Re: [digitalradio] Has anyone looked into FPGA-based digital modes?
Rick W. wrote: Hi Paul, Sounds like you might be getting caught up with some of your other work and can devote some time again to digital modes:) For those who are not aware, it was Paul's paper on ARQ concepts that lead to development of several current uses of ham radio ARQ modes. Some comments and questions: 1. Years ago we had the outboard programmables but they never really were all that popular. I know of only one ham in our area (multi-county rural area) who had one. Can the paradigm be revived? I don't think it can for the average HF digital ham since they do not seem to have that much interest in ARQ modes. Most are quite happy to only use PSK31 and no other mode. When it doesn't work, they don't tend to switch to MFSK16 or Olivia. They just go and do something else. 2. Is it really true that computers (using a sound card) can not switch fast enough? When I toggle the PTT on my sound card modes, I can barely tell there is any delay in switching the rig. While I would not want to key CW that way, it seems plenty fast enough for reasonable switching speeds needed for an ARQ digital mode. Since we would not necessarily need to exactly duplicate Pactor modes, couldn't there just be a few extra milliseconds of padding to take care of differences in any delays depending upon the computer? Based on the timing for Pactor 2 and 3, do you still find that the average computer can not handle the window for the ARQ ACK/NAK response? 3. The SCAMP mode, developed by the Winlink 2000 group, proved conclusively that you don't even need such close timing anyway since you could do the decoding in the background (pipelining) during the time that the next packet was being sent. SCAMP worked fabulously well with good signals. If other slower protocols were used (but still keeping the 1000 wpm speed) it would work with much more difficult conditions. 4. Other than a few of us who have significant interest in public service/emergency communications and the need for absolute accuracy in messaging, there seems to be nearly no interest:( I wish it was not this way, but consider that the FAE400 mode, which is very sensitive, can work under fairly difficult conditions that would make PSK31 impossible, and has ARQ built in, is almost never used after a modest interest in testing it last year. 5. Therefore, it seems important to insure that there is a purpose for the development of a new ARQ mode to meet some unmet need. I might suggest that possible interest in having the capability to handle public service messaging, with total accuracy, and under conditions that may make CW difficult, and yet provide the access to automated e-mail that can also handle time shifting store and hold for later retrieval. As an example, there are probably a few of us who used to be active with CW/phone traffic handling a few decades ago, but who did not want to be forced to adhere to a specific schedule during non emergency times. Packet BBS systems had some of the paradigm but for decentralized systems did not work well on HF since the mode requires very good signals and throughput was often marginal to nil. A decentralized ad hoc, robust, low cost system that gave us a choice of routing e-mail or holding it for a local ham could be a new paradigm that enough radio amateurs might move toward. There is no other system that can do this now and nothing on the horizon. I would personally be interested in hosting such a system. Any other hams feel the same way? Or do you think such an approach would languish? 73, Rick, KV9U Paul L Schmidt, K9PS wrote: Speed and resolution are, of course, relative :) While those chips are capable of crunching on half the HF spectrum at once, I was thinking initially of just audio (for which the on-board converters would be fine) - kind of a super-TNC, with capabilities (speed/bandwidth) similar to Pactor-III with no patents, open-source software, and significantly lower hardware costs. Sound card modes, of course, have gained popularity due to their flexibility and low cost - but can't handle the tight timing needed for pactor-type modes. It just seemed to me that something like a commercially-available low-cost FPGA board might be able to get the best of both worlds. Yeah, I'm suggesting a minor paradigm shift. Scary. 73, Paul / K9PS Seems like I heard the same song and dance when AX.25 and 1200 baud appeared on 2M...what about RTTY and ASCII they asked. But AX.25 at 1200 baud reigns and RTTY and ASCII on 2M no longer exist. Walt/K5YFW
Re: [digitalradio] Has anyone looked into FPGA-based digital modes?
