Coherent PSK and non coherent orthogonal FSK have a difference of ______ in PB.

The non coherent FSK needs ________ Eb/N0 than coherent FSK.

A

1db more

B

1db less

C

3db more

D

3db less

At a given probability of error, binary coherent FSK is inferior to binary coherent PSK by

A

6 dB

B

3 dB

C

2 dB

D

0 dB

An FH binary orthogonal FSK system employs an m 15 stage liner feedback shift register that generates an ML sequence. Each state of the shift register selects one of L non over lapping frequency bands in the hopping pattern. The bit rate is 100 bits/s. The demodulator employ non coherent detection. Suppose the hop rate is increased to 2 hops/bit and the receiver uses square law combining the signal over two hops. The hopping bandwidth for this channel is?

A

3.2767 MHz

B

13.1068 MHz

C

26.2136 MHz

D

1.6384 MHz

An FH binary orthogonal FSK system employs an m 15 stage liner feedback shift register that generates an ML sequence. Each state of the shift register selects one of L non over lapping frequency bands in the hopping pattern. The bit rate is 100 bits/s. The demodulator employ non coherent detection. If the hop rate is one per bit, the hopping bandwidth for this channel is?

A

6.5534 MHz

B

9.4369 MHz

C

2.6943 MHz

D

None of the mentioned

Statement (I): M-ary PSK can be used to transit digital data over a non-linear bandpass channel, whereas M-ary QAM requires the use of a linear channel. Statement (II): M-ary PSK and M-ary QAM are examples of non-linear modulation.

A

Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I).

B

Both Statement (I) and Statement (II) are individually true, but Statement (II) is not the correct explanation of Statement (I).

C

Statement (I) is true, but Statement (II) is false.

D

Statement (I) is false, but Statement (II) is true.

Coherent orthogonal binary FSK modulation is used to transmit two equiprobable symbol waveforms s₁(t) = αcos2πf₁t & s₂(t) = αcos2πf₂t₁ where α = 4 mV. Assume an AWGN channel with two-sided noise power spectral density $$\frac{{{N_0}}}{2} = 0.5 \times {10^{ - 12}}W/Hz.$$ Using an optimal receiver and the relation $$Q\left( v \right) = \frac{1}{{\sqrt {2\pi } }}\int\limits_v^\infty {{\theta ^{\frac{{{u^2}}}{2}}}du,} $$ the bit error probability for a data rate of 500 kbps is

A

Q(2)

B

$$Q\left( {2\sqrt 2 } \right)$$

C

Q(4)

D

$$Q\left( {4\sqrt 2 } \right)$$

A source produces binary data at the rate of 10 kbps. The binary symbols are represented as shown in the figure.
Digital Communication mcq question image

Digital Communication mcq question image

The source output is transmitted using two modulation schemes, namely Binary PSK (BPSK) and Quadrature PSK (QPSK). Let and B2 be the bandwidth requirements of BPSK and QPSK respectively. Assuming that the bandwidth of the above rectangular pulses is 10 kHz, B₁ and B₂ are

A

B₁ = 20 kHz, B₂ = 20 kHz

B

B₁ = 10 kHz, B₂ = 20 kHz

C

B₁ = 20 kHz, B₂ = 10 kHz

D

B₁ = 10 kHz, B₂= 10 kHz

In the following passage, some of the words have been left out. Read the passage carefully and select the correct answer for the given blank out of thefour alternatives. Our reputation and image is most definitely determined by our ______. Also our ______ tend to be habit forming, in that we have a ______ to act in a particularmanner. Hence most people are ______ by their deeds and seem to have little control over their actions. We usually act according to or in response to oursurroundings-our circumstances and the environment which to a great extent ______ our priorities and objectives. we have a ______ to act in a particular manner.

A

immensity

B

propensity

C

viscosity

D

virtuously

ASK, PSK, FSK, and QAM are examples of _____ encoding.

A

digital-to-digital

B

digital-to-analog

C

analog-to-analog

D

analog-to-digital

E

None of the above

PSK and FSK are which type of modulation?

A

Analog Modulation

B

Digital Modulation

C

Both Analog Modulation & Digital Modulation

D

None of these

Coherent PSK and non coherent orthogonal FSK have a difference of ______ in PB.

Related Questions