Question

Consider baseband modulation, with each bit of duration Th. The pulse shape is p(t) = II(t/Tb). The PSDs for the bipolar, on-off, and polar signaling are shown in the figure below. Identify what curve (labeled a -c) corresponds what line code. 1 0.9 0.8 0.7 (a) 0.6 Amplitude 0.5 0.4 0.3 0.2 0.1 0 -2 -1.5 -1 -0.5 0 0.5 1.5 2 f/ To (Hz) Screen Shot 2018-04-21 at 2.29.09 PM.png

Answer 1

Considered baseband modulation 1 to be ON I OFF signalling Symbols independent and equally likely TT (t/T6) O on A. p(t) = plt) Rect (0, To ft) 7 Pf) = To sine (fTo) e j Mf To 1Pff)/? P.S.D - Sulf) Rolk ] ejere To K-- PSD fTb 2. Polar signalling to be Symbols independent and equally likely - A OA P(f) = Ty sinc (4 b)e-inf to PSD Sulf) = 1? To Sinc? (f Tb) CS Scanned with CamScanner

PSD 2, f Tb 3. Bipolas signalling Successive is have alternating polarity Zero Amplitude 0 1 + A oi -A j PSD -sucf) = Tu sineºff To) 92 - Selamat To e-jarif Toy ] t A’To Sinc(f Tb) Sind(ref ) PSD 0.5 A f Tь CSScanned with CamScanner

a comparing with given Pso's Polar Signalling ON/OFF signalling (PSD) Bipolar signalling (PSD) (PSD) C b option is correct. CSScanned with CamScanner