I'm trying to understand the $\\E_b/N_o$ concept and how different coding rates affect it. I've read a bunch of topics, specifically this and this, but I'm still missing something to have a clear picture.
I think I got the idea of $SNR$, as $SNR$ is a ratio of powers that actually exist in the channel, I mean real Watts.
$\\E_s$ from $\\E_s/N_o$ also seems to be clear where comes from, i.e. it is the energy of a symbol in the channel in Joules.
However when it comes to $\\E_b/N_o$ I'm completely lost. Theory says that $\\E_b$ is the energy per information bit, i.e. the bit before an encoder.
- What energy is meant here? The bit is still in the digital domain, right?
Further, I'm trying to compare performance of a simple BPSK transceiver ($BER$ vs $\\E_b/N_o$) under different configurations: $uncoded$, coded with rates $1/2, 1/3, 2/3$.
The channel bit rate (=transceiver bandwidth) is fixed for all configurations, meaning that the information bit rate $(R_b)$ is affected. When it comes to simulation in Simulink of uncoded transceiver I set the following parameters:
Data generator Sample time: $Ts=1$
In the next iteration I added an encoder with the rate $1/2$.
In order to have correct comparison, shall I multiply $Symbol$ $period$ in AWGN by the code rate=$1/2$?
Shall I leave $Ts=1$ at the data generator? If yes, then I'm even more confused, why different values of $Ts$ provide correct result.