Re: [Discuss-gnuradio] PSK Mod Block
Thank you for the fast respond, But, when I use PSK Mod then PSK Demod the output different from the input so no output from the Packet Decoder. Any suggestion? On Tue, Jun 23, 2015 at 9:17 PM, Nowlan, Sean sean.now...@gtri.gatech.edu wrote: Introducing ISI to a PSK signal with a root-raised cosine (RRC) filter is a standard communications technique. At the receiver, use a matched RRC filter to eliminate the intentional ISI introduced at the transmitter. This works because the combined filter response of the two filters is a raised cosine pulse, which satisfies the Nyquist criterion for zero ISI. In the PSK Mod block, the filter construction is not exposed to the user except through the excess bandwidth or roll-off parameter. You could adjust that bandwidth factor to be close to zero, but this will create a very long filter. If you really want to do what you are saying, it would be worth looking at the source code for the PSK Mod block, and taking the filter out. However, it is likely that you don’t really want to do this. Sean *From:* discuss-gnuradio-bounces+sean.nowlan=gtri.gatech@gnu.org [mailto:discuss-gnuradio-bounces+sean.nowlan=gtri.gatech@gnu.org] *On Behalf Of *Surya Agam *Sent:* Tuesday, June 23, 2015 9:47 AM *To:* GNURadio Discussion List *Subject:* [Discuss-gnuradio] PSK Mod Block Hello, I wanna use PSK Mod Block, but the ISI is annoying. Why PSK Mod Block have a it's own ISI? And also is there anyway to disable the ISI from the block? -- Sincerely, Surya Agam University Al Azhar of Indonesia, Jakarta -- Sincerely, Surya Agam University Al Azhar of Indonesia, Jakarta ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] PSK Mod Block
My target is using USRP, but still simulate using a noise channel. The output of PSK Demod is bit 0 a with some 1 and no input data in the output. I attach the input and the output screenshot. On Tue, Jun 23, 2015 at 10:12 PM, Nowlan, Sean sean.now...@gtri.gatech.edu wrote: This depends on your setup. If you’re just simulating with PSK Mod -- PSK Demod and then comparing the input with the output, then you may be seeing some initial output from the filters due to the convolution operations. Try searching through your output after some delay. If you disabled differential encoding, you may be seeing a bitstream that is not correct due to phase locking with a fixed phase offset at the receiver. If you’re going over hardware or through a noise channel, you might not have enough SNR to decode properly. If you’re using USRPs, have you experimented with the benchmark_tx/rx scripts? These implement various types of single carrier modulation, including many variants of PSK. Sean *From:* Surya Agam [mailto:surya11.01a...@gmail.com] *Sent:* Tuesday, June 23, 2015 10:53 AM *To:* Nowlan, Sean *Cc:* GNURadio Discussion List *Subject:* Re: [Discuss-gnuradio] PSK Mod Block Thank you for the fast respond, But, when I use PSK Mod then PSK Demod the output different from the input so no output from the Packet Decoder. Any suggestion? On Tue, Jun 23, 2015 at 9:17 PM, Nowlan, Sean sean.now...@gtri.gatech.edu wrote: Introducing ISI to a PSK signal with a root-raised cosine (RRC) filter is a standard communications technique. At the receiver, use a matched RRC filter to eliminate the intentional ISI introduced at the transmitter. This works because the combined filter response of the two filters is a raised cosine pulse, which satisfies the Nyquist criterion for zero ISI. In the PSK Mod block, the filter construction is not exposed to the user except through the excess bandwidth or roll-off parameter. You could adjust that bandwidth factor to be close to zero, but this will create a very long filter. If you really want to do what you are saying, it would be worth looking at the source code for the PSK Mod block, and taking the filter out. However, it is likely that you don’t really want to do this. Sean *From:* discuss-gnuradio-bounces+sean.nowlan=gtri.gatech@gnu.org [mailto:discuss-gnuradio-bounces+sean.nowlan=gtri.gatech@gnu.org] *On Behalf Of *Surya Agam *Sent:* Tuesday, June 23, 2015 9:47 AM *To:* GNURadio Discussion List *Subject:* [Discuss-gnuradio] PSK Mod Block Hello, I wanna use PSK Mod Block, but the ISI is annoying. Why PSK Mod Block have a it's own ISI? And also is there anyway to disable the ISI from the block? -- Sincerely, Surya Agam University Al Azhar of Indonesia, Jakarta -- Sincerely, Surya Agam University Al Azhar of Indonesia, Jakarta -- Sincerely, Surya Agam University Al Azhar of Indonesia, Jakarta ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] PSK Mod Block
