Analysis of CNR and BER for QPSK satellite link
A satellite data transmission system transmits data from two T1 carriers as a single 3.088 Mbps bit stream using QPSK. The satellite link uses ideal RRC filters with Rolloff = 0.25. At the receiving terminal the clear air value of overall (CNR)o is 16.0 dB and the implementation margin of the QPSK demodulator is 1 dB.
a. What is the bandwidth occupied by this signal, and the noise bandwidth of the receiver for this signal?
b. Find the BER at the receiver output and the average time between errors.
c. Rain affects the downlink from the satellite and the overall CNR in the receiver falls by 6.0 dB to 10.0 dB. What is the bit error rate and time between errors now?