Everyone else has their opinion on this, so I'll give you mine... The data you get from an FFT is equivalent to a voltage, but complex. To get...

Everyone else has their opinion on this, so I'll give you mine... The data you get from an FFT is equivalent to a voltage, but complex. To get the power you need to, for each sample, sum the squares of the real and imaginary parts. This gives you the square of the magnitude which is equivalent to power. Energy is not just the sum of the power, it is the integral of power over tim

how to calculate signal and noise power hello, i have a signal current I(t)=Acos(wt+theta) How can i calculate the signal power and noise power...

how to calculate signal and noise power hello, i have a signal current I(t)=Acos(wt+theta) How can i calculate the signal power and noise power individually? thanks Reza

Hello Forum, near any radiating source like an antenna there is a region called the reactive field: the E and H field are 90 degrees out of...

Hello Forum, near any radiating source like an antenna there is a region called the reactive field: the E and H field are 90 degrees out of phase. The reactive field is region where there is no radiated power...... It acts as a storage power. During one cycle power is given and taken back... I am having a hard time understanding what that means. What does it means that energy is given and...

Hi everybody! As DSP is not really my field I have a question that bothers me and I think someone here has enough experience to at least...

Hi everybody! As DSP is not really my field I have a question that bothers me and I think someone here has enough experience to at least nudge me in the right direction. In my field I frequently use power analyzer to measure RMS (square root of sum of squares) values of voltage and current. Basically I measure power of a signal. From power analyzer specs I know it has sampling frequen...

Hi All, I have been recently placed on a new project related to Power Systems.I am new in this field and not getting a proper place to start...

Hi All, I have been recently placed on a new project related to Power Systems.I am new in this field and not getting a proper place to start with.So please give me your advise. The project is an Active Shunt Type Power Filter used to take out harmonics from the power line. We have an existing product selling in the market,but with an old controller design, TI DSP(TMS320C40) Dual Ram

Question regarding Power Series method of finding IZT ------------------------------------------------------- Hello. I want to clear a doubt...

Question regarding Power Series method of finding IZT ------------------------------------------------------- Hello. I want to clear a doubt regarding Power Series method for Inverse Z-transform If I have X(z) and I'm given a RoC that says that X(z) is a two-sided sequence and I'm supposed to find the IZT by Power Series method. My view is that I would not be able to find it using the said me...

Hi, I think I understand the basic ideas of spectral analysis but I still have no good feeling how to improve. My problem is that I have data...

Hi, I think I understand the basic ideas of spectral analysis but I still have no good feeling how to improve. My problem is that I have data that is broken every 3 minutes for about 20seconds. In order to generate a power spectrum I try several attempts of simulated data to see what will be the best. I know that the power spectrum should be a power law. So I generate a random time series by dra...

I have a question on the power of SSB (Single side band) AM. if transmitted signal is expressed as: u(t)=Ac*m(t)*cos(2pi*fc*t) plus minus...

I have a question on the power of SSB (Single side band) AM. if transmitted signal is expressed as: u(t)=Ac*m(t)*cos(2pi*fc*t) plus minus Ac*H[m(t)]*sin(2*pi*fc*t), Ac=carrier amplitude, fc=carrier frequency, m(t)=message signal, and H[m(t)] is Hilbert transform of m(t). What is the equation for received power (Pr) in terms of power of message signal (Pm)? Some books say Pr=[(Ac^2)...

Bob wrote: > I have a question on the power of SSB (Single side band) AM. > > if transmitted signal is expressed as: > > ...

Bob wrote: > I have a question on the power of SSB (Single side band) AM. > > if transmitted signal is expressed as: > > u(t)=Ac*m(t)*cos(2pi*fc*t) plus minus Ac*H[m(t)]*sin(2*pi*fc*t), > > Ac=carrier amplitude, fc=carrier frequency, m(t)=message signal, and > H[m(t)] is Hilbert transform of m(t). What is the equation for > received power (Pr) in terms of power of message signal (P

I've asked this before in a more complicated thread, and I guess I didn't get a satisfactory answer and forgot while talking about everything...

I've asked this before in a more complicated thread, and I guess I didn't get a satisfactory answer and forgot while talking about everything else. Cool Edit gives a result called "average RMS power", which seems wrong on two counts. 1. "RMS power" is a misnomer. Should be average power, which is merely *determined* from RMS voltage (or amplitude, more generally?). 2. But what does...

