[Discuss-gnuradio] Frequency Hopping/ center frequency /time
From:
Hanno Jung
Subject:
[Discuss-gnuradio] Frequency Hopping/ center frequency /time
Date:
Tue, 8 Dec 2009 12:43:49 +0100
Hi out there,
I have several questions on Frequency Hopping.
I'm trying to send a constant with the *_siggen.py files on different frequencies in short intervalls. Because those frequencies are spread over a band of 25MHz I need to change the center frequency of the board very fast(within micro seconds).
Now the question.
Is the usrp1/2 capable of this via the functions in python? How much time does the usrp need to change the center frequency?
I have read a few articles abut the minimal available time interval on desktop pcs. On ubuntu (hardy) there is a file called /usr/src/linux-Headers-2.6.24-25/kernel/Kconfig.hz where I can adjust the "Timer Interrupt Frequency Configuration" which allows 1000Hz which represents 0.001 seconds. (important for python timer functions)
Now the question. Is this 0.001 s limit really the shortest time span available for this pc? It seems to be too long. Is there an other possibility to send ~8 carriers distributed over a bandwitdh of 25MHz without preprocessed data?
Realtime/Frequency Hopping (tH=~several micro seconds)