Re: [Discuss-gnuradio] OFDM modulator and pilots

On Fri, Aug 27, 2010 at 12:19:53PM -0400, Srinivas wrote: > > Another related question is: Who sets the parameters for the work function > in this block ? particularly noutput_samples. > Srinivas, The parameters passed to work are determined by the GR runtime system. Their values depend on a lo

Re: [Discuss-gnuradio] OFDM modulator and pilots

Tom After reading gr_ofdm_insert_preamble.cc it looks like the pilots are sent periodically after every few payload symbols on all frequency bins. Is it like what I have shown attached ? If yes, then how may payload symbols are sent between two pilots ? Another related question is: Who sets the p

Re: [Discuss-gnuradio] OFDM modulator and pilots

On Tue, Aug 10, 2010 at 9:53 AM, Marcin Szelest wrote: > Hello, > > > I'm trying to add pilots to an OFDM modulation, is it possible with OFDM_mod > block? > How I can "boost" energy of pilot in OFDM signal? > > Regards, > Marcin > http://szelest.org Yes, this is possible. There is a subcarrier m

[Discuss-gnuradio] OFDM modulator and pilots

Hello, I'm trying to add pilots to an OFDM modulation, is it possible with OFDM_mod block? How I can "boost" energy of pilot in OFDM signal? Regards, Marcin http://szelest.org ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.

Re: [Discuss-gnuradio] OFDM tunnel.py HELP REQUIRED

To follow up with Chuck's question, I'm also having problem running tunnel using OFDM. The individual transmissions between the 2 USRPs were fine (albeit that I had to manually adjust the center frequency of 1 USRP (A) to cope with the frequency offset). I had B operating at 2412MHz and A at 2411.9

Re: [Discuss-gnuradio] OFDM spectrum with power rolloff?

On 07/23/2010 09:38 AM, George Nychis wrote: One last question still, do you know where I am missing a factor of two here: 1) My calculation of the bandwidth of the 100 active bins, and the actual bandwidth, is off by a factor of two: (((100 MHz) / 32) / 1024) * 100 = 305.175781 kilohertz, wher

Re: [Discuss-gnuradio] OFDM spectrum with power rolloff?

Thanks a bunch for your response, Matt! > > Since you are using an interpolation is a multiple of 4, you won't see CIC > rolloff, you get a nice flat passband. > Got ya! > There are likely a couple of issues causing the spectrum to look bad. > First, successive symbols coming out of the FFT

Re: [Discuss-gnuradio] OFDM spectrum with power rolloff?

On 07/22/2010 11:51 PM, George Nychis wrote: Hi all, I am generating my own "OFDM" waveform which actually does not modulate anything. Step by step. I am simulating 1024 subcarriers but first generating 1024 zeros, and then I want to only enable the center 100 subcarriers. To do this, I map t

[Discuss-gnuradio] OFDM spectrum with power rolloff?

Hi all, I am generating my own "OFDM" waveform which actually does not modulate anything. Step by step. I am simulating 1024 subcarriers but first generating 1024 zeros, and then I want to only enable the center 100 subcarriers. To do this, I map the center frequency at the first index in the a

Re: [Discuss-gnuradio] OFDM receiver on USRP2

Sorry for bringing up an old thread. I was having the same problem of not receiving packets using benchmark_ofdm_* and changing the receiver frequency to tune to the transmitter frequency indeed solved the problem. However, if I have to manually do it every time, I don't see how I can get ofdm tun

[Discuss-gnuradio] OFDM tunnel.py HELP REQUIRED

Hi,For past one week I have been trying to run tunnel.py in ofdm folder. I have successfully run tunnel.py in digital folder as well as benchmark_ofdm_*.py with 0 packet loss.I have tried different set of parameter settings but to no avail. If any body has successfully ran the tunnel.py in ofdm

Re: [Discuss-gnuradio] OFDM with fft lenght 2048 and 4096 doesn't work

could you try a smaller number of fft sub carriers (e.g., fft=128, occupied=80, cp=32, i/d=32)? usually this works better than an ofdm with a large number of carriers. this might be because the frequency offset of the radio becomes comparable to the bin size when the number of sub carriers is large

Re: [Discuss-gnuradio] OFDM with fft lenght 2048 and 4096 doesn't work

On Mon, Jun 21, 2010 at 9:05 AM, Chris_Spain wrote: > > Hello I'm trying to send with benchmark_ofdm_tx and receive with > benchmark_ofdm_rx a OFDM modulation with next paremeters: > > FFT lenght = 2048 > Chanel occupied = 1512 > Size of package = 1024 > CP_adder = 128 > > and > > FFT lenght = 409

[Discuss-gnuradio] OFDM with fft lenght 2048 and 4096 doesn't work

Hello I'm trying to send with benchmark_ofdm_tx and receive with benchmark_ofdm_rx a OFDM modulation with next paremeters: FFT lenght = 2048 Chanel occupied = 1512 Size of package = 1024 CP_adder = 128 and FFT lenght = 4096 Chanel occupied = 3024 Size of package = 1024 CP_adder = 128 I'm using

Re: [Discuss-gnuradio] ofdm reception affected by python threading?

