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In wireless single-hop multicast with network coding based Automatic Repeat reQuest (NC-ARQ) scheme, the sender needs to combine one or several lost packets as one retransmission packet to reduce the number of multicast transmissions. This paper proposes a new scheme, called Dynamic Network Coding based ARQ (DNC-ARQ), to improve the efficiency of the multicast transmissions. The main idea is to allow...
In this paper, we investigate low-complexity user scheduling schemes for the downlink (DL) massive multiuser multiple-input multiple-output (MU-MIMO) system, where an M-antenna (M is very large) base station (BS) serves K (K > 2) N-antenna (N > 1) users with linear transceivers. Establishing the theoretical foundation of our scheduling schemes, we first investigate the asymptotic sum-rates of...
In this paper, we consider the operation of a mobile multi-radio wireless device, which may simultaneously utilize several radio access technologies when transmitting its data. Whereas the use of multiple radios does improve network capacity and user connectivity experience, it also results in a significant growth of device energy demands. To compensate for it, the device may leverage the excess availability...
Today the world is moving towards wireless system. Wireless networks are gaining popularity to its peak today, as the users want wireless connectivity irrespective of their geographic position. Vehicular ad-hoc networks (VANETs) are considered to be the special application of infrastructure-less wireless Mobile ad-hoc network (MANET). In these networks, vehicles are used as nodes. In this paper, we...
Cooperative relay is considered as an efficient scheme to improve the physical layer security of a wireless relay system in the presence of eavesdroppers. In this paper, multiple-level relay scheme is proposed. We consider relay weight design for secrecy rate maximization subject to a power constraint. The results show that a higher achievable secrecy rate is achieved in the two-level relay channel...
This paper considers a two-cell multiple-input single-output (MISO) interference channel, where the Pareto boundary of the achievable rate region is computed through linear beamforming design. A distributed beamforming strategy is provided by solving the signal-to-leakage-plus-noise (SLNR) maximization problem with per base station (BS) power constraints. After some conversion, a single real-valued...
As everyone knows, the energy of signals diminishes with increasing distance, so users at the edge of hexagon cells have lower signal-to-noise ratio (SNR) than users at the center, which means they are more easily interfered by signals from other base stations. So we consider the application of relay to the cellular case to help users at the edge to eliminate interferences and obtain higher sum-rate...
This paper investigates the design of interference alignment (IA) for a three-cell constant cellular interfering network, where three base stations in the cellular network simultaneously transmit signals to a group of users in their own cells while causing interference to each other. While determining the existence of IA with reaching the degrees of freedom (DoF) outer bound is still a very challenging...
Heterogeneous Network (HetNet) is a promising solution to enhance network capacity and extend network coverage by increasing cell site density in Long Term Evolution-Advanced (LTE-Advanced) systems. However, dense deployment of cell sites not only increases desired signal strength, but also intercell interference as cell sites get closer. To combat with intercell interference, Joint Processing Coordinated...
The channel estimation is one of important techniques to ensure reliable broadband signal transmission. Broadband channels are often modeled as a sparse channel. Comparing with traditional dense-assumption based linear channel estimation methods, e.g., least mean square/fourth (LMS/F) algorithm, exploiting sparse structure information can get extra performance gain. By introducing ℓ1-norm penalty,...
This paper presents an application-agnostic Quality of service (QoS) framework forWireless Body Area Networks (WBAN). The applications of WBAN includes several areas such as smart health care, assisted elderly living and emergency response. In the WBAN, obtaining an acceptable QoS performance is extremely important due to its relation with human health and emergency situation. The QoS requirements...
Sum feedback rate can be a bottleneck for codebook-based multiple-input-multiple-output (MIMO) beamforming. So we propose a scheme using pseudorandom beamforming vectors and a threshold for feedback to address this problem. In our scheme, the basestation produces beamforming vectors in a pseudorandom way, and user calculates the angle between the beamforming vectors and its channel state information...
Improving the energy efficiency is a major challenge of the next-generation wireless networks. In this regard, several network level green applications have been proposed during the last few years. In this paper, we review some of these applications, and describe how the awareness about the presence of clusters of nearby communicating nodes can enhance them. The considered applications fall into the...
In this paper, a multiuser two-way filter-and- forward relaying scheme for wireless communication over wideband channels is considered. We propose pre/post-rake processing in conjunction with optimized filtering at the relay to reduce the signal processing burden at the source and destination nodes. Two relay filter design problem formulations are introduced, namely (a) a convex optimization problem...
Cooperative transmission utilizes the presence of multiple radio transmission equipment including base stations, antennas and mobile stations to create transmission such that capacity and performance of the transmission are improved. This paper proposes a new transmission model embedded with a modified ant colony algorithm to improve transmission performance whilst reducing computational complexity.
Wireless communication is widely used in Implantable Medical Devices (IMDs) to facilitate data transmission, device programming, and real time monitoring. However, wireless systems are easy targets for attackers to inspect and potentially breach. Thus, security and privacy have become principal design requirements for IMDs. The challenge in secure IMD design stems from the conflicting constraints...
In Multilevel Polarization Modulation (MPM), the abrupt switching among the discrete Sates of Polarization (SOPs) brings discontinuity of signal waveforms, which will broaden bandwidth and decrease the bandwidth efficiency consequently. To alleviate the problem, in this paper a Multilevel Continuous Polarization Modulation (MCPM) scheme is proposed with continuous SOP to produce continuous signal...
The widely used broadband wireless technology enables a novel application of providing high-quality communications between vehicles and traffic control centers, which is collectively referred to as vehicle-to-ground communications. Channel modeling is in rapidly increasing demand to design and optimize the vehicle-to-ground communication systems. And practical channel models are only available when...
This paper focuses on downlink interference issues in the open subscriber group (OSG) mode of heterogeneous network (HetNet). In OSG mode, the inter macro-user interference is the main interference to macro user equipments (UEs), and the inter cell interference (ICI), containing the inter picocell interference and the cross-layer interference from macro base station (BS), is the main interference...
This paper proposes an efficient low-complexity polyphase interleaving and inversion (PII) scheme based on enhanced parallel tabu search (TS) for the reduction of peak-to-average power ratio (PAPR) in space-frequency block-coded orthogonal frequency-division multiplexing (SFBC-OFDM) systems. PII is a technique that can significantly reduce the PAPR of SFBC-OFDM symbols by exchanging SFBC symbols between...
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