Problem 6:

6. OFDM Simulation [25 points]

In this problem you will simulate a communication system using OFDM. Start with the simula-

tion sim1.m (on Canvas).

(a) Generate two data waveforms, si(t) and s2(t) with different data streams.

(b) Combine the two streams mixed onto two different carriers at frequency fa = 8 Hz and

fb = 12 Hz.

s(t) = $1(t)√2 cos(2π fat) + s2 (1)√2 cos(27 fit).

(c) Add noise n(t) with signal-to-noise ratio Eb/No = 30 dB.

(d) Before filtering the received signal, mix down to baseband by multiplying by √2 cos(2n fat)

and √2 cos(27 fit).

(e) Filter each of the two signals after mixing down with a matched filter (a filter with the

same impulse response) as used in generate the waveforms, namely a filter with impulse

response pr(t) where T = 1 second./nTurn in the following: (a) Your Matlab code (b) A figure showing the data signal si(t) in the

time domain and S₁(f) in the frequency domain. (c) A figure showing the signal s(t) in the time

and frequency domain. (d) A figure showing the noise signal in the time and frequency domain.

(e) A figure showing the received signal in the time and frequency domain. (f) A figure showing

the output of the receiver filter (time domain and frequency domain) for the first data stream.

Overlay the time domain plot with the original data signal (si(t)). (g) A figure showing the

output of the receiver filter (time domain and frequency domain) for the second data stream.

Overlay the time domain plot with the original data signal (s2(t)).