The received baseband signal at sample index n is given by r[n] = 2s[n − 1] − s[n − 2] + 0.5s[n − 3] + v[n] where s[.] is the transmitted signal and v[.] is the additive white Gaussian noise. State the Channel Impulse Response (CIR) h[n], and sketch as well as carefully label the signal flow graph of a finite impulse response filter which models the CIR.