Forums

QAM demapper

Started by r_i_k_k_a_r_d_o March 1, 2007
Hi,
is there anyone who can explain me how does it work the QAM demapper
in the DVB demo of Simulink?
Can you please give hints on how create a demapper for 16 QAM and QPSK?

Thanks a lot.

Riccardo Calonaci
It depends on the aping pattern. For QPSK is grey mapping is used (B0
B1) -> X

00 -> -1-j

01 -> -1+j

11 -> +1+j

10 -> +1-j

Then soft demapping value for bit B0 and B1

B0 = real(X)

B1 = imag(X)

You can consult:

Simulation Techniques: Models of Communication Signals and Processes

Floyd M. Gardner, John D. Baker

Thanks and Regards,

Amit Shaw

From: m... [mailto:m...] On Behalf
Of r_i_k_k_a_r_d_o
Sent: Wednesday, February 28, 2007 6:57 PM
To: m...
Subject: [matlab] QAM demapper

Hi,
is there anyone who can explain me how does it work the QAM demapper
in the DVB demo of Simulink?
Can you please give hints on how create a demapper for 16 QAM and QPSK?

Thanks a lot.

Riccardo Calonaci

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