I hadn't thought of trying a high-speed VHF/UHF modem :) Maybe that's because I live away from what most people call civilization and there aren't many VHF/UHF signals around here. I'd figured on using a CPU personality for overall control, and doing the work in hardware. Is the Spartan-3E starter kit (Digilent/Xilinx) the one you're using? 73, - ps John B. Stephensen wrote: The ADC and DAC are certainly adequate for audio so it will work. I've been interested in VHF and UHF high-speed modems so I have a starter kit outfitted with a high-speed ADC and DAC that plug into J3. So far I've tested the DDS and am in the middle of testing the second version of a 16-bit soft MCU. After that, I have a lot of Verilog code imported from a Spartan-3 project and converted from ISE 7 to ISE 10 that needs to be integrated and tested. That should eventualy result in an OFDM modem that operates at up to 2 Mbps. Real-time signal processing is done in dedicated modules for filtering, FFT and CORDIC, but in this design the soft processor is to handle everything between the FFT and the Ethernet port. Think of it as an Intersil HSP50214 plus an FFT and MCU in one FPGA. The soft MCU would probably be enough to process 8 ksps audio for a modem as it has a MAC instruction. 3 or 4 would fit in an XC3S500E. 73, John KD6OZH
Re: [digitalradio] Has anyone looked into FPGA-based digital modes?
Yes, I'm using the $150 board sold by Xilinx and Digilent. The XC3S500E seems to have just enough logic and memory for this application, but the starter kit power supplies aren't very clean when you're digitizing signals in the low HF range. I'Il use custom hardware with linear regulators when I have a complete modem running on the starter kit. We have similar ideas on the overall architecture. The Spartan-3E seems to be about 25% faster than the Spartan-3 and Xilinx now supplies FFT IP that uses only 2 block RAMs for a 512-point FFT. Consequently, you can do more with an inexpensive FPGA. Since I've always been interested in CPU architecture, I spent a lot of time on the soft CPU and need to move on with the rest of the project. It's just so easy to tweak the Verilog code and try different architecures and instruction sets. Much easier than my first experience in the early 1970's with MSI TTL. 73, John KD6OZH - Original Message - From: Paul L Schmidt, K9PS To: digitalradio@yahoogroups.com Sent: Monday, August 04, 2008 23:15 UTC Subject: Re: [digitalradio] Has anyone looked into FPGA-based digital modes? I hadn't thought of trying a high-speed VHF/UHF modem :) Maybe that's because I live away from what most people call civilization and there aren't many VHF/UHF signals around here. I'd figured on using a CPU personality for overall control, and doing the work in hardware. Is the Spartan-3E starter kit (Digilent/Xilinx) the one you're using? 73, - ps John B. Stephensen wrote: The ADC and DAC are certainly adequate for audio so it will work. I've been interested in VHF and UHF high-speed modems so I have a starter kit outfitted with a high-speed ADC and DAC that plug into J3. So far I've tested the DDS and am in the middle of testing the second version of a 16-bit soft MCU. After that, I have a lot of Verilog code imported from a Spartan-3 project and converted from ISE 7 to ISE 10 that needs to be integrated and tested. That should eventualy result in an OFDM modem that operates at up to 2 Mbps. Real-time signal processing is done in dedicated modules for filtering, FFT and CORDIC, but in this design the soft processor is to handle everything between the FFT and the Ethernet port. Think of it as an Intersil HSP50214 plus an FFT and MCU in one FPGA. The soft MCU would probably be enough to process 8 ksps audio for a modem as it has a MAC instruction. 3 or 4 would fit in an XC3S500E. 73, John KD6OZH
Re: [digitalradio] Has anyone looked into FPGA-based digital modes?
John B. Stephensen wrote: FPGAs are useful for signal processing as you can do many operations in parallel. FIR filter, FFT and CORDIC modules are available in the free development software from Xilinx. They are very good for processing wideband signals or digitizing an entire amateur band and then filtering the result. Unfortunately, the starter kit has only low-speed low-resolution ADCs and DACs. 73, John KD6OZH Speed and resolution are, of course, relative :) While those chips are capable of crunching on half the HF spectrum at once, I was thinking initially of just audio (for which the on-board converters would be fine) - kind of a super-TNC, with capabilities (speed/bandwidth) similar to Pactor-III with no patents, open-source software, and significantly lower hardware costs. Sound card modes, of course, have gained popularity due to their flexibility and low cost - but can't handle the tight timing needed for pactor-type modes. It just seemed to me that something like a commercially-available low-cost FPGA board might be able to get the best of both worlds. Yeah, I'm suggesting a minor paradigm shift. Scary. 73, Paul / K9PS
Re: [digitalradio] Has anyone looked into FPGA-based digital modes?
