Comments on: Shannon theorem – demystified https://www.gaussianwaves.com/2008/04/channel-capacity/ Signal Processing for Communication Systems Sat, 25 Mar 2023 15:49:07 +0000 hourly 1 https://wordpress.org/?v=6.7.1 By: Abdullah Arif https://www.gaussianwaves.com/2008/04/channel-capacity/#comment-39964 Wed, 25 Sep 2019 11:03:35 +0000 http://www.gaussianwaves.com/2008/04/channel-capacity/#comment-39964 How channel capacity can be increased numerically using the definition of information?

]]> By: Arac Wu https://www.gaussianwaves.com/2008/04/channel-capacity/#comment-35217 Fri, 04 May 2018 21:33:00 +0000 http://www.gaussianwaves.com/2008/04/channel-capacity/#comment-35217 Nice blog, throughout and clear!

]]> By: deema https://www.gaussianwaves.com/2008/04/channel-capacity/#comment-30156 Tue, 20 Dec 2016 18:45:00 +0000 http://www.gaussianwaves.com/2008/04/channel-capacity/#comment-30156 Hello Sir, i’m a master student and i have a problem in one of my codes, can i please have your email address to contact with you. it will not take much of your time.

]]> By: Mathuranathan https://www.gaussianwaves.com/2008/04/channel-capacity/#comment-30153 Tue, 20 Dec 2016 07:01:00 +0000 http://www.gaussianwaves.com/2008/04/channel-capacity/#comment-30153 In reply to Adnan Khan.

The term “limit” is used for power efficiency (not for bandwidth).

This tells us , now matter how much bandwidth we have (B-> infinity), the transmission power should always be more than the Shannon power efficiency limit in terms of Eb/N0 (-1.59 dB)

]]> By: Adnan Khan https://www.gaussianwaves.com/2008/04/channel-capacity/#comment-30142 Fri, 16 Dec 2016 11:51:00 +0000 http://www.gaussianwaves.com/2008/04/channel-capacity/#comment-30142 How the “unconstrained Shannon power efficiency Limit” is a limit for band limited system when you assumed B = infinite while determining this value?

]]> By: chandrasekaran karuppannan https://www.gaussianwaves.com/2008/04/channel-capacity/#comment-27531 Fri, 27 Mar 2015 00:22:00 +0000 http://www.gaussianwaves.com/2008/04/channel-capacity/#comment-27531 Hi
1)We have to use error control coding to reduce BER in the noisy channel even if we send the data much below the capacity of the channel… am i right ?

2)If i say the channel has the capacity 1000 bits/sec ( as per Shannon – Hartley Equation)
this 1000 bit/s is ( information + error control data) OR information alone ( excluding error control data)..???

3)can you elaborate on capacity reaching codes ? which capacity they are trying to reach ?

]]> By: Mathuranathan https://www.gaussianwaves.com/2008/04/channel-capacity/#comment-26815 Sun, 05 Oct 2014 15:45:00 +0000 http://www.gaussianwaves.com/2008/04/channel-capacity/#comment-26815 In reply to Parvathi.

Two scenarios here,

If the system is a low pass system , the bandwidth is 10Hz. You can apply Shannon capacity equation and find the capacity for the given SNR.

If the system is a bandpass system, since fH=FL=10Hz, it is assumed to be same as some carrier frequency fc=10Hz. Thus the bandwidth is zero (nothing around the carrier frequency) and if you apply the shannon capacity equation for AWGN, C is zero in this case. This calculation of capacity seems absurd, as we know that we not sending any information (just a carrier here and no information ) and therefore capacity is zero. By doing this calculation we are not achieving anything.

]]> By: Parvathi https://www.gaussianwaves.com/2008/04/channel-capacity/#comment-26756 Mon, 22 Sep 2014 18:02:00 +0000 http://www.gaussianwaves.com/2008/04/channel-capacity/#comment-26756 Dear Sir,
If I use only one Sine wave (say f=10Hz), then is the bandwidth zero (since fH = 10Hz and fL = 10Hz)? Then is the capacity zero? Say modulation is on-off keying to communicate 1 bit data.
When can the capacity be zero?

Thank you.

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