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Entropy before and after Huffmann coding vs. channel capacity

Started by qfran in comp.dsp4 hours ago 2 replies

Dear all, please help me to interpret some strange(?) behaviour of Huffmann coding and entropy. Let me explain it at an example: Consider a...

Dear all, please help me to interpret some strange(?) behaviour of Huffmann coding and entropy. Let me explain it at an example: Consider a source emitting four symbols x1-x4 with probabilities P(x1)=1/3, P(x2)=1/3, P(x3)=1/6, P(x4)=1/6. Calculating the entropy with H=sum(P(xi)*log2(P(xi)) gives us: H=1.918 Bit/symbol. So far so good. We perform Huffmann-Coding, arranging the symbols in the...


Reed-Solomon FEC necessary to have the same characteristic for symbols and words?

Started by lrq3000 in comp.dsp1 day ago 4 replies

Hi there, I have implemented an almost "universal" (read: compatible with most other decoders output) Reed-Solomon codec. I feel like I have a...

Hi there, I have implemented an almost "universal" (read: compatible with most other decoders output) Reed-Solomon codec. I feel like I have a good intuitive grasp on the whole codec, except for one thing: I just can't understand why we are tied to the same characteristic at both the symbol level and at the word level. Let me explain: if for example you choose to work on GF(2^8), this means ...


hamming window overlap #2

Started by mavavilj in comp.dsp2 days ago 1 reply

Continuing an old post regarding Hamming window overlaps: http://www.dsprelated.com/showthread/comp.dsp/105321-1.php The first answer...

Continuing an old post regarding Hamming window overlaps: http://www.dsprelated.com/showthread/comp.dsp/105321-1.php The first answer gives: "a 50% overlap would give a sum of 1.08". If I wish to reconstruct the input signal perfectly (so the amplitudes are exactly the same), then can I merely subtract the extra ~".08" from all the samples? --------------------------------------- Post...


Find periodicity of a signal

Started by sia4uin in comp.dsp2 days ago 5 replies

Hello All I have two signals and I want to know which signal is more periodic than other. My approach: 1. Make both signals zero mean. 2....

Hello All I have two signals and I want to know which signal is more periodic than other. My approach: 1. Make both signals zero mean. 2. Take FFT of both signals. 3. Take sum of squared values of the output FFT within a band of 0.8 Hz to 2.6 Hz If the sum of first signal is high then the signal 1 is more periodic. This approach works but only 90% time. I need the success rate to be ...


How to plot S-Curve for TED ?

Started by Eshwar varma in comp.dsp2 days ago 2 replies

hi all , I simulated OQpsk modulated data which has 4 samples per symbol (base band). I also simulated the squaring and differentiating...

hi all , I simulated OQpsk modulated data which has 4 samples per symbol (base band). I also simulated the squaring and differentiating based Timing error detector .Now i want to know how well is it performing for that i want to simulate and draw the s -curve. can anyone suggest me a best method to plot s-curve! thanks in advance...


kelly lochbaum closed mouth

Started by sonoro in comp.dsp3 days ago

Trying to implement kelly lochbaum for vocal tract I have a problem to represent closed mouth: 0 area gives a k=1, (total reflection of...

Trying to implement kelly lochbaum for vocal tract I have a problem to represent closed mouth: 0 area gives a k=1, (total reflection of presure wave seems ok to me) but 1+k=2 means pressure is not 0 in last tube section just after this junction. What am i misunderstanding? Thanks for your attention victor bombi --------------------------------------- Posted through http://www.DSPRelated.c...


Round-half-even or Round-toward-nearest

Started by Kathy_pdx in comp.dsp4 days ago 1 reply

I just finished the reading of An introduction to different rounding algorithms, http://www.eetimes.com/document.asp?doc_id=1274485. I...

I just finished the reading of An introduction to different rounding algorithms, http://www.eetimes.com/document.asp?doc_id=1274485. I must admit I never pay much attention on the trick of the quantization. The approach of Round-toward-nearest is always used in my design. Did anyone have practical experiences to show the DSP filter performance improved or degraded by using Round-half-even ins...


detecting an echo in DTMF tone in echo canceler

Started by alpha1 in comp.dsp4 days ago 4 replies

I am facing some issue with my echo cancellation module. I am having a correlator and an adaptive filter modules. My correlator will detect...

I am facing some issue with my echo cancellation module. I am having a correlator and an adaptive filter modules. My correlator will detect presence of echo in the DTMF tones and will activate the adaptive filter. The adaptive filter will remove the echo present in the DTMF tones. Activation of adaptive filter is done only if the correlation is above a certain threshold. My issue is t...


Need a reference for a very simple filter

Started by nadavsof in comp.dsp6 days ago 2 replies

Hello. I've developed a software that uses STFT with a very simple filter. What the software does is draw a graph of the frequencies as the...

Hello. I've developed a software that uses STFT with a very simple filter. What the software does is draw a graph of the frequencies as the y axis and of time as the x axis. The filter is used to determined which points in the graph will be painted. The filter is extremely simple, it linear, time in-variant, and simply paints only points (f,t) for which their magnitude is in a predefined...


The Best Name for Signal Recovery Matched Filtering

Started by Bret Cahill in comp.dsp7 days ago 12 replies

I just assumed "matched filtering" included the deconvolution and other steps to recover the original signal's shape. In this case it was...

I just assumed "matched filtering" included the deconvolution and other steps to recover the original signal's shape. In this case it was actually easier to invent a new filter -- I assumed it already existed -- than to be scholarly and do some research. To avoid confusion with the terminology from now on the filter that takes the convolution of a noisy signal like a conventional matche...


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