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(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

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