On Tue, May 24, 2011 at 13:55, Tom Rondeau <[email protected]> wrote: > On Tue, May 24, 2011 at 7:04 AM, Martin Braun <[email protected]> wrote: >> >> On Mon, May 23, 2011 at 11:50:52PM +0400, Alexander Chemeris wrote: >> > Hi community, >> >> Hi Alex, >> >> > Our WiMAX Scanner project (http://code.google.com/p/wimax-scanner/) >> > approaches the moment when we should start writing C/C++ code - our >> > Matlab model decodes broadcast messages from all recordings we have on >> > hands. >> >> That's great. I think GNU Radio would benefit from having big, cool >> projects. >> Here's my thoughts and experiences: >> >> > At this point we have to make a choice - rely on GnuRadio or create >> > our own framework. Until recently I was sure would create our own >> > framework, but recent discussions on this list made me think GnuRadio >> > may be an option. So, I'm looking for the community help with the the >> > following questions: >> > >> > 1) How well is GnuRadio suited for packet data processing? WiMAX is >> > essentially a packet-oriented system. >> >> What you're writing is receiver-only, right? In that case, GNU Radio >> will be able to handle all your data just fine. It gets tricky when you >> have a transceiver with timing-sensitive operations, but it seems your >> project would work well. GNU Radio is pretty agnostic of the data moved >> between blocks. > > I know I might be slightly biased here, but, yes, I think you'd be fine > handling the receiver code in GNU Radio.
What about transmitter side? We should be sure that we can implement full 4G modem in GnuRadio. > You are going to have to work a bit > on the receiver side packet handling, though, because I know WiMax has the > concept of the downlink map that you have to properly separate. I'd look > into the stream tagging infrastructure that we have now to handling passing > around the necessary information. Yes! DL-MAP is one of the nicest features of WiMAX, bu it makes packet decoding highly non-linear process. I.e. you should decode header, find out about encoding parameters of different zones and then decode zone-by-zone. So we need a tight integration with MAC layer here, which should command what to decode. IIRC LTE has similar concept, so it's a must for 4G systems. BTW, Wireless Innovation Forum is about to kick off a project about open-source implementation of LTE-Advanced. We're discussing right now whether we should join forces and create a reconfigurable WiMAX/LTE implementation. It's a project with wonderful complexity and it needs a good platform to stay on. >> > 2) We don't want to use Python. Is there anything we can't do without >> > it? And where can we find examples of C++-only flowgraphs? >> >> There are some examples in gnuradio-examples/c++. It's really not that >> hard, and I've done some C++-only projects with great success. >> >> However, let me ask why you don't want to use Python. Is it because you >> want a final product that works without Python, or do you have a real >> 'allergy'? >> Because I recommend that *even* for a C++-only project, you still use >> Python for unit tests. Also, this gives you the opportunity to quickly >> click together tests using GRC. This will make development a *lot* >> easier. >> Side note: Porting from Matlab to Python is much simpler than going from >> Matlab to C++ (for porting your unit tests). > > What Martin said. C++ is definitely doable, but you might want to start in > Python, anyway. I've done a handful of C++-based flowgraphs, and it's > relatively trivial to take a flowgraph in Python and convert it to C++, as > long as you recognize anything that you did that is Pythonic in nature. When I write in C++ I prefer to be C++-ish ;) (if I understood you comment correctly) Tom, it would be great to hear your opinion about licensing issues. You're the leader of the community and your word is important here. And if I understand correctly, you're also a liaison to FSF? -- Regards, Alexander Chemeris. _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
