Repetition codes are one of the few known codes whose code rate can be automatically adjusted to varying channel capacity, by sending more or less parity information as required to overcome the channel noise, and it is the only such code known for non-erasure channels.
12.
The master output was attenuated at the rate of 3 dB for every doubling of NOM . This master output reduction was the solution used by Yamaha Pro Audio two decades later in their DME series of digital signal processing ( DSP ) products, incorporating an automixer function which was otherwise an 8-or 16-channel noise gate.
13.
In a sense, improvements in FIR equalization using FFTs or partial FFTs leads mathematically closer to OFDM, but the OFDM technique is easier to understand and implement, and the sub-channels can be independently adapted in other ways than varying equalization coefficients, such as switching between different QAM constellation patterns and error-correction schemes to match individual sub-channel noise and interference characteristics.
14.
In the case of communication of information over a noisy channel, this abstract concept was made concrete in 1948 by Claude Shannon in his paper " A Mathematical Theory of Communication ", in which " information " is thought of as a set of possible messages, where the goal is to send these messages over a noisy channel, and then to have the receiver reconstruct the message with low probability of error, in spite of the channel noise.
