Non-orthogonal schemes and diversity techniques for massive machine-type communications
Document typeMaster thesis
Rights accessOpen Access
This thesis performs a global overview of machine-type communications (MTC), which refer to automated data between devices, enabling a broad range of applications from mission-critical services to massive deployment of devices. The main MTC requirements and challenges toward 5G systems are also analysed, and several existing techniques to satisfy them are also studied. Different non-orthogonal multiple access (NOMA) technologies, able to accommodate a massive number of devices, are studied. In addition, a feedback-free network-assisted domain multiple access (FF-NDMA) system is analytically modelled and evaluated through simulation. This scheme is able to provide satisfactory performance in terms of throughput, delay and energy consumption, as well as a significant reduction of number of collisions with respect to previous protocols. Hence, FF-NDMA is a potential candidate to support MTC applications.
5G systems envision massive Machine-type Communication (MTC) with tens of billions of low-cost connected devices and sensors deployed. MTC devices pose requirements such as high device density, low energy consumption, small packet size and low traffic volumes per device. For that reason, transmissions in MTC are done through a random access channel. In addition, mission-critical MTC will require ultra-reliable connectivity with guaranteed availability and reliability.