GATE EC 2024 Set 1 — Question 45
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Communications → Digital Modulation & Detection → Error Probability
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Question
A source transmits a symbol , taken from with equal probability, over an additive white Gaussian noise channel. The received noisy symbol is given by , where the noise is zero mean with variance 4 and is independent of . Using , the optimum symbol error probability is _______.
Correct answer
(B) (4)/(3)Q(1)
Solution
The symbols are with . The noise has variance , so . For equiprobable symbols, the optimum decision boundaries are at the midpoints: and .
1.Conditional Error Probabilities:
- For : Error occurs if .
- For : Error occurs if .
- For : Error occurs if or or .
2.Total Symbol Error Probability:
.Thus, the correct option is (B).Continue learning with Success Tracker
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