A digital communication system uses continuous-phase FSK with modulation size M = 8. The center frequency is fc = 500 MHz, the bitrate is Rb = 30 Mbps, the received signal power is S = 6 nW, and the channel is AWGN with double-sided power spectral density N0/2 = 2 ˆ™ 10-21 W.
1) What are the instantaneous frequencies to be used for each symbol, in order to minimize the required transmission bandwidth, and what is then the value of such bandwidth? How much is the resulting spectral efficiency?
2) What is the value of the bit energy to noise density ratio?