MATLAB帮助对功率谱密度的纵坐标单位的阐释及个人理解
% NOTE 1: To express the result of PSD, Pxx, in units of% Power per Hertz multiply Pxx by 1/Fs .
%
% NOTE 2: The Power Spectral Density of a continuous-time signal,
% Pss (watts/Hz), is proportional to the Power Spectral
% Density of the sampled discrete-time signal, Pxx, by Ts
% (sampling period).
%
% Pss(w/Ts) = Pxx(w)*Ts, |w| < pi; where w = 2*pi*f*Ts
% References:
% Petre Stoica and Randolph Moses, Introduction To Spectral
% Analysis, Prentice hall, 1997, pg, 15
% A.V. Oppenheim and R.W. Schafer, Discrete-Time Signal
% Processing, Prentice-Hall, 1989, pg. 731
% A.V. Oppenheim and R.W. Schafer, Digital Signal
% Processing, Prentice-Hall, 1975, pg. 556
我觉得讲得比较明白了，分享给大家，所列的参考文献后两本相信多数人看过的
下面是我个人对功率谱的理解：
1）自/互功率谱，反映了信号功率在频域随频率成分的分布；功率谱=功率谱密度 （随频率分布！对比概率密度的定义）
2）数字信号来说，设w=2*pi*f/fs，Px（w）*dw= 区间(w,w+dw)之间的“平均功率”
3）得出数字信号功率谱Px(w)后，数值上乘以Ts=1/fs，即得到物理的功率单位：watts/Hz, 瓦/Hz
[ 本帖最后由 Robotech 于 2009-4-22 16:51 编辑 ]
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