On Fri, May 28, 2010 at 04:10:12PM -0700, Veljko Pejovic wrote: > Hi Eric, > > Thanks for the tip. I tried it out on a faster machine, and I observed > no such problems. The first machine that produces this problem has a > single core 2.8GHz CPU and the second one, which works fine, has a > dual c

Re: [Discuss-gnuradio] ofdm reception affected by python threading?

Hi Eric, Thanks for the tip. I tried it out on a faster machine, and I observed no such problems. The first machine that produces this problem has a single core 2.8GHz CPU and the second one, which works fine, has a dual core Intel Atom D510, both machines have 2GB of RAM each. I should note that

Re: [Discuss-gnuradio] ofdm reception affected by python threading?

On Fri, May 21, 2010 at 02:15:15PM -0700, Veljko Pejovic wrote: > Hi, > > I'm using two USRP2 with XCVR2450s, a week old gnuradio git master and > Ubuntu 9.10. > > A few months ago while using the OFDM code I observed that I tend to > receive (or send?) packets in groups, although I was sending t

[Discuss-gnuradio] ofdm reception affected by python threading?

Hi, I'm using two USRP2 with XCVR2450s, a week old gnuradio git master and Ubuntu 9.10. A few months ago while using the OFDM code I observed that I tend to receive (or send?) packets in groups, although I was sending them individually. Now, I finally isolated the problem. I added a few simple p

[Discuss-gnuradio] OFDM Transceiver

Hello, I have a USRP1 with two RFX2400 cards and I'm trying to implement a OFDM transceiver. So, having as reference the two examples benchmark_ofdm_tx and benchmark_ofdm_rx, I made a new script. Both blocks are taking the same parameters (freq, gain, fusb block size, fusb nblocks...). The __init

[Discuss-gnuradio] OFDM with arbitrary modulations

This might be relevant to the "ofdm occupied tones concept" thread on this list. I have uploaded some code on github that implements an OFDM tx/rx with arbitrary modulation schemes per carrier. The user specifies a list of constellations (say, zeros, or pilots or QPSK or 16QAM) and then the index

Re: [Discuss-gnuradio] ofdm occupied tones concept

On 05/03/2010 08:09 AM, Tom Rondeau wrote: On 5/3/2010 1:48 AM, George Nychis wrote: On Sun, May 2, 2010 at 4:08 AM, jf w mailto:jfwang...@gmail.com>> wrote: Hi all, I'm thinking about implementing non-contiguous OFDM with gnuradio. So I read the ofdm codes of gnuradio. And I find the occupie

Re: [Discuss-gnuradio] ofdm occupied tones concept

George, > Since the code they built to do the NC-OFDM was based originally on the > code inside GNU Radio, doesn't it make sense to put that back into GNU Radio > instead of CGRAN? The way that I originally wrote the code was to allow for > people to do this by manipulating the subcarrier map, so

Re: [Discuss-gnuradio] ofdm occupied tones concept

On 5/3/2010 1:48 AM, George Nychis wrote: On Sun, May 2, 2010 at 4:08 AM, jf w > wrote: Hi all, I'm thinking about implementing non-contiguous OFDM with gnuradio. So I read the ofdm codes of gnuradio. And I find the occupied tones concept in gnuradi

Re: [Discuss-gnuradio] ofdm occupied tones concept

On Sun, May 2, 2010 at 4:08 AM, jf w wrote: > Hi all, > > I'm thinking about implementing non-contiguous OFDM with gnuradio. So I > read the ofdm codes of gnuradio. And I find the occupied tones concept in > gnuradio. Is it designed for non-contiguous OFDM? Or it is for other > reasons > There

[Discuss-gnuradio] ofdm occupied tones concept

Hi all, I'm thinking about implementing non-contiguous OFDM with gnuradio. So I read the ofdm codes of gnuradio. And I find the occupied tones concept in gnuradio. Is it designed for non-contiguous OFDM? Or it is for other reasons? -- Thanks, Jianfei BUAA _

