Information Rate

Information Rate or Code Rate is the average number of bits of #Information are transmitted within a second. Thus, its unit is in bit/second. It is formally defined as the following:

$$ R = rH $$

Where:

$R$ is the Information Rate
$r$ is how much symbols are transmitted within a second (symbol/second)
$H$ is the Entropy#

Or in Channel Coding Theorem:

$$ r = k/n $$

Where:

$r$ is the Information Rate or Code rate
$k$ and $n$ are defined in #Block Code where $n > k$

Links to this page

TIT3131 Chapter 2: Channel Capacity and Coding

Information Rate
TIT3131 Chapter 1: Information Sources and Sources Coding

Rate of Information
Error Control Coding

Error Control Coding is a practical solution to enable acceptable Information# quality in a channel with fixed $\frac{E_b}{N_0}$ (from #Channel Capacity Theorem). To achieve acceptable error performance, Error Control Coding usually trade-offs bandwidth and system complexity (due to redundancy from #Channel Encoder).
Critical Rate

Critical Rate represents the maximum possible #Information Rate transfer over the channel, which is defined as:
Channel Coding Theorem

$r$ is the Information Rate# which is defined as $\frac{T_C}{T_S}$
Block Code

Block Code is a message sequence that is subdivided into sequential blocks each $k$ bits long (message bits), and each $k$-bit block is mapped into a $n$-bit block (codeword bits), where $n > k$. The number of redundant bits added by the encoder to each transmitted block is $n - k$ bits which is related to $k$ message bits. Thus, we can calculate the code rate#.

#math