申論題

6. [20%] As shown in Figure 4, the transmitted signal has a binary number . The received signal is added by a random noise N with the probability density function (PDF) as depicted in the figure. The resultant signal Y is also binary and obtained with a sign-function as the decision threshold is at Z, i.e.,.

(b) If the binary number of Xis transmitted with unequal probabilities P(+1)=0.6 and P(-1) = 0.4. Find the optimum decision threshold Z such that the error probability for detecting X from Y is minimum? What is the minimum detection error probability? (10%)