 Home
 Products
 Integration
 Tutorial
 Barcode FAQ
 Purchase
 Company
barcode generator for ssrs /Ideal Zeroorder hold in Software
/Ideal Zeroorder hold Code 128 Code Set B Recognizer In None Using Barcode Control SDK for Software Control to generate, create, read, scan barcode image in Software applications. Making Code 128A In None Using Barcode maker for Software Control to generate, create Code 128 Code Set B image in Software applications. interpolating filter
Scan ANSI/AIM Code 128 In None Using Barcode reader for Software Control to read, scan read, scan image in Software applications. Code 128 Code Set B Generation In C#.NET Using Barcode printer for .NET framework Control to generate, create ANSI/AIM Code 128 image in Visual Studio .NET applications. Fig. 38. (a) The magnitude of the frequency response of a zeroorder
Print ANSI/AIM Code 128 In .NET Framework Using Barcode encoder for ASP.NET Control to generate, create Code 128A image in ASP.NET applications. Create Code 128 Code Set A In .NET Using Barcode printer for Visual Studio .NET Control to generate, create USS Code 128 image in Visual Studio .NET applications. hold compared to the ideal reconstruction filter. (b)The ideal reconstruction compensation filter.
Make Code 128B In Visual Basic .NET Using Barcode encoder for .NET Control to generate, create Code 128A image in .NET framework applications. EAN128 Generation In None Using Barcode drawer for Software Control to generate, create GS1128 image in Software applications. DISCRETETIME PROCESSING OF ANALOG SIGNALS
Bar Code Maker In None Using Barcode maker for Software Control to generate, create barcode image in Software applications. Making Data Matrix 2d Barcode In None Using Barcode creator for Software Control to generate, create DataMatrix image in Software applications. One of the important applications of A D and D/A converters is the processing of analog signals with a discretetime system. In the ideal case, the overall system, shown in Fig. 39, consists of the cascade of a C/D converter, a discretetime system, and a D/C converter. Thus, we are assuming that the sampled signal is not quantized and that an ideal lowpass filter is used for the reconstruction filter in the D/C converter. Because the input x a ( t ) and the output ya(t) are analog signals, the overall system corresponds to a continuoustime system. To analyze this system, note that the C/D converter produces the discretetime signal x ( n ) , which has a DTFT given by Paint Code128 In None Using Barcode drawer for Software Control to generate, create Code 128 Code Set A image in Software applications. Universal Product Code Version A Drawer In None Using Barcode maker for Software Control to generate, create GTIN  12 image in Software applications. If the discretetime system is linear and shiftinvariant with a frequency response H ( e j W ) , MSI Plessey Creation In None Using Barcode encoder for Software Control to generate, create MSI Plessey image in Software applications. Create Code 3/9 In None Using Barcode drawer for Online Control to generate, create Code39 image in Online applications. CHAP. 31
Painting Bar Code In Java Using Barcode generator for Android Control to generate, create barcode image in Android applications. Data Matrix ECC200 Decoder In None Using Barcode reader for Software Control to read, scan read, scan image in Software applications. SAMPLING
EAN / UCC  13 Recognizer In None Using Barcode reader for Software Control to read, scan read, scan image in Software applications. Painting UPCA In Java Using Barcode drawer for Java Control to generate, create UPCA Supplement 2 image in Java applications. Fig. 39. Processing an analog signal using a discretetime system.
Drawing UPCA In ObjectiveC Using Barcode generator for iPhone Control to generate, create GTIN  12 image in iPhone applications. EAN13 Supplement 5 Reader In Java Using Barcode decoder for Java Control to read, scan read, scan image in Java applications. Finally, the D/C converter produces the continuoustime signal y,(t) from the samples y ( n ) as follows: ~ ~= ( t C0 y ( n )sin n ((  nT,)/ Ts ~ tnT,)/Ts
n =  ~
Either using Eq. (3.7) or by taking the DTFT directly, in the frequency domain this relationship becomes If x,(t) is bandlimited with X , ( j Q ) = 0 for IQI > T I T , , the lowpass filter H , ( j Q ) eliminates all terms in the sum except the first one, and Therefore, the overall system behaves as a linear timeinvariant continuoustime system with an effective frequency response n H(ejnK) lQl I H,(jQ) = 1 0 otherwise TS Just as a continuoustime system may be implemented in terms of a discretetime system, it is also possible to implement a discretetime system in terms of a continuoustime system as illustrated Fig. 310. The signal x,(t) is related to the sequence values x ( n ) as follows: Fig. 310. Processing a discretetime signal using a continuoustime system.
Because x,(t) is bandlimited, y,(t) is also bandlimited and may be represented in terms of its samples as follows: SAMPLING
[CHAP. 3
The relationship between the Fourier transform of x a ( t )and the DTFT of x ( n ) is
X a ( j n )= cx(ejaTs) Is21 < T, otherwise
and the relationship between the Fourier transforms of x, (t ) and ya (t) is
n Y a ( j n )= ( ~ ~ ( j ~ r ( j" I W< Ts otherwise
Therefore, and the frequency response of the equivalent discretetime system is
3.5 SAMPLE RATE CONVERSION
In many practical applications of digital signal processing, one is faced with the problem of changing the sampling rate of a signal. The process of converting a signal from one rate to another is called sample rate conversion. There are two ways that sample rate conversion may be done. First, the sampled signal may be converted back into an analog signal and then resampled. Alternatively, the signal may be resampled in the digital domain. This approach has the advantage of not introducing additional distortion in passing the signal through an additional D/A and A D converter. In this section, we describe how sample rate conversion may be performed digitally. 3.5.1 Sample Rate Reduction by an Integer Factor
Suppose that we would like to reduce the sampling rate by an integer factor, M. With a new sampling period T,' = MT,, the resampled signal is Therefore, reducing the sampling rate by an integer factor M may be accomplished by taking every Mth sample of x(n). The system for performing this operation, called adownsampler, is shown in Fig. 31 l(a). Downsampling generally results in aliasing. Specifically, recall that the DTFT of x ( n ) = x,(nT,) is Similarly, the DTFT of x&) = x(n M ) = x,(n M T,) is
Note that the summation index r in the expression for Xd(ejo)may be expressed as
r=i+kM
CHAP. 31
SAMPLING
Fig. 311. (a)Downsamplingby an integer factor M . ( b )Decimation by a factor of M, where H ( e j U )is a lowpass filter with a cutoff frequency where oo < k < oo and 0 5 i 5 M  1. Therefore, X d ( e J Wmay be expressed as ) The term inside the square brackets is
Thus, the relationship between x ( e j w ) and X d ( e j w )is
xd (ejw) = _ C ~ ( ~ i i w  2 n k l l1M
Therefore, in order to prevent aliasing, x ( n ) should be filtered prior to downsampling with a lowpass filter = that has a cutoff frequency o,. n / M . The cascade of a lowpass filter with a downsampler illustrated in Fig. 3 11(b) is called a decimator.

