Implementation of a QPSK Modulation System for Bandpass Transmission

This MATLAB model demonstrates a QPSK modulation system designed for transmission over a bandpass channel with center frequency fc = 100 Hz and bandwidth B = 30 Hz, incorporating AWGN at the receiver. The system employs SRRC filters with excess bandwidth α = 0.18, and implements an NDA timing recovery loop followed by a DD phase recovery loop in the receiver chain.