Hello Sreena, the frequency translating FIR translates and then filters, ie. it moves your baseband signal to -19kHz and then filters a 1kHz band around 0Hz -- thus cutting away all your signal.
By the way: I assume you want to produce sounds at 19kHz with your built-in sound card: you won't hear much [1] unless you're very young, and your sound card has wide filters -- most cost-conscious soundcards will simply have only exactly one very simple analog filter with a cutoff frequency around 20kHz, and don't pay much attention to a narrow transition width, since humans won't easily notice attenuation in frequencies they can barely perceive anymore, and most speakers won't be linear at high frequencies, either. Greetings, Marcus [1]http://hypertextbook.com/facts/2003/ChrisDAmbrose.shtml On 12/15/2014 01:08 PM, sreena p h wrote: > Hi > > I am trying to implement the following acoustic communication > transmitter with PC > > File Source --> Packet encoder --> gmsk mod --> Rational resampler > --> Frequency Xlating FIR filter --> comp to real --> audio sink > > Pc has inbuilt sound card. packet encoder is taking 8 samples per > symbol, Resampler interpolates samples by 500, FIR filter is set at > 19k carrier frequency and 1K bandwidth. > > The problem is that I wont get any sort of output at the audio sink. I > added an GUI FFT sink at the end of FIR filter, it also showed now > output. Please tell what's gone wrong. I am using gnuradio 3.7.4 version. > > Thanks in advance > > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
_______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
