New answers tagged qpsk
0
If you actually were to scope the output of say a RF software defined radio transmitting pulse shaped BPSK (similar for QPSK) - you'll see something like the top trace "RF Out" below:
A couple notes to explain: you can't see it unless zoomed in but the rf carrier is oscillating very fast which is why it appears solid, however it's envelope traces ...
0
QPSK in its raw form would appear just as the OP has shown, where the information is encoded into four symbols given by the four phase states alone. The problem is this has a very wide transmit spectrum given the pulse shapes are rectangular and the Fourier Transform of a rectangular pulse is a Sinc function (whose peaks roll-off in frequency only at the ...
2
Do you know how ADS is plotting the spectrum? Plotting the spectrum without doing some kind of normalization will give you a higher magnitude. Once you determine the size of the FFT, normalizing by the length will give you the same magnitude no mater what sampling rate you choose.
For example let's take two rectangular signals, one sampled at 1 MHz and the ...
Top 50 recent answers are included