Hello, I wanna use PSK Mod Block, but the ISI is annoying. Why PSK Mod Block have a it's own ISI? And also is there anyway to disable the ISI from the block? -- Sincerely, Surya Agam University Al Azhar of Indonesia, Jakarta ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] PSK Mod Block
So, it appears that PSK Mod expects packed bytes = from Packet Encoder direct to PSK Mod the Demod block outputs a stream of bits with 1 meaningful bit in the LSB position = Repack Bits 1 to 8 (packet alignment = input) the result, without delay the output is similar but not same. I don't know if need a long delay (the input and output from attachment not from the same packet) or I use a wrong Repack Bits block setting. On Tue, Jun 23, 2015 at 11:51 PM, Nowlan, Sean sean.now...@gtri.gatech.edu wrote: Looking quickly at the documentation, for PSK Mod and Demod blocks, it appears that PSK Mod expects packed bytes (8 bits of meaningful data in each byte) and that the Demod block outputs a stream of bits with 1 meaningful bit in the LSB position. Use a Repack Bits block. However, you may need to play with the delay (insert a Delay Block) to make sure that the Repack Bits block is aligning bits into bytes properly. Mod: “The input is a byte stream (unsigned char), treated as a series of packed symbols. Symbols are grouped from MSB to LSB.” Demod: “The output is a stream of bytes, each representing a recovered bit. The most significant bit is reported first.” *From:* discuss-gnuradio-bounces+sean.nowlan=gtri.gatech@gnu.org [mailto:discuss-gnuradio-bounces+sean.nowlan=gtri.gatech@gnu.org] *On Behalf Of *Marcus Müller *Sent:* Tuesday, June 23, 2015 11:59 AM *To:* discuss-gnuradio@gnu.org *Subject:* Re: [Discuss-gnuradio] PSK Mod Block Then you really want some pulse shaping filter, like the RRC that is used by default. On 06/23/2015 05:39 PM, Surya Agam wrote: My target is using USRP, but still simulate using a noise channel. The output of PSK Demod is bit 0 a with some 1 and no input data in the output. I attach the input and the output screenshot. On Tue, Jun 23, 2015 at 10:12 PM, Nowlan, Sean sean.now...@gtri.gatech.edu wrote: This depends on your setup. If you’re just simulating with PSK Mod -- PSK Demod and then comparing the input with the output, then you may be seeing some initial output from the filters due to the convolution operations. Try searching through your output after some delay. If you disabled differential encoding, you may be seeing a bitstream that is not correct due to phase locking with a fixed phase offset at the receiver. If you’re going over hardware or through a noise channel, you might not have enough SNR to decode properly. If you’re using USRPs, have you experimented with the benchmark_tx/rx scripts? These implement various types of single carrier modulation, including many variants of PSK. Sean *From:* Surya Agam [mailto:surya11.01a...@gmail.com] *Sent:* Tuesday, June 23, 2015 10:53 AM *To:* Nowlan, Sean *Cc:* GNURadio Discussion List *Subject:* Re: [Discuss-gnuradio] PSK Mod Block Thank you for the fast respond, But, when I use PSK Mod then PSK Demod the output different from the input so no output from the Packet Decoder. Any suggestion? On Tue, Jun 23, 2015 at 9:17 PM, Nowlan, Sean sean.now...