Hi All, I am reading an article about GSM MLSE equalizer. The article link is here. http://www.freescale.com/files/dsp/doc/app_note/AN2943.pdf?fpsp=1&WT_TYPE=Application%20Notes&WT_VENDOR=FREESCALE&WT_FILE_FORMAT=pdf&WT_ASSET=Documentation This article is quite brief, and I have two questions here 1) is the Equation 6 in the article correct? 2) How can I get Equation 6 from Equation 5? Can anybody give some idea or good detailed reference? Thank you. Richard

# branch metric of MLSE equalizer for GSM

Started by ●July 14, 2008

Reply by ●July 14, 20082008-07-14

>Hi All, > >I am reading an article about GSM MLSE equalizer. The article link is >here. > >http://www.freescale.com/files/dsp/doc/app_note/AN2943.pdf?fpsp=1&WT_TYPE=Application%20Notes&WT_VENDOR=FREESCALE&WT_FILE_FORMAT=pdf&WT_ASSET=Documentation > >This article is quite brief, and I have two questions here > >1) is the Equation 6 in the article correct? >2) How can I get Equation 6 from Equation 5? Can anybody give some ideaor>good detailed reference? > >Thank you. > > >Richard >%%%% Hi To understand MLSE equaliser properly, try to read Digital Communications by John G Proakis, 4th edition. Read section 10.1.2 to 10.1.3, i.e. from page 601 to 607. he has also given one example. chintan

Reply by ●July 15, 20082008-07-15

On Jul 14, 3:34 am, "richard_zhang" <hardhear...@yahoo.com.cn> wrote:> Hi All, > > I am reading an article about GSM MLSE equalizer. The article link is > here. > > http://www.freescale.com/files/dsp/doc/app_note/AN2943.pdf?fpsp=1&WT_... > > This article is quite brief, and I have two questions here > > 1) is the Equation 6 in the article correct? > 2) How can I get Equation 6 from Equation 5? Can anybody give some idea or > good detailed reference? > > Thank you. > > RichardRichard, I haven't analysed it completely but what you'll want to do to prove the result is to express the equation in vector form So, the metric to be maximized can be written as the norm of an L- sized vector: M^\tilde[k] = || x - A*h ||^2 where x and h are L*1 vectors and A is an L*L matrix containing the symbols to be decoded. Then, use vector algebra to simplify, some of the terms will get removed because each element of A has magnitude=1 and you should get the form in equation 6. Thanks, Dilip.