Hi Paul, Sounds like you might be getting caught up with some of your other work and can devote some time again to digital modes:) For those who are not aware, it was Paul's paper on ARQ concepts that lead to development of several current uses of ham radio ARQ modes. Some comments and questions: 1. Years ago we had the outboard programmables but they never really were all that popular. I know of only one ham in our area (multi-county rural area) who had one. Can the paradigm be revived? I don't think it can for the average HF digital ham since they do not seem to have that much interest in ARQ modes. Most are quite happy to only use PSK31 and no other mode. When it doesn't work, they don't tend to switch to MFSK16 or Olivia. They just go and do something else. 2. Is it really true that computers (using a sound card) can not switch fast enough? When I toggle the PTT on my sound card modes, I can barely tell there is any delay in switching the rig. While I would not want to key CW that way, it seems plenty fast enough for reasonable switching speeds needed for an ARQ digital mode. Since we would not necessarily need to exactly duplicate Pactor modes, couldn't there just be a few extra milliseconds of padding to take care of differences in any delays depending upon the computer? Based on the timing for Pactor 2 and 3, do you still find that the average computer can not handle the window for the ARQ ACK/NAK response? 3. The SCAMP mode, developed by the Winlink 2000 group, proved conclusively that you don't even need such close timing anyway since you could do the decoding in the background (pipelining) during the time that the next packet was being sent. SCAMP worked fabulously well with good signals. If other slower protocols were used (but still keeping the 1000 wpm speed) it would work with much more difficult conditions. 4. Other than a few of us who have significant interest in public service/emergency communications and the need for absolute accuracy in messaging, there seems to be nearly no interest:( I wish it was not this way, but consider that the FAE400 mode, which is very sensitive, can work under fairly difficult conditions that would make PSK31 impossible, and has ARQ built in, is almost never used after a modest interest in testing it last year. 5. Therefore, it seems important to insure that there is a purpose for the development of a new ARQ mode to meet some unmet need. I might suggest that possible interest in having the capability to handle public service messaging, with total accuracy, and under conditions that may make CW difficult, and yet provide the access to automated e-mail that can also handle time shifting store and hold for later retrieval. As an example, there are probably a few of us who used to be active with CW/phone traffic handling a few decades ago, but who did not want to be forced to adhere to a specific schedule during non emergency times. Packet BBS systems had some of the paradigm but for decentralized systems did not work well on HF since the mode requires very good signals and throughput was often marginal to nil. A decentralized ad hoc, robust, low cost system that gave us a choice of routing e-mail or holding it for a local ham could be a new paradigm that enough radio amateurs might move toward. There is no other system that can do this now and nothing on the horizon. I would personally be interested in hosting such a system. Any other hams feel the same way? Or do you think such an approach would languish? 73, Rick, KV9U Paul L Schmidt, K9PS wrote: Speed and resolution are, of course, relative :) While those chips are capable of crunching on half the HF spectrum at once, I was thinking initially of just audio (for which the on-board converters would be fine) - kind of a super-TNC, with capabilities (speed/bandwidth) similar to Pactor-III with no patents, open-source software, and significantly lower hardware costs. Sound card modes, of course, have gained popularity due to their flexibility and low cost - but can't handle the tight timing needed for pactor-type modes. It just seemed to me that something like a commercially-available low-cost FPGA board might be able to get the best of both worlds. Yeah, I'm suggesting a minor paradigm shift. Scary. 73, Paul / K9PS
Re: [digitalradio] Has anyone looked into FPGA-based digital modes?
