DPSK Questions

[jwsegar]

Can someone please explain in detail DPSK from the encoder to the decoder please? I understand that the phase change transmitted by the encoder/modulator is the difference between the current phase change and the previous polar position (i.e. the phase difference between a 90 degree phase shift and 180 degree phase shift is 90, so assuming our current value is 180 and our previous was 90 then a 90 degree phase shift is what is transmitted and our reference point now becomes 180 degrees)

Am I on track with this idea?

Thanks in advance.

[aksmanian]

yes, I believe you have the concept right. DPSK decoder does not require phase lock with respect to the encoding oscillator and only needs to decode the present state with respect to the one received last. - aksmanian