Hello David. High respect, very well-done youtube series, good explanation and very good and instructive examples. I'm using some of these with a goup of fellow radio amateurs to explain a few basics about information theory, and the videos are just *great* for that purpose. With respect to the first example of slide 11, however, I believe "noisy channel" maybe misunderstood easily: SNR~0 can be read as "SNR~0 *dB*", which would be a noisy channel; "SNR~0" rather is a channel of noise with ~no signal at all. Considering capacity with ~no signal is a bit pointless an exercise, isn't it? 73 de Andreas.
Quick comment David, on slide 12, you're asking for the maximum bitrate while defining the minimum SNR. Since the former is monotonically increasing with the latter, the maximum bitrate should be infinity (assuming an SNR being only lower bounded). What am I missing?
You are correct, in the question as posed it would be infinity. A better form of the questions is what is the maximum bit rate you could expect with the min SNR of 30 dB. Basically, you would design a system to consider the lowest SNR, so then what would the maximum bit rate be for that SNR? That was the intent of the problem.
Although it was already covered in the very first modules and you can easily look it up on Wikipedia, I'm going to state what you need to do. Suppose "x" represents a variable in the linear scale while "y" is the corresponding variable in the db scale; then the relation connecting the two is simply: y = 10 ∗ log(x) x = 10^( y / 10 ) Yeah it's that simple. (ex. 30 db = 10^(30/10) = 10^3). It should be noted that x is implicitly stated to be strictly positive (always larger than 0). No, Sakshi, y there are no restricitions on y.
![[Live สด] การออกรางวัลสลากกินแบ่งรัฐบาล งวดวันที่ 16 พฤศจิกายน 2567](http://i.ytimg.com/vi/wPd7VFfWHIA/mqdefault.jpg)
![กี่หมื่นฟ้า | Your Sky Series EP.1 [1/4]](http://i.ytimg.com/vi/vLGjxFL6U_I/mqdefault.jpg)
Hello David. High respect, very well-done youtube series, good explanation and very good and instructive examples. I'm using some of these with a goup of fellow radio amateurs to explain a few basics about information theory, and the videos are just *great* for that purpose.
With respect to the first example of slide 11, however, I believe "noisy channel" maybe misunderstood easily: SNR~0 can be read as "SNR~0 *dB*", which would be a noisy channel; "SNR~0" rather is a channel of noise with ~no signal at all. Considering capacity with ~no signal is a bit pointless an exercise, isn't it? 73 de Andreas.
Quick comment David,
on slide 12, you're asking for the maximum bitrate while defining the minimum SNR. Since the former is monotonically increasing with the latter, the maximum bitrate should be infinity (assuming an SNR being only lower bounded).
What am I missing?
You are correct, in the question as posed it would be infinity. A better form of the questions is what is the maximum bit rate you could expect with the min SNR of 30 dB. Basically, you would design a system to consider the lowest SNR, so then what would the maximum bit rate be for that SNR? That was the intent of the problem.
Can you tell me how to convert db into linear or vice versa?
Although it was already covered in the very first modules and you can easily look it up on Wikipedia, I'm going to state what you need to do.
Suppose "x" represents a variable in the linear scale while "y" is the corresponding variable in the db scale; then the relation connecting the two is simply:
y = 10 ∗ log(x)
x = 10^( y / 10 )
Yeah it's that simple. (ex. 30 db = 10^(30/10) = 10^3). It should be noted that x is implicitly stated to be strictly positive (always larger than 0).
No, Sakshi, y there are no restricitions on y.