@gtri.gatech.edu wrote: Introducing ISI to a PSK signal with a root-raised cosine (RRC) filter is a standard communications technique. At the receiver, use a matched RRC filter to eliminate the intentional ISI introduced at the transmitter. This works because the combined filter response of the two filters is a raised cosine pulse, which satisfies the Nyquist criterion for zero ISI. In the PSK Mod block, the filter construction is not exposed to the user except through the excess bandwidth or roll-off parameter. You could adjust that bandwidth factor to be close to zero, but this will create a very long filter. If you really want to do what you are saying, it would be worth looking at the source code for the PSK Mod block, and taking the filter out. However, it is likely that you don’t really want to do this. Sean *From:* discuss-gnuradio-bounces+sean.nowlan=gtri.gatech@gnu.org [mailto:discuss-gnuradio-bounces+sean.nowlan=gtri.gatech@gnu.org] *On Behalf Of *Surya Agam *Sent:* Tuesday, June 23, 2015 9:47 AM *To:* GNURadio Discussion List *Subject:* [Discuss-gnuradio] PSK Mod Block Hello, I wanna use PSK Mod Block, but the ISI is annoying. Why PSK Mod Block have a it's own ISI? And also is there anyway to disable the ISI from the block? -- Sincerely, Surya Agam University Al Azhar of Indonesia, Jakarta -- Sincerely, Surya Agam University Al Azhar of Indonesia, Jakarta -- Sincerely, Surya Agam University Al Azhar of Indonesia, Jakarta ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio -- Sincerely, Surya Agam University Al Azhar of Indonesia, Jakarta ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org
Re: [Discuss-gnuradio] USRP Handshake
I want to transmitted digital file (i.e. .jpg) with file source on Tx side then received the file with file sink. It's not about silence or noise because I use access code from packet decoder, the problem is when I start the Rx's fg the file sink immediately write file output even Tx's fg not run. Or when I start the Tx's fg first, the file transmitted (repeat = off) but the Rx's fg not start yet. I doubt these situation will compromised the output file. I haven't test it yet, still working to remove the noise from transmission. On Thu, Jun 11, 2015 at 5:15 AM, Chris Kuethe chris.kue...@gmail.com wrote: Examples of the squelch block include http://www.ece.uvic.ca/~elec350/grc_doc/ar01s01s03.html and http://files.ettus.com/tutorials/labs/Lab_1-5.pdf I've never used timed events in gnuradio, I just know that you can do things in a time-aligned way. You may want to google for gnuradio squelch and gnuradio timed Out of curiousity, why do you need to handshake? What's wrong with a little bit of silence or noise at the beginning and end of your recording? On Wed, Jun 10, 2015 at 3:02 PM, Surya Agam surya11.01a...@gmail.com wrote: Would you mind to tell me how? I have no idea. On Thu, Jun 11, 2015 at 4:54 AM, Chris Kuethe chris.kue...@gmail.com wrote: Maybe use a squelch block and wait for for received power to exceed some critical level? Or use timed events? On Wed, Jun 10, 2015 at 1:47 PM, Surya Agam surya11.01a...@gmail.com wrote: Hello everyone, I try to transmitting a file using PSK modulation with 2 x USRP B200 as Tx and Rx. When I run the Tx's fg, the Tx only transmitted before the Rx fg completely run. But when I run the Rx's fg, the file sink already write something before I run the Tx's fg. Is there any way to both Tx and Rx handshake before transmission started? -- Sincerely, Surya Agam University Al Azhar of Indonesia, Jakarta ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio -- GDB has a 'break' feature; why doesn't it have 'fix' too? -- Sincerely, Surya Agam University Al Azhar of Indonesia, Jakarta -- GDB has a 'break' feature; why doesn't it have 'fix' too? -- Sincerely, Surya Agam University Al Azhar of Indonesia, Jakarta ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] USRP Handshake
Hello everyone, I try to transmitting a file using PSK modulation with 2 x USRP B200 as Tx and Rx. When I run the Tx's fg, the Tx only transmitted before the Rx fg completely run. But when I run the Rx's fg, the file sink already write something before I run the Tx's fg. Is there any way to both Tx and Rx handshake before transmission started? -- Sincerely, Surya Agam University Al Azhar of Indonesia, Jakarta ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] USRP Handshake
