A Reliable Multiple Access Scheme Based on Chirp Spread Spectrum and Turbo Codes

Nowadays, smart devices are the indispensable part of everyone's life and they play an important role in the advancement of industries and businesses.These devices are able to communicate with themselves and build the super network of the Internet of Things(IoT). Therefore, the need for the underlying structure of wireless data communications gains momentum. We require a wireless communication to support massive connectivity with ultra-fast data transmission rate and ultra-low latency. This research explores two possible methods of tackling the issues of the current communication systems for getting closer to the realization of the IoT. First, a grant-free scheme for uplink communication is proposed. The idea is to the combine the control signals with data signals by superimposing them on top of each other with minimal degradation of both signals. Moreover, it is well-established that orthogonal multiple access schemes cannot support the massive connectivity. Ergo, the second part of this research investigates a Non-Orthogonal Multiple Access(NOMA) scheme that exploits the powerful notion of turbo codes for separating the signals in a slow fading channel. It has been shown that in spite of the simplicity of the design, it has the potentials to surpass the performance of Sparse Code Multiple Access(SCMA) scheme