Re: [Discuss-gnuradio] CPFSK mod/demod + strange behavior

2016-06-10 Thread Achilleas Anastasopoulos
Olivier, the link you gave us does not work. It says: " *That file isn’t here anymore * Someone might’ve deleted the file or disabled the link " Achilleas PS: I attach here a simple simulation grc file for you to "play" with. If you are not clear about it there is no point going on with more co

Re: [Discuss-gnuradio] CPFSK mod/demod + strange behavior

2016-06-10 Thread Mark Napier
Hey Olivier, I hoped you pulled that file back off quickly. By publicly posting the file and password you violated the crap out of the license agreement to RTCA and linked your name to the act. Mark *From*: Olivier Goyette *Subject*: Re: [Discuss-gnuradio] CPFSK mod/demod + strange

Re: [Discuss-gnuradio] CPFSK mod/demod + strange behavior

2016-06-10 Thread Mark Napier
Date: Thu, 9 Jun 2016 15:24:37 -0400 From: Olivier Goyette To: discuss-gnuradio@gnu.org Subject: Re: [Discuss-gnuradio] CPFSK mod/demod + strange behavior Message-ID: Content-Type: text/plain; charset="utf-8" My flowgraph is based on what I've read throughout the differe

Re: [Discuss-gnuradio] CPFSK mod/demod + strange behavior

2016-06-10 Thread Olivier Goyette
As promised, I'm giving the documentation I talked about yesterday and hop it will clarify some of the things we discussed earlier. https://www.dropbox.com/s/1blrausidm66tg4/DO-282B%20with%20Corrigendum%201_bx87er.pdf?dl=0 the password is bx87er on page 23, you will find what the transmission sp

Re: [Discuss-gnuradio] CPFSK mod/demod + strange behavior

2016-06-10 Thread Achilleas Anastasopoulos
Olivier, can you point EXACTLY at the reference (page no, etc so we don't have to search) where it requires an RRC after the CPFSK and an RRC at the input of the receiver. Achilleas On Thu, Jun 9, 2016 at 3:04 PM, Achilleas Anastasopoulos wrote: > Why are you using the RRC filters? > > I hope

Re: [Discuss-gnuradio] CPFSK mod/demod + strange behavior

2016-06-10 Thread Achilleas Anastasopoulos
Marcus, any PAM signal with symbol rate R can be transmitted using bandwidth R/2 (essentially a sinc pulse; this is the case when you put 0 as the roll-off factor of an RRC). I thought your comment was not specifically for CPFSK, but general transmission schemes thus my clarification. If it is

Re: [Discuss-gnuradio] CPFSK mod/demod + strange behavior

2016-06-10 Thread Marcus Müller
Hi Olivier, On 10.06.2016 03:06, Olivier Goyette wrote: > Excuse me for not understanding everything, but there seem to be a > lack of comprehension coming from me. > > 1- Where is your "625 kHz" coming from ? 2x312.5kHz, your FSK deviation, and what looks like to be about your filter bandwidth! >

Re: [Discuss-gnuradio] CPFSK mod/demod + strange behavior

2016-06-09 Thread Olivier Goyette
Excuse me for not understanding everything, but there seem to be a lack of comprehension coming from me. 1- Where is your "625 kHz" coming from ? 2- The links I provided are only the reference where I took the information for trying to build things up. I didn't include the link where it specifies

Re: [Discuss-gnuradio] CPFSK mod/demod + strange behavior

2016-06-09 Thread Marcus Müller
Hi Olivier! On 10.06.2016 00:05, Olivier Goyette wrote: > > You are wrong ! > That being the case very often, I think the error's on your side, this time :) So, I will need you to *explain* how you can transport 1.somethingMb/s through a 625kHz wide channel if every time you use that channel to tr

Re: [Discuss-gnuradio] CPFSK mod/demod + strange behavior

2016-06-09 Thread Olivier Goyette
You are wrong ! 1 sample/symbol is when I run simulation (no transmission over the air). When I want to transmit over the air ( cable between Tx and Rx ) I need to use 6 samples/symbol. This is what I've told earlier, 1 sps is the only way I could send a message and retrieve it at the end of the

Re: [Discuss-gnuradio] CPFSK mod/demod + strange behavior

2016-06-09 Thread Marcus Müller
Re: 1) Well, if this doesn't work on a stream with sps>1, it's no use trying it over the air. You just get additional problems! Also, I kind of doubt you should use the term FSK for something that is only one sample long – a single sample doesn't have a frequency, right? Re: 3) wait! You have a bi

Re: [Discuss-gnuradio] CPFSK mod/demod + strange behavior

2016-06-09 Thread Olivier Goyette
My flowgraph is based on what I've read throughout the different forums on the internet because : 1- I'm a newbie to GRC and GNUradio in general 2- It's my first time trying to develop a telecomm application 3- I'm using a RRC filter because it's a requirement stated in the documentation I have ab

Re: [Discuss-gnuradio] CPFSK mod/demod + strange behavior

2016-06-09 Thread Achilleas Anastasopoulos
Why are you using the RRC filters? I hope you are realizing that filtering a CPFSK signal is not the same as filtering its instantaneous frequency (which is a PAM signal with rectangular pulses). As a result, the next question is why in your poly-phase filter you are using RRC filter taps? Achill

Re: [Discuss-gnuradio] CPFSK mod/demod + strange behavior

2016-06-09 Thread Marcus Müller
Hi Olivier, trying to catch up with you here. I've got a few questions! Please excuse if they've been answered by you before; it's not really easy to navigate your emails – hint: it gets easier for us to help you if you use the "reply" button in your email client, so that things get clearly sorted

[Discuss-gnuradio] CPFSK mod/demod + strange behavior

2016-06-09 Thread Olivier Goyette
Something else I observed : https://www.dropbox.com/s/ztlyujesvjlwexy/Receiver2.png?dl=0 . The data seems to be mixed with the carrier, am I right ? We see like an AM modulation in the upper graph. Is there a way to eliminate the carrier's presence ? Thanks Olivier ___

[Discuss-gnuradio] CPFSK mod/demod + strange behavior

2016-06-09 Thread Olivier Goyette
I think I might have something at my receiver, but I'm not sure how to deal with it. If you take a look at this picture : https://www.dropbox.com/s/sp1hrhl8qgj2xct/Receiver.png?dl=0 , we clearly see 2 spikes centered at + 312.5kHz and - 312.5kHz. That's what I should have. The upper graph is the ou

Re: [Discuss-gnuradio] CPFSK mod/demod + strange behavior

2016-06-09 Thread Tomaž Šolc
On 08. 06. 2016 14:59, Olivier Goyette wrote: > 1st concern : when I enable the rational resampler with > Interpolation set to : baud_rate and Decimation set to : sample_rate, > GRC seems to not execute the flowgraph at all as if the calculations > were too big ?! Since *sample_rate* / *baud_rate*

[Discuss-gnuradio] CPFSK mod/demod + strange behavior

2016-06-08 Thread Olivier Goyette
Hello dear community ! I'm actually trying to develop an application with GRC that does CPFSK mod/demod but I haven't got some satisfying results yet and I hope you will be able to get me back in the right way. The flowgraph i've made ( https://www.dropbox.com/s/6vuyleerbwl3df2/UAT.png?dl=0) is b