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QPSK modulation system with recover loops

version 1.0 (104 KB) by

A model to simulate carrier and timinf recovery loops in a QPSK modulation system.

8 Ratings



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This is a model of a QPSK modulation system for transmission over a bandpass channel with fc = 100 Hz and B = 30 Hz and AWGN at the receiver. SRRC filters with excess bandwidth α = 0.18 are employed. The receiver includes an NDA timing recovery loop followed by a DD phase recovery loop. The transmitter?s symbol period is T and set to a value of 100 ms. The symbol period at the receiver is Tr. The model will produce six windows: Two constellation plots and two eye diagrams (for the real part only), at the output of the matched filters and after the recovery loops; a plot of the phase error (output of the NCO) and a plot of the fractional timing error (used in the interpolator). The frequency offset at the receiver is denoted by deltaf. The model simulates the transmission of 8000 QPSK symbols.

Comments and Ratings (13)


Meisam (view profile)

Thanks,I needed it.


Heyyo (view profile)

Why cannot I see anything?

Rum Chang

I see nothing except the definition, what is wrong?

Rum Chang

How to download?

nouri naziha

salut est ce qu'il ya tester la performance de ce model cad la mesure de BER en fonction de SNR merci de me repondre

shahid siddique


basel rih

gaurav ratra


ahmad rafiq


Fainan Hanif

mohammad turkman

block QPSK


Implements a NDA timing recovery loop (Farrow interpolator) and a DD phase recovery loop for QPSK.
Very useful, thank you !

Robert Morelos-Zaragoza

Change the summary:

A model to simulate carrier and timing recovery loops in a QPSK modulation system.

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