Nt1310 Unit 9 Exam Paper
Q1.
Various digital-to-digital encoding techniques are as follows:
a) Signal spectrum – a transmission contains lack of high frequency components which means less bandwidth is required and direct current component is also desirable. With no dc component, ‘ac’ coupling via transformer is possible. Finally, the magnitude of the effects of signal distortion and interference depend on the spectral properties of the transmitted signal.
b) Clocking – to provide a separate clock lead to synchronize the transmitter and receiver by using encode synchronization mechanism.
c) Error detection – It is useful to have some error detection capability built into the physical signaling encoding scheme. This allows to be detected more quickly.
d) Signal interference …show more content…
For QAM, each carrier is ASK modulated. The two independent signals are simultaneously transmitted and at the receiver, the two signals are demodulated, and the results combined to produce the original binary input.
Q4.
Sampling theorem: An analog signal can be exactly reconstructed from its samples if the sampling rate is at least twice the highest frequency component present in the signal.
This means, if the signal contains the highest frequency component of 1KHz, the sampling must be at least 2 kilo Samples/Seconds. This sampling rate is also known as Nyquist rate.
Q5. Q6.
Bipolar violation is the occurrence of separating two consecutive + or – pulses. In the received bipolar sequence +-0+-0-+ the bipolar violation can be seen at two consecutive – pulses as – 0-
Following the two scenarios where if one bit is converted and results in the same received pattern +-0+-0-+
a) +-0+-0-+
If + in the 6th position is converted to 0 , the same received pattern will be produced
b) +-0+00-+
If 0 in the 5th position is converted to an pattern similar to the received pattern will be produced.
Various digital-to-digital encoding techniques are as follows:
a) Signal spectrum – a transmission contains lack of high frequency components which means less bandwidth is required and direct current component is also desirable. With no dc component, ‘ac’ coupling via transformer is possible. Finally, the magnitude of the effects of signal distortion and interference depend on the spectral properties of the transmitted signal.
b) Clocking – to provide a separate clock lead to synchronize the transmitter and receiver by using encode synchronization mechanism.
c) Error detection – It is useful to have some error detection capability built into the physical signaling encoding scheme. This allows to be detected more quickly.
d) Signal interference …show more content…
For QAM, each carrier is ASK modulated. The two independent signals are simultaneously transmitted and at the receiver, the two signals are demodulated, and the results combined to produce the original binary input.
Q4.
Sampling theorem: An analog signal can be exactly reconstructed from its samples if the sampling rate is at least twice the highest frequency component present in the signal.
This means, if the signal contains the highest frequency component of 1KHz, the sampling must be at least 2 kilo Samples/Seconds. This sampling rate is also known as Nyquist rate.
Q5. Q6.
Bipolar violation is the occurrence of separating two consecutive + or – pulses. In the received bipolar sequence +-0+-0-+ the bipolar violation can be seen at two consecutive – pulses as – 0-
Following the two scenarios where if one bit is converted and results in the same received pattern +-0+-0-+
a) +-0+-0-+
If + in the 6th position is converted to 0 , the same received pattern will be produced
b) +-0+00-+
If 0 in the 5th position is converted to an pattern similar to the received pattern will be produced.