Question

A communication system has a Gaussian pdf with zero mean, o = 1/2 variance and a bandwidth W = 10kHz with noise power No 10-15 W/Hz. The transmission loss power is 100dB. Calculate the transmitted power, St, to achieve the output signal to noise ratio, (Sp)... = 40 dB for each modulation scheme as listed below. Show your all calculations for each modulation scheme in detail and explain your solutions clearly. SSB b. DSB-LC with modulation index u = 1 and u = 0.5 PM with phase deviation A = i d. FM with modulation index, ß = 1,5 and 10. a. c.

Answer 1

given bundwidth= lokne, No = 105 wille Pouse loss loodB (bout 40 dB > transmitted Power Sy(SSB) Sy= Pent Total Power required akTBA signd Power power loss - No JB + signdpower x porter dess Power loss lop= løtug (!) lo signd road 10 x 2x105 = 0.2 watty (since she lot) Thound noise & wel = 1.38x133, x290xloxlo? 4. oralalt Total Powd required (ocha 4.0024107 +0.24 10 watts & 100 watts SSB ST=cn 4 Let ml (critid rodziction)

Sy= lo X - 5x10 watts 2 1st=98.98 dB USB-le "=1 & ei sypeme Pa 100 watts Sy= 10 lo (4=1) 2 sxid 96.98 dB STCdB) = Sy= Pent a=0.5 -100 x(0.512 1.25x 109 SyldB) = 90.96 dB

(C) Pon with Pile deviation of all so Af=ß=3114 (87) Profo=(total Fowels Py = Sp= 100 watts in 100dB

d Fon with modyl bin index 8 = 1,5, 10 se Pelleft) ($=1) for N8fm Ses &(1+2) = 2 kc Se= x 10 = 1.5x1! watts St=101.76 dB Syspe=100 watts for($71) ice worm ice Pe=AC = 2 = 10 watts for B=5&10 Pe - looda