Unable to find header decoding block

GNU Radio
1

Dear All,

I was exploring the narrowband benchmark codes, I am not able to figure
out
how the header of an incoming packet is read. It appears that the
connections made are:

uhd_receiver->[channel_filter->(demodulator->correlator->framer_sink)]
where framer_sink has the received packet queue. However, the
queue_watcher
function is defined so to unmake the payload, which means that the
header
has been read apriori. I would like to know in which step the packet
header
is read, and how to access the signal processing block that does it.

I need to customize the packet header and add extra processing to the
header decoding block. Any help would be much appreciated.

Thanks and Regards,
Dhrubo

2

Dhrubo
,
demodulator->correlator->framer_sink

Correlator (input=1 bit-per-byte) detects the header while framer_sink
separates the payload.
Output of correlator the 1st bit location represents input data (1
bit-per-byte) while 2nd bit location represents the detection of header.
Framer sinks keeps on checking this 2nd bit and separates payload bits.

-Adeel

On Thu, Mar 1, 2012 at 1:37 AM, Dhrubojyoti R.