Information Theory and Reliable Communication
Information Theory and Reliable Communication
| Hi-index | 22.14 |
The performance limitations on the linear control of a linear plant, due to the presence of a feedback channel with finite information capacity, are considered in this paper. This situation may arise in such diverse applications as (a) the remote control of a plant, using a digital data link for feedback, (b) where quantization errors and bit errors of a digital controller may be modelled as occurring in a noisy digital channel in cascade with an ideal controller, and (c) in human-operator modelling, where the sensory feedback channels are characterized by fixed information capacity due to neural noise. The principle result obtained is that, given the state-dimension n of the plant and the channel capacity @e, reliability function E(R), and block encoding time T 1C, the optimum data-rate R satisfies the equation 2R=nE(R). This rate provides the optimum tradeoff between the effects of quantization errors and message errors. It is seen that R"o"p"t-C as n becomes large, but that good channel performance is retained provided that nT.