DPSK in digital electronics | Msc. Physics HPU

What is DPSK? DPSK is a type of Phase Shift Keying, just like BPSK. But here’s the twist: Instead of comparing the signal with a reference carrier, DPSK compares each bit’s phase with the previous bit’s phase. That’s why it’s called “Differential” — we are encoding the difference in phase, not the absolute phase. --- 📡 How Does DPSK Work? In DPSK: A bit 1 is represented by no change in phase. A bit 0 is represented by a 180° phase change from the previous signal. Let’s understand this with an example: If the first bit is 1 → we send the carrier as it is. Now: If the next bit is also 1 → no change in phase. If the next bit is 0 → flip the phase. And so on… So, the information is stored in how the phase changes from one bit to the next. --- 📶 DPSK Waveform Example: Say we have this bit stream: 1 0 1 1 0 Start with a reference phase for the first 1. For the 0 → change the phase. For the next 1 → keep the phase same as previous. And so on... This gives a waveform where changes in phase carry the data, not the absolute phase.