Simulate a digital communication system using Matlab Simulink

Simulate a digital communication system using Matlab Simulink including the following components:

1.QPSK modulator (Tx)

2.AWGN channel

3.QPSK demodulator (Rx)

The simulated system should able to

1.Calculate the BER at the receiver

2.Plotting the waveform of the QPSK signal

3.Plotting the spectrum of the QPSK signal

4.Plotting the constellation diagram of the QPSK signal before and after the channel