Comments on: Softbit for 16QAM http://www.dsplog.com/2009/07/05/softbit-16qam/ Signal Processing for Communication Fri, 10 Feb 2012 01:03:15 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Krishna Sankar http://www.dsplog.com/2009/07/05/softbit-16qam/#comment-95776 Krishna Sankar Sat, 14 Jan 2012 14:10:11 +0000 http://www.dsplog.com/?p=636#comment-95776 @aizza: The LLR (log likelihood ratio) captures the likelihood of the received symbol corresponding to transmission of bit zero OR one. The log likelihood ratio is used to compute the euclidean distance. Helps? @aizza: The LLR (log likelihood ratio) captures the likelihood of the received symbol corresponding to transmission of bit zero OR one. The log likelihood ratio is used to compute the euclidean distance.
Helps?

]]> By: aizza ahmed http://www.dsplog.com/2009/07/05/softbit-16qam/#comment-94355 aizza ahmed Tue, 10 Jan 2012 04:48:41 +0000 http://www.dsplog.com/?p=636#comment-94355 Hi Krishna, please clarify a doubt of mine 1.In hard decision viterbi decoder, we use hamming distance as criterion..meaning. we get the hard decided points and compute the distance between hard decided points and EXPECTED points in that branch 2. In soft decision, we use euclidean distance..meaning..whatever received constellation point we get, we take them forward and compute the distance between received constellation point and EXPECTED constellation points in that branch 3. can you please tell me where is this LLR fitting into this whole scenario. Thanks aizza ahmed Hi Krishna,
please clarify a doubt of mine
1.In hard decision viterbi decoder, we use hamming distance as criterion..meaning. we get the hard decided points and compute the distance between hard decided points and EXPECTED points in that branch
2. In soft decision, we use euclidean distance..meaning..whatever received constellation point we get, we take them forward and compute the distance between received constellation point and EXPECTED constellation points in that branch
3. can you please tell me where is this LLR fitting into this whole scenario.

Thanks
aizza ahmed

]]> By: MNS http://www.dsplog.com/2009/07/05/softbit-16qam/#comment-59399 MNS Fri, 24 Jun 2011 13:00:37 +0000 http://www.dsplog.com/?p=636#comment-59399 http://www.scribd.com/doc/24329042/Hindawi-Publishing-Corporation-Research-Letters-in-Communications-Volume-2007-Article This article is also more near to your article..what your wrote.. http://www.scribd.com/doc/24329042/Hindawi-Publishing-Corporation-Research-Letters-in-Communications-Volume-2007-Article

This article is also more near to your article..what your wrote..

]]> By: Krishna Sankar http://www.dsplog.com/2009/07/05/softbit-16qam/#comment-40072 Krishna Sankar Tue, 16 Nov 2010 23:59:50 +0000 http://www.dsplog.com/?p=636#comment-40072 @andjas: I was unable to find the typo. Can you please point that out. @andjas: I was unable to find the typo. Can you please point that out.

]]> By: andjas http://www.dsplog.com/2009/07/05/softbit-16qam/#comment-39993 andjas Tue, 16 Nov 2010 06:26:35 +0000 http://www.dsplog.com/?p=636#comment-39993 aaaahh, thank you Krishna. Btw, I think there are some mistype. It type 'r' rather than 'y_er'. in last equation of: - soft bit b0, region 3 - soft bit b1, region 1&2 aaaahh,
thank you Krishna.

Btw, I think there are some mistype.
It type ‘r’ rather than ‘y_er’.
in last equation of:
- soft bit b0, region 3
- soft bit b1, region 1&2

]]> By: Krishna Sankar http://www.dsplog.com/2009/07/05/softbit-16qam/#comment-39839 Krishna Sankar Sun, 14 Nov 2010 05:27:09 +0000 http://www.dsplog.com/?p=636#comment-39839 @andjas: For each article, there is "Print" option in the top right corner. Did you try using that? Maybe that helps. @andjas: For each article, there is “Print” option in the top right corner. Did you try using that? Maybe that helps.

]]> By: andjas http://www.dsplog.com/2009/07/05/softbit-16qam/#comment-39723 andjas Fri, 12 Nov 2010 03:33:10 +0000 http://www.dsplog.com/?p=636#comment-39723 Thank you again Mr. Krishna. Btw, when I copy the above page, some equations could not be copied. I like to copy in Win Word and print it. I use to study by paper and make notes in the paper. Regards, Thank you again Mr. Krishna.

Btw, when I copy the above page, some equations could not be copied. I like to copy in Win Word and print it. I use to study by paper and make notes in the paper.

Regards,

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