Figure describes the block diagram of a generalized M-ary QAM modulator. Basically, the modulator includes a mapper that produces a complex amplitude am input for m = 0, 1, ¼, M - 1, The real and imaginary parts of am input the basis functions f1( t ) and f2 (t ) respectively. The modulator is generalized in that it embodies M-ary PSK and M-ary PAM as special cases.
a. Formulate the underlying mathematics of the modulator described in Figure.
b. Hence, show that M-ary PSK and M-ary PAM are indeed special cases of the M-ary QPSK generated by the block diagram of Figure.
