Both downsampling and decimation can be synonymous with compression, or they can describe an entire process of bandwidth reduction and samplerate reduction. Examples of multidimensional signals include images in two dimensions and video in three dimensions. Multirate signal processing is at the heart of most modern compression systems and standards, including jpeg, mpeg, and so on. Lecture series on digital signal processing by prof. In practice, this usually implies lowpassfiltering a signal, then throwing away some of its samples.
Consider the design of a digital voice recorder, a system that will digitize a voice signal, store the data in digital form, and later reconstruct the signal for playback. Motivated by recent developments, this paper studies the concept of spectrum folding aliasing for graph signals under the downsamplethenupsample operation. Full text of multirate filtering for digital signal. An economical class of digital filters for decimation and interpolation ieee trans. Baas, eec 281 432 multirate signal processing advantages of lower sample rates may require less processing likely to reduce power dissipation, p cv2 f, where f is frequently directly proportional to the sample rate likely to require less storage.
Multirate filters alter the sample rate of the input signal during the filtering process. Signal processing on graphs finds applications in many areas. The focus here is to be able to view in the frequency domain what is happening at each stage of a system involving upsamplers, downsamplers, and lowpass filters. Change the sample rates of a sinusoid and a recorded speech sample. Lets say that now youre creating a stereo fm signal. Polyphase structure for decimation and interpolation filters. Sometimes you have to interpolate increase the sampling rate. Code is provided for the desired test signal to be polyphase interpolated, save the wideband time. Multirate refers to the fact that different sequences may have different time scales. Downsampling is a more specific term which refers to just the process of throwing away samples, without the lowpass filtering operation. Decimate, interpolate, or change the sample rate of signals, with or without intermediate filtering. Building blocks for traditional singlerate digital signal processing. Multirate systems are sometimes used for samplingrate conversion 3. Then decimate to 48khz by removing 146 samples in every.
Full text of multirate filtering for digital signal processing matlab applications see other formats. Block diagram of a decimator and example signal spectra for m3. Simulate the output of a sampleandhold system by upsampling and filtering a signal. Pdf digital signal processing dsp has become one of the most. Multirate digital signal processing systems that employ multiple sampling rates in the processing of digital signals are called multirate digital signal processing systems. Downsampling is a more specific term which refers to just the process of throwing. In this paper we present a tutorial overview of multirate digital signal processing as applied to systems for decimation and interpolation. Multirate sampling simulation using matlabs signal. Multirate digital signal processing prasanta kumar ghosh oct 25, 2018. To recreate intelligible speech, the system must capture the.
Upsample example multrate signal processing is used for the practical applications in signal processing to save costs, processing time, and many other practical reasons. One of the basic operations in multirate signal processing is upsampling. Multirate digital signal processing in multirate digital signal processing the sampling rate of a signal is changed in order to increase the eciency of various signal processing operations. Loosely speaking, decimation is the process of reducing the sampling rate.
Multirate digital signal processing zena mohammed 2. In digital signal processing, downsampling, compression, and decimation are terms associated with the process of resampling in a multirate digital signal processing system. Decimation sampling rate decrease by an integer factor m. Multirate signal processing an overview sciencedirect. This site is like a library, use search box in the widget to get ebook. Multirate signal processing consists of using different sample rates within a system to achieve computational efficiencies that are impossible to obtain with a system that operates on a single fixed sample rate. Deepa kundur university of torontomultirate digital signal processing. Multirate signal processing discrete time signal processing. Multirate digital signal processing university of newcastle upon tyne page 9. Multirate data conversion digital signal processing. Good reference texts for background material on multidimensional signal processing are dudgeon and mersereau16 and lim26. Applications of multirate signal processing fundamentals decimation interpolation resampling by rational fractions multirate identities polyphase representations maximally decimated. The multistage decimation values can therefore be d 1 8 and d 2 4, creating an intermediate signal with sampling.
Multirate signal processing techniques are widely used in many areas of modern engineering such as communications, digital audio, measurements, image and signal processing, speech processing, and. Basu, department of electrical engineering, iit kharagpur. This chapter extends the basic concepts of multirate signal processing to multidimensional multirate signal processing. When the process is performed on a sequence of samples of a. We note that mfold decimation in the time domain changes the signal spectrum in two ways. Ece700 multirate notes phil schniter march 27, 2006. Defines a multistage filter and describes its uses. You need to shift the spectrum of the lm signal from the range 015 khz to the range 2338 khz. Video lecture on multirate signal processing from multirate signal processing chapter of discrete time signals processing for electronics engineering students. Why compute filter output and then throw away samples. Theory of multirate signal processing with application to. Current practice and next generation techniques fredric j harris.
Multirate signal processing can reduce costs and improve performance in applications ranging from laboratory instruments to cable modems, wireless systems, and consumer entertainment products. This example shows how to design lowpass fir nyquist filters. The subject of aliasing in decimated signals is covered in more detail in section 9. Decimation and interpolation the basic decimator model is a lowpass filter followed by a downsampler. All computations will be performed using matlab and the signal processing toolbox. As an example, consider the following lowpass filter. Multirate signal processing for communication systems. Multirate digital signal processing newcastle university staff. Interpolation and decimation of digital signalsa tutorial. Sampling rate conversion with cascaded integrator comb filters. Decimation and interpolation building blocks for traditional singlerate digital signal processing.
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