Question

The bit rate for a baseband signal is 1.544 Mb/s, and FEC at a code rate of 7/8 is applied before the signal is used to modulate the carrier. Given that the system uses raisedcosine filtering with a rolloff factor of 0.2, determine the bandwidth required for: (a) BPSK, and (b) QPSK.

Explain what is meant by coding gain as applied to error correcting coding. When FEC coding is used on a digital link, a coding gain of 3 dB is achieved for the same BER as the uncoded case. What decibel reduction in transmitted carrier power does this imply?

Answer 1