[Discuss-gnuradio] OFDM modulation in grc

Iam trying the OFDM modulation and loopback in grc and not able to see modulated output and message signal in oscilloscope sink.grc codes are attached for both. can any one help me in buiding ofdm(mod, demod, loopback , ofdm transmit to USRP sink and ofdm rx through another USRP source ) in grc --

Re: [Discuss-gnuradio] OFDM receiver on USRP2

On 2/20/2010 7:43 PM, Srinivas wrote: Hi Tom, I tried increasing the bandwidth of the filter and also tried changing the window type to KAISER, but it didn't improve on the offset error. I am getting a constant frequency offset value "-10". Currently, I am just compensating for the offset at

Re: [Discuss-gnuradio] OFDM receiver on USRP2

Hi Tom, I tried increasing the bandwidth of the filter and also tried changing the window type to KAISER, but it didn't improve on the offset error. I am getting a constant frequency offset value "-10". Currently, I am just compensating for the offset at the receiver or specifying a minimum BW to

Re: [Discuss-gnuradio] OFDM receiver on USRP2

On Thu, Feb 18, 2010 at 12:49 AM, Srinivas wrote: > Hi Tom, Matt > > replied inline: > > On Wed, Feb 17, 2010 at 10:26 AM, Tom Rondeau > wrote: >> >> On Tue, Feb 16, 2010 at 5:45 PM, Srinivas wrote: >> > Matt, >> > >> > Thanks for verifying the data rate calculation! >> > >> > I tried the other

Re: [Discuss-gnuradio] OFDM receiver on USRP2

Hi Tom, Matt replied inline: On Wed, Feb 17, 2010 at 10:26 AM, Tom Rondeau wrote: > On Tue, Feb 16, 2010 at 5:45 PM, Srinivas wrote: > > Matt, > > > > Thanks for verifying the data rate calculation! > > > > I tried the other solutions that you suggested, namely, > > > > - increasing the data ra

Re: [Discuss-gnuradio] OFDM receiver on USRP2

On Tue, Feb 16, 2010 at 5:45 PM, Srinivas wrote: > Matt, > > Thanks for verifying the data rate calculation! > > I tried the other solutions that you suggested, namely, > > - increasing the data rate by a factor of 2 or 4 > It works. > > - modifying the OFDM code to widen the search range - How do

Re: [Discuss-gnuradio] OFDM receiver on USRP2

On 02/16/2010 02:45 PM, Srinivas wrote: Matt, Thanks for verifying the data rate calculation! I tried the other solutions that you suggested, namely, *- increasing the data rate by a factor of 2 or 4 *It works. * - modifying the OFDM code to widen the search range* - How do I widen the search

Re: [Discuss-gnuradio] OFDM receiver on USRP2

Matt, Thanks for verifying the data rate calculation! I tried the other solutions that you suggested, namely, *- increasing the data rate by a factor of 2 or 4 *It works. * - modifying the OFDM code to widen the search range* - How do I widen the search range ? Should I be looking in the "ofdm_s

Re: [Discuss-gnuradio] OFDM receiver on USRP2

That formula will give you the number of occupied tones per second. You need to multiply by the number of bits per tone to get bps. If you are using BPSK, multiply by 1. If using QPSK, you'll need to multiply by 3, 8PSK by 3, etc. I meant to say: BPSK - multiply by 1 QPSK - mult by 2 (not 3

Re: [Discuss-gnuradio] OFDM receiver on USRP2

On 02/12/2010 03:53 PM, Srinivas wrote: Matt, There was a frequency offset of ~30 KHz at the Rx w.r.t Tx so I compensated for it and it worked!. The settings I am using is as follows: ./benchmark_ofdm_tx.py -f 2.45G --tx-amplitude 0.9 -M 8 -s 200 -m bpsk --fft-length=512 --occupied-tones=80 -i

Re: [Discuss-gnuradio] OFDM receiver on USRP2

Matt, There was a frequency offset of ~30 KHz at the Rx w.r.t Tx so I compensated for it and it worked!. The settings I am using is as follows: ./benchmark_ofdm_tx.py -f 2.45G --tx-amplitude 0.9 -M 8 -s 200 -m bpsk --fft-length=512 --occupied-tones=80 -i 64 --tx-gain=10 --cp-length=128 ./benchma

Re: [Discuss-gnuradio] OFDM receiver on USRP2

On 02/11/2010 04:45 PM, Srinivas wrote: Hi All, I have 2 pairs of USRP2s with GNURadio-3.2 installed on their hosts. On one pair I am able to successfully run OFDM (benchmark_ofdm_tx & rx) with almost 95+% packet success rate. However on the other pair I am not receiving even 1 packet! I am usi

