This page describes decimation process with figures and example,mention matlab command for decimation. The problem is there really is no guarantee that your received signal is 40MHz, esp. Oversampling is capable of improving resolution and signal-to-noise … 10.1(a). usually refers to one step of the process, but sometimes the terms are used interchangeably. Hence it is also called Down sampling. This will allow greater frequency resolutions at low frequencies for vibration measurements and similar applications. This feature is used to achieve a lower sampling rate than that supported by the sound card. In multirate digital signal processing the sampling rate of a signal is changed in or-der to increase the e–ciency of various signal processing operations. rate is lower than the sampling rate of the available data. The figure(b) is my answer. Decimation process Decimation. Decimation Ratio The decimation ratio value controls the ratio with which the digitized audio is down-sampled". Given X with sampling rate Ft Hz and is used to generate another sequence Y with sampling rate Ft' Hz, then Sampling Rate ratio R is given by, Ft' R = ---- Ft if R > 1, sampling process is known as interpolation R < 1, sampling process is known as decimation Example Usage: t = 1:1/10:2; X = sin (2 * pi * 10 * t) % 10 Hz sine wave in communication where additive white noise (AWGN) is a big part of the model. Decimating, or downsampling, a signal x(n) by a factor of D is the process of creating a new signal y(n) by taking only every Dth sample of x(n). That is, the frequency component between 3/10*Fs to 5/10*Fs can not be represented correctly. The term downsampling usually refers to one step of the process,but sometimes the terms are used interchangeably.Complementary to upsampling,which increases sampling rate,decimation is a specific case of sample rate conversion in a multi-rate digital signal processing system The process Of sampling rate converston in the digital domain can be viewed as a linear filtering operation. Since the sampling rate is reduced to 3/5*Fs, the aliasing happens. In this case, we must use a process called decimation to reduce the sampling rate of the signal. The process of reducing a sampling rate by an integer factor is referred to as downsampling of a data sequence.We also refer to downsampling as ''decimation'' (not taking one of ten). The Nyquist rate is defined as twice the bandwidth of the signal. Some applications of multirate The term ''decimation'' used for the downsampling process has been … The figure(a) is the original one you provided. Complementary to upsampling, or interpolation, which increases sampling rate, decimation is a specific case of sample rate conversion in a multi-rate digital signal processing system. The input signal x(n) is characterized by the sampling rate FI = 1/Tx and the output signal y(m) is characterized by the sampling rate Fy = where and are the corre- sponding sampling intervals. Decimation is the process which decreases the sampling rate of the signal. as illustrated in Fig. In signal processing, oversampling is the process of sampling a signal at a sampling frequency significantly higher than the Nyquist rate.Theoretically, a bandwidth-limited signal can be perfectly reconstructed if sampled at the Nyquist rate or above it. Therefore y(n) is simply x(Dn). Decimation, or down-sampling, reduces the sampling rate, whereas expansion, or up-sampling, fol-lowed by interpolation increases the sampling rate.