The standard is ETSI TS 125 213 (Spreading and modulation FDD), not 113 as I claimed below.
Jens On Sat, Jun 10, 2006 at 04:20:10PM +0200, Jens Elsner wrote: > Dan, > > I sampled an UTRA FDD downlink signal and implemented the widely know > standard cell search algorithm (see for example > http://www.umtsworld.com/technology/cell_search.htm). To understand the > details, you need to download the right document in the standard (ETSI > TS 125 113, if I remember correctly) which is available at www.etsi.com. > There are also loads of papers at the IEEE. > > The algorithm: > > 0. Resampling to N*3.84 Mcps, internal oversampling needed to compensate > for non-ideal sampling, matched filtering > 1. DFT stage for coarse frequency aquisition using the PSC (synch to > slot) > 2. correlation with SSCs to get code group (synch to frame) > 3. try the 8 different scrambling codes in code group > 4. fine frequency aquisition using known symbols on the CPICH > 5. start to despread data channels using CPICH as phase reference > > Nothing fancy at all. If it works in Matlab, it should work this way in GNU > Radio, too? Would be a nice project, I guess. I'm not planning on > implementing the whole show in Matlab (which would be close to > impossible for me). One purpose was to show that this works with > the USRP. > > A tricky part is the scrambling code generation, which is described not > very clearly in the standard. If you have further questions, just ask. > > Jens > > On Sat, Jun 10, 2006 at 09:24:19AM -0400, Dan Veeneman wrote: > > Hi Jens, > > > > I'm quite interested in WCDMA, and spread spectrum in general, and > > would certainly be interested in learning more about your algorithm. > > If you can't send the code, do you have a description of the final > > algorithm you worked out? Perhaps even a small section of the > > code that does the search and despreading? > > > > > > Regards, > > > > Dan > > > > > > At 04:12 AM 6/10/06, you wrote: > > >Hello everybody, > > > > > >I did some work the last couple of weeks implementing the cell search > > >algorithm and despreading of basic channels for WCDMA (UMTS) using the USRP > > >in Matlab. > > > > > >Unfortunately I do not have the copyright, so I can't post the code. > > > > > >But if anyone is interested in playing with WCDMA in GNU Radio, I'd be > > >glad to share my insight. For now I'll get back to DAB. > > > > > >Jens > > > > > > > > >_______________________________________________ > > >Discuss-gnuradio mailing list > > >[email protected] > > >http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
