[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Discuss-gnuradio] Running OFDM files

From: Tom Rondeau
Subject: Re: [Discuss-gnuradio] Running OFDM files
Date: Tue, 04 Mar 2008 11:39:47 +0000
User-agent: Thunderbird (Windows/20080213)

Jose Emilio Gervilla Rega wrote:
Hello all,

I will give you more details about my problem because someone has asked me for them(thank you):

The OFDM system we are using is which is defined in this link:


The file ofdm.py is the transmitter and the other ones are receiver and synchronization modules. When I run ofdm.py which I've copied into the folder I told you on the other topic(the first one), appear some errors. If I type ./ofdm.py the output is:

./ofdm.py: line 23: import: order not found
from: can't read /var/mail/numpy
from: can't read /var/mail/gnuradio
./ofdm.py: line 26: import: order not found
from: can't read /var/mail/gnuradio.blksimpl.ofdm_receiver
./ofdm.py: line 35: sintax error near token no hoped `('
./ofdm.py: line 35: `class ofdm_mod(gr.hier_block):'

I'm using Linux Ubuntu 7.04 and gnuradio 3.1.1.

Thank you all for help us!!


You are not quite using those blocks correctly, anyway. They depend on their location to be properly imported. All of the core OFDM blocks are locaked in blks2impl and can be imported using gnuradio.blks2:

from gnuradio import gr, blks2

Then you can access blks2.ofdm or blks2.ofdm_receiver.

If you are working on a new type of synchronization, you'll want to place that in blks2impl. You'll find there are already four different types already there: ofdm_sync_pn, ofdm_sync_pnac, ofdm_sync_ml, and ofdm_sync_fixed. The fixed version simply knows how long to delay the triggering and assumes no frequency offset and was used just to test the mod/demod blocks. Of the rest, only the PN sequence synchronization currently works (and may be the only one that will ever work of these).

I think a bit of reorganization is due for the sync blocks, anyway. They do 1 or 2 steps too many. I would like to remove the ofdm_sampler from it, put that block in ofdm_receiver and output two streams from each sync: a timing trigger for when the preamble is detected and the fine frequency derotated OFDM symbol. The idea being a general interface for different OFDM sync blocks like yours that we could fit in.

Make sense?


reply via email to

[Prev in Thread] Current Thread [Next in Thread]