EURASIP Journal on Wireless Communications and Networking

http://link.springer.com/journal/13638

List of Papers (Total 2,951)

Cross-Layer Design and Analysis of Downlink Communications in Cellular CDMA Systems

A cellular CDMA network with voice and data communications is considered. Focusing on the downlink direction, we seek for the overall performance improvement which can be achieved by cross-layer analysis and design, taking physical layer, link layer, network layer, and transport layer into account. We are concerned with the role of each single layer as well as the interaction among ...

ZSBT: A Novel Algorithm for Tracing DoS Attackers in MANETs

Denial of service (DoS) attack is a major class of security threats today. They consume resources of remote hosts or network and make them deny or degrade services for legitimate users. Compared with traditional Internet, the resources, such as bandwidth, memory, and battery power, of each node are more limited in mobile ad hoc networks (MANETs). Therefore, nodes in MANETs are more ...

Energy-Efficient Medium Access Control Protocols for Wireless Sensor Networks

A key challenge for wireless sensor networks is how to extend network lifetime with dynamic power management on energy-constraint sensor nodes. In this paper, we propose two energy-efficient MAC protocols: asynchronous MAC (A-MAC) protocol and asynchronous schedule-based MAC (ASMAC) protocol. A-MAC and ASMAC protocols are attractive due to their suitabilities for multihop networks ...

Opportunistic Nonorthogonal Packet Scheduling in Fixed Broadband Wireless Access Networks

In order to mitigate high cochannel interference resulting from dense channel reuse, the interference management issues are often considered as essential part of scheduling schemes in fixed broadband wireless access (FBWA) networks. To that end, a series of literature has been published recently, in which a group of base stations forms an interferer group (downlink transmissions ...

A Novel Cluster-Based Cooperative MIMO Scheme for Multi-Hop Wireless Sensor Networks

A cluster-based cooperative multiple-input-multiple-output (MIMO) scheme is proposed to reduce the adverse impacts caused by radio irregularity and fading in multi-hop wireless sensor networks. This scheme extends the LEACH protocol to enable the multi-hop transmissions among clusters by incorporating a cooperative MIMO scheme into hop-by-hop transmissions. Through the adaptive ...

Optimal and Suboptimal Finger Selection Algorithms for MMSE Rake Receivers in Impulse Radio Ultra-Wideband Systems

The problem of choosing the optimal multipath components to be employed at a minimum mean square error (MMSE) selective Rake receiver is considered for an impulse radio ultra-wideband system. First, the optimal finger selection problem is formulated as an integer programming problem with a nonconvex objective function. Then, the objective function is approximated by a convex ...

Nonregenerative Dual-Hop Cooperative Links with Selection Diversity

The end-to-end performance of dual-hop cooperative diversity systems equipped with nonregenerative relays and a selection combining receiver at the destination terminal over independent and nonidentical Nakagami- fading channels is studied. Closed-form expressions for the cumulative distribution function and the probability density function of the end-to-end signal-to-noise ratio ( ...

Multiple-Channel Security Architecture and its Implementation over SSL

This paper presents multiple-channel SSL (MC-SSL), an architecture and protocol for protecting client-server communications. In contrast to SSL, which provides a single end-to-end secure channel, MC-SSL enables applications to employ multiple channels, each with its own cipher suite and data-flow direction. Our approach also allows for several partially trusted application proxies. ...

A Sigma-Delta ADC with Decimation and Gain Control Function for a Bluetooth Receiver in 130 nm Digital CMOS

We present a discrete-time second-order multibit sigma-delta ADC that filters and decimates by two the input data samples. At the same time it provides gain control function in its input sampling stage. A 4-tap FIR switched capacitor (SC) architecture was chosen for antialiasing filtering. The decimation-by-two function is realized using divided-by-two clock signals in the ...

Adaptive Downlink Resource Allocation Strategies for Real-Time Data Services in OFDM Cellular Systems

This paper presents a detailed performance analysis of adaptive downlink resource allocation based on users' instantaneous channel responses using power minimization (PM) and bandwidth constrained power minimization (BCPM) strategies. This study shows that, in cellular systems, where interference is a dominant factor, the link outage performance of a resource allocation strategy ...

Transceiver Design for Multiband OFDM UWB

Ultra-wideband (UWB) is an emerging broadband wireless technology enabling data rates up to Mbps. This paper provides an overview of recent design approaches for several circuit functions that are required for the implementation of multiband OFDM UWB transceivers. A number of transceiver and synthesizer architectures that have been proposed in literature will be reviewed. Although ...

A General Theory for SIR Balancing

We study the problem of maximizing the minimum signal-to-interference ratio (SIR) in a multiuser system with an adaptive receive strategy. The interference of each user is modelled by an axiomatic framework, which reflects the interaction between the propagation channel, the power allocation, and the receive strategy used for interference mitigation. Assuming that there is a ...

