When Statistical Signal Transmission Meets Nonorthogonal Multiple Access: A Potential Solution for Industrial Internet of Things

With the global promotion of fifth-generation (5G) communications, researches for sixth generation (6G) communications are being globally launched from various perspectives. Industrial Internet of Things (IIoT), which is the most representative application that reflects the ubiquitous connectivity characteristics of 6G, has attracted much attention. To explore for a feasible perspective in promoting ubiquitous connectivity and improving IIoT abilities, in this article, we seek solutions to incorporate two promising techniques, i.e., nonorthogonal multiple access (NOMA) and statistical signal transmission (SST). To accomplish such a motivation, we conceive the feasible transceiver architecture for the union of NOMA-SST technique, and elaborate workflow and detection procedures for both uplink and downlink modes. A dedicated resilient window strategy is designed thereafter, which largely strengthen weaker NOMA users’ SST performance without depressing stronger users. The proposed technique is finally testified through both simulation experiments and practical applications. Numerical results verify that NOMA-SST technique has satisfactory detection performance in common IIoT environments. It is also manifested that the proposed technique can refine various aspects, including recall rate and sensing accuracy of monitoring services, successful handling rate of emergency situations, etc., for practical IIoT applications. Such advantages are promising for practice.

I. Introduction

Wireless communication technologies have experienced incredible development in the past years. Nowadays, the global commercial progress of the fifth generation (5G) communication system has shown an unexpected growth trend, which significantly promoted the transformation of global social production modes, as well as the digital upgrading of the economy and society [1], [2], [3], [4], [5]. However, these promotions bring in novel challenges: the amounts of terminals, including mobile phones, wearable machines, Internet of Things (IoT) sensors, vehicle-to-vehicle (V2V) devices, etc., are expanding rapidly. The explosively growing demand for device connectivity, the complex and diverse urban environment, and the scarcity or imbalance of spectrum resources have brought enormous pressure to the current 5G communication systems [6], [7], [8], [9]. To overcome the above challenges, the worldwide academia and industry have worked together and completed the foundational document for sixth generation (6G), which was announced at the Radio Communication Division of the International Telecommunication Union Working Party 5-D (ITU-R WP5D) in June 2023 [10]. The document defined six major scenarios, including ubiquitous connectivity for 6G. Thus, the specific development directions of 6G have finally reached a global consensus.