where could one finds these modes MATTHEW A. GREGORY KC2PUA - Original Message From: Rick W. [EMAIL PROTECTED] To: digitalradio@yahoogroups.com Sent: Sunday, August 3, 2008 11:46:11 AM Subject: Re: [digitalradio] Has anyone looked into FPGA-based digital modes? Hi Paul, Sounds like you might be getting caught up with some of your other work and can devote some time again to digital modes:) For those who are not aware, it was Paul's paper on ARQ concepts that lead to development of several current uses of ham radio ARQ modes. Some comments and questions: 1. Years ago we had the outboard programmables but they never really were all that popular. I know of only one ham in our area (multi-county rural area) who had one. Can the paradigm be revived? I don't think it can for the average HF digital ham since they do not seem to have that much interest in ARQ modes. Most are quite happy to only use PSK31 and no other mode. When it doesn't work, they don't tend to switch to MFSK16 or Olivia. They just go and do something else. 2. Is it really true that computers (using a sound card) can not switch fast enough? When I toggle the PTT on my sound card modes, I can barely tell there is any delay in switching the rig. While I would not want to key CW that way, it seems plenty fast enough for reasonable switching speeds needed for an ARQ digital mode. Since we would not necessarily need to exactly duplicate Pactor modes, couldn't there just be a few extra milliseconds of padding to take care of differences in any delays depending upon the computer? Based on the timing for Pactor 2 and 3, do you still find that the average computer can not handle the window for the ARQ ACK/NAK response? 3. The SCAMP mode, developed by the Winlink 2000 group, proved conclusively that you don't even need such close timing anyway since you could do the decoding in the background (pipelining) during the time that the next packet was being sent. SCAMP worked fabulously well with good signals. If other slower protocols were used (but still keeping the 1000 wpm speed) it would work with much more difficult conditions. 4. Other than a few of us who have significant interest in public service/emergency communications and the need for absolute accuracy in messaging, there seems to be nearly no interest:( I wish it was not this way, but consider that the FAE400 mode, which is very sensitive, can work under fairly difficult conditions that would make PSK31 impossible, and has ARQ built in, is almost never used after a modest interest in testing it last year. 5. Therefore, it seems important to insure that there is a purpose for the development of a new ARQ mode to meet some unmet need. I might suggest that possible interest in having the capability to handle public service messaging, with total accuracy, and under conditions that may make CW difficult, and yet provide the access to automated e-mail that can also handle time shifting store and hold for later retrieval. As an example, there are probably a few of us who used to be active with CW/phone traffic handling a few decades ago, but who did not want to be forced to adhere to a specific schedule during non emergency times. Packet BBS systems had some of the paradigm but for decentralized systems did not work well on HF since the mode requires very good signals and throughput was often marginal to nil. A decentralized ad hoc, robust, low cost system that gave us a choice of routing e-mail or holding it for a local ham could be a new paradigm that enough radio amateurs might move toward. There is no other system that can do this now and nothing on the horizon. I would personally be interested in hosting such a system. Any other hams feel the same way? Or do you think such an approach would languish? 73, Rick, KV9U Paul L Schmidt, K9PS wrote: Speed and resolution are, of course, relative :) While those chips are capable of crunching on half the HF spectrum at once, I was thinking initially of just audio (for which the on-board converters would be fine) - kind of a super-TNC, with capabilities (speed/bandwidth) similar to Pactor-III with no patents, open-source software, and significantly lower hardware costs. Sound card modes, of course, have gained popularity due to their flexibility and low cost - but can't handle the tight timing needed for pactor-type modes. It just seemed to me that something like a commercially- available low-cost FPGA board might be able to get the best of both worlds. Yeah, I'm suggesting a minor paradigm shift. Scary. 73, Paul / K9PS
Re: [digitalradio] Has anyone looked into FPGA-based digital modes?
Hi Matt, For the ARQ modes, the main one that works with the weaker signals is FAE400 and is only found in the Multipsk program invented by Patrick, F6CTE. He took the 8FSK 125 baud waveform from the old MIL-STD-188-141A ALE protocol and slowed the speed down to 50 baud, then added compression, and amazingly added memory ARQ, similar to what Pactor does and what others have said for years could never be done. The performance is dramatically improved over the 141A protocol and is competitive with other non-ARQ sound card modes. It is not quite as competitive as Olivia and MFSK modes, but then those modes are slower. http://f6cte.free.fr/index_anglais.htm - - - - - There are two other ARQ technologies that can work with weaker signals ... PSKmail and NBEMS. PSKmail runs only on Linux and is going nowhere here in the U.S. Perhaps better in some other countries? I am hopeful that it will catch on to a greater degree, but until a critical mass of hams adopt Linux here in the U.S. or PSKmail is developed for MS Windows (which the developer says will not happen), I don't see how it can become useful without enough available hams. My understanding is that PSKmail can also do peer to peer ARQ chat as well as automatic e-mailing. It can run on the Linux version of the EeePC for excellent portability. PSKmail uses various speeds of PSK, especially PSK63 and is designed primarily for HF use with the narrow modes. http://pskmail.wikispaces.com/ - - - - - NBEMS (Narrow Band Emergency Messaging System) is manually operated which requires operators at