Channel Coding and Low Latency HARQ for Industrial Wireless Sensor Networks

Industrial wireless sensor networks (IWSN) begin to occupy wide areas in the industry for applications such as factory automation. To meet the strict latency and reliability requirements for (IWSN), channel coding is proposed to be used in the physical layer. To this aim, a comparison study is carried out in this paper among three different modern coding techniques, i.e. turbo, LDPC, and convolutional coding. The goal of this study is to define which coding technique better meets IWSN requirements. LDPC is shown to provide a good performance by means of latency and reliability. In addition, low latency HARQ based on error rate estimation is proposed in this paper. The proposed scheme utilizes few LDPC decoder iterations and can provide up to 5 dB gain compared to another scheme where the decoding process is completely skipped.