Hi Sergiy, Thanks for pointing out the rather large memory requirements for the FDMDV modem states.
Yes it is possible to significantly reduce the size of these arrays. I don't have time to do this right now but if some one else would like to work on this here are a few notes: 1/ tx_filter_memory is mainly filled with zeros, so it's possible to re-arrange the for loops to use NSYM*Rs of storage rather than NSYM*M. A good example is fdmdv_8_to_48() 2/ rx_filter_memory the oversampled (by M) filter memory is reqd to get the timing accuracy we need for resampling. However the demod could be perhaps be re-arranged. One possibility is to store 1 FDM rx signal at this sample rate, rather than the NC+1 baseband signals. When the correct timing instant is found, each baseband signal could be down converted and filtered at the same time. See also the fdmdv page on my web site for more info on how the modem works and the various sample rates. A quicker fix that might work is to allocate storage for the FDMDV structure storage from the heap, rather than the stack, assuming you have 400k available on the heap. Cheers, David On Tue, 2012-05-15 at 23:39 +0300, Sergiy wrote: > As I see, the largest buffers in FDMDV are two-dimensional arrays > tx_filter_memory[NC+1][NFILTERTIMING] and rx_filter_memory[ NC > +1][NFILTERTIMING] where total size of each contains 115200 bytes. > Maybe there is some algo that can use smaller arrays to met embedded > device requirements? > > 2012/5/15 Bruce Perens <[email protected]> > David commented that the largest buffer was used for logging > and statistical collection rather than decoding. > ------------------------------------------------------------------------------ > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. Discussions > will include endpoint security, mobile security and the latest in malware > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ Freetel-codec2 mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
