nonzero phase spectrum from FFT of even function with zero imag part
Hello Forum, the fft of a rectangular, even, symmetric sequence show a nonzero real part and a zero imaginary part. All good so far. However the phase spectrum is nonzero: zero at some frequencies, pi at some frequencies , -pi at some others.... The phase spectrum is given by atan(Imag(fft)/real(fft)), so it s... 27 Jun 2010 12:48
Phase-frequency detector with synchronous output?
I'm looking at ways of implementing a PLL (minus the VCXO) entirely in an FPGA. Our traditional approach has been to have PFD in the FPGA, take the up/down pulses and run them into an external charge pump- filter->VCXO. I would like to move everything up to the VCXO inside the FPGA (naturally there ould be a D-A i... 24 Jun 2010 15:14
Kalman fiter for accelerometer
Hi The problem i'm trying to face is to filter the accelerometer noise using a kalman filter without any other input. I'm new to kalman filter and i don't know exactly how to model and develop such a filter. As a first attempt i tried to describe the problem as follows: (p = position, v = velocity, a = accelerati... 25 Jun 2010 03:19
real FFT (in theory)....
Hello forum, I can easily calculate the fft of a 1D Gaussian function, which is a real, even function. In theory, Its FFT should be real (zero imaginary part). Instead the simulation shows an imaginary part definitely not zero and oscillating...Why? where is my mistake? Here my brief matlab code: mu=0; ... 25 Jun 2010 10:57
Reply stategy - was [Re: Use of MATLAB fftshift]
Greg Heath wrote: *SNIP* Please do not send separate copies of the same post to different newsgroups. Just post one copy but include all group names, separated by commas, on the newsgroup line. Did you follow your own advice ? *NOT* lol Was it possible? ??? ????? [I'm using SeaMonkey 2.0.5 as re... 23 Jun 2010 23:51
OQPSK Constellation Display, how is it done?
For standard QPSK, the I and Q channels are (conceptually speaking) displayed as XY on a scope and the scope beam is turned on at the symbol instant. Ideally the combination of I and Q will be at one of the 4 corner symbol locations during the symbol time. The scope beam can also be turned on dimly during the... 25 Jun 2010 13:10
Call for Papers: International Conference on Internet and Multimedia Technologies ICIMT 2010
Call for Papers: International Conference on Internet and Multimedia Technologies ICIMT 2010 CFP: International Conference on Internet and Multimedia Technologies ICIMT 2010 Draft Paper Submission Deadline: 2 July, 2010 Camera-Ready Papers Due & Registration Deadline: 30 July, 2010 ICIMT 2010: San Francisco, U... 23 Jun 2010 10:35
OMAP DSP starting vector
On TI OMAP-L138 DSP, there is a system register which contains "DSP reset vector" (HOST1CFG::DSP_ISTP_RST_VAL). For some reason, the lower 10 bits of this register are set to 0. Is this the address from which the DSP starts executing, or is this a pointer to memory location from which the DSP reads the start... 23 Jun 2010 08:24
Use of MATLAB fftshift
I've seen discussion here of the correct use of MATLAB's fftshift() function. I'd like to verify my interpretation, and to ask what are the effects when people do not use it correctly. Basically, MATLAB implements an fft (as do other sets of functions) whose results AND inputs are ordered (for an array of N el... 26 Jun 2010 14:06
Dmitry Terez frequency estimation method.
Dmitry Terez wrote: /"\ |\./| | | | | |>~<| | | /'\| |/'\.. /~\| | | | \ | =[@]= | | \ ... 22 Jun 2010 14:54