1. Consider a baseband binary PAM receiver shown below. The additive channel noise n(t) is whit with power spectral density SN(f) = N0/2 = 10-20 W/Hz. The low-pass filter is ideal with unity gain and cutoff frequency 1 MHz. Let Yk represent the random variable y(tk). Yk = nNk if transmitted bit bk = 0 Yk = a + Nk if transmitted bit bk = 1 Where Nk represents the noise sample value. The noise sample has a probability density function, PNk(n) = 0.5a e-a|n| (This has mean zero and variance 2/a 2). Assume transmitted bits to be equiprobable and threshold z is set to a /2 = 10-6 V. The value of the parameter a (in V-1) is