#Torrent Signal Processing First series#

The process of sampling rate decrease is called decimation, and the process of sampling rate increase is called interpolation. Sampling rate conversion systems are used to change the sampling rate of a signal. Multirate Filtering for Digital Signal Processing. Decimators can be used to reduce the sampling frequency, whereas interpolators can be used to increase it. Decreasing the sampling rate is known as decimation. Digital Signal Processing: Principles, Algorithms and Applications (3rdВ ed.).

Generally, this approach is applicable when the ratio Fy/Fx is a rational, or an irrational number, and is suitable for the sampling rate increase and for the sampling rate decrease. In reality the processes of bandwidth reduction and sample rate reduction are merged in a single process called a multirate filter. The sample rate of the output sequence is then reduced Q-to-1 to a rate commensurate with the reduced signal bandwidth.

#Torrent Signal Processing First series#

The process starts as an input series x(n) that is processed by a filter h(n) to obtain the output sequence y(n) with reduced bandwidth. The process of down sampling can be visualized as a two-step progression. Upper Saddle River, NJ: Prentice Hall PTR. Multirate Signal Processing for Communication Systems. Handbook of Formulas and Tables for Signal Processing (1В ed.). The term decimation used for the downsampling process has been accepted and used in many textbooks and fields. We also refer to downsampling as decimation. The process of reducing a sampling rate by an integer factor is referred to as downsampling of a data sequence. Discrete-Time Signal Processing (2ndВ ed.). The calculation performed by a decimating FIR filter for the n th output sample is a dot product: y = в€‘ k = 0 K в€’ 1 x в‹… h, cycles per intermediate sample, is the lower frequency. With FIR filtering, it is an easy matter to compute only every M th output. When the anti-aliasing filter is an IIR design, it relies on feedback from output to input, prior to the second step. Also see undersampling for information about decimating bandpass functions and signals. In this application, the filter is called an anti-aliasing filter, and its design is discussed below. Step 1, when necessary, suppresses aliasing to an acceptable level. Step 2 alone allows high-frequency signal components to be misinterpreted by subsequent users of the data, which is a form of distortion called aliasing.

Decimate the filtered signal by M that is, keep only every M th sample.

Reduce high-frequency signal components with a digital lowpass filter.

Rate reduction by an integer factor M can be explained as a two-step process, with an equivalent implementation that is more efficient: Decimation by an integer factor is also called compression. A system component that performs decimation is called a decimator. For example, if compact disc audio at 44,100 samples/second is decimated by a factor of 5/4, the resulting sample rate is 35,280. This factor multiplies the sampling interval or, equivalently, divides the sampling rate. But in signal processing, decimation by a factor of 10 actually means keeping only every tenth sample. When the process is performed on a sequence of samples of a signal or a continuous function, it produces an approximation of the sequence that would have been obtained by sampling the signal at a lower rate (or density, as in the case of a photograph).Дecimation is a term that historically means the removal of every tenth one. Both downsampling and decimation can be synonymous with compression, or they can describe an entire process of bandwidth reduction ( filtering) and sample-rate reduction.

In digital signal processing, downsampling, compression, and decimation are terms associated with the process of resampling in a multi-rate digital signal processing system.