Coding gain

The code gain and coding gain, describes the coding theory, the difference of the required bit energy in relation to noise power spectral density between the uncoded and the coded message in order to reach the same bit error rate. The uncoded message is the reference, with the coding by means of channel coding, message is compared.

The encoding of a message is always done in this context by the channel coding which has the task of ensuring by adding redundant information more security against, for example, transmission or storage errors. Causes of errors can thereby be disturbances as they are triggered for example by noise.

The influence of the defect size is expressed in coding theory by the bit energy to noise power density ratio, which represents the ratio of time spent on an information bit energy Eb to the noise spectral density N0.

The bit energy is normalized and takes into account that for transmission of the coded redundant bits to be transmitted.

Noise and coding influence the bit error rate when transmitting information.

• Coding Theory