Index-Domain Division Multiple Access for IoT Applications

Facing the worldwide explosive growth of the wireless devices, the future wireless network is required to provide seamless access for the users with diverse Quality-of-Service (QoS) requirements. In this article, a novel multiple access scheme based on the principle of multidomain index modulation is proposed to address the downlink multiple access problem for users with diverse QoS requirements, including the Internet-of-Things (IoT) devices and the smart electronic devices. Unlike the conventional nonorthogonal multiple access (NOMA) schemes which utilize power-domain diversities to realize multiple access, in the proposed scheme, information for different users is conveyed by different domains of the transmitted signals, including the constellation domain, frequency domain, time domain, and spatial domain. As a result, the intracluster interference among users is alleviated and the successive interference cancellation is avoided to reduce the computational complexity of signal detection at the receiver side, which is well suited for the IoT devices. The closed form lower bounds and approximations of the achievable rate of the proposed scheme are further derived to provide accurate estimation of the achievable rate of the communication system. Simulation results validate the superior performance of the proposed scheme over the conventional orthogonal and NOMA schemes.