❓ Help COMMUNICATIONS 2: MODULATION AND CODING TECHNIQUES Coursework 5, NEED CORRECT ANSWERS

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COMMUNICATIONS 2: MODULATION AND CODING TECHNIQUES
Coursework 5



Question 1
Note:
Integer, decimal, or E notation allowed
Determine the CRC remainder for the message: 10010011101001 and the CRC divisor: 100011





Question 2
Use the same message and append the crc remainder in question 1. Assume that this message was received with no error. Demonstrate the process of error detection at the receiver using binary division. What is the remainder? Show complete solution.
Note:
Integer, decimal, or E notation allowed



Question 3
Explain how to generate the CRC using binary divison



Question 4
Explain how CRC detects error at the receiver

 

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### Question 1:

Given message: 10010011101001
CRC divisor: 100011

Performing CRC division:

• Append 5 zeros to the message: 1001001110100100000
• Perform binary division: 1001001110100100000 / 100011 = 100011000000101 (remainder)

Therefore, the CRC remainder for the given message and CRC divisor is 10001100000.

### Question 2:

Given message with CRC remainder appended: 1001001110100110000
Assuming no errors in the received message.

Performing error detection at the receiver using binary division:

• Received message: 1001001110100110000
• Perform binary division: 1001001110100110000 / 100011 = 100100111010 (remainder)

The remainder after division is 100100111010.

### Question 3:

To generate the CRC using binary division, follow these steps:
1. Append n zeros (n = degree of CRC polynomial - 1) to the message.
2. Perform binary division of the augmented message with the CRC polynomial (divisor).
3. Calculate the remainder, which becomes the CRC.

### Question 4:

CRC detects errors at the receiver by checking the remainder obtained after dividing the received message (including CRC bits) by the CRC polynomial (divisor). If the remainder is not zero, it indicates that errors are present in the received message. The CRC technique is designed in a way that when the message is error-free, the remainder will be zero, and any non-zero remainder signifies the presence of errors.