FAQ Database Discussion Community


Generate 16 QAM signal

matlab,signal-processing,software-defined-radio
I know the way to generate QPSK signals using the following TxS=round(rand(1,N))*2-1; % QPSK symbols are transmitted symbols TxS=TxS+sqrt(-1)*(round(rand(1,N))*2-1); In the above, the symbols are 2 alphabets +1/-1. But I cannot understand how to generate 16- Quadrature Amplitude Modulation signal for the same alphabet space? Is it possible? Or what...

What is frequency-domain entropy in FFT result and how to calculate it?

signal-processing,fft,software-defined-radio
I am a programmer but quit bad on math.. I recently read an article which mentioned frequency-domain entropy,he calculated that thing from a FFT power spectrum but didn't tell me how to do that. I cannot find enough information online to understand what it is . I'm appreciate for any...

What should I supply to the “freq” input for Frequency Xlating FIR Filter for GnuRadio Companion?

filtering,gnuradio,software-defined-radio
I am using GnuRadio Companion (GRC) 3.75 and I am trying to use the Frequency Xlating FIR Filter (FXFF) block to perform some filtering. All the tutorials I've seen had this FXFF block take in only 1 input (such as this), which is the complex signal (blue in colour). However,...

How exactly is hier_block 's behaviour different then that of a sync_block in GNU Radio?

python,gnuradio,software-defined-radio
This is a continuation of this question. I understand that we cannot access input_items in __init__ of a sync_block but we can do so in hier_block (eg. here). I wanted to add a panel on the top block frame which can only be done by assigning a panel to self.win...