Unformatted text preview: -6-2.15Interference is avoided under frequency division multiplexing by the use of guardbands, which are unused portions of the frequency spectrum betweensubchannels.2.16A synchronous time division multiplexer interleaves bits from each signal andtakes turns transmitting bits from each of the signals in a round-robin fashion.AANSWERS TO NSWERS TO PPROBLEMSROBLEMS2.1Period = 1/1000 = 0.001 s = 1 ms.2.2 a.sin (2πft – π) + sin (2πft + π) = 2 sin (2πft + π) or 2 sin (2πft – π) or - 2 sin (2πft)b.sin (2πft) + sin (2πft – π) = 0.2.3NCDEFGABCF264297330352396440495528D33332244445533W1.251.1110.930.830.750.670.63N = note; F = frequency (Hz); D = frequency difference; W = wavelength (m)2.42 sin(4πt + π); A = 2, f = 2, φ= π2.5(1 + 0.1 cos 5t) cos 100t = cos 100t + 0.1 cos 5t cos 100t. From the trigonometricidentity cos a cos b = (1/2)(cos(a + b) + cos(a – b)), this equation can be rewritten asthe linear combination of three sinusoids:cos 100t + 0.05 cos 105t + 0.05 cos 95tcos 100t + 0....
View Full Document
- Fall '11
- Frequency, Wavelength, Cos, Time-division multiplexing, 352 22 1 G