Sorry, forgot to reply to list: On Fri, Aug 26, 2011 at 5:16 AM, Zhonghua <zhong...@sics.se> wrote:
> ** > Hi everyone, > When I start to assemble *'gnuradio/examples/digital/benchmark_tx.py' and > **'gnuradio/examples/digital/benchmark_rx.py', *I found there is no output > from the 'rx_callback' function defined in benchmark_rx.py. I inspected it > further and found no message is stored in the *'framer_sink'*. I got rid > of the 'USPR' part from both transmitter and receiver ports, then just > connect the remainder parts such as modulator,demodulator,correlator and > framer_sink. There is also no any message in the framer_sink. I wrote my > own test-bench in which I made a packet with the * > 'packet_utils.make_packet'* tool and transmitted the packet to the > modulator(*blks2.mod_pkts*),then connect to the demodulator(*'dbpsk_demod' > class of dbpsk.py)* and correlator (*gr.correlate_access_code_bb(access_code, > threshold)*). I watched the input and output of the correlator and found > that the correlator looks does nothing but just delays the input for 64 > bits. The input and output data are as below: > It's actually working exactly as designed. The correlate_access_code_bb block outputs the original 1-bit-per-byte data and sets the second bit to "1" when it finds a correlator match. --n > input: > (0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 1, > 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 0, > 0, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 0, 1, 0, 0, 0, 1, > 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, > 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, > 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, > 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, > 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, > 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, > 0, 0, 0) > The input length is 228 > output: > (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, > 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, > 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, > 1, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 1, > 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, > 0, 1, 1, 1, 1, 0, 0, 1, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, > 1, 1, 1, 1, 1, 1, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, > 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, > 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, > 1, 0, 0) > The output length is 228 > We can see that the output of the correlator is just 64 bits delayed string > of the input and there even has an error bit of '2' in the string. Because > the input vector has been delayed, the original last 64 bits are > eliminated. > As my understanding the correlator which input is 1 bit per input byte > should do the access_code detection and then output a string of 2 bits per > byte. The data following the access_code would be detected and so could be > seen as effective data to send to the framer_sink. But my factual output of > the correlator is not like that. Could anybody tell me why? My gnuradio > version is gnuradio-3.3.0. > > BR, > Zhonghua > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > >
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