[Discuss-gnuradio] OFDM problem with USRP and GRC

Hi all I am trying OFDM transmission and receive test. I’m using Ubuntu 9.10, gnuradio version 3.3 and two USRP boards with basic TX and RX and I am using GRC. In the GRC I make simple test signal flow with usrp Tx : File source -> OFDM mod -> USRP sink Rx : USRP source-> OFDM demod

Re: [Discuss-gnuradio] OFDM modulation/demodulation over USRP2

; Patrik Eliardsson >> >>> -Original Message- >>> From: >>> discuss-gnuradio-bounces+patrik.eliardsson=foi...@gnu.org >>> [mailto:discuss-gnuradio-bounces+patrik.eliardsson=foi...@gnu. >>> org] On Behalf Of Veljko Pejovic >>> Sent: We

Re: [Discuss-gnuradio] OFDM modulation/demodulation over USRP2

io-bounces+patrik.eliardsson=foi...@gnu. >> org] On Behalf Of Veljko Pejovic >> Sent: Wednesday, January 13, 2010 10:22 PM >> To: discuss-gnuradio@gnu.org >> Subject: [Discuss-gnuradio] OFDM modulation/demodulation over USRP2 >> >> Hi, >> >> I&

RE: [Discuss-gnuradio] OFDM modulation/demodulation over USRP2

ss-gnuradio-bounces+patrik.eliardsson=foi...@gnu.org > [mailto:discuss-gnuradio-bounces+patrik.eliardsson=foi...@gnu. > org] On Behalf Of Veljko Pejovic > Sent: Wednesday, January 13, 2010 10:22 PM > To: discuss-gnuradio@gnu.org > Subject: [Discuss-gnuradio] OFDM modulation/demodulation

[Discuss-gnuradio] OFDM modulation/demodulation over USRP2

Hi, I'm using Ubuntu 9.10, gnuradio version 3.2.2 and two USRP2 boards with XCVR2450 daughter boards. The boards are about a meter apart from each other. I'm trying to get OFDM working over USRP2 boards and for that I'm using GRC. I created a simple local loop (without USRPs): signal_source->modu

[Discuss-gnuradio] OFDM tranceiver not responding as intended on USRP2

Hi All, I am implementing a OFDM tranceiver. I am following the benchmark.py and tunnel.py for achieving it. I am facing the following problems while performing receive--> transmit--> receive: 1.It receives on the startup of the code. 2.It transmits and then it does not receive at all. I hav

[Discuss-gnuradio] Ofdm spectrum

Hello everyone, I was trying to implement some OFDM transmission with a rfx2400 without using the ofdm code that comes with gnuradio but creating my own one. I make a 256 bean Ifft transform after the windowing, and I've tried two different types of window the rectangular one (aka no window :)

[Discuss-gnuradio] ofdm - adjust subcarriers

Hi out there, I'm trying to send an ofdm signal. I don't want to tramsit any data, I only want to see the reslting spectrum. Now I'm wondering how to turn off certain carriers. I know this is possible by adjusting the transmitted data but is there a better way to do this? For example by commandl

[Discuss-gnuradio] OFDM IFFT question

Hi, I found the OFDM IFFT caculation is very different from what I got in MATLAB. In detail, my command is shown below ./benchmark_ofdm_tx.py -f 10M -i 512 --fft-length=64 --occupied-tones=32 --cp-length=4 (bpsk) The packet size is 8 bits, after a serials of operation, it added 4 bytes in

Re: [Discuss-gnuradio] OFDM block in GRC

On Fri, Jul 31, 2009 at 12:52:44AM +, maher manai wrote: > > i'm working on wlan system wich is 802.11a/g it use OFDM mod . in > GRC i found a ofdm mod block wich contains mod type ,ifft , cyclic > prefix but i think it doesn't support the number of subcarrier > pilots and there position wich a

[Discuss-gnuradio] OFDM block in GRC

i'm working on wlan system wich is 802.11a/g it use OFDM mod . in GRC i found a ofdm mod block wich contains mod type ,ifft , cyclic prefix but i think it doesn't support the number of subcarrier pilots and there position wich are 4 pilots . so i ask if smeone can explain to me if there is any s

[Discuss-gnuradio] OFDM modulator o/p sampling rate

i am trying to transmit sound through OFDM system using the USRP i was able to transmit and receive audio in OFDM system without the USRP and also was able to transmit and receive audio using the USRP without OFDM when i try to merge the 2 system using the scope i see that there is a signal bef

