Incremental Decoding based Low-Latency Communication for Real-Time Control

In the emerging Industrial Internet of Things (IIoT), real-time control is expected to play a key role. How to minimize the cost to be paid due to the transmission delay of digital signaling in real-time control system becomes a challenging problem. In this paper, we study incremental decoding based low latency communication for a real-time control system. The real-time control action will be updated, whenever a new bit is received instead of the entire codeword. In other words, when the controller obtains partial information of the digital signaling, it executes the control action immediately instead of waiting until the complete information is obtained, which is in contrast to the conventional real-time control. Our aim is to minimize the expected cumulative control cost over the control process by joint design of source coding and its corresponding real-time control scheme. To this end, we first show a recursive structure that reveals the relationship of minimal expected cumulative control cost among two adjacent decision epochs. Based on such structure, the optimal solution can be obtained by a recursive algorithm presented by us. Finally, our numerical results also demonstrate that the cumulative control cost over the control process can be significantly reduced by implementing the source codebook we proposed, compared with traditional source coding.