
and 8 PSK with BPSK, power penalties measured at BER = 10
5
are 4 and 15 dB,
respectively. When the phase noise is negligible and the symbol rate is kept
constant, the theoretical power penalty of M-ary PSK relative to BPSK is given
as 1/sin
2
(/M), which are 3 and 8.3 dB for QPSK and 8-PSK, respectively. In the
case of 8-PSK, considering the 1-dB penalty due to the phase noise, we find that
our experiment still includes a 5.7-dB excess penalty. The distribution of the
complex amplitude of the received signal in the error-free state is depicted in
Figure 3.17. Compared to BPSK and QPSK, we find that the constellation map of
8-PSK is disordered due to ...