Question 3: Project 3: QPSK (20 points)
A modulated QPSK symbols are $S_1, S_3, S_0, S_2, S_1$.
1. What is the bit stream delivered over I-channel and Q-channel, respectively?
2. Sketch the waveforms where $R_b = 1$ Mbits/s and $f_c = 4$ MHz.
3. A QPSK modulation can be expressed as,
$s(t) = b_I(t)\sqrt{\frac{2E_b}{T_b}}\cos(2\pi f_ct) + b_Q(t)\sqrt{\frac{2E_b}{T_b}}\sin(2\pi f_ct)$
where $b_I(t) = b_Q(t) = \pm 1$. Calculate energy per symbol $E_s = \int_0^{T_s} s(t)^2 dt$ where $T_s = 2T_b$
5. How to retrieve $b_I(t)$ and $b_Q(t)$ for QPSK, mathematically
