A Quadrature Signals Tutorial: Complex, But Not Complicated

Understanding the 'Phasing Method' of Single Sideband Demodulation

Complex Digital Signal Processing in Telecommunications

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Hi all, I am new to communication region. We know that Eb/No means "the ratio of the transmitted signal energy per bit to the noise spectrum density". What's Es/No mean? And what's their difference? Any suggestions will be appreciated! Best regards, Davy

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Instead of just giving you the answer, I'll step you through it logically. Very simple of course. If you were to transmit multiple bits, what would you call this multiple bit transmission. ie those multiple bits would be encoded into a signal transmitted s..... (the word will fit if the dots are replaced with the correct letters) Via phonic spelling it's also a percussion instrument. Davy wrote: > Hi all, > > I am new to communication region. > > We know that Eb/No means "the ratio of the transmitted signal energy > per bit to the noise spectrum density". > > What's Es/No mean? And what's their difference? > > Any suggestions will be appreciated! > Best regards, > Davy >

Bevan Weiss wrote: > Instead of just giving you the answer, I'll step you through it > logically. Very simple of course. > > If you were to transmit multiple bits, what would you call this multiple > bit transmission. ie those multiple bits would be encoded into a signal > transmitted s..... (the word will fit if the dots are replaced with the > correct letters) > > Via phonic spelling it's also a percussion instrument. > > > Davy wrote: > > Hi all, > > > > I am new to communication region. > > > > We know that Eb/No means "the ratio of the transmitted signal energy > > per bit to the noise spectrum density". > > > > What's Es/No mean? And what's their difference? > > > > Any suggestions will be appreciated! > > Best regards, > > Davy > > Another distinction -- in a system with FEC, Eb/No normally refers to the *information* bits, before any FEC is applied. Es/No refers to the *channel* symbols, after FEC is applied. The channel symbols may in fact still be "bits" though. For example, if a r=1/2, K=7 code is used with BPSK, a textbook might show a BER vs Eb/No curve with two traces on it, coded and uncoded. The uncoded one will have a 1e-5 BER at the familiar 9.6 dB Eb/No. The coded one will hit 1e-5 BER at approx 4.5 dB Eb/No (just over 5 dB gain). The Es/No for the coded case is actually 4.5 + 10*log10(r) = 1.5 dB. John

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What's Es/No mean? And what's their difference? it's mean symbol energy to noise ratio. 2. symbol means a cllection of bit Es=nEb. in digital communication u can send your signal by bit (0/1) or symbol (0/1 s0 s1 for bpsk 00 010 10 11s0 s1 s2 s3 for qpsk so here eatch symbol represnt two bit) it's totally up to u.

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Hi, You can have a look at : http://www.sss-mag.com/ebn0.html and replace "Energy per Bit (Eb)" with "Energy per Symbol (Es)" as explained in the other answers. Regards, Matthieu

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Hi john, Thank you for your help! A simple question: Does 10*log10(rate) mean the code gain of BPSK modulation? And is there code gain of QAM modulation? Any suggestions will be appreciated! Best regards, Davy

Davy wrote: > Hi john, > > Thank you for your help! > > A simple question: > Does 10*log10(rate) mean the code gain of BPSK modulation? > And is there code gain of QAM modulation? > > Any suggestions will be appreciated! > Best regards, > Davy 10*log10(rate) is the rate of the error correction code, expressed in decibels. The rate of the code is the ratio of number of input bits to number of output bits. For a convolutional code this is the inverse of an integer, for example 1/2, 1/3, etc. It is important to take this factor into account when comparing coded and uncoded systems, because to be fair the coded system should be compared to the uncoded system running at a lower bit rate. Coding gain is achievable for QAM modulation. John