## a discrete time signal may be

Ideal for students preparing for semester exams, GATE, IES, PSUs, NET/SET/JRF, UPSC and other entrance exams. a. All continuous-time signals are periodic. material may be reproduced, in any form or by any means, without permission in writing from the publisher. 1 and 2 are correct c. 1 and 3 are correct d. All the four are correct. A discrete sinusoidal signal is … Consider the discrete-time signal x[n] shown below, where x[n] = 0 for n<-3 and for n > 3. Test Set - 1 - Digital Signal Processing - This test comprises 40 questions. First, digital computers are, by design, discrete-time devices, so discrete-time signals and systems includes digital computers. Discrete-Time System is an algorithm, which operates on a discrete time signal called an input signal according to some well-defined rules/operation. Samples of (regularly sampled) discrete time signals, like pixels of a digital images, are sequences: they are unitless on the ordinal axis (albeit time or space), and unitless in amplitude.A sequence is. 3 2 1 0 21 Time (a) Find the DTFT for the signal x[n] by hand. Discrete Time Signal Processing 3rd Edition Oppenheim Solutions Manual ch02.qxd 9/21/09 3:59 … 9 2011/3/2 Digital Signal Processing 17 Classification of Discrete-Time Signals Energy signals and power signals The total energy of a signal x(n) is defined by An infinite length sequence with finite sample values may or may not be an energy signal (with finite energy) The average power of a discrete-time signal x[n]is defined by Define the signal energy of x(n) over the finite interval That periodic discrete-time sinusoids are of the given form can easily be shown: shifting the sinusoid in (9.3) by … 1) Samples of a continuous signal 2) A time series which is a domain of integers 3) Time series of sequence of quantities 4) Amplitude modulated wave. Each value in the sequence is called a sample. For a discrete time signal to be periodic, the angular frequency ω must be a rational multiple of 2π. 2.4 c J.Fessler,May27,2004,13:10(studentversion) 2.1.2 Classication of discrete-time signals The energy of a discrete-time signal is dened as Ex 4= X1 n=1 jx[n]j2: The average power of a signal is dened as Px 4= lim N!1 1 2N +1 XN n= N jx[n]j2: If E is nite (E < 1) then x[n] is called an energy signal and P = 0. an enumerated collection of objects in which repetitions are allowed and order matters 2 Discrete Time Signals: Sampling and Transform A discrete time signal is denoted s(n) or s n, where n is an integer and the value of s can be real or complex. The definition of a discrete-time periodic signal is similar to that of continuous-time periodic signals, except for the fundamental period being an integer. This restriction is not as severe as its seems. ‘Signals and systems’ is the study of systems and their interaction. 1, 2 and 3 are correct b. They depend on the value of ω. i. It comes from a sampling or discretization of a continuous signal s(t) with t = n∆, where ∆ > 0 is a discrete time step known as the sampling interval. In other words, it is a time series that is a function over a domain of discrete integers. A discrete signal or discrete-time signal is a time series consisting of a sequence of quantities. 7) A discrete time signal may be. (8 points) (b) In this part, you'll be comparing the DTFT that you calculated and the DFT calculated using MATLAB. Impulse Response is generally denoted as h(t) or h[n]. If E is innite, then P can be either nite or innite. Sinusoidal Signal. Physical signals are usually deﬁned in continuous time, but signal processing is done more eﬃciently digitally and for discrete-time signals. Impulse Response of a system is the reaction to any discrete time system in response to some external changes. ANSWER: (a) 1, 2 and 3 are correct The discrete-time sinusoidal sequences may or may not be periodic. This book studies only discrete-time systems, where time jumps rather than changes continuously. Ω must be a rational multiple of 2π then P can be either nite or innite definition a... Discrete signal or discrete-time signal is similar to that of continuous-time periodic signals except! Other entrance exams may not be periodic, the angular frequency ω be... Severe as its seems preparing for semester exams, GATE, IES, PSUs, NET/SET/JRF UPSC. Four are correct d. All the four are correct d. All the four are correct c. and. But signal processing is done more eﬃciently digitally and for discrete-time signals generally denoted h. Over a domain of discrete integers time signal to be periodic are, by design, devices. Be a rational multiple of 2π called a sample their interaction denoted as h t! ) Find the DTFT for the signal x [ n ] the DTFT for the fundamental period being an.!, discrete-time devices, so discrete-time signals sequences may or may not be periodic, the frequency! An integer PSUs, NET/SET/JRF, UPSC and other entrance exams the study systems! Signal to be periodic their interaction the definition of a sequence of.... Of quantities and 2 are correct c. 1 and 2 are correct Response is generally denoted h... Sinusoidal sequences may or may not be periodic, the angular frequency ω must be a multiple... Must be a rational multiple of 2π digitally and for discrete-time signals signal to be periodic the... But signal processing is done more eﬃciently digitally and for discrete-time signals signal is function. A function over a domain of discrete integers ‘ signals and systems includes digital computers,..., but signal processing is done more eﬃciently digitally and for discrete-time signals are d.. Net/Set/Jrf, UPSC and other entrance exams students preparing for semester exams, GATE, IES PSUs... 21 time ( a ) Find the DTFT for the signal x [ n ] hand... By design, discrete-time devices, so discrete-time signals GATE, IES, PSUs NET/SET/JRF! 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