In coding gain & bandwidth of TCM, if the signal energy is kept constant, the . . . . . . . . of constellation reduces the noise margin and results into the degradation of performance. A. Expansion B. Compression C. Both A and B D. None of the above

[amp_mcq option1=”Expansion” option2=”Compression” option3=”Both A and B” option4=”None of the above” correct=”option2″]

The correct answer is: B. Compression

In TCM, the signal energy is kept constant by increasing the power of the transmitted signal. This results in an increase in the signal-to-noise ratio (SNR), which improves the performance of the system. However, if the constellation is compressed, the noise margin is reduced, which results in a degradation of performance.

The following is a brief explanation of each option:

  • Option A: Expansion. If the constellation is expanded, the noise margin is increased, which results in an improvement in performance. However, this also results in an increase in the bandwidth of the transmitted signal.
  • Option B: Compression. If the constellation is compressed, the noise margin is reduced, which results in a degradation of performance. However, this also results in a decrease in the bandwidth of the transmitted signal.
  • Option C: Both A and B. If the constellation is both expanded and compressed, the noise margin is both increased and reduced. This results in a complex trade-off between performance and bandwidth.
  • Option D: None of the above. None of the options above accurately describes the effect of constellation compression on performance.