both ends. It allows for ARQ messages to be sent without error as files. It does not include peer to peer ARQ chat but can operate compatibly with non-ARQ chat modes such as PSK, MFSK, and even RTTY. w1hkj.com and http://w1hkj.com/NBEMS/index.html NBEMS is one of the only cross platform systems since it runs on Linux and MS Windows. It ARQ's the fldigi multimode software with flarq using fast light development. The Windows side currently uses VBdigi, but we have heard that Dave, W1HKJ, is working on a Windows version of fldigi. NBEMS can use several different sound card protocols, including PSK and MFSK and we have heard that they are developing a new mode(s)? for this system. It was initially developed primarily for VHF, but can be used on HF. - - - - - SCAMP (Sound Card Amateur Messaging Protocol) was developed several years ago by the Winlink 2000 software developer and was to be available as an alternative to the very expensive and single sourced proprietary SCS modem (~ $1000). I found the program to work extremely well when conditions were good (close to +10 dB S/N) since it had a top speed of close to 1000 wpm for the HF version. You had to see it in operation to see how powerful it was. But, as expected, using the RDFT protocol, it was not possible to handle even zero dB S/N signals, much less below zero dB as many improved sound card modes can do now. They discontinued all further development, but did say they were planning on making it available to the amateur community. As far as I was able to find out, they never did. not to do this. The only logical reason seems to me to prevent other hams from more easily developing systems that could compete with Winlink 2000. So with the new developments have been somewhat reinvention of the wheel:) The software had self destruct timers built in to insure that it could never be used after a few months and so is no longer available:( The higher speed version for VHF also did not appear to be developed further, however I only was involved with the HF side. Perhaps with the completion of major changes to the Winlink 2000 system, they will revisit further development? If you have any other questions please let us know. Often someone here has the information. 73, Rick, KV9U matt gregory wrote: where could one finds these modes MATTHEW A. GREGORY KC2PUA - Original Message From: Rick W. [EMAIL PROTECTED] To: digitalradio@yahoogroups.com Sent: Sunday, August 3, 2008 11:46:11 AM Subject: Re: [digitalradio] Has anyone looked into FPGA-based digital modes? Hi Paul, Sounds like you might be getting caught up with some of your other work and can devote some time again to digital modes:) For those who are not aware, it was Paul's paper on ARQ concepts that lead to development of several current uses of ham radio ARQ modes. Some comments and questions: 1. Years ago we had the outboard programmables but they never really were all that popular. I know of only one ham in our area (multi-county rural area) who had one. Can the paradigm be revived? I don't think it can for the average HF digital ham since they do not seem to have that much interest in ARQ modes. Most are quite happy to only use PSK31 and no other mode. When it doesn't work, they don't tend to switch to MFSK16 or Olivia. They just go and do something else. 2
Re: [digitalradio] Has anyone looked into FPGA-based digital modes?
Paul you just hit the nail right square on the head. I have said just that for years. Don't say that to long and loud. The anti-wide pople will come and get you. John At 08:27 AM 8/3/2008 -0400, you wrote in part: Sound card modes, of course, have gained popularity due to their flexibility and low cost - but can't handle the tight timing needed for pactor-type modes. Paul / K9PS
Re: [digitalradio] Has anyone looked into FPGA-based digital modes?
The ADC and DAC are certainly adequate for audio so it will work. I've been interested in VHF and UHF high-speed modems so I have a starter kit outfitted with a high-speed ADC and DAC that plug into J3. So far I've tested the DDS and am in the middle of testing the second version of a 16-bit soft MCU. After that, I have a lot of Verilog code imported from a Spartan-3 project and converted from ISE 7 to ISE 10 that needs to be integrated and tested. That should eventualy result in an OFDM modem that operates at up to 2 Mbps. Real-time signal processing is done in dedicated modules for filtering, FFT and CORDIC, but in this design the soft processor is to handle everything between the FFT and the Ethernet port. Think of it as an Intersil HSP50214 plus an FFT and MCU in one FPGA. The soft MCU would probably be enough to process 8 ksps audio for a modem as it has a MAC instruction. 3 or 4 would fit in an XC3S500E. 73, John KD6OZH - Original Message - From: Paul L Schmidt, K9PS To: digitalradio@yahoogroups.com Sent: Sunday, August 03, 2008 12:27 UTC Subject: Re: [digitalradio] Has anyone looked into FPGA-based digital modes? John B. Stephensen wrote: FPGAs are useful for signal processing as you can do many operations in parallel. FIR filter, FFT and CORDIC modules are available in the free development software from Xilinx. They are very good for processing wideband signals or digitizing an entire amateur band and then filtering the result. Unfortunately, the starter kit has only low-speed low-resolution ADCs and DACs. 73, John KD6OZH Speed and resolution are, of course, relative :) While those chips are capable of crunching on half the HF spectrum at once, I was thinking initially of just audio (for which the on-board converters would be fine) - kind of a super-TNC, with capabilities (speed/bandwidth) similar to Pactor-III with no patents, open-source software, and significantly lower hardware costs. Sound card modes, of course, have gained popularity due to their flexibility and low cost - but can't handle the tight timing needed for pactor-type modes. It just seemed to me that something like a commercially-available low-cost FPGA board might be able to get the best of both worlds. Yeah, I'm suggesting a minor paradigm shift. Scary. 73, Paul / K9PS
Re: [digitalradio] Has anyone looked into FPGA-based digital modes?
