Optical Fiber Communications 4th Edition by Gerd Keiser

Exercise 7

A homodyne ASK receiver has a 100-MHz bandwidth and contains a 1310-nm pin photodiode with a responsivity of 0.6 A/W. It is shot noise limited and needs a signal-to- noise ratio of 12 to achieve a 10 -9 BER. Find the photocurrent that is generated if the local oscillator power is -3 dBm and the phase error is 10°. Assume that both the signal and the local oscillator have the same polarization.