| Summary |
This study address a source coding scheme to reduce the amount of transmitted data in wireless feedback control systems. Entropy coding is one of the source coding schemes, which is based on the frequency of occurrence of data symbols. It assigns data symbols with high frequency of occurrence to short codewords and that with low frequency of occurrence to long codewords. In an erroneous wireless channel, the longer the code length, the more error bits there are in data symbols. If the frequency of occurrence of important control information is low, entropy coding may deteriorate the control quality. In addition, under a data-rate constraint, the longer the code length, the longer the transmission delay. Consequently, data symbols may not be transmitted in the period of control. In this study, the performance of a wireless feedback control system with Huffman coding, which is an example of entropy coding, under a data-rate constraint is verified by simulation. |