DSP

frequency modulation
[IMG]http://i49.tinypic.com/219w36q.png[/IMG] Question reads: Give the required value of frequency multiplication, n. Also, fully define the mixer by giving two permissible frequencies for the local oscillator. Am I correct in saying that D_1=0.05 and D_2=20?, However the solution has Solution: f_d2=nf_d1 ... 19 Jun 2010 19:58

Measure frequenzy?
I must measure the grid frequency (50Hz here). I don't have any zero crossing detector on board. But I can sample the voltage. I don't want to sample too often. But the voltage is going to be noisy and have disturbances so I think i must filter my samples before trying to analyze the frequency. Any tip? ... 16 Jun 2010 18:48

combining small CONSECUTIVE FFTs to make a larger FFT
Hello everybody. I have got a DSP question for all of you. I'd like to know if it is possible to obtain a large FFT (for example 1024 samples) combining small SEQUENTIAL FFTs(128 samples). It is really important for me that the input samples are consecutive (so it is not possible to apply the usual trick of even... 20 Jun 2010 16:44

OMAP-L1x Processor Universal Serial Bus 2.0
Hi, We are referring TMS320C674x/OMAP-L1x Processor Universal Serial Bus 2.0 (USB2.0) Controller specification (User's guide) and use case examples given in this document to implement data transfer in C6748 DSP eval board as peripheral device with a PC as a host USB. 1) Is referring the above mentioned user guide i... 16 Jun 2010 11:01

Costas Loop for 4QAM
Dear professionals, I am a newbie to the topic of carrier recovery. I have to build up a point-to-point wireless communication link consisting of a quadrature modulator and demodulator. I think to apply -1/+1 PRBS signals on I and Q inputs of the transmitter. So I will get 4QAM constellation (45°/135°/-45°/-135°). ... 16 Jun 2010 13:14

forward error correction capabilities?
I have training with matalb and de differences of the result between a señal with error rate(before viterbi) -6 and a signal with error rate -3(before viterbi) is cero from the view of the instaler is more easy to make a installation with a ber of -3 than with a ber of -6 Co... 15 Jun 2010 20:55

Derotation effects in multipath channel
Hi, I'm simulating a DFE equalizer in Matlab for a MSK modulated signal. The channel I'm testing is Ricean with max doppler shift of 50 Hz. I noticed that the performance of the DFE deeply improves if I apply the derotation before sending the samples to the equalizer. Has anybody ever observed the same behavior? ... 16 Jun 2010 15:27

FFT for ADC output
Hi, I'm new to DSP and FFT. My question is how to do FFT for ADC digital output code,as FFT algorithms i've seen in Internet always ask for real and imaginary parts input for the FFT algorithm. So what is the input for FFT, if we want to do it for digital codes? Thanks ... 16 Jun 2010 16:34

The Old
>Tim Wescott <tim(a)seemywebsite.now> wrote in news:MZOdnTlMb9jXyYvRnZ2dnUVZ_uSdnZ2d(a)web-ster.com: On 06/13/2010 06:42 PM, Randy Yates wrote: Does anyone remember these? I used to love reading these, apparently in Electronic Products, way back when. I find one on the web just tonight and thought ... 14 Jun 2010 22:54

Average of set of samples from gaussian distribution?
So I'm looking at the timing error associated with a correlation function. I'm basically taking 10 correlations and I'm curious about change in standard deviation when I average two different ways. If I average before calculating standard deviation, I improve my SNR by 10x and will see a sqrt(10) reduction in standar... 15 Jun 2010 15:22