The USRP (Universal Software Radio Project) uses Xilinx FPGA's for it's main processing and interface. It's compatible with GNURadio and is well supported. Paul L Schmidt, K9PS wrote: I've been thinking about getting an FPGA board to play with and see what it will do as far as hosting an HF modem, or at least the A/D and DSP portions of one. The board I'm considering has a Xilinx Spartan 3E FPGA and all of the peripheral hardware (A/D, D/A, VGA, ethernet, serial, etc.) one would probably need to do it. http://www.digilentinc.com/Products/Detail.cfm?Prod=S3EBOARDNav1=ProductsNav2=Programmable Anyone tried (or thought of trying) something like that? 73, Paul / K9PS Announce your digital presence via our Interactive Sked Page at http://www.obriensweb.com/sked Check our other Yahoo Groups http://groups.yahoo.com/group/dxlist/ http://groups.yahoo.com/group/contesting http://groups.yahoo.com/group/themixwgroup Yahoo! Groups Links
Re: [digitalradio] Has anyone looked into FPGA-based digital modes?
I would be very interested in hearing from enyone who has used one of these boards and pictures and info would be welcome to start a database. ken Message Received: Aug 02 2008, 08:05 AM From: Don Fanning To: digitalradio@yahoogroups.com Cc: Subject: Re: [digitalradio] Has anyone looked into FPGA-based digital modes? The USRP (Universal Software Radio Project) uses Xilinx FPGA's for it's main processing and interface. It's compatible with GNURadio and is well supported. Paul L Schmidt, K9PS wrote: I've been thinking about getting an FPGA board to play with and see what it will do as far as hosting an HF modem, or at least the A/D and DSP portions of one. The board I'm considering has a Xilinx Spartan 3E FPGA and all of the peripheral hardware (A/D, D/A, VGA, ethernet, serial, etc.) one would probably need to do it. http://www.digilentinc.com/Products/Detail.cfm?Prod=S3EBOARDNav1=ProductsNav2=Programmable Anyone tried (or thought of trying) something like that? 73, Paul / K9PS Announce your digital presence via our Interactive Sked Page at http://www.obriensweb.com/sked Check our other Yahoo Groups http://groups.yahoo.com/group/dxlist/ http://groups.yahoo.com/group/contesting http://groups.yahoo.com/group/themixwgroup Yahoo! Groups Links
Re: [digitalradio] Has anyone looked into FPGA-based digital modes?
FPGAs are useful for signal processing as you can do many operations in parallel. FIR filter, FFT and CORDIC modules are available in the free development software from Xilinx. They are very good for processing wideband signals or digitizing an entire amateur band and then filtering the result. Unfortunately, the starter kit has only low-speed low-resolution ADCs and DACs. 73, John KD6OZH - Original Message - From: Paul L Schmidt, K9PS To: digitalradio@yahoogroups.com Sent: Saturday, August 02, 2008 00:19 UTC Subject: [digitalradio] Has anyone looked into FPGA-based digital modes? I've been thinking about getting an FPGA board to play with and see what it will do as far as hosting an HF modem, or at least the A/D and DSP portions of one. The board I'm considering has a Xilinx Spartan 3E FPGA and all of the peripheral hardware (A/D, D/A, VGA, ethernet, serial, etc.) one would probably need to do it. http://www.digilentinc.com/Products/Detail.cfm?Prod=S3EBOARDNav1=ProductsNav2=Programmable Anyone tried (or thought of trying) something like that? 73, Paul / K9PS
[digitalradio] Has anyone looked into FPGA-based digital modes?
I've been thinking about getting an FPGA board to play with and see what it will do as far as hosting an HF modem, or at least the A/D and DSP portions of one. The board I'm considering has a Xilinx Spartan 3E FPGA and all of the peripheral hardware (A/D, D/A, VGA, ethernet, serial, etc.) one would probably need to do it. http://www.digilentinc.com/Products/Detail.cfm?Prod=S3EBOARDNav1=ProductsNav2=Programmable Anyone tried (or thought of trying) something like that? 73, Paul / K9PS
