Internet of Things (IoT) for MC-CDMA-Based Cognitive Radio Network (CRN) in 5G: Performance Results

Both the internet-connected devices, i.e. IoT and Cognitive Radio Network (CRN) are considered to be the future technologies for the fifth generation of cellular wireless standards (5G). On the one hand, Internet of Things (IoT) focuses primarily on how to allow general objects to see, hear, and smell their own physical environment and make them connected to share the observations. On the other hand, a CRN is based on a complex spectrum allocation system, and licenced primary users (PUs) or unlicenced secondary users (SUs) are allowed to share the spectrum, provided they do not cause significant interference. The IoTs are meaningless if IoT objects are not equipped with cognitive radio capability. In cognitive radio, it is important to control the transmission power of SUs so that the interference should not be harmful to the quality of service of PUs. In this paper, the authors addressed the effects of imperfect power control between primary users (PUs) and the secondary users (SUs) of an IoT-based CRN. The effect of the co-channel interference (CCI) and adjacent channel interferences (ACIs) occurring in CRN using MC-CDMA system is also analysed. A new expression of the signal-to-interference-noise ratio (SINR) for CRN-based MC-CDMA system over a Nakagami-[Formula: see text] fading channel with imperfect power control condition is derived and investigated. The performance of IoT-based CRN using MC-CDMA system over the frequency selective multipath fading channel is examined with varying the number of users, the SINR per bit, number of fading path and number of sub-carriers. From the simulation results, we have seen that the SINR performance is affected by these parameters. The result of the analysis will provide relevant information to design the physical layer protocol for high-speed IoT-based CRN system for 5G.

Downlink Congestion Control for TD-SCDMA Trunking System

In TD-SCDMA trunking system, imperfect power control and user mobility are disadvantages for the capacity and performance of the system. In order to meet the requested Quality of Service (QoS) of group users, in this paper, we introduce a congestion control mechanism in downlink for TD-SCDMA trunking system. The mechanism is based on Adaptive Multi-Rate (AMR) mode selection and interrupt connections of users, analyzed in detail and verified by using MATLAB to structure a dynamic system level simulation platform. The simulation results reveal that system performance can be significantly improved.