Scalar and vector streams

GNU Radio
1

hello,
first of all thanks to everybody in the list for the huge amount of
suggestions about hard-disk reading speeds I was provided with a few
days ago. :slight_smile:

then another question: which is the wisest way to convert a scalar
stream to a vector stream and then back to a scalar stream within a
python flow graph… if there is one, of course!

what I’m trying to do is:

         source_c--->gr.fft_vcc--->rest_of_the_flow_graph_c

is this reasonable?

best regards
vincenzo

2

Specification of the A5/3 Encryption Algorithms for GSM and EDGE, and
the
GEA3 Encryption Algorithm for GPRS

Get’em before their not (as in there)

http://cryptome.org/a53-gea3/a53-gea3.htm

3

On 2/19/07, Vincenzo P. [email protected] wrote:

PS2
is there any other paper available describing the gnuradio blocks, apart
from DaweiShen’s tutorial 9?

There is a gr-howto-write-a-block module within SVN that shows how to
write a block and has an XML document describing what is going on.

http://gnuradio.org/trac/browser/gnuradio/trunk/gr-howto-write-a-block

Brian

4

On Mon, Feb 19, 2007 at 04:37:18PM +0100, Vincenzo P. wrote:

shall I just guess and then bother some experienced guy on the list? :slight_smile:

for example @ the moment I’m looking for a block that can map bytes to
symbols… but how can I learn if gr.chunks_to_symbols can be a
candidate… and how to use it?
I mean: tutorial 9 is fine for the blocks it covers… but for the
others?

There are a couple of ways to map bytes to symbols.
gr.chunks_to_symbols is the most general. It’s usually used with
gr.packed_to_unpacked_bb in front of it. That lets you split your
byte stream into k-bit chunks for use with gr.chunks_to_symbols.

http://gnuradio.org/doc/doxygen/classgr__packed__to__unpacked__bb.html
http://gnuradio.org/doc/doxygen/classgr__chunks__to__symbols__bc.html

Eric

5

thanks Josh,
it worked fine!

vincenzo

PS
to obtain an ifft instead of a fft,i should use gr.fft_vcc with the
boolean
argument “forward” set to false, right?

PS2
is there any other paper available describing the gnuradio blocks, apart
from DaweiShen’s tutorial 9?

2007/2/18, Josh B. [email protected]:

6

thanks Josh,

(yes… I’m trying to move as near as possible to ofdm on the python
level)
before diving into c++ block designing.

I usually watch the doxygen… but the point is:
how can I be sure… and learn details about the usage… eg. the
question about gr_fft you’ve just kindly asked…
…
shall I just guess and then bother some experienced guy on the list? :slight_smile:

for example @ the moment I’m looking for a block that can map bytes to
symbols… but how can I learn if gr.chunks_to_symbols can be a
candidate… and how to use it?
I mean: tutorial 9 is fine for the blocks it covers… but for the
others?

best regards
vincenzo