convolutional codes - cs

What is the purpose of convolutional codes in digital communication?

• A. To compress data before transmission
• B. To add redundancy to data for error detection and correction
• C. To encrypt data for secure transmission
• D. To increase the speed of data transmission

Which of the following is true about convolutional codes?

• A. They can only correct single-bit errors
• B. They are less effective than block codes at detecting errors
• C. They can correct errors in a block of data without knowing the location of the error
• D. They require a large amount of redundancy to be added to the data

What is the constraint length of a convolutional code with a feedback polynomial of g(x) = 1 + x + x^3?

• A. 1
• B. 2
• C. 3
• D. 4

What is the effect of increasing the constraint length of a convolutional code?

• A. It increases the number of output bits for a given input
• B. It increases the complexity of encoding and decoding
• C. It decreases the probability of error
• D. It has no effect on the performance of the code

How can the performance of a convolutional code be improved?

• A. By increasing the number of input bits
• B. By decreasing the constraint length
• C. By using a better feedback polynomial
• D. By increasing the transmission power

Which of the following is not a type of convolutional code?

• A. Recursive systematic convolutional code
• B. Non-recursive convolutional code
• C. Parallel concatenated convolutional code
• D. Trellis-coded modulation

What is the difference between a rate 1/2 and rate 1/3 convolutional code?

• A. Rate 1/2 codes use less redundancy than rate 1/3 codes
• B. Rate 1/3 codes can correct more errors than rate 1/2 codes
• C. Rate 1/2 codes have a higher data rate than rate 1/3 codes
• D. Rate 1/3 codes have a shorter constraint length than rate 1/2 codes

How does Viterbi decoding work for convolutional codes?

• A. By searching for the most likely sequence of transmitted bits given the received sequence
• B. By calculating the minimum distance between the received sequence and all possible codewords
• C. By generating a syndrome vector and using it to correct errors
• D. By multiplying the received sequence by the inverse of the generator matrix

How can Convolutional Codes be used in satellite communication systems?

• a) To compress images
• b) To encrypt data transmissions
• c) To correct errors in data transmission
• d) None of the above

How do Convolutional Codes improve the reliability of data transmission in noisy channels?

• a) By adding redundant bits to the data
• b) By compressing the data
• c) By encrypting the data
• d) None of the above