Low-Complexity Error Correction for ISO/IEC/IEEE 21451-5 Sensor and Actuator Networks

ISO/IEC/IEEE 21451-5 standard provide a wireless communication model to facilitate access of smart sensors and actuators to a network. However, the 21451-5 standard integrates different wireless communication protocols in a sensor network system, and the overall complexity is higher than traditional sensor networks. Moreover, 21451-5 sensor networks that used in industrial control systems require better bit-error rate performance, and error correction is one of the key issues for the sensor networks. To address these obstacles, the double binary convolutional turbo code is applied to the 21451-5 sensor and actuator networks, and a low-complexity decoding solution is proposed for the iterative decoding, in which the focus is concentrated on simplification of the multivariable max^* operator. In the implementation of a multivariable max^* operator, this research shows recursion of the Jacobian logarithm is not necessary, and the computational error is small. Furthermore, we propose to approximate the Jacobian logarithm with simple compare, shifting, and addition operations. Since errors introduced by recursion of the Jacobian logarithm are removed, decoding performance of the proposed solution is superior to that of the near optimal decoding algorithm, and only slightly reduced as compared with the Log-MAP algorithm. By hardware implementation analysis, decoding complexity related to the multivariable max^* operator is substantially reduced.