Recovery of MPSK
Modulated Signals in Noisy Environment.
For detecting the MPSK
signals in modern digital receivers, device of phase automatic frequency control (PLL) are widely used.
MQAM has least probability of error than both MDPSK and MPSK
in the Weibull fading scenario.
In this study, 8PSK modulated PCMA signals are used as an example to examine the algorithm performance, and it can also be extended to other high-order MPSK
and QAM modulated PCMA signals.
After that we pick out the useful symbols according to "sub-carrier on / off information" and perform MPSK
demodulation to recover the original data denoted as x'(n).
In Figure 10, the concept of quadrature subharmonic sampling for the purpose of coherent direct demodulation of an MPSK
modulated microwave signal with suppressed carrier is introduced.
Interestingly, there is no contradictions when PM is combined with traditional modulation techniques (e.g., MPSK
, MQAM, FSK) which utilize the amplitude, phase, and frequency as information-bearing parameters.
Since MRC is applied at the destination, we derive the close-form expression by using MGF according to , where the ASER of an M-ary phase-shift keying (MPSK
) modulated system is given by
This block diagram is used to describe two types of adaptive modulation schemes which is based on MQAM and MPSK
Considering that BER is an another important performance measure of communication systems in fading channel, we will give the BER performance analysis of the DAS over composite fading channel in this section, and derive the average BER expressions of the system with MQAM and MPSK
Similarly, we may employ the above analytical method to derive the BER expression of DAS-AS with MPSK
For example, a = 1, b = 1 corresponds to binary phase shift keying (BPSK) modulation, and a = 2, b = [sin.sup.2] [pi]/M corresponds to Mary-phase shift keying (MPSK
) modulation for M [greater than or equal to] 4.