Why is Bit Error Rate (BER) Plotted on a Log Scale?

Explains the relationship between BER and the ratio of signal energy and noise energy (Eb/No) in digital communications. Shows an example of BPSK modulation in AWGN channels, and demonstrated that it is a nonlinear relationship involving an integral of an exponential function. This motivates the use of a Log function when plotting BER.
Related videos: (see: iaincollings.com)
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Full categorised list of all videos with Summary Sheets: iaincollings.com
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[@user-iu7qg9lo7y]

you channel is a great way to revision heavy courses in a few minutes excellent work, i saw that you made a great video about amplitude modulation, i think you should do the same with frequency modulation

[@iain_explains]

Glad you like the channel. Thanks for the topic suggestion of FM. I've added it to my "to do" list.

[@pitmaler4439]

Thank you. I just thought about the value -(Eb)^0.5 and (Eb)^0.5. I assume that are voltage values, so it can be -2 V and +2 V. But how do you guarantee thet these values are constant? We transmit with an altenate current, so the value changes over time this way or another. It seems to be a bit confusing. I want to transmit the value -2 V for bit 0, but it changes constantly. Thanks.

[@iain_explains]

Yes, they are voltage values. You might like to watch this video, which answers your question: "What is a Constellation Diagram?" kzbin.info/www/bejne/oZetln9qgbZnadU

[@kumudinipatel2565]

Sir please explain negative energy concept in signal context. Please

[@iain_explains]

Sorry, but what do you mean by "negative energy"?

[@tuongnguyen9391]

if it a linear function in the log scale, does that imply that if we increase the Eb/N0 the BER will decrease linearly in the linear scale ? Although this is a stupid question but go back and forth between linear scale and log scale really confuse me ...

[@iain_explains]

Sorry for the confusion, it means log(BER) = - C_1 log(Eb/No) + C_2 . In other words, it is a straight line with a negative slope on the figure where Eb/No is plotted in dB on the horizontal axis, and where the vertical axis plots log(BER) (as shown in the figure on the bottom right hand side in the video).

[@iain_explains]

I've just put the Matlab code for the plots in the video on my website iaincollings.com on the Digital Communications page, under the Modulation and Demodulation tab, in case you'd like to see exactly the equation I implemented.

[@rohansharma8731]

mangificient

[@solitonam9410]

Give us a good book to study!

[@iain_explains]

I don't respond well to demands, sorry.

[@solitonam9410]

@@iain_explains No problem!!! And Thanks you.