Anomaly detection in big data is a key problem in the big data analytics domain. In this paper, the definitions of anomaly detection and big data were presented. Due to the sampling and storage burden and the inadequacy of privacy protection of anomaly detection based on uncompressed data, compressive sensing theory was introduced and used in the anomaly detection algorithm. The anomaly detection criterion based on wavelet packet transform and statistic process control theory was deduced. The proposed anomaly detection technique was used for through-wall human detection to demonstrate the effectiveness. The experiments for detecting humans behind a brick wall and gypsum based on ultra-wideband radar signal were carried out. The results showed that the proposed anomaly detection algorithm could effectively detect the existence of a human being through compressed signals and uncompressed data.

Nowadays, the needs of healthcare for the elderly are growing rapidly. To provide continuous all-day medical monitoring and diagnoses at low cost, wireless body area networks (WBANs) have become a forward-looking technology since it is regarded as a potential solution for the remote collecting of physical and symptoms information. Because of its application characteristics, reliability and delay are the most important, as the energy consumption also needs to be considered. However, due to the limitation of the large propagation loss and the complicated channel conditions, the existing routing algorithms cannot completely address the above problems. To balance the node energy consumption and reduce the transmission delay, a simplified energy-balanced alternative-aware routing algorithm (SEAR) for WBANs is proposed in this paper. The residual energy and the current load of a candidate of the next hop destination are considered during the routing request forwarding procedures. The required information is exchanged during the improved routing request and routing request response procedures, and the routing cost is modified accordingly. To improve the compatibility and robustness, the added path is introduced as an alternative path in our algorithm. The simulation results show that SEAR achieves significantly higher network residual energy and network throughput, and end-to-end delay is also reduced. Therefore, the lifetime of the network is extended effectively.INDEX TERMS Wireless body area networks (WBANs), routing request, residual energy, routing algorithm, simplified, NS2.

As two promising candidate techniques for the 5G mobile communication system, device-todevice (D2D) communications and full-duplex communications have drawn significant research interests. Since full-duplex communications are suitable for use in low transmit power scenarios to lower the residual self-interference (SI), while D2D communications work in short distance scenarios which result in low transmit power, it is natural to integrate full-duplex into D2D communications. In this paper, we investigate the power control for full-duplex D2D communications underlaying cellular networks. Specifically, we formulate the power control problem by maximizing the achievable sum-rate of the full-duplex D2D link while fulfilling the minimum rate requirement of the cellular link under the maximum transmit power constraint of the cellular user and D2D users. Two algorithms are proposed to solve the optimization problem. For the first algorithm, we convert the objective function into a concave function based on difference of convex (D. C.) structure and propose an iterative algorithm to solve the optimization problem. For the second algorithm, we consider the received signal-to-interference-plus-noise ratios (SINRs) at the D2D users are high. Based on high-SINR approximation, closed-form optimal solutions are obtained for different boundaries of the feasible region. Numerical results are presented to illustrate the effect of the channel gains and SI cancellation ability on the optimal transmit power and the achievable sum-rate of the full-duplex D2D link.INDEX TERMS D2D communications, full-duplex, power control, underlaying cellular networks.

Due to its wide application range and attractive features, Wireless Body Area Networks (WBAN) is considered as a revolutionary technology which is envisaged to change how people manage and think about their health and their life styles. In this paper, we propose a Self-organized Dynamic Clustering (SDC) method and its multiple access mechanism to mitigate the interference and improve the QoS in multiple WBANs environment. To the best of our knowledge, this is the first paper which focuses on the spectrum allocation for multiple WBANs. We borrow the concepts of cell and cluster from cellular networks to allocate the channels for different WBANs. The clustering is self-organized to improve the data transmission for intra-WBAN communication by the information exchange via inter-WBAN communication. Additionally, based on the cluster architecture, an inter-WBAN relaying (IWR) protocol for packets with low privacy or high reliability is also investigated. The simulation results show that SDC has better signal to interference ratio compared with existing framework. Besides, SDC and IWR also provide better QoS performance in terms of higher data packet delivery ratio and lower packet delay.

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