Digital Communication - Study Mode
[#116] Four signals m 1 (t) = cos(ω 0 t), m 2 (t) = 0.5cos(ω 0 t), m 3 (t) = 2cos(ω 0 t) and m 4 (t) = cos(4ω 0 t) are multiplexed by time division multiplexing system. The commutator speed is
Correct Answer
(D) 8f 0
[#117] For a binary FSK signal with a mark frequency of 49 kHz, a space frequency of 51 kHz and an input bit rate of 2 kbps, the peak frequency deviation will be
Correct Answer
(B) 1.0 kHz
[#118] A single bit, equally likely to be 0 and 1, is to be sent across an additive white Gaussian noise (AWGN) channel with power spectral density N 0 /2. Binary signaling, with 0 → p(t) and 1 → q(t), is used for the transmission, along with an optimal receiver that minimizes the bit-error probability. Let ϕ 1 (t), ϕ 2 (t), form an orthonormal signal set. If we choose p(t) = ϕ 1 (t) and q(t) = -ϕ 1 (t), we would obtain a certain bit-error probability P b . If we keep p(t) = ϕ 1 (t), but take q(t) = $$sqrt { ext{E}} $$ ϕ 2 (t), for what value of E would we obtain the same bit-error probability P b ?
Correct Answer
(B) 3
[#119] In PCM, the signal-to-quantisation noise ratio for a sinusoidal signal quantized using 10-bit PCM is:
Correct Answer
(C) 60 dB
[#120] Six message signals, each of bandwidth 5 KHz, are time-division-multiplexed and transmitted. The signaling rate and minimum channel bandwidth to avoid cross-talk in TDM, respectively, are:
Correct Answer
(B) 60 kbps, 30 kHz