Digital Communication - Study Mode

[#136] Which of the following modulation schemes gives the maximum probability of error?
Correct Answer

(A) ASK

[#137] In QPSK the average probability of bit error in AWGN channel is obtained as
Correct Answer

(A) $${P_{eQPSK}} = Qleft[ {sqrt {frac{{2{E_b}}}{{{N_o}}}} } ight]$$

[#138] A signal x(t) = 100cos(24π × 10 3 )t is ideally sampled with a sampling period of 50 µsec and then passed through an ideal lowpass filter with cutoff frequency of 15 kHz. Which of the following frequencies is/are present at the filter output?
Correct Answer

(D) 12 kHz and 8 kHz

[#139] In a M-ary PSK digital communication system, it is required to transmit the data with 80 Mbps bit rate within maximum allowable channel bandwidth of 16 MHz. The value of M is
Correct Answer

(A) 1024

[#140] To overcome slope overload problem which type of integrator is used in delta modulation?
Correct Answer

(B) Variable slope integrator