Which of the following are examples of data encoding schemes?
A. Non-Return to Zero (NRZ)
B. Manchester Encoding
C. Amplitude Modulation
D. Hamming code
E. Bipolar AMI
Choose the correct answer from the options given below:

Correct option is D

The question asks which of the following are examples of data encoding schemes. Let's go through each option and understand whether they are data encoding schemes:
A. Non-Return to Zero (NRZ): Non-Return to Zero (NRZ) is a data encoding scheme used in digital communication. It represents binary data as either high or low voltage levels with no return to zero between bits. It is widely used because of its simplicity and efficiency in encoding binary data.
· Conclusion: NRZ is a data encoding scheme.
B. Manchester Encoding: Manchester Encoding is another data encoding scheme that represents binary values by transitions. For a '0', there is a transition from high to low voltage in the middle of the bit period, while for a '1', the transition goes from low to high. This encoding helps with synchronization and timing recovery in data transmission.
· Conclusion: Manchester Encoding is a data encoding scheme.
C. Amplitude Modulation (AM): Amplitude Modulation (AM) is a modulation technique used in analog communication, not a data encoding scheme. In AM, the amplitude of the carrier wave is varied in proportion to the data signal. It is used for transmitting information like voice or audio but is not typically categorized as a data encoding scheme.
· Conclusion: AM is not a data encoding scheme.
D. Hamming Code: Hamming Code is a error-correcting code used to detect and correct errors in data transmission. It is often used in conjunction with data encoding schemes to ensure that transmitted data is correct. While Hamming code isn't strictly a data encoding scheme, it is closely related to the process of encoding data for error detection and correction.
· Conclusion: Hamming code is not a traditional data encoding scheme, but it is related to encoding because it deals with data error correction.
E. Bipolar AMI (Alternate Mark Inversion): Bipolar AMI is a data encoding scheme used in digital communication. In Bipolar AMI, binary data is represented with alternating positive and negative voltages for '1', and '0' is represented by zero voltage. It is used to avoid long sequences of zeroes, ensuring synchronization and maintaining a balanced signal.
· Conclusion: Bipolar AMI is a data encoding scheme.
From the given choices, the data encoding schemes are:
· A. Non-Return to Zero (NRZ)
· B. Manchester Encoding
· E. Bipolar AMI
Thus, the correct answer is: Option d: A, B and E Only.
Information Booster:
1. Non-Return to Zero (NRZ) is a simple encoding scheme with two voltage levels representing binary '1' and '0'.
2. Manchester Encoding provides synchronization by ensuring a transition at the middle of each bit period, offering more reliability in timing.
3. Bipolar AMI ensures a balanced signal with alternating polarities for '1', which is helpful in preventing the signal from drifting and is suitable for long-distance communication.
Additional Knowledge:
· Amplitude Modulation (AM) is a technique used for modulating an analog signal, such as in radio broadcasting. It is not a data encoding scheme but is used in the transmission of analog signals.
· Hamming Code deals with error detection and correction and is not a primary data encoding scheme, but rather a coding technique used to ensure that data transmitted through noisy channels can be corrected in case of errors.