In a mobile radio system (e.g., cell phones), there is one type of degradation that can be modeled easily with sinusoids. This is the case of multipath fading caused by reﬂections of the radio waves interfering destructively at some locations. Suppose that a transmitting tower sends a sinusoidal signal, and a mobile user receives not …

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In a mobile radio system (e.g., cell phones), there is one type of degradation that can be modeled easily with sinusoids. This is the case of multipath fading caused by reﬂections of the radio waves interfering destructively at some locations. Suppose that a transmitting tower sends a sinusoidal signal, and a mobile user receives not …

Continue reading "In a mobile radio system (e.g., cell phones), there is one type of degradation that can be…"
We have seen that musical tones can be modelled mathematically by sinusoidal signals. If you read music or play the piano, you know that the piano keyboard is divided into octaves, with the tones in each octave being twice the frequency of the corresponding tones in the next lower octave. To calibrate the frequency scale, …

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To see why the derivative of the angle function would be the instantaneous frequency, repeat the experiment of Section 3-7.2. (a) Use the following parameters to define a chirp signal: f1 = 1 Hz, f2 = 9 Hz, T2 = 2 s Determine α and β in (3.46) to define x(t) so that it sweeps …

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In the rotating disk and strobe demo, we observed that different flashing rates of the strobe light would make the spot on the disk stand still. (a) Assume that the disk is rotating in the counterclockwise direction at a constant speed of 12 rev/s. Express the movement of the spot on the disk as a …

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Suppose that an LTI system has system function equal to The input to the system is the sequence x[n] = 2δ[n] + 3δ[n − 3] − 8δ[n − 6] + 3δ[n − 9] (a) Without actually computing the output, determine the values of N1 and N2 so that the following is true: (b) Using N1 …

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Suppose that a system is defined by the system function (a) Write the time-domain description of this system in the form of a difference equation. (b) Write a formula for the frequency response of the system. (c) Derive simple formulas for the magnitude response versusωˆ and the phase response versus ωˆ. These formulas must contain …

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Given an IIR filter defined by the difference equation (a) When the input to the system is a unit-step sequence, u[n], determine the functional form for the output signal y[n]. Use the inverse z-transform method. Assume that the output signal y[n] is zero for n (b) Find the output when x[n] is a complex exponential …

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Answer the following questions about the system whose z-transform system function is (a) Determine the poles and zeros of H (z). (b) Derive a simple expression (purely real) for the magnitude squared of the frequency response (c) Is this filter a lowpass filter or a high pass filter? Explain your answer in terms of the …

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Malani wants to determine whether children whose preschool classroom has a window differ in their receptive vocabulary as compared to children whose classroom does not have a window. At the beginning of the school year, Malani randomly assigns 10 children at Rainbow Butterfly Preschool to one of two different classrooms: one classroom has a window …

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