[Discuss-gnuradio] OFDM Timout

sorry if i keep asking a lot of questions but this time i tried google 1st and didn't find a solution to my problem i am trying to transmit audio through ofdm modulator then USRP then from the Rx of the USRP (same USRP) to OFDM demod to audio sink i am using basic Tx and basic Rx connected to ea

Re: [Discuss-gnuradio] OFDM Mod C++ source code

On Wed, Jul 8, 2009 at 14:02, Abdalla Sokar wrote: > i downloaded gnuradio from the update manager not from the source > and when i searched for gr_ofdm i only found the .h files but i need the > .cpp files Do: $ apt-get source gnuradio Johnathan _

Re: [Discuss-gnuradio] OFDM Mod C++ source code

-gnuradio] OFDM Mod C++ source code To: "discuss-gnuradio@gnu.org" Date: Wednesday, July 8, 2009, 5:52 PM try something like: $ find [gnuradio-build-tree-path] -name gr_ofdm* find, grep and others are friendly, you just have to talk to them... So are the man- pages =;oP //Mattias > &g

Re: [Discuss-gnuradio] OFDM Mod C++ source code

try something like: $ find [gnuradio-build-tree-path] -name gr_ofdm* find, grep and others are friendly, you just have to talk to them... So are the man- pages =;oP //Mattias > > how can i get the C++ source code of the blocks in GRC > i mainly need that of the OFDM mod and demod i tried browsing

[Discuss-gnuradio] OFDM Mod C++ source code

how can i get the C++ source code of the blocks in GRC i mainly need that of the OFDM mod and demod i tried browsing "browse source" tab in gnuradio.org but it is something like a tree where i dont understand any thing can any one plz help _

Re: [Discuss-gnuradio] OFDM benchmark - premature termination

Katy Qian wrote: Hi, For the majority of my tests (ex. below), with benchmark_ofdm_*, the receiver terminates prematurely with: ... ok: True pktno: 7501 n_rcvd: 4537n_right: 4263 ok: True pktno: 7502 n_rcvd: 4538n_right: 4264 ok: True pktno: 7503 n_rcv

[Discuss-gnuradio] OFDM benchmark - premature termination

Hi, For the majority of my tests (ex. below), with benchmark_ofdm_*, the receiver terminates prematurely with: ... ok: True pktno: 7501 n_rcvd: 4537n_right: 4263 ok: True pktno: 7502 n_rcvd: 4538n_right: 4264 ok: True pktno: 7503 n_rcvd: 4539n_right:

Re: [Discuss-gnuradio] OFDM Updates

adib_sairi wrote: adib_sairi wrote: thanks Eric.. now i am trying to install from the trunk (revision 10978). i am using fedora 9. ./bootstrap command was success but ./configure give me an error. it tell be that i dont have the boost package. I think i had install the boost package using yu

Re: [Discuss-gnuradio] OFDM Updates

adib_sairi wrote: > > > > thanks Eric.. now i am trying to install from the trunk (revision 10978). > i am using fedora 9. ./bootstrap command was success but ./configure give > me an error. it tell be that i dont have the boost package. I think i had > install the boost package using yum inst

Re: [Discuss-gnuradio] OFDM Updates

Eric Blossom wrote: > > > > If you mean that you have local changes that are based on the 3.1.3 > tarball, then the most straight-forward way to handle this is to > generate a "diff -u" between the unmodified 3.1.3 source and your > modified source, then apply that difference to a virgin copy

[Discuss-gnuradio] OFDM blocks now in GRC

I just added the blks2.ofdm_mod/demod blocks to GRC in the gnuradio trunk. svn up! The generated code looks a bit odd... but so are the OFDM blocks: - options class containing parameters to ofdm mod and demod (why not *args and **kwargs?) - no input stream to ofdm mod, has a send_pkts functio

[Discuss-gnuradio] OFDM implementation problem

From: Tushar Patel To: discuss-gnuradio-requ...@gnu.org, j...@joshknows.com, wcn_s...@googlegroups.com Date: Wed, 11 Mar 2009 17:10:41 -0700 Subject: OFDM example HI all, I try to run OFDM example which is build in gnu-radio example packages. Actually there is no READ ME file in it, so do not unde

Re: [Discuss-gnuradio] OFDM Updates

On Mon, Feb 02, 2009 at 08:45:37PM -0800, adib_sairi wrote: > > > I had download the whole trunk (Revision 10377) but i cannot run the > example in it (benchmark_ofdm_tx.py) and i think it is because i does not > merge it with my GNU Radio yet. I use GNU Radio 3.1.3. how can i merge the > trunk

