Use Matlab to generate code
This problem uses Matlab to simulate QPSK modulation and demodulation. To this end, let the
duration of each QPSK signal be normalized to Ts=1 second, the energy of each signal be Es=1
Joule. With these normalizations the coordinates of the QPSK signals are shown in table below
Bit Pattern 00 01 11 10
QPSK signal S1(t) S2(t) S3(t) S4(t)
Signal Coordinates (1,0) (0,1) (-1.0) (0,-1)
Perform the following in Matlab
Generate a random binary information sequence of length L=1000 bits, whose
elements are drawn from {0,1}. Take two bits at a time, and grey map them to one of
the four QPSK signals (shown in table above).
Add to each transmitting QPSK signal zero mean AWGN of variance No/2.
Plot the received signals in the signal space diagram together with the optimum
boundary. Remarks: Use different colors when plotting the different QPSK signals. Determine the values of variance to that the bit error probabilities of QPSK are of 10-110-2 10-3 10-4. Run your program for each such case and comment on the differences. .(5 points)
