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 Stevenson <address@hidden>
To: address@hidden
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(2*pi*fc*t). Should we multiply the complex symbols with cos(2*pi*fc*t) or with exp(2*pi*fc*t)? Should we sample the symbols after multiplying carrier or before multiplying carrier? thank you!!!
Bill
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com