Hey Guys, I wrote a blind turbo equaliser for LDPC encoded data a few years ago in GNU Radio, the code is probably pretty horrific, and it wasn't optimised very well, but it worked as a proof on concept, I could dig out the code if anyone was interested?
John On Sat, Mar 1, 2014 at 10:33 AM, Jan Kraemer <[email protected]>wrote: > Hey Nguyen Anh Duc, > > thanks for your input. It's nice to see that there seems to be some guys > interested in the whole turbo EQ topic. These are some interesting points > you mentioned. To be honest i never thought about using MLSE/MAP for the > equalizer part. Same goes with another turbo decoder in the turbo equalizer > cause I discarded them as to computationally heavy to be implemented in > software. > > But it seems that right now there is greater need to speed up the > gr-trellis module before attempting a full turbo equalizer. > > Best regards, > Jan > Am 28.02.2014 16:57, schrieb Anh Duc Nguyen: > > Dear Jan Krämer, > > I am very interested in your proposal. However, to my best of knowledge, > turbo equalizer (TB) is pretty complicated and computationally heavy, then > it is challenging to have an effective real-time implementation of TB. I > would like to have some questions as follows: > > 1. Your ISI channels' characteristics: fixed/ known beforehand or > time-variant, how dispersive they are > 2. which techniques do you wish to use for equalizer part: MMSE, MAP, or > MLSE? > 3. coding: as you presented above - it may be a convolutional or turbo > code, and others? > 4. Some special hardware platform may require > 5. why do you select 2. and 3. to have the best performance in terms of > complexity or quality, and that combination is realistic to be real-time > implemented in GnuRadio plus 4. > > To be honest, I have desperately struggled these question for quite a > long time, then you and some others can help work together to find the > answers, > > Best regards, > Nguyen Anh Duc > > > On Tue, Feb 25, 2014 at 8:59 PM, Jan Krämer > <[email protected]>wrote: > >> Hi everyone, >> >> I am a student at Communications Engineering Lab (CEL) at Karlsruhe >> Institute of Technology. I major in "communication systems" and I am >> currently doing my masterthesis on "Parallel log-map decoders for manycore >> architectures". I am interested in participating in GSoC 2014. >> >> There is an older GNURadio GSoC proposal from 2013 to implement a turbo >> equalizer module in GNURadio in which i am particularly interested working >> on, as it is closely connected to my current field of study. >> So i would like to share my thoughts on a possible Update of the old >> turbo equalizer proposal (and maybe upgrading it to a current proposal ?). >> >> ------------------------------------------------------------- >> *Turbo Equalizer* >> >> A Turbo Equalizer is a receiver component that is highly effective when >> receiving messages corrupted by Intersymbol Interference (ISI). To archive >> this, the turbo equalizer uses an Equalizer to eliminate the ISI and a >> Log-Map Decoder for Forward Error Correction. Both components pass soft >> information to each other to increase the performance. >> >> *Objectives* >> >> Possible (sub-)projects: >> 1. Implement the Log-Map decoder >> - preferably it can be fully configurable (constraint length, number >> of states, trellis structure) >> - preferably optimized for real time applications >> 2. Implement the linear equalizer >> - preferably optimized for real time applications >> >> *Skills* >> Knowledge of digital signal processing, C/C++, Python >> >> *Potential mentor(s)* >> Sebastian Koslowski, Michael Schwall >> >> >> ---------------------------------------------------------------------------------- >> >> That would be a project I think would be really interesting to work on >> and i think it fits well with some of the other proposals for new GNU Radio >> Modules. As the turbo eq itself is a highly complex architecture, it could >> also be beneficial to split the tasks in this project. It would be great to >> get some feedback from you, if this was a proposal that would benefit >> GNURadio and if it has the potential to be included in the GSoC list of >> ideas. >> >> Thanks and regards, >> Jan Krämer >> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> [email protected] >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> > > > _______________________________________________ > Discuss-gnuradio mailing > [email protected]https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > >
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