Attached is the pulse shaping generator in Dqpsk Modulator
pulse shaping filter
self.rrc_taps = gr.firdes.root_raised_cosine(
self._samples_per_symbol, # gain (sps since we're interpolating
by sps)
self._samples_per_symbol, # sampling rate
1.0, # symbol rate
self._excess_bw, # excess bandwidth (roll-off
factor)
ntaps)
self.rrc_filter = gr.interp_fir_filter_ccf(self._samples_per_symbol,
self.rrc_taps).
thank u!
Bill
----- Original Message ----
From: Bill S. [email protected]
To: [email protected]
Sent: Monday, April 14, 2008 12:20:47 AM
Subject: [Discuss-gnuradio] how to transmit a DQPSK Modulated Sequence
through USRP (how to handel the carrier?)
Hello, everybody
I am trying to transmit a DQPSK Modulated Sequence into sky through
USRP, but after the symbols whose types are complex go through the pulse
shaping filter, how can we put them onto a carrier, say cos(2pifct).
Should we multiply the complex symbols with cos(2pifct) or with
exp(2pifc*t)? Should we sample the symbols after multiplying carrier
or before multiplying carrier? thank you!!!
Bill
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