QPSK modulator and demodulator

Can anyone help me How to modulate and demodulate using LLR Data of qpsk in matlab. But without uisng objeccs

[Walter Roberson]

When you say "without using objeccs" do you mean without using the system objects provided to do the modulation and demodulation? In other words, is your task to write a modulator and demodulator yourself without using the toolbox modulation and demodulation routines?

[Nitin Sapre]

Yes I meant not to use "comm.qpskmodulator" and all... Yes I want to write myself.

[Walter Roberson]

What does your textbook say that the theory of qpsk modulation is?

[Nitin Sapre]

It says that we need to take two bit at a time even and odd bits then multipy signals with inphase and quadratuer phase components. ul get modulated output. But How to get demodulated output using LLR I am not able to understand

Answer 1

[Kaashyap Pappu]

To perform QPSK modulation and demodulation, you can use the “pskmod” and “pskdemod” functions by setting the order of modulation to 4.

The “pskmod” function is elaborated upon here, with the example of QPSK modulation provided, and the “pskdemod” function is elaborated upon here, with an example of the entire process of modulation, channel modelling and demodulation.

Hope this helps!

Answer 2

[Nitin Sapre]

Thanks for soln, but I have done with this method. I have already said that i Dont want to use objects. i need to code it fully by own means. if anyone can help me to design a modulator without using objects it will be much appretiated.