DEQPSK modulation

[Patrick]

Hello,

I have implemented a DEQPSK demodulator with complex multiplication.

Ak = Ik.Ik-1 + Qk.Qk-1
Bk = Qk.Ik-1 - Ik.Qk-1

This demodulator good functionning with pi/4 DQPSK

I would like to demodulate ŕ classic DQPSK with this complex multiplication

Is it possible and so what is the mapping at the modulator ?

Thanks