267. Two sinusoidal signals of same amplitude and frequencies 10 kHz and 10.1 kHz are added together. The combined signal is given to an ideal frequency detector. The output of the detector is

A. 0.1 kHz sinusoid

B. 20.1 kHz sinusoid

C. a linear function of time

D. ,a constant

268. The positive frequencies where Y(/) has spectral peaks are

A. 1 kHz and 24 kHz

B. 2 kHz and 24 kHz

C. I kHz and 14 kHz

D.21cHz and 141cHz

269. During transmission over a certain binary communication channel, bit errors occur independently with probability p. The probability of AT MOST one bit in error in a block of n bits is given by

A. pn

B. 1 - p"

C. np (1 - p)n-I + (1 - p)n

D. 1 -(1 _p)"

270. In a GSM system, 8 channels can co-exist in 200 kHz bandwidth using TDMA. A GSM based cellular operator is allocated 5 MHz bandwidth. Assuming a frequency reuse factor of ?5 , i.e. a five-cell repeat pattern, the maximum number of simultaneous channels that can exist in one cell is

A.200

B.40

C.25

D.5

271. In a Direct Sequence CDMA system the chip rate is 1.2288 x 106 chips per second. If the processing gain is desired to be AT LEAST 100, the data rate

A. must be less than or equal to 12.288 x 103 bits per sec.

B.must be greater than 12.288 x 103 bits per sec.

C. must be exactly equal to 12.288 x 103 bits per sec

D. can take any value less than 122.88 x 103 bits per sec.

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