# GSoC2014 Turbo Equalizer **URL:** \ **Category:** GNU Radio\ **Created:** [February 25, 2014, 4:40pm UTC](https://www.ruby-forum.com/t/gsoc2014-turbo-equalizer/239419 "2014-02-25T16:40:55Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![musicdenotation](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ea666f/32.png) [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Post date:** [February 25, 2014, 4:40pm UTC](https://www.ruby-forum.com/t/gsoc2014-turbo-equalizer/239419/1 "2014-02-25T16:40:55Z")
Just FYI, the gr-trellis has implementations of all these components you suggested. One interesting project is to take the core algorithms of gr-trellis (Viterbi and SISO) and make them threaded for multi-core (eg, by parallelizing forward/backward recursions, or by parallelizing using overlapping subblocks, etc) best Achilleas ---
**Author:** ![Achilleas\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/74df32/32.png) [@Achilleas\_A](https://www.ruby-forum.com/u/Achilleas_A)\ **Post date:** [February 25, 2014, 4:48pm UTC](https://www.ruby-forum.com/t/gsoc2014-turbo-equalizer/239419/2 "2014-02-25T16:48:34Z")
On Tue, Feb 25, 2014 at 10:39 AM, Achilleas A. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Just FYI, the gr-trellis has implementations of all these components you > suggested. > > One interesting project is to take the core algorithms of gr-trellis > (Viterbi and SISO) and make them threaded for multi-core > (eg, by parallelizing forward/backward recursions, or by parallelizing using > overlapping subblocks, etc) > > best > Achilleas Also using VOLK inside gr-trellis blocks should provide significant speedup there. Tom ---
**Author:** ![Achilleas\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/74df32/32.png) [@Achilleas\_A](https://www.ruby-forum.com/u/Achilleas_A)\ **Post date:** [February 25, 2014, 7:10pm UTC](https://www.ruby-forum.com/t/gsoc2014-turbo-equalizer/239419/3 "2014-02-25T19:10:31Z")
On 02/25/2014 04:39 PM, Achilleas A. wrote: > Just FYI, the gr-trellis has implementations of all these components you > suggested. > > One interesting project is to take the core algorithms of gr-trellis > (Viterbi and SISO) and make them threaded for multi-core > (eg, by parallelizing forward/backward recursions, or by parallelizing > using overlapping subblocks, etc) Jan, gr-trellis would be a good place to start looking, but there’s still enough to do between gr-trellis and a fully working, optimized, real-time capable Parallel log-map-siso turbo equalizer. When you write a proposal, make sure you’ve had a look at gr-trellis beforehand. M ---
**Author:** ![Achilleas\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/74df32/32.png) [@Achilleas\_A](https://www.ruby-forum.com/u/Achilleas_A)\ **Post date:** [February 25, 2014, 5:03pm UTC](https://www.ruby-forum.com/t/gsoc2014-turbo-equalizer/239419/4 "2014-02-25T17:03:53Z")
Yes, I agree with Tom. A good starting point is the three or four core algorithms in gr-trellis/lib/core\_algorithms.cc viterbi\_algorithm, siso\_algorithm, sccc\_decoder pccc\_decoder (and their “\_combined” versions) Jan, let me know if you decide to work on these; I can provide some ideas if you are interested. best, Achilleas ---
**Author:** ![Achilleas\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/74df32/32.png) [@Achilleas\_A](https://www.ruby-forum.com/u/Achilleas_A)\ **Post date:** [February 25, 2014, 7:37pm UTC](https://www.ruby-forum.com/t/gsoc2014-turbo-equalizer/239419/5 "2014-02-25T19:37:00Z")
I know I could look to Google / do an internet search, but maybe asking here would be better. What is/are the -seminal- paper/s on “parallel log-map-siso decoding”? I implemented the non-parallel version of the log-map algorithm -way- back in 2001 on whatever the portable Mac was at the time (5300ce, IIRC). I stripped all of the crap out, and made it -really- fast for non-parallel / non-intrinsics / non-Altivec / non-SIMD / non-accelerated (beyond whatever the compiler did). I thought a lot about how to parallelize the algorithm, but since this was for a class & all I needed was the fastest (which it was) my thoughts ended in May with graduation. I have no idea if I still have this code around, but I keep up with channel coding research to some degree since it’s been an interest for years. Hence, my question. Thanks! - MLD ---
**Author:** ![Achilleas\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/74df32/32.png) [@Achilleas\_A](https://www.ruby-forum.com/u/Achilleas_A)\ **Post date:** [February 26, 2014, 9:39am UTC](https://www.ruby-forum.com/t/gsoc2014-turbo-equalizer/239419/6 "2014-02-26T09:39:39Z")
On 25.02.2014 19:09, Martin B. wrote: > gr-trellis would be a good place to start looking, but there’s still > enough to do between gr-trellis and a fully working, optimized, > real-time capable Parallel log-map-siso turbo equalizer. When you write > a proposal, make sure you’ve had a look at gr-trellis beforehand. > > M > Hi, Thanks to all for their input. I will have a look at gr-trellis but this definitely sounds like something I’d like to work on! Achilleas, I’d be happy to exchange ideas about parallelizing the SiSo and Viterbi algorithms in gr-trellis. Jan