Error Control Coding in Low-Power Wireless Sensor Networks: When Is ECC Energy-Efficient?

This paper examines error control coding (ECC) use in wireless sensor networks (WSNs) to determine the energy efficiency of specific ECC implementations in WSNs. ECC provides coding gain, resulting in transmitter energy savings, at the cost of added decoder power consumption. This paper derives an expression for the critical distance , the distance at which the decoder's energy ...

TCP-M: Multiflow Transmission Control Protocol for Ad Hoc Networks

Recent research has indicated that transmission control protocol (TCP) in its base form does not perform well in an ad hoc environment. The main reason identified for this behavior involves the ad hoc network dynamics. By nature, an ad hoc network does not support any form of quality of service. The reduction in congestion window size during packet drops, a property of the TCP used ...

Charge-Domain Signal Processing of Direct RF Sampling Mixer with Discrete-Time Filters in Bluetooth and GSM Receivers

RF circuits for multi-GHz frequencies have recently migrated to low-cost digital deep-submicron CMOS processes. Unfortunately, this process environment, which is optimized only for digital logic and SRAM memory, is extremely unfriendly for conventional analog and RF designs. We present fundamental techniques recently developed that transform the RF and analog circuit design ...

Space-Time Water-Filling for Composite MIMO Fading Channels

We analyze the ergodic capacity and channel outage probability for a composite MIMO channel model, which includes both fast fading and shadowing effects. The ergodic capacity and exact channel outage probability with space-time water-filling can be evaluated through numerical integrations, which can be further simplified by using approximated empirical eigenvalue and maximal ...

Transient and Steady-State Analysis of Nonlinear RF and Microwave Circuits

This paper offers a review of simulation methods currently available for the transient and steady-state analysis of nonlinear RF and microwave circuits. The most general method continues to be the time-marching approach used in Spice, but more recent methods based on multiple time dimensions are particularly effective for RF and microwave circuits. We derive nodal formulations for ...

Equalization of Sparse Intersymbol-Interference Channels Revisited

Sparse intersymbol-interference (ISI) channels are encountered in a variety of communication systems, especially in high-data-rate systems. These channels have a large memory length, but only a small number of significant channel coefficients. In this paper, equalization of sparse ISI channels is revisited with focus on trellis-based techniques. Due to the large channel memory ...

Fiber over Wireless Chromatic Dispersion Compensation for a Better Quality of Service

"Anywhere" and, in particular, "anyhow": these are the two best words that can describe an ad hoc wireless network that is due to the increasing demand for connectivity in such an information society. Ad hoc wireless networks can be described as dynamic multihop wireless networks with mobile nodes. However, the mobility condition can be relaxed, and we can consider an ad hoc ...

QoS Topology Control for Nonhomogenous Ad Hoc Wireless Networks

This paper discusses the energy-efficient QoS topology control problem for nonhomogenous ad hoc wireless networks. Given a set of nodes with different energy and bandwidth capacities in a plane, and given the end-to-end traffic demands and delay bounds between node-pairs, the problem is to find a network topology that can meet the QoS requirements and the maximum energy utilization ...

Traffic Agents for Improving QoS in Mixed Infrastructure and Ad Hoc Modes Wireless LAN

As an important complement to infrastructured wireless networks, mobile ad hoc networks (MANET) are more flexible in providing wireless access services, but more difficult in meeting different quality of service (QoS) requirements for mobile customers. Both infrastructure and ad hoc network structures are supported in wireless local area networks (WLAN), which can offer high ...

A Frame Synchronization and Frequency Offset Estimation Algorithm for OFDM System and its Analysis

Orthogonal frequency division multiplexing (OFDM) is a parallel transmission scheme for transmitting data at very high rates over time dispersive radio channels. In an OFDM system, frame synchronization and frequency offset estimation are extremely important for maintaining orthogonality among the subcarriers. In this paper, for a preamble having two identical halves in time, a ...

CMOS Silicon-on-Sapphire RF Tunable Matching Networks

This paper describes the design and optimization of an RF tunable network capable of matching highly mismatched loads to 50 at 1.9 GHz. Tuning was achieved using switched capacitors with low-loss, single-transistor switches. Simulations show that the performance of the matching network depends strongly on the switch performances and on the inductor losses. A 0.5 m ...

Multipass Channel Estimation and Joint Multiuser Detection and Equalization for MIMO Long-Code DS/CDMA Systems

The problem of joint channel estimation, equalization, and multiuser detection for a multiantenna DS/CDMA system operating over a frequency-selective fading channel and adopting long aperiodic spreading codes is considered in this paper. First of all, we present several channel estimation and multiuser data detection schemes suited for multiantenna long-code DS/CDMA systems. Then, ...