Re: [Discuss-gnuradio] OFDM Updates

I had download the whole trunk (Revision 10377) but i cannot run the example in it (benchmark_ofdm_tx.py) and i think it is because i does not merge it with my GNU Radio yet. I use GNU Radio 3.1.3. how can i merge the trunk with my gnu radio? can you help me for this? thank you. adib Eric Blo

Re: [Discuss-gnuradio] OFDM Updates

On Mon, Feb 02, 2009 at 06:53:32PM -0800, adib_sairi wrote: > > > oh ok.. so do i need to copy the whole trunk to run the example? or do i > need to copy the whole library (rev @9989)? $ svn co http://gnuradio.org/svn/gnuradio/trunk Eric ___ Discus

Re: [Discuss-gnuradio] OFDM Updates

oh ok.. so do i need to copy the whole trunk to run the example? or do i need to copy the whole library (rev @9989)? Eric Blossom wrote: > > On Fri, Jan 30, 2009 at 06:52:24AM -0800, adib_sairi wrote: >> >> hi, >> i would like to try the OFDM example but i cannot find the >> benchmark_ofdm_tx

[Discuss-gnuradio] OFDM modulator

Hi, I'm trying to implement an OFDM modulator. I've almost done but I have a question: In the new version of the ofdm.py (the one included in the trunk version, under the "dab" folder) I have to pass two inputs to the ofdm_mod class: the first of 96 bytes (depending on the numbers of the carreers)

Re: [Discuss-gnuradio] OFDM Updates

On Fri, Jan 30, 2009 at 06:52:24AM -0800, adib_sairi wrote: > > hi, > i would like to try the OFDM example but i cannot find the > benchmark_ofdm_tx.py and benchmark_ofdm_rx.py file in > /gnuradio-example/python/digital. did i search it in the wrong place or did > the file being remove from the gn

Re: [Discuss-gnuradio] OFDM Updates

hi, i would like to try the OFDM example but i cannot find the benchmark_ofdm_tx.py and benchmark_ofdm_rx.py file in /gnuradio-example/python/digital. did i search it in the wrong place or did the file being remove from the gnuradio-3.1.3.tar ? trondeau wrote: > > For anyone working with the

Re: [Discuss-gnuradio] ofdm benchmark

I think you could change the value of -d and -i and see. This is what I tried. ./benchmark_ofdm_tx.py -f 440M -T A --tx-amplitude 5000 -v -i 128 --fft-length 128 --occupied-tones 80 --cp-length 32 ./benchmark_ofdm_rx.py -f 440M -R A -v -d 64 --fft-length 128 --occupied-tones 80 --cp-length 32 A

[Discuss-gnuradio] ofdm benchmark

Hi everyone, I want to do some work in OFDM system on usrp.So I tested benchmark_ofdm_tx.py and benchmark_ofdm_rx.py. HW:USRP-PKG/XCVR2450/VERT2450 SW:ubuntu Gnuradio: svn trunk First, I run benchmark_ofdm_tx.py on one computer and observe ofdm spectrum by usrp_fft.py on another computer.

[Discuss-gnuradio] OFDM benchmark USRP padding

Hello everyone, I noticed that in the OFDM benchmark implementation, the padding for the USRP is set to false in transmit_path.py when creating the ofdm modulator, whereas in the digital/benchmark it is set to true. I do not see where else in the OFDM implementation the packets to be sent through

[Discuss-gnuradio] OFDM-Code: DC-Carriers and ofdm_mapper

Hi, I'm currently trying to get a hang of the OFDM-internals and I'm stuck in gr_ofdm_mapper_bcv. I hope someone might be able to enlighten me... First of all, how exactly does gr_ofdm_mapper_bcv decide which carriers are used? I really, really hate having to ask this kind of question when I have

[Discuss-gnuradio] OFDM output in spectrum analyzer

Hello, I am testing the OFDM trunk code 9798 in openSUSE 10.3 (i586). I run the benchmark_ofdm_tx.py script while having connected the USRP to a spectrum analyzer and to my surprise, using the default parameters of the script (those are: Modulation Type: bpsk, FFT length: 512, Occupied Tones: 200,

Re: [Discuss-gnuradio] OFDM results.

Bob McGwier wrote: The USRP is not in the same league with the USRP2. The on board oscillator is much better but external oscillators will make it even better. So the answer is a big yes, the USRP2 will be better. Actually, I need to disagree again here :) The master oscillator on the USRP1

Re: [Discuss-gnuradio] OFDM results.

