Channel Estimation and Equalization

[wee]

channel estimation and equalization

Hi guys,

I have a query in mind for both Channel Estimation and Equalization.

As you know, the channel of the communication systems corrupts the useful modulated signal which we transmitted over the air interface. Before the corrupted signal from the channel is demodulated, it has to undergo Channel Estimation using MMSE or MLSE or LMS or RMS, etc. Equalization for Non-linear will be Viterbi.

Bits -> Modulation -> Channel -> Estimation -> Demodulation -> Equalization

What are the other methods for Channel Estimation and Equalization? How do they actually take place.

Also, does the methods applicable to all Modulation techniques such as GMSK, Spread Spectrum, etc?

Please advice.

Thank you very much.

Regards.

 

[silawi]

channel estimation and equalization using matlab

hiiii

i am interested recently in this topic, so i will be grateful for u if u help me by telling me what are the useful resources about this topic? books,papers, etc..

thanx 4 ur cooperation..............

 

[mimomod]

channel estimation

Hi wee,

actually the general block diagram of communication system is Bits -> Modulation -> Channel -> Demodulation -> Detection

In detection part, you have two options to "inverse" the distortion of the channel. You do channel estimation followed by channel inversion (2 separate task), or you could do channel equalization directly based on a certain criteria such as MMSE. After one of the aforementioned process, then you do the decision based on the signal constellation of the transmitted signal, e.g. for BPSK then you just compare the data with 0.

In communication systems, all channel estimation and signal equalization are done on so-called baseband representation of signal and channel, so all theory work just the same independent of the modulation used. So the methods are applicable to GMSK, spread-spectrum, OFDM, etc.

It is important though you have the correct baseband representation (usually in complex numbers) of each modulation. But after you have the baseband representation, then all methods work just the same.

best

 

[wee]

baseband representation

Hi wee,

actually the general block diagram of communication system is Bits -> Modulation -> Channel -> Demodulation -> Detection

In detection part, you have two options to "inverse" the distortion of the channel. You do channel estimation followed by channel inversion (2 separate task), or you could do channel equalization directly based on a certain criteria such as MMSE. After one of the aforementioned process, then you do the decision based on the signal constellation of the transmitted signal, e.g. for BPSK then you just compare the data with 0.

In communication systems, all channel estimation and signal equalization are done on so-called baseband representation of signal and channel, so all theory work just the same independent of the modulation used. So the methods are applicable to GMSK, spread-spectrum, OFDM, etc.

It is important though you have the correct baseband representation (usually in complex numbers) of each modulation. But after you have the baseband representation, then all methods work just the same.

best

Hi mimomod,

Thank you very much for the reply.

In fact, i have successfully created the GMSK model through Fading and AWGN Channels. To analyse the BER of this algorithm, i implement a Viterbi algorithm after the demodulation for estimation. However, when i compared the BER of the Non-Viterbi GMSK Demodulated bits with Viterbi GMSK Demodulated bits, the Non-Viterbi GMSK Demodulated bits score better than the equalized one. 8O I am really puzzled. Please advice.

Thank you.

Regards,
Wee

 

[mimomod]

channel estimation in ofdm

Hi Wee,

I don't know what exactly happened. If you did the simulation on matlab, please send me the script to check it out.

best

 

[wee]

gmsk viterbi

Hi mimomod,

Please check your pm.

Thank you.

Regards,
Wee

 

[matlab1983]

channel estimation viterbi

hi all
can you send me the matlab file for estimation???

 

[Aya2002]

channel equalization and estimation

Hi silawi, please check your private inbox

 

[gayathri123]

viterbi gmsk

can make help for coding in channel estimation

 

[vandang44]

can you send me matlab code for channel estimation with insert pilot?
Please hepl me!
my email: vandang44@gmail.com
Thanks for sharing!

 

[SpirosZ]

can you send me matlab code for channel estimation with insert pilot?
Please hepl me!
my email: vandang44@gmail.com
Thanks for sharing!

I need the same.
My email: spzettas @ gmail.com

regards

 

[MAlsharif]

hi guys

can you send me matlab code for channel estimation with insert pilot?

my email: moh859@gmail.com

thank in advance

 

[mazdaspring]

can you send me code by pm as well. thank you.