Forums

Progamming DSPs for Comm algos

Started by third_person December 18, 2009
Hi, I'm a student of communication engineering, with interest in software
defined radio.

Can you tell me what are good references for learning to implement
communication algorithms on Digital Signal Processors? My univ has c6416
and c6713 so have the facility to work on them.

From posts in this group I see that most people are in this field, so
perhaps you can give me good tips to develop my skills in this field.

I use Matlab at my current level. At what level do you think this can help
me? Mathworks says that its recent versions like 2009a have the facility of
converting "matlab files .m" to ".c" files that can be used for DSP
programming (directly creating programs for algos is an option too)

Therefore, continuing, I used Kronecker product followed by normalizing to
create a simple DSSS modem. Can similar strategy be used with DSPs? But I
can't think of how this would bring together the effect of sample rate
change which occurs in DSSS where sample rate changes from that of input
data (bit rate) to that of spreading sequence (chip rate)
On Dec 18, 11:27&#2013266080;am, "third_person" <third_per...@ymail.com> wrote:
> Hi, I'm a student of communication engineering, with interest in software > defined radio. > > Can you tell me what are good references for learning to implement > communication algorithms on Digital Signal Processors? My univ has c6416 > and c6713 so have the facility to work on them. > > From posts in this group I see that most people are in this field, so > perhaps you can give me good tips to develop my skills in this field. > > I use Matlab at my current level. At what level do you think this can help > me? Mathworks says that its recent versions like 2009a have the facility of > converting "matlab files .m" to ".c" files that can be used for DSP > programming (directly creating programs for algos is an option too) > > Therefore, continuing, I used Kronecker product followed by normalizing to > create a simple DSSS modem. Can similar strategy be used with DSPs? But I > can't think of how this would bring together the effect of sample rate > change which occurs in DSSS where sample rate changes from that of input > data (bit rate) to that of spreading sequence (chip rate)
Get a copy of Frerking's book "Digital Signal Processing in Communications Systems" and start coding up the stuff in the book. This will get you moving along pretty well. Also use you university library access to look up articles. You have a lot of reading and coding ahead of you, but this is how you will learn this material. Clay
On Dec 18, 11:27&#2013266080;am, "third_person" <third_per...@ymail.com> wrote:
> Hi, I'm a student of communication engineering, with interest in software > defined radio. > > Can you tell me what are good references for learning to implement > communication algorithms on Digital Signal Processors? My univ has c6416 > and c6713 so have the facility to work on them. > > From posts in this group I see that most people are in this field, so > perhaps you can give me good tips to develop my skills in this field. > > I use Matlab at my current level. At what level do you think this can help > me? Mathworks says that its recent versions like 2009a have the facility of > converting "matlab files .m" to ".c" files that can be used for DSP > programming (directly creating programs for algos is an option too) > > Therefore, continuing, I used Kronecker product followed by normalizing to > create a simple DSSS modem. Can similar strategy be used with DSPs? But I > can't think of how this would bring together the effect of sample rate > change which occurs in DSSS where sample rate changes from that of input > data (bit rate) to that of spreading sequence (chip rate)
Begin from bare metal and get something simple running such as a FIR filter applied to an A/D stream and fed out to a D/A. When you get it working, add a twist such as a frequency shift. Try to do everything yourself in C and assembly, do not relay on code generators or frameworks such as DSP Bios. It is only after you learn the hard way how to operate the DSP chip yourself that you will be in a position to evaluate these tools. John

John wrote:

> On Dec 18, 11:27 am, "third_person" <third_per...@ymail.com> wrote: > >>Hi, I'm a student of communication engineering, with interest in software >>defined radio. >> >>Can you tell me what are good references for learning to implement >>communication algorithms on Digital Signal Processors?
> Begin from bare metal and get something simple running such as a FIR > filter applied to an A/D stream and fed out to a D/A. When you get it > working, add a twist such as a frequency shift. Try to do everything > yourself in C and assembly, do not relay on code generators or > frameworks such as DSP Bios. It is only after you learn the hard way > how to operate the DSP chip yourself that you will be in a position to > evaluate these tools.
Seconded. Well said, Mr. John. VLV
On Fri, 18 Dec 2009 09:21:58 -0800, John wrote:

> On Dec 18, 11:27&nbsp;am, "third_person" <third_per...@ymail.com> wrote: >> Hi, I'm a student of communication engineering, with interest in >> software defined radio. >> >> Can you tell me what are good references for learning to implement >> communication algorithms on Digital Signal Processors? My univ has >> c6416 and c6713 so have the facility to work on them. >> >> From posts in this group I see that most people are in this field, so >> perhaps you can give me good tips to develop my skills in this field. >> >> I use Matlab at my current level. At what level do you think this can >> help me? Mathworks says that its recent versions like 2009a have the >> facility of converting "matlab files .m" to ".c" files that can be used >> for DSP programming (directly creating programs for algos is an option >> too) >> >> Therefore, continuing, I used Kronecker product followed by normalizing >> to create a simple DSSS modem. Can similar strategy be used with DSPs? >> But I can't think of how this would bring together the effect of sample >> rate change which occurs in DSSS where sample rate changes from that of >> input data (bit rate) to that of spreading sequence (chip rate) > > Begin from bare metal and get something simple running such as a FIR > filter applied to an A/D stream and fed out to a D/A. When you get it > working, add a twist such as a frequency shift. Try to do everything > yourself in C and assembly, do not relay on code generators or > frameworks such as DSP Bios. It is only after you learn the hard way how > to operate the DSP chip yourself that you will be in a position to > evaluate these tools. > > John
I second that, too. Learn how to 'program' DSP by using Matlab's conversion program, and you'll be forever beholden to the Math Works, you'll be hamstrung by Matlab's limitations, and you'll be responsible for bloatware for the rest of your career. I read a post recently on a metalworking group, by a guy who took a machining class at his local community college. The first term was about how to use hacksaws, files, and drills. He chafed at not being introduced to the 'real' tools -- the lathes and milling machines and surface grinders. After the term was over, though, he realized that without that hands-on training, he'd never be more than machine operator -- with it, he's on the road to being a machinist. The same holds true for DSP programming. -- www.wescottdesign.com

>Get a copy of Frerking's book "Digital Signal Processing in >Communications Systems" and start coding up the stuff in the book.
Thanks for the info. But the book costs too much for me at this time. I understand that this book would be really helpful, but it costs Rs 10,000 + Would you suggest a similar book but not so expensive?
On Jan 2, 3:56=A0am, "third_person" <third_per...@ymail.com> wrote:
> >Get a copy of Frerking's book "Digital Signal Processing in > >Communications Systems" and start coding up the stuff in the book. > > Thanks for the info. But the book costs too much for me at this time. > > I understand that this book would be really helpful, but it costs Rs > 10,000 + > > Would you suggest a similar book but not so expensive?
If you don't want to buy a book then I would suggest looking at the app notes from your DSP vendor. A long time ago, I remember getting good use out of the free paperback books published by Analog Devices about their fixed point DSPs. AD did a really nice job on these books. I don't know of anything from TI that is as good. They are free (see Using the AD2100 Family). http://www.analog.com/en/embedded-processing-dsp/ADSP-21xx/processors/manua= ls/resources/index.html John