I am trying channel coding in gnuradio. I am using convolutional encoder with K=7 and R=1/2 with polynomials [109, 79] (default). However I am not getting the expected result. I input a known bit sequence, single frame using head block, and observe the output of the encoder using file sink. The output I think is not correct according to the given polynomials. Input bit stream is
http://pastebin.com/thsYtLFG
I am getting this output
http://pastebin.com/P42QNjiE
http://pastebin.com/thsYtLFG
I am getting this output
http://pastebin.com/P42QNjiE
However, I am expecting (in hex)
00 00 E3 32 63 D7 4B FA D3 ......
00 00 E3 32 63 D7 4B FA D3 ......
I have attached the flowgraph I am using for this purpose. I did a dry run by drawing a diagram of the encoder and inputing initial two bytes. Diagram of the encoder is also attached. I also used MATLAB script to test and found that my dry run output matches with MATLAB but not with Gnuradio output. I also played with the endianness but could not get the desired result. Maybe I am doing something wrong in configuring the encoder?
Also another thing I noticed is that in QA codes of gr-fec I found
import fec_swig as fec
import blocks_swig as blocks
import fec_swig as fec
import blocks_swig as blocks
I think this should be
from gnuradio import fec, blocks
from gnuradio import fec, blocks
Am I right? I am using gnuradio 3.7.8.
--
Bob
No comments:
Post a Comment