An orthogonal set of signals is characterized by the property An orthogonal set of signals is characterized by the property that the inner product any pair of signals in the set is zero. Figure shows a pair of signals s1 (t) and s2 (t) that satisfy this condition. Construct the signal constellation for s1 (t) […]
An interesting property of π/4-shifted DQPSK signals is tha An interesting property of Ď/4-shifted DQPSK signals is that they can be demodulated using an FM discriminator. Demonstrate the validity of this property.
An FSK system transmits binary data at the rate An FSK system transmits binary data at the rate of 2.5 x 106 bits per second. During the course of transmission, white Gaussian noise of zero mean and power spectral density 10-20 W/Hz is added to the signal. In the absence of noise, the amplitude of […]
An FDM system uses single-sideband modulation to combine 12 An FDM system uses single-sideband modulation to combine 12 independent voice signals and then uses frequency modulation to transmit the composite band 0.3 to 3.4 kHz; the system allocates it a bandwidth of 4 kHz. For each voice signal, only the lower sideband is transmitted. The […]
Consider a chain of (n — 1) regenerative repeaters, with Consider a chain of (n â 1) regenerative repeaters, with a total of n sequential decisions made on a binary PCM wave, including the final decision made at the receiver. Assume that any binary symbol transmitted through the system has an independent probability p1 of […]
An FM signal with modulation index β = 1 is transmitted an An FM signal with modulation index β = 1 is transmitted an ideal band-pass filter with mid-band frequency A?c and bandwidth 5A?m, where A?c is the carrier frequency and A?m is the frequency of the sinusoidal modulating wave. Determine the magnitude spectrum of […]
An Fm signal with a frequency deviation of 10 kHz An Fm signal with a frequency deviation of 10 kHz at a modulation frequency of 5 kHz is applied to two frequency multiplier connected is cascade. The first multiplier doubles the frequency and the second multiplier triples the frequency. Determine the frequency deviation and the […]
Consider Equation (4.108), which defines the impulse response of Figure shows the cascade connection of a linear channel and a synchronous tapped delay-line equalizer. The impulse response of the channel is denoted by c (t), and that of the equalizer is denoted by h (t). The h (t) is defined by, where T is the […]
Consider a pair of complex-valued signals s1 (t) and s2 (t) that Consider a pair of complex-valued signals s1 (t) and s2 (t) that are respectively represented by s1 (t) = a11 F1 (t) + a12 F2 (t), â 8 < t=””>< 8,=”” s2=”” (t)=”a21″ F1=”” (t)=”” +=”” a22=”” F2=”” (t),=”” â=”” 8=””>< t=””>< 8,=”” […]
Consider a narrowband FM signal approximately defined by s Consider a narrowband FM signal approximately defined by s (t) = Ac cos (2pA?ct) – ßAc sin (2pA?ct) sin (2pA?mt) (a) Determine the envelope of this modulated signal. What is the ratio of the maximum to the minimum value of this envelope? Plot this ratio versus […]