Would you mind to tell me how? I have no idea. On Thu, Jun 11, 2015 at 4:54 AM, Chris Kuethe chris.kue...@gmail.com wrote: Maybe use a squelch block and wait for for received power to exceed some critical level? Or use timed events? On Wed, Jun 10, 2015 at 1:47 PM, Surya Agam surya11.01a...@gmail.com wrote: Hello everyone, I try to transmitting a file using PSK modulation with 2 x USRP B200 as Tx and Rx. When I run the Tx's fg, the Tx only transmitted before the Rx fg completely run. But when I run the Rx's fg, the file sink already write something before I run the Tx's fg. Is there any way to both Tx and Rx handshake before transmission started? -- Sincerely, Surya Agam University Al Azhar of Indonesia, Jakarta ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio -- GDB has a 'break' feature; why doesn't it have 'fix' too? -- Sincerely, Surya Agam University Al Azhar of Indonesia, Jakarta ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] PSK demod
Hello everyone, I try to simulate PSK modulation and demodulation without channel model to calculate BER. The flow graph as shown below. From File Source to PSK Mod is working, I can see the constellation even with ISI. But after PSK demod there's no output. Is there's anything wrong with my fg? -- Sincerely, Surya Agam University Al Azhar of Indonesia, Jakarta ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Error using Packet Encoder -- Packet Decoder
I try different random access code and preamble but the output still 0kB. Would you mind to give an example or reference about it? On Sun, May 24, 2015 at 2:09 AM, Surya Agam surya11.01a...@gmail.com wrote: Would you mind to give an example or reference about it? I try random bit but I still have nothing. Surya On Sat, May 23, 2015 at 2:57 PM, Laur Joost darem...@gmail.com wrote: I'm away from my computer right now, so I can't verify anything. But here's what I remeber from getting it to work. For testing whether it works, just set them to a bunch of 1-s and 0-s. Preamble is used by the demodulator for carrier and symbol timing recovery, so it should have many transitions and be long enough to give the recovery loops time to lock (I think I tried 32 bits and it worked). Access code is used to detect the start of packet after the preamble, so it should have low autocorrelation, i.e. it should be as different as possible from shifted versions of itself (Meaning, don't set it to 10101010. It could work when simulating perfect signals, but it's a Bad Idea). There are criteria and methods for selecting good ones for both, check the relevant Wikipedia articles for relevant articles :D All the best Laur 23.05.2015 9:49 kirjutas kuupäeval Surya Agam surya11.01a...@gmail.com : I leave it blank. My setting for Encoder is Sample/Symbol = 2 Bit/Symbol = 1 (based on documentation for BPSK) preamble = blank access code = blank USRP pad = no Payload Strength = 0 My Decoder Access code = blank Threshold = -1 How to set the preamble and access code? Surya On Sat, May 23, 2015 at 11:37 AM, Laur Joost darem...@gmail.com wrote: Have you set the preamble and access code? The leave blank for automatic didn't work for me. Laur 23.05.2015 6:53 kirjutas kuupäeval Surya Agam surya11.01a...@gmail.com: Hello everyone, I want to simulate file transmission using BPSK modulation, with block diagram File Source -- Packet Encoder -- BPSK Mod -- BPSK Demod -- Packet Decoder -- File Sink But the result is 0 kB. Then I remove the Encoder-Decoder and Modulation block. File Source -- File Sink Then I have the file and it's operable (-5 bytes from original file) Next step I add Packet Encoder - Decoder File Source -- Packet Encoder -- Packet Decoder -- File Sink But the file size is 0 kB I don't know what is wrong with the Encoder-Decoder. Thank you Regards, Surya Agam ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio -- Sincerely, Surya Agam University Al Azhar of Indonesia, Jakarta ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] BPSK output abnormal
