-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Ok, I think don't know why it overflows, but I get a better feeling for your system :) thanks.
So: You have four UHD sources in parallel, feeding your block's four input streams simultaneously, is that right? So, in that case, you have a total sample rate of 2MS/s, which is more in regions where PCs might be underpowered. You have to do a covariance matrix every 16µs on average; this is quite a lot, possibly, though I have no idea of the complexity that involves when using armadillo. Maybe, you are I/O bound; do you write data to your hard drive or do something similar after processing? I think Martin's approach makes very much sense. Could you take the four USRP sources, do a "streams to vector" and save that using a file_sink? Do you still get overruns then? Then, using file source and a vector to streams, could you process your data offline and see if the would be sufficient for real time processing? Greetings, Marcus On 05.02.2014 10:55, sarankumar wrote: > Hi, There is no throttle block in my flow graph. The USRP source is > directly connected to the custom block. In the custom block, I form > a 4x8 matrix with 4 being number of USRP's and 8 is the number of > samples from each of them. Then I do cross co-variance of the > matrix(4x8) with its transpose(8x4). The resulting 4x4 matrix is > inverted. I use Armadillo linear algebra package for the > co-variance and inverse operations. The computer is equipped with 8 > Gig ram and gigabit ethernet card. > > Regards, Saran On Wed, Feb 5, 2014 at 2:56 PM, Marcus Müller > <mar...@hostalia.de> wrote: > > Also, since this is a very common mistake: Maybe you have a > throttle block in your flowgraph. If that's the case, remove it. > > Greetings, Marcus > > (Um, how do you invert a 4x8 matrix?) > > On 05.02.2014 03:52, Martin Braun wrote: >>>> On 04.02.2014 18:46, sarankumar wrote: >>>>> Hi all, I am encountering overflow errors in my custom >>>>> block in GRC even for low USRP sample rates of 500 Ksps. >>>>> The flow graph goes like 4 USRP's connected to the custom >>>>> block. The block does matrix correlation and inverse. The >>>>> size of the matrix is 4x8. Any help? Regards, Saran >>>> >>>> Your flow graph is probably running too slowly. You could >>>> record IQ data and try w/ offline data. >>>> >>>> MB >>>> >>>> >>>> _______________________________________________ >>>> Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org >>>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> _______________________________________________ Discuss-gnuradio >> mailing list Discuss-gnuradio@gnu.org >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> > -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJS8ipkAAoJEAFxB7BbsDrLYfMH/itHwES1O7cXxd5iTXjHmfkv h1T2JEhVIVSLTN2s419Fh7t4iD0fW2DXPzQjOAEuqSlatmB+S2u4O7NnKUtuQURe 0CJQ3rybow/2bPksxufaZRja9703S1zhFILoAapsxfGgklcf61uw39fRjhicMx65 BgAQJHt6zMUmKMVVP9t7Rxyy+0QpzNge7H2PiMxZIrPuyWCOSKBhIabLdazfs420 P8Ko/TqEl0Mm9SVDTionlpx8dkfyUaVmtMahCalFqdgHtBiB4Ji6IIz/VPlJ7BXO 29DIHbJaZUf+OsrdkxmFRUx4R4vVmfQHGiEanMKiLLTrs4ffusQtPKtxqc5MUKM= =szn5 -----END PGP SIGNATURE----- _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio