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The throughput of conventional wireless multicast systems is limited by the multicast user with the lowest channel quality, which leads to a very low throughput especially if the number of users is large. In this paper, we show that hybrid-automatic repeat request with Chase combining (HARQ-CC) is a promising technique to overcome this problem and optimize the transmission rate of wireless multicast...
Indoor Wireless sensor networks require a highly dynamic, adaptive routing scheme to deal with the high rate of topology changes due to fading of indoor wireless channels. Besides that, energy consumption rate needs to be consistently distributed among sensor nodes and efficient utilization of battery power is essential. If only the link reliability metric is considered in the routing scheme, it may...
As the traffic grows rapidly in wireless communication, the spectrum becomes scarce. The current inefficient fixed spectrum allocation schemes will not satisfy the growing spectrum demand. This paper proposes a double auction based dynamic spectrum sharing scheme for multiple operators adopting OFDMA in the downlink. More specifically, this scheme allows free subcarriers trading between operators...
In this paper, we propose an antenna selection algorithm for down link MIMO SDMA OFDM system. For each user, the data rate corresponding to each transmit antenna is maximized using the optimal bit loading algorithm. A data rate matrix is constructed and used for the antenna selection algorithm assuming the base station (BS) knows the signal-to-noise ratio on all antenna-user pairs of all sub-carriers...
In wireless dual-hop decode-and-forward (DF) relaying networks, multiple relay stations (RS) and users construct a multiple-in-multiple-out (MIMO) broadcast channel (BC). Due to unpredictable decoding failure, scheduling the transmission for the decode-and-forward broadcast channel (DFBC) should depend on not only channel qualities but also the availability of errorless data at individual RSs. Based...
In this paper we investigate channel state information (CSI) feedback strategy for a basestation (BS) scheduling multiple users for data transmissions in the downlink. For the purpose of fair provisioning of service among users with possibly heterogeneous channel statistics, we adopt scheduling algorithms based on scores: specifically the maximum quantile (MQ) scheduling is used as one of such schedulers...
A framework of joint antenna selection and source coding strategy for scalable video transmission over wireless systems was proposed. Each layer of a bit-stream could be switched among multiple transmit antennas in order to achieve unequal error protection (UEP) for prioritized video layered bit-streams. At first wavelet-based 3D ESCOT codec generates layered bit streams that need prioritized delivery...
Recent security methods propose to generate secret keys from Ultra Wide Band (UWB) channels. These solutions rely on the reciprocity and spatial channel correlation principles. This work aims at presenting empirical studies on the aforesaid properties. First, we verify the UWB reciprocity for different multipath scenarios. In these experiences, the reciprocity is always valid independently of distance...
This paper investigates multi-cell coordinated shared relay with joint processing (JP) scheme in interference limited network. In general, multi-cell coordinated shared relay network increases the Signal to Interference-plus-Noise Ratio (SINR) in cell edge users, but resource usage efficiency is decreased by two-phase transmission of relay protocol. We propose JP of cooperating BSs and shared relay...
In this paper indoor wireless Infrared (IR) technology for healthcare monitoring is studied. Monitoring provides a continuous and reliable vital sign measurement to secure patient staying in the hospital. Considering that patient moving is inevitable, we focus on a mobile IR channel based on diffuse propagation. A model of mobile channel is developed through the study of statistical distributions...
The Wireless over Cable (WoC) paradigm is a new technique to enable distributed antennas systems. WoC is based on the relay of radio frequency wireless signals over a cable infrastructure through a bidirectional (analog) amplify and forward device that translates the bandwidth of wireless signals to comply with the specifications of the wired links. Following the WoC concept, here the xDSL connection...
In this paper, we propose a simple time-domain replica correlation (TDRC) based symbol timing synchronization scheme in orthogonal frequency division multiplexing systems. By allocating a locally concatenated sequence of a base sequence and its modified sequence to total feasible frequency resources, we can achieve both hardware complexity and frequency offset reductions. The hardware complexity of...
This paper proposes an analytic model to study queuing effect on the handoff performance of Mobile IPv6 (MIPv6), which has not been particularly investigated in previous literature. The presented model regards handoff process as tandem service system, and adopts a simple two-moment approximation throughout the theoretic modeling. Without other specific assumptions, the model presents a generic approach...
The 60 GHz technology has an immense potential to provide wireless communication at multi-gigabit rates. At 60 GHz frequency band, severe attenuation of the signals can significantly degrade communication performance. To cope with the attenuation problem, directional antennas with high directive gains can be utilized. When network nodes use directional antennas, the neighbor discovery process becomes...
Cooperative decoding is powerful technique for establishing good quality TV broadcasting. In cooperative decoding, some TV receivers, nodes, are cooperated, each other. These share the received information signal and thus obtain good quality information signal. Incremental-Maximum Ratio Combining (I-MRC) is one of the cooperative decoding methods. In I-MRC, the best condition's node and second one...
Wireless Body Area Network (WBAN) allows the integration of low-power, miniaturized, intelligent, invasive or/and non-invasive wireless sensor nodes that are used to monitor the health status of a patient with real-time updates to a base-station/physician. Since multiple low-power sensor nodes are deployed in/on a human body, Medium Access Control (MAC) protocols are required to share the channel...
In this paper we consider an IEEE 802.15.4-based Wireless Body Area Network, where wearable sensor devices are distributed on a body and have to send the measured data to a coordinator. The Carrier Sense Multiple Access with Collision Avoidance algorithm defined by the standard is used as Medium Access Control protocol, whereas different modulation schemes are assumed to be available at the physical...
In this paper, we proposes a resource reuse scheme for femtocell networks. In this context, macrocells operate in a Frequency Division Duplexing mode while all femtocells employ the macrocellular uplink spectrum in a Time Division Duplexing mode. We propose two solutions. In the first one, a centralized scheduling is performed via list-coloring based on the overall conflict graph. The second solution...
During recent years Wireless Body Area Networks (WBANs) have been experienced continuous developments by researchers both in academia as well as industry due to its capabilities and various promising applications, for instance, in the areas of healthcare, sports, military, etc. One of the crucial requirements in designing a WBAN, especially, for the healthcare applications is network reliability since...
The dawn of the Future Internet (FI) era poses new requirements to modern communication networks namely, the demand for new applications/ services, the support for diversified services, the expanded use of wireless access and the need for increased efficiency in resource provisioning and utilization. In this paper we propose a solution to address these requirements. In particular, the proposed solution...
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