Multiple reception simultaneously

Hi,
i am trying if its possible to do reception of FM signals at the same
time
and produce the output at the same instant in different loudspeakers.i
mean
whether its possible to tune to multiple FM channels at the same time
and
hear those channels at mutlipe output simultaneously.i also want to try
this
out in video signals.but i found that colour decoding is a tedious
task.i am
new to this field.

can anybody please help me in this issue…

thanking you

Ranjini Ram

On Wed, Feb 09, 2011 at 10:03:41AM +0530, ranjini ram wrote:

Hi,
i am trying if its possible to do reception of FM signals at the same time and
produce the output at the same instant in different loudspeakers.i mean whether
its possible to tune to multiple FM channels at the same time and hear those
channels at mutlipe output simultaneously.i also want to try this out in video
signals.but i found that colour decoding is a tedious task.i am new to this

Depends on what kind of hardware you have. The simplest way–and using
only one USRP–is to increase the incoming bandwidth, and select the
individual channels by a decimating, and frequency x-lating, filter.
Then you send those signals through parallel demodulators und dump the
result on an audio sink each (from your question, I’m assuming you have
two soundcards). Or you could put one station on the left and one on the
right speaker by using different inputs of one audio sink.

This is less computationally intensive if the stations are close
together. Say you have one station at 100MHz and one at 101MHz, simply
tune to 100.5MHz, sample at 2MS/s and yank a 200kHz section at
+/-500kHz offset each; then pass that to the FM demodulator.

If you’re new to GR, definitely use gnuradio-companion.

MB

Karlsruhe Institute of Technology (KIT)
Communications Engineering Lab (CEL)

Dipl.-Ing. Martin B.
Research Associate

Kaiserstraße 12
Building 05.01
76131 Karlsruhe

Phone: +49 721 608-43790
Fax: +49 721 608-46071
www.cel.kit.edu

KIT – University of the State of Baden-Württemberg and
National Laboratory of the Helmholtz Association

On Tue, Feb 8, 2011 at 11:33 PM, ranjini ram [email protected]
wrote:

thanking you

Ranjini Ram

Look into using the pfb_channelizer_ccf block (it is not in gnuradio
companion, yet). Make the USRP capture wide enough to receive multiple
channels and pass this to the channelizer with the appropriate
settings. For N channels, you get N outputs of the channelizer. Each
should be 200 kHz wide that you can send to an FM demodulator path.

Tom