Fountain Coded Cooperative Communications for LTE-A Connected Heterogeneous M2M Network

Machine-to-machine communication over long-term evolution advanced (LTE-A) network has emerged as a new communication paradigm to support a variety of applications of Internet of Things. One of the most effective techniques to accommodate a large volume of machine type communication (MTC) devices in LTE-A is clustering where devices (nodes) are grouped into number of clusters and forward their traffics to the base station (e.g., LTE eNodeB) through some special nodes called cluster heads (CHs). In many applications, the CHs change location with time that causes variation in distances between neighboring CHs. When these distances increase, the performance of data transmission may degrade. To address this issue, we propose to employ intermediate non-CH nodes as relays between neighboring CHs. Our solution covers many aspects from relay selection to cooperative formation to meet the user's QoS requirements. As the number of total relay plays a significant role in cooperative communications, we first design a rateless-coded-incremental-relay selection algorithm based on greedy techniques to guarantee the required data rate with a minimum cost. After that, we develop both source-feedback and non-source-feedback-based fountain coded cooperative communication protocols to facilitate the data transmission between two neighbor CHs. Numerical results are presented to demonstrate the performance of these protocols with different relay selection methods under Rayleigh fading channel. It shows that the proposed source-feedback-based protocol outperforms its non-source-feedbackprotocol counterpart in terms of a variety of metrics.