Tugas Perhitungan Sistem Telekomunikasi Digital

TUGAS SISTEM TELEKOMUNIKASI DIGITAL SOAL1 Dibimbing Oleh: RACHMAD SAPTONO, ST. MT.

OLEH: ELSA LOLITA ANGGRAINI JTD-2A 1441160009

D4-JARINGAN TELEKOMUNIKASI DIGITAL JURUSAN TEKNIK ELEKTRO POLITEKNIK NEGERI MALANG

2015 Tugas Perhitungan Sistem Telekomunikasi Digital 1. Analog signal is expressed by the equation x(t) = 3 cos 50πt + 10 cos 300πt – cos 100πt. Calculate the Nyquist rate for this signal. Jawab: x(t) = 3 cos 50πt + 10 cos 300πt – cos 100πt ω1 = 50π = 2πf1  f1 = 25 Hz ω2 = 300π = 2πf2  f2 = 150 Hz ω3 = 100π = 2πf3  f3 = 50 Hz  fs = 2 x fm fs = 2 x 150 Hz = 300 Hz 1 1  Ts = f s = 300 = 3,3 ms

2. Find the nyquist rate and the nyquist interval for the signal x(t) = (4000πt) . cos(1000πt)  2cosA cosB Jawab: 1 x(t) = 2 π . cos (4000πt) . cos(1000πt)

=

1 π 2

3000 πt cos 500 πt+cos ¿ 1 ¿ 2 ¿

500 πt 3000 πt cos ¿ ¿ 1 = cos ¿+ π ¿ 4 1 π¿ 4 ω1 = 2πf1  f1 =

5000 π =2,5 KHz 2π

ω1 = 2πf2  f2 =

3000 π =1,5 KHz 2π

1 fs

1 5 KHz

−3 = 0,2 x 10 s



Ts =



fs = 2 x fm fs = 2 x 2,5 KHz = 5 KHz

=

1 π 2

. cos

3. Determine the nyquist rate for the continueus time signal x(t) = 3 sin (2000πt) . cos (100πt) Jawab: x(t) = 3 sin (2000πt) . cos (100πt) 3 = 2 [( sin 300 π t ) +sin ( 100 π t ) ]

{

=

3 3 ( sin 300 π t )+ ( sin100 π t ) 2 2

ω1 = 2πf1  f1 =

300 π =150 Hz 2π

ω1 = 2πf2  f2 =

100 π =50 Hz 2π



}

fs = 2 x fm fs = 2 x 150 Hz = 300 Hz 1 1 −3 Ts = f s = 300 Hz = 3,3 x 10 s