QPSK system is superior to BPSK system because
(a) its bandwidth is higher than that of BPSK System (b) interchannel interference in QPSK system is less then that in BPSK system (c) bandwidth of QPSK system is half of the bandwidth of BPSK system (d) in QPSK system inter-symbol interference is improved
(a) its bandwidth is higher than that of BPSK System (b) interchannel interference in QPSK system is less then that in BPSK system (c) bandwidth of QPSK system is half of the bandwidth of BPSK system (d) in QPSK system inter-symbol interference is improved