Matt Ettus wrote: Jeff Brower wrote: Bob- In your sixteen QAM and other figures I see two effects. Notice just the slightest hint that arcs through the top four constellation points in the 16 QAM is not straight. This curvature is caused by nonlinearity. Your result almost surely can NOT

Re: [Discuss-gnuradio] OFDM results.

Bob- > Good to hear from you again. I am distinguishing betwen clock recovery > operations in the receiver and the oscillator feeding the down > conversion mixers. Even though there is some commonality in the sources > for these two DIFFERENT things on the USRP, implementation factors of > the

Re: [Discuss-gnuradio] OFDM results.

Jeff: Good to hear from you again. I am distinguishing betwen clock recovery operations in the receiver and the oscillator feeding the down conversion mixers. Even though there is some commonality in the sources for these two DIFFERENT things on the USRP, implementation factors of the clo

Re: [Discuss-gnuradio] OFDM results.

PROTECTED] Sent: den 6 juni 2008 09:23 To: Per Zetterberg Cc: discuss-gnuradio@gnu.org; 'Per Zetterberg' Subject: Re: [Discuss-gnuradio] OFDM results. In your sixteen QAM and other figures I see two effects. Notice just the slightest hint that arcs through the top four constellation poi

Re: [Discuss-gnuradio] OFDM results.

Jeff Brower wrote: Bob- In your sixteen QAM and other figures I see two effects. Notice just the slightest hint that arcs through the top four constellation points in the 16 QAM is not straight. This curvature is caused by nonlinearity. Your result almost surely can NOT be clock jitter.

Re: [Discuss-gnuradio] OFDM results.

Bob- > In your sixteen QAM and other figures I see two effects. > > Notice just the slightest hint that arcs through the top four > constellation points in the 16 QAM is not straight. This curvature is > caused by nonlinearity. > > Your result almost surely can NOT be clock jitter. If you had

RE: [Discuss-gnuradio] OFDM results.

> -Original Message- > From: Bob McGwier [mailto:[EMAIL PROTECTED] > Sent: den 6 juni 2008 09:23 > To: Per Zetterberg > Cc: discuss-gnuradio@gnu.org; 'Per Zetterberg' > Subject: Re: [Discuss-gnuradio] OFDM results. > > In your sixteen QAM a

Re: [Discuss-gnuradio] OFDM results.

In your sixteen QAM and other figures I see two effects. Notice just the slightest hint that arcs through the top four constellation points in the 16 QAM is not straight. This curvature is caused by nonlinearity. Your result almost surely can NOT be clock jitter. If you had a lot of clock

Re: [Discuss-gnuradio] OFDM results.

> where is the inaccuracy in sampling frequency exactly happening? > In USRP? Yes - the sampling frequency is inaccurate, because the crystal on the USRP is not oscillating at exactly 64 MHz. FYI, the samples in the plot are actually not from an USRP (I didn't record them myself) - the inaccuracy

Re: [Discuss-gnuradio] OFDM results.

iscuss-gnuradio] OFDM results. Hello Per > What is the cause of the problems. Clock jitter ?, non-linearities ? > No idea what could be the problem in your case, but maybe try also plotting the phase of all symbols in one OFDM symbol vs the offset from the central carrier. I'm cur

Re: [Discuss-gnuradio] OFDM results.

Hello Per > What is the cause of the problems. Clock jitter ?, non-linearities ? > No idea what could be the problem in your case, but maybe try also plotting the phase of all symbols in one OFDM symbol vs the offset from the central carrier. I'm currently working on DAB and I found some probl

[Discuss-gnuradio] OFDM results.

Dear all, I am experimenting with OFDM between two USRPs. Unfortunately, I am not yet able to master the gnuradio framework so I have made my own implementation. The results are given in the link below. http://www.s3.kth.se/~perz/usrp/OFDM_results.pdf How does this compare with the gnuradio OF

[Discuss-gnuradio] OFDM Modification

Hey, I add two parameters in gnuradio-core/python/ofdm.py expert.add_option("","--onoff",type ="intx", default = 0, help="set the number of use multi_constellation decision [defalut=%default]") for (i = 0 ; ihttp://lists.gnu.

