On Tue, Oct 2, 2012 at 9:01 AM, Martin Braun (CEL) <martin.br...@kit.edu> wrote: > On Mon, Oct 01, 2012 at 05:17:33PM -0400, Tom Rondeau wrote: >> Yes, harris' book is the best to start with. There is another paper >> from him called "Let's Assume the System is Synchronized" that also >> goes over it. I'm not sure if he's published a paper that discusses >> the specifics of the filter derivation, yet, though. It's based on the >> derivative of the half cosine waveform of the RRC filter rolloff. The >> system behaves much better this way than just generating any random >> band edge filter. >> >> In theory, this should work for any signal using an RRC pulse shaping. >> For specific constellations, you could use a Costas loop with a wider >> lock in bandwidth to handle the frequency offset. >> >> Oh, and I might be the only one who calls this the "FLL band edge >> filter" specifically to point out that this is only one possible >> implementation of an FLL for coarse frequency tracking. Other >> algorithms are welcome :) > > Thanks for these pointers. For future reference (and the mailing list > archives): > > * The paper "Let's Assume the System is Synchronized" is a good > introduction and provides a great and simple explanation. > * Harris' book "Multirate Signal Processing: for communication systems" > is the more complete version, down to polyphase implementation > details. > * I should have realized this is a way to implement an ML Frequency > correction for RRC spectra without a-priori knowledge. This is more > generally derived in "Synchronization techniques for digital > receivers" by Mengali/D'Andrea[1], and probably many other places. > > M > > [1] In general, Fred Harris books and papers are more fun to read, > though.
Yeah, Mengali's great, but dense and mathematical. harris provides a more big-picture, system's oriented look at the problems. Tom _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
