have the full channel state
information (CSI). This is only relevant in simulation.
In MATLAB, the Communications Toolbox object rayleighchan gives you
access to the "PathGains" property of the channel object. So the
receiver can use that information.
In Simulink, the Rayeleigh Channel block in Communications Blockset can
also output the path gains.
Looking at the documentation for either the rayleighchan function or the
Rayleigh Channel block will give you some examples on how to use these
outputs.
If you're looking for Simulink examples, I have some models on MATLAB
Central that you can download and take a look at.
HTH,
Idin

Subject: Channel State Information with a Rayleigh channel

From: Ali Fakoorian

Date: 19 Jan, 2009 06:36:55

Message: 8 of 8

Hi Idin,

Thank you for your information and your helpful files.

Best regards,
Ali

Tags for this Thread

What are tags?

A tag is like a keyword or category label associated with each thread. Tags make it easier for you to find threads of interest.

Anyone can tag a thread. Tags are public and visible to everyone.

Contact us