(This question is coming from an OFDM perspective but is obviously not confined to OFDM) If you are computing the peak to average power ratio...

(This question is coming from an OFDM perspective but is obviously not confined to OFDM) If you are computing the peak to average power ratio (PAPR) of a block of data, do you include the peak in computing the average power? For example, do you compare the peak power with the average of all the rest? Or do you compare the peak with the whole block including itself? I am pretty sure that ...

Hello ; Can anyone explain me what exactly is power limited channels and band limited channels?? Can a same signal be transmitted through power...

Hello ; Can anyone explain me what exactly is power limited channels and band limited channels?? Can a same signal be transmitted through power limited as well as band limited channel??what could be limitations? And how one can decide that a particular signal is suitable for power limited or band limited channels??

Hi! Is there a relationhsip between power density (Watt/m^2) and power spectral density (dbm/Hz) ? Thanks Suterr

Hi! Is there a relationhsip between power density (Watt/m^2) and power spectral density (dbm/Hz) ? Thanks Suterr

I have a large board which asks for three power supplies, +3V, +3.3V and +-5V. First two can be easily satisfied with two HP power supplies...

I have a large board which asks for three power supplies, +3V, +3.3V and +-5V. First two can be easily satisfied with two HP power supplies (each has its own GND pin also). Regarding +-5V, can I replace with an HP power supply set to 10V, -5V pin connect to HP's ground and +5V to power?

Hi, If i calculate the power spectral density of a speech signal using Welchs method i get power/Hz, right ? If i want to find power or...

Hi, If i calculate the power spectral density of a speech signal using Welchs method i get power/Hz, right ? If i want to find power or energy under 500 Hz i just integrate(or square) from 0-500 Hz? If this is correct would it be the same if i low passed the signal at 500 Hz, and apply Welch? Tommy,

I'm new to DSP and am attempting to use an FFT to approximate in software the output of a hardware spectrum analyzer. Using MATLAB, I calculate...

I'm new to DSP and am attempting to use an FFT to approximate in software the output of a hardware spectrum analyzer. Using MATLAB, I calculate the power as follows: fftOut = fft(samples,512); magnitude = fftOut. * conj(fftOut); scaled = magnitude. / 512; power = 10 * log10(scaled); The resultant power spectrum looks like the signal displayed on the spectrum analyzer, however the range i...

I am having trouble understanding the effect of aliasing/imaging on the power of an output signal. Imagine I am using a DAC to generate a single...

I am having trouble understanding the effect of aliasing/imaging on the power of an output signal. Imagine I am using a DAC to generate a single frequency sine wave with frequency f well below fs/2 and with power P. Assume there is no reconstruction filter. So this frequency will image repeatedly across the frequency domain at n.fs-f and n.fs+f. I do not understand how the original power, P, i...

I need to estimate the power in a signal in the frequency range of 30 to 40 Hz. 1) should I simply create a butterworth bandpass filter to...

I need to estimate the power in a signal in the frequency range of 30 to 40 Hz. 1) should I simply create a butterworth bandpass filter to estimate power in that range? Or, do I need to estimate activity in this range using power spectral density estimation (using pwelch or similar approach) 2) what is the critical difference between bandpass filtering a signal and getting estimate of...

Ok suppose we have an R-C network - low pass filter with tf G(s)=1/(1+sT) where T=CR. We can easily calculate the output power spectrum if...

Ok suppose we have an R-C network - low pass filter with tf G(s)=1/(1+sT) where T=CR. We can easily calculate the output power spectrum if this is driven by zero-mean white noise as Phiyy(w)=mag(G(jw))^2 x power of input noise and the area under the PSD is the total average power. Now let's do the same thing digitally...and produce an equivalent digital filter G(z) The output p...

Hi everyone, I have been using a Goertzel algorithm to measure the power of 50 and 60 Hz tones in ADC data on a C6713 demo board. The...

Hi everyone, I have been using a Goertzel algorithm to measure the power of 50 and 60 Hz tones in ADC data on a C6713 demo board. The technique is very succesful given a strong signal tone. Given a signficant tone, the measured power levels match precisely the input power and have a very low varying range (about 1dB). However, as the signal decreases, the variance of the measured power incre...