frequency domain analysis comsol

... book. 150 FREQUENCY- DOMAIN ANALYSIS xlabel(’Normalized frequency ) subplot(1,2,2) plot(w,HdB);grid title(’Magnitude in dB of the frequency response’) ylabel(’Magnitude in dB’) xlabel(’Normalized frequency ) figure(2) subplot(1,2,1) plot(w,ph);grid title(’Phase ... 2πk) 120 FREQUENCY- DOMAIN ANALYSIS There is some ambiguity in the published literature regarding the definition of what is called the Nyquist frequency. Most of the books define half the sampling frequency ... 3.15, respectively. 148 FREQUENCY- DOMAIN ANALYSIS Suppose that we are given the transfer function of an IIR filter: H(z −1 ) =  M k=0 b k z −k 1 +  N k=1 a k z −k There are two equivalent approaches to find the frequency...

Ngày tải lên: 29/09/2013, 21:20

... 3) CHAPTER 2 Time -Domain Analysis and z Transform 2.1 A LINEAR, TIME-INVARIANT SYSTEM The purpose of analysis of a discrete-time system is to find the output in either the time or frequency domain of ... and model it by equations in the z domain, instead of the equivalent model given by equations (2.1) in the time domain. This example is chosen to illustrate the analysis of a discrete-time system ... natural frequency equal to (0.2) and the term −0.088(0.1) n u(n) with the natural frequency of (0.1), while the zero state response y 0s (n) also contains the term 0.5(0.2) n u(n) with the natural frequency of ( 0.2 ) ....

Ngày tải lên: 29/09/2013, 21:20

... Fourier transform (DFT)  Inverse Fourier transform (IDFT) An M-function Filtering in the Frequency Domain function g = dftfilt(f, H) F = fft2(f, size(H, 1), size(H, 2)); % Perform filtering. g ... 1 2 5 8 5 4 5 8 clear all; clc [U, V] = dftuv(5, 5); D2=U.^2+V.^2 D2c=fftshift(D2) Obtain Frequency Domain Filters from Spatial Filters h= fspecial ('sobel') h = 1 2 1 0 0 0 -1 -2 -1 Paddedsize ... sigma); G=H.*F; g=real(ifft2(G)); subplot(2, 2, 3) imshow(g(1:size(f),1:size(f))) subplot(2, 2, 4) imshow(g) Obtain Frequency Domain Filters from Spatial Filters 2D Fourier transform and its inverse 1 1 2 ( / / ) 0 0 (...

Ngày tải lên: 28/04/2014, 10:35

... the frequency domain. Filtering in frequency domain Original signal Low-pass filtered High-pass filtered function [U, V] = dftuv(M, N) function [U, V] = dftuv(M, N) %DFTUV Computes meshgrid frequency ... … 'FontSize',14) Obtain Frequency Domain Filters from Spatial Filters  The syntax: H = freqz2 (h, R, c) Where h is a 2-D spatial filter and H is the corresponding 2-D frequency domain filter. Consider ... 0.0000 Filtering in the frequency domain The convolution theorem:  Linear spatial convolution is by convolving f(x,y) and h(x,y). The same result is obtained in the frequency domain by multiplying...

Ngày tải lên: 28/04/2014, 10:35

... purposes) Regression plots for low frequency common drive time versus frequency domain techniquesFigure 4 Regression plots for low frequency common drive time versus frequency domain techniques. Regression ... between the time and frequency domain estimates. The use of a short duration window in the time domain method results in the inclusion of multiple frequencies in the time domain correlation estimation ... recordings. One is a frequency domain method and uses the coherence function to determine the degree of linear correlation between each frequency component of the signals. The other is a time domain method...

Ngày tải lên: 19/06/2014, 10:20

... in the frequency domain. IEEE Trans Commun. 53(1), 110–121 (1995) 5. N Benvenuto, S Tomasin, On the comparison between OFDM and single carrier modulation with a DFE using a frequency domain feedforward ... structure for orthogonal frequency division multiple access-based uplink multiuser multiple-input multiple-output systems. The numerical results show that the proposed frequency- domain equalization ... multiple-input multiple-output (MIMO), frequency- domain equalization 1 Introduction Multiple-input multiple-output (MIMO) techniques in combination with orthogonal frequency division multiple access...

Ngày tải lên: 20/06/2014, 22:20

... in frequency- selective channels. Some STBC schemes to deal with frequency selectiv ity have been proposed for orthogonal frequency division multiplexing (OFDM) [6], single-carrier (SC) time -domain ... detection over frequency- selective channels due to intersymbol interference (ISI). In [11], adaptive algorithms to miti- gate ISI effects for frequency domain equalization (FDE) in frequency- selective ... transmission over frequency- selective fading channels. IEEE Trans Inf Theory 49(1), 164–179 (2003). doi:10.1109/TIT.2002.806158 22. S Zhou, G Giannakis, Space-time coding with maximum diversity gains over frequency- selective...

Ngày tải lên: 21/06/2014, 00:20

... sin- gle carrier with frequency domain equalization systems have been proposed in optical communication as an alternative to OFDM [12, 13]. In [12], single carrier frequency domain EURASIP Journal ... al., Frequency- domain equalisation for optical transmission systems,” Electronics Letters, vol. 44, no. 14, pp. 870–872, 2008. [13] C C. Hsieh and D S. Shiu, “Single carrier modulation with frequency ... vector  S I =  S I + −  S I − ,  S Q =  S Q + −  S Q − . (29) The frequency domain transmitted symbols S are then estimated as  S =  S I + j  S Q , (30) where j = √ −1. We then obtain the time domain signal by the taking an...

Ngày tải lên: 21/06/2014, 08:20

... time -domain equalization schemes have been proposed in [9, 10]. Recently, we proposed a near ML-based reduced com- plexity frequency- domain equalization scheme, which is called frequency- domain ... becomes extremely high in a severely frequency- selective channel [2]. Therefore, several suboptimal linear detection schemes, such as time -domain and frequency- domain linear equalization schemes, ... and cost analysis, ” IEEE Transactions on Communica- tions, vol. 32, no. 2, pp. 169–176, 1984. [17] K. Takeda, H. Tomeba, and F. Adachi, “Joint Tomlinson- Harashima precoding and frequency- domain...

Ngày tải lên: 21/06/2014, 08:20

... is required. Another FFT operation is required for the transfor- mation of the time -domain IBI term into frequency- domain. Notice that exact computation of the tanh( ·)functioncan be costly, however ... Blanchi, Frequency domain detectors for ultra-wideband indoor communications,” IEEE Transactions on Wireless Communications, vol. 5, no. 10, pp. 2654–2658, 2006. [8] S. Morosi and T. Bianchi, Frequency ... Bhargava, Frequency- domain turbo equalization and multiuser detection for DS-UWB systems,” IEEE Transactions on Wireless Communications,vol.7,no.9, pp. 3280–3284, 2008. [11] Y. Wang and X. Dong, Frequency- domain...

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