[Discuss-gnuradio] OFDM Modification

Hi, I use an array to implement supporting multi-constellation scheme for OFDM system, but I got a problem in modifying the code for /trunk/ gnuradio-core/src/python/gnuradio/blks2impl/ofdm.py in which I generate a parameter multi_modulation[i][j] while i is the ith subcarrier, and j is the us

Re: [Discuss-gnuradio] OFDM serial to parallel mappping

CHIN-YA HUANG wrote: Hi, Does anyone have clear idea about how gunradio implements serial to parallel mapping since 802.11 has 52 channels? I check the gr_ofdm_mapper_bcv.cc , but still have no idea about it. In further, I want to apply an array mapping to implement that different channels us

[Discuss-gnuradio] OFDM serial to parallel mappping

Hi, Does anyone have clear idea about how gunradio implements serial to parallel mapping since 802.11 has 52 channels? I check the gr_ofdm_mapper_bcv.cc , but still have no idea about it. In further, I want to apply an array mapping to implement that different channels use different constellat

Re: [Discuss-gnuradio] OFDM Updates

rch 31, 2008 10:54 am Subject: Re: [Discuss-gnuradio] OFDM Updates To: CHIN-YA HUANG <[EMAIL PROTECTED]> Cc: discuss-gnuradio@gnu.org > I wonder if you are told several more times that it is already > released > in an svn branch if you will finally look to see how to get it? > &g

Re: [Discuss-gnuradio] OFDM Updates

to modify it. Chin-Ya - Original Message - From: Bob McGwier <[EMAIL PROTECTED]> Date: Monday, March 31, 2008 11:54 pm Subject: Re: [Discuss-gnuradio] OFDM Updates To: CHIN-YA HUANG <[EMAIL PROTECTED]> Cc: discuss-gnuradio@gnu.org > I wonder if you are told several more

Re: [Discuss-gnuradio] OFDM Updates

in-Ya - Original Message - From: Tom Rondeau <[EMAIL PROTECTED]> Date: Wednesday, March 26, 2008 9:50 am Subject: Re: [Discuss-gnuradio] OFDM Updates To: CHIN-YA HUANG <[EMAIL PROTECTED]> Cc: discuss-gnuradio@gnu.org CHIN-YA HUANG wrote: Hello Tom, Based on your information

Re: [Discuss-gnuradio] OFDM Updates

Hi Tom, Would you mind release your modified code for me as reference first? Thanks Chin-Ya - Original Message - From: Tom Rondeau <[EMAIL PROTECTED]> Date: Wednesday, March 26, 2008 9:50 am Subject: Re: [Discuss-gnuradio] OFDM Updates To: CHIN-YA HUANG <[EMAIL PROTECTED]>

Re: [Discuss-gnuradio] OFDM insufficient ports

Sarang Mandke wrote: I used Tom Rondeau's changeset 7848 and applied it to my current updated code. Currently I am getting a runtime error from ofdm sampler saying that there are "insufficient output ports". Has anyone faced a similar issue? Esp. for OFDM over air, this is a major prob. [ch

Re: [Discuss-gnuradio] OFDM Updates

merge my current branch, which will be in a few days, hopefully. Tom From: Tom Rondeau Subject:[Discuss-gnuradio] OFDM Updates Date: Thu, 07 Feb 2008 14:09:58 + User-agent: Thunderbird 2.0.0.9 (Windows/20071031) For anyone working with the OFDM code, my latest check-in t

Re: [Discuss-gnuradio] OFDM Updates

Hello Tom, Based on your information below I know the problem will be receiver. However, if I want to solve the receiver's problem. Where is the starting point you suggestion? From the gnu-radio core part? Chin-Ya From: Tom Rondeau Subject:[Discuss-gnuradio] OFDM Updates

[Discuss-gnuradio] OFDM sync ml

Hi, thank you a lot for your advice of OFDM packets. I try ofdm system with default parameters and the result is good.(PN synchronization) I have been trying to test Ofdm system shift into rx sync. The test failed when I change sync in receive.py ( for example ml). I use realese number 7324 and

Re: [Discuss-gnuradio] OFDM packets

Crespi Floriana wrote: Scrive Eric Blossom <[EMAIL PROTECTED]>: On Thu, Feb 28, 2008 at 12:51:18PM +0100, Crespi Floriana wrote: Hi, I have a problem with OFDM system. I transmit OFDM signal at 2.4 GHz, but I receive half of the total packets. Moreover, only half of the packets receive

Re: [Discuss-gnuradio] OFDM packets

Scrive Eric Blossom <[EMAIL PROTECTED]>: > On Thu, Feb 28, 2008 at 12:51:18PM +0100, Crespi Floriana wrote: > > Hi, > > I have a problem with OFDM system. > > I transmit OFDM signal at 2.4 GHz, but I receive half of the total packets. > > Moreover, only half of the packets received are correct. >

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