Question: 1. We want to build a digital data transmission system with a desired Pe of 10-3. Compare the necessary signal-to-noise ratios required for PRK, OOK, FSK, noncoherent FSK, noncoherent OOK, and DPSK.
2. Derive the optimum receiver structure of a DPSK system under the usual assumptions of additive white noise. Prove that the bit error probability is given by Pe = ½ exp(-E/No). Note that 3-dB advantage of DPSK over noncoherent FSK arises because the total energy in the message bearing waveforms is twice that of FSK.