61. In binary frequency shift keying (FSK), the given signal waveforms are
u0(t) = 5cos(20000πt); 0 ≤ t ≤ 7 and u1(t) = 5cos(22000πt); 0 ≤ t ≤ T,
where T is the bit-duration interval and t is in seconds. Both u0(t) and u1(t) are zero outside the interval 0 ≤ t ≤ T. With a matched filter
(correlator) based receiver, the smallest positive
value of T (in milliseconds) required to have u0(t) and u1(t) uncorrelated is
u0(t) = 5cos(20000πt); 0 ≤ t ≤ 7 and u1(t) = 5cos(22000πt); 0 ≤ t ≤ T,
where T is the bit-duration interval and t is in seconds. Both u0(t) and u1(t) are zero outside the interval 0 ≤ t ≤ T. With a matched filter (correlator) based receiver, the smallest positive value of T (in milliseconds) required to have u0(t) and u1(t) uncorrelated is
62. BPSK stands for
63. Companding is used in PCM to
64. For atmost distortionless reception of signal in pulse modulation it is required that the speed should be:
65. Which of the following statements about the matched filter in a communication receiver are correct?
1. Its impulse response depends on the signal shape
2. It maximizes the SNR at the detection instant
3. It produces ISI
4. It may produce phase error if synchronization is improper
Select the correct answer from the options given below:
1. Its impulse response depends on the signal shape
2. It maximizes the SNR at the detection instant
3. It produces ISI
4. It may produce phase error if synchronization is improper
Select the correct answer from the options given below:
66. Which one of the following statements is not correct regarding the features of CDMA?
67. A 1.0 kHz signal is flat top sampled at the rate of 1800 samples/sec and the samples are applied to an ideal rectangular LPF with cut-off frequency of 1100 Hz, then the output of the filter contains
68. The outputs of 18 numbers of 20 Hz low pass filters are sampled, multiplexed and A/D converted. If the sampling is at the Nyquist rate of 40 samples/s, corresponding to signal of 20 Hz band-width and if we use 3 bits/sample to represent each voltage sample, the bit rate is
69. The modulation techniques used to convert analog signal into digital signal are
70. During transmission over a communication channel, bit errors occur independently with probability p. If a block of n bits is transmitted, the probability of at most one bit error is equal to
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