Just as in an ordinary QPSK modulator, the output of a /4-shifted DQPSK modulator may be expressed

Just as in an ordinary QPSK modulator, the output of a π/4-shifted DQPSK modulator may be expressed in terms of its in–phase and quadrature components as follows; s(t) = s₁(t) cos(2πf_ct) – s_Q(t) sin (2πf_ct) formulate the in-phase component s1(t) and quadrature component s_Q(t) of the π/4-shifted DQPSK signal. Hence, outline a scheme for the generation of π/4-shifted DQPSK signals.