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Multicarrier complementary-coded code division Multiple Access (MC CC-CDMA) is becoming an attractive multiple access technique for high data rate transmission in future wireless communication systems. MC CC-CDMA systems transmitting over frequency-selective channels suffer from multiple access interference (MAI) owing to non-ideal correlation properties of complementary codes (CC). MC CC-CDMA with...
Traditional positioning needs lots of measurements between the target and anchors. However, this requirement is faced with significant challenge in the most practical scenarios. The cooperation between mobile nodes is an effective solution. In order to avoid large computational complexity, we need to cooperate with neighbors selectively. This paper proposes a novel node selection algorithm based on...
Wireless mobile networks frequently need remote software updates to add or adjust the tasks of mobile nodes. Software update traffic, particularly in the Internet of Things (IoT), should be carefully handled since attackers can easily compromise a number of unattended devices by modifying a piece of code in the software update routine. These attacks are quite realistic and harmful as seen in the real...
With new forms of media such as Twitter becoming increasingly popular, the Internet is now the main conduit of individual and interpersonal messages. A considerable amount of people express their personal opinions about news-related subject through Twitter, a popular SNS platform based on human relationships. It provides us a data source that we can use to extract peoples’ opinions which are important...
Adaptive ultra-wideband wireless body area network (WBAN) is proposed in this paper as a feasible mobile health platform, offering a high-speed and robust service. It employs a space-time-frequency-coded (STFC) multiband orthogonal frequency division multiplexing ultra-wideband technology. It is designed to improve the average bit error performance for high data rate applications while maintaining...
Although promising the formidable configuration, vigorous evolution, and satisfactory performance, software-defined networking (SDN) is in its initial period all the same. Some essential issues still remain not completely resolved, and the scalability of control plane is the most intractable one with the explosive increase of network traffic. To address this issue, many researchers have proposed multiple...
Besides the prior study of energy efficiency (EE) that focuses on single component (antenna, radio frequency (RF) chain, circuit, etc.), or limited to one base station (BS) area, in this paper, EE is integrated, investigated with various components (antenna, RF chain, circuit, coverage area) considering in, based on an optimized system model. That is, one optimized multi-BS system model is introduced...
Under the impact of co-channel interference (CCI) at two source nodes and the relay, we investigate the performance of dual-hop amplify-and-forward (AF) relaying networks. In terms of energy harvesting, the power-constrained relay first scavenges energy from the received signal and CCI signals then amplifies them and forwards them to the destination. In particular, we provide closed-form expressions...
It is very important that the radar sensor network has autonomous capabilities such as self-managing, etc. Quite often, MIMO interference channels are applied to radar sensor networks, and for self-managing purpose, interference management in MIMO interference channels is critical. Interference alignment (IA) has the potential to dramatically improve system throughput by effectively mitigating interference...
In a heterogeneous wireless environment, mobility particularly vertical handover between WiFi and cellular data service has to be supported. The support for multihoming feature makes Stream Control Transmission Protocol (SCTP) become a promising transport layer-based handover scheme for end users. Although the benefits of applying SCTP for multimedia delivery and handover have been proved to be extremely...
Cyber-Physical Systems (CPS) are often composed of a great number of mobile, wireless networked devices. In order to guarantee the system performing, management policies focused on becoming transparent to high-level applications, the changes in the hardware platform have to be implemented. However, traditional reactive methodologies and basic proposed predictive solutions are not valid either due...
Mobile network operators (MNOs) are deploying carrier-grade Wireless Local Area Network (WLAN) as an important complementary system to cellular networks. Access network selection (ANS) between cellular and WLAN is an essential component to improve network performance and user quality-of-service (QoS) via controlled loading of these systems. In emerging heterogeneous networks characterized by different...
One fundamental tradeoff in the cross-layer design of a communications system is delay allocation. We study delay budget partitioning in a wireless multimedia system between two of the main components of delay: the queuing delay in the source encoder output buffer and the delay caused by the interleaver. In particular, we discuss how to apportion the fixed delay budget between the source encoder and...
Superposed multicarrier transmission is one of the schemes that achieve efficient use of frequency resources. In the scheme, desired signals are interfered by other systems sharing the same frequency band, which causes unreliable LLR (log-likelihood ratio) setting and leads to degradation of the BER (bit error rate) performance. In many conventional schemes for OFDM (orthogonal frequency division...
A popular means of social communication for online users has become a trend with rapid growth of social networks in the last few years. Facebook, Myspace, Twitter, LinkedIn, etc. have created huge amounts of data about interactions of social networks. Meanwhile, the trend is also true for offline scenarios with rapid growth of mobile devices such as smart phones, tablets, and laptops used for social...
Ina wireless ad hoc network, single-antenna nodes can cooperate in their transmissions to create a virtual multiple-input multiple-output (MIMO) channel for maximizing the spatial multiplexing gain. However, implementing virtual-MIMO transmission can result in overwhelming overhead, such as channel state information (CSI) feedback and local data exchange, as the number of cooperating nodes increases...
As one of the key challenges in network virtualization, the problem of virtual network embedding has attracted significant attention from researchers. In this problem, it needs to embed virtual networks with both node and link demands into a shared physical network. The main goal of this problem is to embed more virtual networks to gain more revenue. However, the prior approaches still suffer from...
Most applications require high reliability with low delay in wireless sensor networks (WSNs). Unfortunately, it is a challenge issue to achieve reliable communication because of the lossy nature of wireless channels. In this paper, a novel unequal redundancy level (URL) data collection scheme is proposed to achieve high reliability for wireless sensor networks while long lifetime can be still guaranteed...
This paper introduces a new direction-of-arrival (DOA) estimation method for wideband signal sources. The new method estimates the DOA of wideband signal sources based on squared test of orthogonality of projected subspaces (Squared TOPS) which is an improved method of TOPS. TOPS and Squared TOPS use the signal and noise subspaces of multiple frequency components of wideband signal sources. Although...
Employment of massive multi-input multi-output (m-MIMO) transmission techniques has recently been considered as a key technology for the provision of high capacity to a large number of users. Zero-forcing beamforming (ZFBF) techniques can be employed to maximize the transmission capacity, but they may require high implementation complexity in multi-user m-MIMO transmission environments. In this paper,...
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