[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Discuss-gnuradio] How to generate a FM signal?
From: |
nansai hu |
Subject: |
Re: [Discuss-gnuradio] How to generate a FM signal? |
Date: |
Tue, 27 Oct 2009 11:27:04 -0400 |
I just want to do a demo about two radios in one USRP by time divition, both are FM&FH, but with the intention to distingrish these radios,the FM deviation and FH hop step should be different.Now I could control the hop step,but the FM deviation can't be controled(FM deviation should be12.5K and 25K,which input to max_dev in WBFM module)
2009/10/26 Josh Blum
<address@hidden>
nansai hu wrote:
I appracite you could tell me what is the meaning of following paramaters:
address@hidden audio_rate: sample rate of audio stream, >= 16k
address@hidden audio_rate: integer
address@hidden quad_rate: sample rate of output stream
address@hidden quad_rate: integer
This is the input and output rates of the block.
address@hidden tau: preemphasis time constant (default 75e-6)
address@hidden tau: float
address@hidden max_dev: maximum deviation in Hz (default 75e3)
address@hidden max_dev: float
No idea, check the source, but the default values are good to get a working wbfm radio.
I try to change the max_dev from 10 to 1000,and give it to a usrp source as
baseband signal,
For transmit, the usrp expects numbers between +/- 2**15. Your transmit amplitude should be on the order of 10k. What are you sending it?
-Josh
but, the bandwith on spectrum analyize don not change.How to change
deviation of a fm signal?
2009/10/26 nansai hu <address@hidden>
I tried to run your code wfm, but there is nothing happened in my spectrum
analyzer.
I am just wondering that your code is in baseband or how to add a carrier
freq by usrp source.
2009/10/24 Josh Blum <address@hidden>
nansai hu wrote:
Is anybody had a experiment about How to generate a FM signal?
Use the wideband and/or narrowband fm blocks; just specify your data
rates.
http://gnuradio.org/cgit/gnuradio.git/tree/gnuradio-core/src/python/gnuradio/blks2impl
or tell me how to use FM MOD or VCO module in GRC, what is the paramater
sensitive means?
check the source :-)
-Josh