# WiMAX decoding: DL-PUSC question

**URL:** <https://www.ruby-forum.com/t/wimax-decoding-dl-pusc-question/205538>\
**Category:** GNU Radio\
**Created:** [April 8, 2011, 11:16am UTC](https://www.ruby-forum.com/t/wimax-decoding-dl-pusc-question/205538 "2011-04-08T11:16:48Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![dubstep](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/cdc98d/32.png) [@dubstep](https://www.ruby-forum.com/u/dubstep)\
**Post date:** [April 8, 2011, 11:16am UTC](https://www.ruby-forum.com/t/wimax-decoding-dl-pusc-question/205538/1 "2011-04-08T11:16:48Z")

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Hi all,

This is a little bit offtopic for this mailing list, but I can’t find  
a better place to ask this question.

We’re doing an open-source project on WiMAX decoding  
([Google Code Archive - Long-term storage for Google Code Project Hosting.](http://code.google.com/p/wimax-scanner/)) and at this point we have a  
trouble with correct subchannelization of DL-PUSC, so we’re looking  
for some advise on what we’re doing wrong. Or may someone could just  
contribute some code for correct subchannelization?

My implementation is available as Matlab code and as Excel spreadsheet  
here:  
[http://code.google.com/p/wimax-scanner/source/browse/matlab/get\_slot\_data.m](http://code.google.com/p/wimax-scanner/source/browse/matlab/get_slot_data.m)  
[http://code.google.com/p/wimax-scanner/source/browse/matlab/PUSC-permutation.xls](http://code.google.com/p/wimax-scanner/source/browse/matlab/PUSC-permutation.xls)  
It is able to correctly list sub-carriers for FCH of segment 0 (i.e.  
for subchannels 0-3), but looks like it gives incorrect results for  
all other subchannels. The result of this is that I can see only two  
consecutive repetitions of slot data in DL-MAP part of the header,  
where I should see 4 or 6 repetitions. The standard is very vague and  
unclear on this topic and people who write textbooks certainly thinks  
it’s an obvious part and no one document it in an understandable way.

If you have a working implementation of DL-PUSC subchannelization,  
which you can’t share with us, we would appreciate if you just share  
mappings of subchannels to sub-carriers for a few sets of parameters.  
That would be very helpful for us to debug our own code.

PS If you’re interested in contributing to an open-source WiMAX  
implementation - you’re very welcome to join the effort! We believe we  
can make a real difference in the wireless world.

–  
Regards,  
Alexander C…

> **[Fairwaves is a winner of the GSMA Connected Society Innovation Fund - Fairwaves](https://fairwaves.co/)**
>
> Fairwaves Inc. is a winner of the GSMA Connected Society Innovation Fund for Rural Connectivity, a project which aims to support innovative mobile internet connectivity solutions for unconnected rural communities. more details

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**Author:** ![alcost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/4da419/32.png) [@alcost](https://www.ruby-forum.com/u/alcost)\
**Post date:** [April 8, 2011, 11:55pm UTC](https://www.ruby-forum.com/t/wimax-decoding-dl-pusc-question/205538/2 "2011-04-08T23:55:42Z")

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Ok, we’ve found the problem ourselves:

> **[Google Code Archive - Long-term storage for Google Code Project Hosting.](https://code.google.com/archive/p/wimax-scanner/source)**

Now we can see DL-MAP in our test captures.

On Fri, Apr 8, 2011 at 13:15, Alexander C.  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> Regards,  
> Alexander C..  
> [http://www.fairwaves.ru](http://www.fairwaves.ru)

–  
Regards,  
Alexander C..

> **[Срок регистрации домена истек](http://www.fairwaves.ru)**
>
> Срок регистрации домена истек. Требуется продление, чтобы возобновить работу домена и его сервисов