1d correlation / convolution

Started by Anonymous in comp.dsp7 hours ago 1 reply

I have the absolute amplitude of a digital signal that I want to auto correlate with self , also cross correlate with a different digital...

I have the absolute amplitude of a digital signal that I want to auto correlate with self , also cross correlate with a different digital signal [ absolute magnitude ] . I'm using a complex 1d fft to implement this . I only have the absolute values of the spectra to work with ; where the absolute value is defined as : square root of (Real^2 + Imaginary^2). After multiplying the a...


All-digital symbol timing recovery scheme constraints?

Started by Mehtap özkan in comp.dsp19 hours ago

Dear All, In page 8 of http://www.cs.tut.fi/kurssit/TLT-5806/Synch.pdf it is stated: All-digital symbol timing recovery scheme requires...

Dear All, In page 8 of http://www.cs.tut.fi/kurssit/TLT-5806/Synch.pdf it is stated: All-digital symbol timing recovery scheme requires higher-than-symbol-rate sampling. If this statement is correct what should be the minimum ratio? We have also a constraint on the max sampling rate of the ADC. It is 2.2x symbol rate. If we sample at 2.2x symbol rate should we also adjust the Matched filter...


What is the phase margin for a PLL of critically damped?

Started by fl in comp.dsp1 day ago 1 reply

Hello, all: I read an online PLL tutorial, which says "the design of critically damped loops, a PM of about 70 degrees, does not lead to the...

Hello, all: I read an online PLL tutorial, which says "the design of critically damped loops, a PM of about 70 degrees, does not lead to the fastest settling time for third order CP PLLs." It is known that a critically damped second order loop has zeta=1, i.e. two real roots of the same value. But I can't get its phase margin 70 degrees. What do you think about phase margin remark? ...


Averaging of phase noise?

Started by Peter Mairhofer in comp.dsp6 days ago 4 replies

Hi all, My most basic question can be summarized as: "Can phase noise be averaged out?" And subsequentially, is there a difference if the...

Hi all, My most basic question can be summarized as: "Can phase noise be averaged out?" And subsequentially, is there a difference if the input signal is a sinusoid or wideband? What happens after averaging infinitely many times? My first reaction is: No, it can't (at least not in a similar manner as white noise where SNR is increased by 10dB for every additional 10x of averaging) becau...


frequency measurement and time-frequency uncertainty

Started by Randy Yates in comp.dsp2 weeks ago 34 replies

We have a requirement to measure a 32.768 KHz TTL output quickly and with a certain accuracy. If one used an N-bit ADC sampling at F samples...

We have a requirement to measure a 32.768 KHz TTL output quickly and with a certain accuracy. If one used an N-bit ADC sampling at F samples per second, what is the relationship between T_m and F_delta, where T_m is the minimum measurement time (say, in seconds) for a maximum frequency error of F_delta (say, in PPM)? For this discussion assume the frequency is stable over the measureme...


[FAR Off Topic] Backup email providder - Help please

Started by Richard Owlett in comp.dsp2 weeks ago 9 replies

I am of opinion that "free" can "cost too much". My email provider is having 'problems'. I've dealt with them for decades - they were my ISP in...

I am of opinion that "free" can "cost too much". My email provider is having 'problems'. I've dealt with them for decades - they were my ISP in dial-up days. Their solar system headquarters is less than 5 miles from my home in rural SW Missouri. I just did not realize how much I would miss email. Are there any ethical free email providers. TIA


Cool piece on Google's neural network engines

Started by Rob Gaddi in comp.dsp3 weeks ago 7 replies

Linked in today's Ganssle. Interesting...

Linked in today's Ganssle. Interesting stuff. https://cloud.google.com/blog/big-data/2017/05/an-in-depth-look-at-googles-first-tensor-processi ng-unit-tpu -- Rob Gaddi, Highland Technology -- www.highlandtechnology.com Email address domain is currently out of order. See above to fix.


OT: Those arithmetic questions

Started by Anonymous in comp.dsp3 weeks ago 25 replies

Often you see questions on social media such as - find the answer to 9/3(1+2) (they usually use the divide symbol which nobody uses of course...

Often you see questions on social media such as - find the answer to 9/3(1+2) (they usually use the divide symbol which nobody uses of course so= I have replaced it with a slash) and they spout on about order of operations and so left to right the answer= is 3x 3 =3D9 and the catch is that people answer 9/9 =3D 1. Ha, they don't= know their order of operations which was agreed by conve...


Variable data rate PSK modem

Started by Mehtap özkan in comp.dsp4 weeks ago 9 replies

Dear All, I have a fixed data rate PSK receiver which works fine. Now I have to design a variable data rate PSK receiver. The Block Diagram...

Dear All, I have a fixed data rate PSK receiver which works fine. Now I have to design a variable data rate PSK receiver. The Block Diagram looks like this(Hope ASCII Art works): ADC-> AGC-> RRC-> Complex Mixer-> Coarse/Fine Carr.Recov-> Timing Rec-> BPSK/QPSK | | NCO---------------- When I try to add


DCT in video compression

Started by RichD in comp.dsp4 weeks ago 14 replies

The mp3 standard uses the discrete cosine transform (DCT), rather than the full DFT. Doesn't that imply throwing away half the...

The mp3 standard uses the discrete cosine transform (DCT), rather than the full DFT. Doesn't that imply throwing away half the information? Can anyone explain this? -- Rich


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