Oh sorry I forgot to reply to all. Now there's a new problem. I use Packet Encoder to add preamble, the setting is: Encoder - sps = 2 - bps = 1 (bpsk) - preamble = 101001000010 - access code = 101011001101110110100100111000100010100011101100 - pad for USRP = no - payload strength = 16 Decoder - access code = 101011001101110110100100111000100010100011101100 - threshold = -1 both access code and preamble are from http://gnuradio.org/doc/sphinx-3.7.2/digital/pkt_utils.html The output now become 0kB On Mon, May 25, 2015 at 10:09 PM, Tom Rondeau t...@trondeau.com wrote: On Sun, May 24, 2015 at 4:25 PM, Surya Agam surya11.01a...@gmail.com wrote: Oh thank you Tom, I can recover the file size. About frame synchronization, am I need Polyphase Clock Sync Block? And also I have no idea about You can zero-pad the input to push the samples through.? (please keep emails on the mailing list) The PFB clock sync handles symbol synchronization -- it finds where the bits are. You'll need another level of synchronization to find the start of the frame, usually by looking for a known start pattern, preamble, etc. And there are many ways to accomplish the zero-padding. I'll leave that up to you to figure out :) Tom On Mon, May 25, 2015 at 12:34 AM, Tom Rondeau t...@trondeau.com wrote: On Sun, May 24, 2015 at 4:54 AM, Surya Agam surya11.01a...@gmail.com wrote: Hi everyone, I try to simulate file transfer using BPSK with block diagram File Source -- PSK Mod -- PSK Demod -- File Sink The block setting is File Source : -file type = .jpg (282,8 kB (282.765 bytes)) -repeat = no -vec length = 1 PSK Mod : -num of constellation = 2 -gray code = yes -diff. encoding = yes -sample/symbol = 2 -excess BW = 0.35 -verbose = off =log = off PSK Demod : -num of constellation = 2 -diff. encoding = yes -sample/symbol = 2 -excess BW = 0.35 -frequency BW = 6.28/100.0 -timing BW = 6.28/100.0 -phase BW = 6.28/100.0 -gray code = yes -verbose = off -log = off File Sink -vec length = 1 -unbuffered = on -append file = overwrite The size of input file = 282,8 kB (282.765 bytes) but the size of output file = 2,3 MB (2.262.066 bytes) What's wrong with my fg? Thank you, Surya Agam The output is unpacked. So each sample only represents a single bit. You have to repack them into 8 bits per byte, but you'll also need to know where to start through some kind of frame synchronization. 282765*8 = 2262120 The rest of the difference is due to delays in the filters. You can zero-pad the input to push the samples through. Tom ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] BPSK output abnormal
Hi everyone, I try to simulate file transfer using BPSK with block diagram File Source -- PSK Mod -- PSK Demod -- File Sink The block setting is File Source : -file type = .jpg (282,8 kB (282.765 bytes)) -repeat = no -vec length = 1 PSK Mod : -num of constellation = 2 -gray code = yes -diff. encoding = yes -sample/symbol = 2 -excess BW = 0.35 -verbose = off =log = off PSK Demod : -num of constellation = 2 -diff. encoding = yes -sample/symbol = 2 -excess BW = 0.35 -frequency BW = 6.28/100.0 -timing BW = 6.28/100.0 -phase BW = 6.28/100.0 -gray code = yes -verbose = off -log = off File Sink -vec length = 1 -unbuffered = on -append file = overwrite The size of input file = 282,8 kB (282.765 bytes) but the size of output file = 2,3 MB (2.262.066 bytes) What's wrong with my fg? Thank you, Surya Agam ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Error using Packet Encoder -- Packet Decoder
Hello everyone, I want to simulate file transmission using BPSK modulation, with block diagram File Source -- Packet Encoder -- BPSK Mod -- BPSK Demod -- Packet Decoder -- File Sink But the result is 0 kB. Then I remove the Encoder-Decoder and Modulation block. File Source -- File Sink Then I have the file and it's operable (-5 bytes from original file) Next step I add Packet Encoder - Decoder File Source -- Packet Encoder -- Packet Decoder -- File Sink But the file size is 0 kB I don't know what is wrong with the Encoder-Decoder. Thank you Regards, Surya Agam ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
