标签:main 时域 src parse atl rsh bsp problem color
证明:
代码:
%% ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ %% Output Info about this m-file fprintf(‘\n***********************************************************\n‘); fprintf(‘ <DSP using MATLAB> Problem 5.21 \n\n‘); banner(); %% ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ % --------------------------------------------------------------------------------- % % Parseval relation % sum[abs(x(n))^2] = sum[abs(X(k))^2]/N % % --------------------------------------------------------------------------------- n = [0:10]; x = [5, 4, 3, 2, 1, 0, 0, 1, 2, 3, 4]; % N=11 sequence N = length(x); Exn = sum(abs(x).^2) m1 = -5; N1 = 12; n1 = [0:N1-1]; m2 = 8; N2 = 15; n2 = [0:N2-1]; % ----------------------------------------------------- % 1st way to get circular shift---time domain % ----------------------------------------------------- y1_1 = cirshftt(x, m1, N1); y2_1 = cirshftt(x, m2, N2); % -------------------------------------------------------- % 2rd way to get circular shift --- freq domain % -------------------------------------------------------- y1_2 = cirshftf(x, m1, N1); y2_2 = cirshftf(x, m2, N2); figure(‘NumberTitle‘, ‘off‘, ‘Name‘, ‘P5.21.a x(n) and its cir shift‘) set(gcf,‘Color‘,‘white‘); subplot(3,1,1); stem(n, x); xlabel(‘n‘); ylabel(‘x(n)‘); title(‘x(n), N=11‘); grid on; subplot(3,1,2); stem(n1, y1_1); xlabel(‘n‘); ylabel(‘y(n)‘); title(‘TIME domain circular shift x(n), m=-5, N=12‘); grid on; subplot(3,1,3); stem(n1, y1_2); xlabel(‘n‘); ylabel(‘y(n)‘); title(‘FREQ domain circular shift x(n), m=-5, N=12‘); grid on; axis([0, N1, 0, 6]); figure(‘NumberTitle‘, ‘off‘, ‘Name‘, ‘P5.21.b x(n) and its cir shift‘) set(gcf,‘Color‘,‘white‘); subplot(3,1,1); stem(n, x); xlabel(‘n‘); ylabel(‘x(n)‘); title(‘x(n), N=11‘); grid on; subplot(3,1,2); stem(n2, y2_1); xlabel(‘n‘); ylabel(‘y(n)‘); title(‘TIME domain circular shift x(n), m=8, N=15‘); grid on; subplot(3,1,3); stem(n2, y2_2); xlabel(‘n‘); ylabel(‘y(n)‘); title(‘FREQ domain circular shift x(n), m=8, N=15‘); grid on; axis([0, N2-1, 0, 6]); % ---------------------------------------------------- % DFT of sequence % ---------------------------------------------------- Xk_DFT = dft(x, N); k = n; magXk_DFT = abs( [ Xk_DFT ] ); % DFT magnitude angXk_DFT = angle( [Xk_DFT] )/pi; % DFT angle realXk_DFT = real(Xk_DFT); imagXk_DFT = imag(Xk_DFT); EXk = sum(magXk_DFT .^ 2)/N Y11k_DFT = dft(y1_1, N1); k1 = n1; magY11k_DFT = abs( [ Y11k_DFT ] ); % DFT magnitude angY11k_DFT = angle( [Y11k_DFT] )/pi; % DFT angle realY11k_DFT = real(Y11k_DFT); imagY11k_DFT = imag(Y11k_DFT); EY11k = sum(magY11k_DFT.^2)/N1 Y21k_DFT = dft(y2_1, N2); k2 = n2; magY21k_DFT = abs( [ Y21k_DFT ] ); % DFT magnitude angY21k_DFT = angle( [Y21k_DFT] )/pi; % DFT angle realY21k_DFT = real(Y21k_DFT); imagY21k_DFT = imag(Y21k_DFT); EY21k = sum(magY21k_DFT.^2)/N2 figure(‘NumberTitle‘, ‘off‘, ‘Name‘, ‘P5.21 X(k), DFT of x(n)‘) set(gcf,‘Color‘,‘white‘); subplot(2,2,1); stem(k, magXk_DFT); xlabel(‘k‘); ylabel(‘magnitude(k)‘); title(‘magnitude DFT of x(n), N=11‘); grid on; subplot(2,2,3); stem(k, angXk_DFT); %axis([-N/2, N/2, -0.5, 50.5]); xlabel(‘k‘); ylabel(‘angle(k)‘); title(‘angle DFT of x(n), N=11‘); grid on; subplot(2,2,2); stem(k, realXk_DFT); xlabel(‘k‘); ylabel(‘real (k)‘); title(‘real DFT of x(n), N=11‘); grid on; subplot(2,2,4); stem(k, imagXk_DFT); %axis([-N/2, N/2, -0.5, 50.5]); xlabel(‘k‘); ylabel(‘imag (k)‘); title(‘imag DFT of x(n), N=11‘); grid on; figure(‘NumberTitle‘, ‘off‘, ‘Name‘, ‘P5.21 Y11(k), DFT of x((n+5))12‘) set(gcf,‘Color‘,‘white‘); subplot(2,2,1); stem(k1, magY11k_DFT); xlabel(‘k‘); ylabel(‘magnitude(k)‘); title(‘magnitude DFT of y11(n), N=12‘); grid on; subplot(2,2,3); stem(k1, angY11k_DFT); %axis([-N/2, N/2, -0.5, 50.5]); xlabel(‘k‘); ylabel(‘angle(k)‘); title(‘angle DFT of y11(n), N=12‘); grid on; subplot(2,2,2); stem(k1, realY11k_DFT); xlabel(‘k‘); ylabel(‘real (k)‘); title(‘real DFT of y11(n), N=12‘); grid on; subplot(2,2,4); stem(k1, imagY11k_DFT); %axis([-N/2, N/2, -0.5, 50.5]); xlabel(‘k‘); ylabel(‘imag (k)‘); title(‘imag DFT of y11(n), N=12‘); grid on; figure(‘NumberTitle‘, ‘off‘, ‘Name‘, ‘P5.21 Y21(k), DFT of x((n-8))15‘) set(gcf,‘Color‘,‘white‘); subplot(2,2,1); stem(k2, magY21k_DFT); xlabel(‘k‘); ylabel(‘magnitude(k)‘); title(‘magnitude DFT of y21(n), N=15‘); grid on; subplot(2,2,3); stem(k2, angY21k_DFT); %axis([-N/2, N/2, -0.5, 50.5]); xlabel(‘k‘); ylabel(‘angle(k)‘); title(‘angle DFT of y21(n), N=15‘); grid on; subplot(2,2,2); stem(k2, realY21k_DFT); xlabel(‘k‘); ylabel(‘real (k)‘); title(‘real DFT of y21(n), N=15‘); grid on; subplot(2,2,4); stem(k2, imagY21k_DFT); %axis([-N/2, N/2, -0.5, 50.5]); xlabel(‘k‘); ylabel(‘imag (k)‘); title(‘imag DFT of y21(n), N=15‘); grid on;
运行结果:
序列的圆周移位
原始序列x(n)的DFT
圆周移位序列1的DFT
圆周移位序列2的DFT
上图可知,时域的能量和频域的能量相等。
《DSP using MATLAB》Problem 5.21
标签:main 时域 src parse atl rsh bsp problem color
原文地址:https://www.cnblogs.com/ky027wh-sx/p/9429760.html