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(b) The signal space for QPSK (quadrature phase shift keying) is shown in Fig. 4-1. $\phi_2(t)$ \textbf{01} $s_2(t)$ $s_3(t)$ \textbf{11} 0 \textbf{10} $s_4(t)$ Fig. 4-1 $E_s$ $s_1(t)$ $\phi_1(t)$ \textbf{00} (i) Draw the QPSK signal for the bit sequence 10010011. (ii) The probability of error for QPSK is given as $Q \left(\sqrt{\frac{2E}{N_0}}\right)$, which is the same as the error probability for B-PSK, even though the signal space for QPSK is more crowded with four signals compared to two signals for B-PSK. Explain why the error probability for QPSK is not significantly worse than B-PSK.

          (b) The signal space for QPSK (quadrature phase shift keying) is shown in Fig. 4-1.
\(\phi_2(t)\)
\textbf{01}
\(s_2(t)\)
\(s_3(t)\)
\textbf{11}
0
\textbf{10} \(s_4(t)\)
Fig. 4-1
\(E_s\)
\(s_1(t)\)
\(\phi_1(t)\)
\textbf{00}
(i) Draw the QPSK signal for the bit sequence 10010011.
(ii) The probability of error for QPSK is given as $Q \left(\sqrt{\frac{2E}{N_0}}\right)$, which is the same as the error probability for B-PSK, even though the signal space for QPSK is more crowded with four signals compared to two signals for B-PSK. Explain why the error probability for QPSK is not significantly worse than B-PSK.

(b) The signal space for QPSK (quadrature phase shift keying) is shown in Fig. 4-1.
ϕ2(t)
01
s2(t)
s3(t)
11
0
10 s4(t)
Fig. 4-1
Es
s1(t)
ϕ1(t)
00
(i) Draw the QPSK signal for the bit sequence 10010011.
(ii) The probability of error for QPSK is given as Q (√((2E)/(N0))), which is the same as the error probability for B-PSK, even though the signal space for QPSK is more crowded with four signals compared to two signals for B-PSK. Explain why the error probability for QPSK is not significantly worse than B-PSK.

Added by Rachel W.

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