Communication

A novel energy-efficient resource allocation algorithm based on immune clonal optimization for green cloud computing
Cloud computing is a style of computing in which dynamically scalable and other virtualized resources are provided as a service over the Internet. The energy consumption and makespan associated with the resources allocated should be taken into account. This paper proposes an improved clonal selection algorithm based on time cost and energy consumption models in cloud computing environment. We h...


Theoretical analysis and compensation for the joint effects of HPA nonlinearity and RF crosstalk in VBLAST MIMO-OFDM systems over Rayleigh fading channel
In this paper, we investigate the joint effects of nonlinear distortions due to high-power amplifier (HPA) and radio-frequency (RF) crosstalk on the performance of a multiple-input multiple-output-orthogonal frequency division multiplexing (MIMO-OFDM) system. The performance of the vertical bell laboratories layered space-time (VBLAST) MIMO-OFDM system, in terms of bit error rate (BER) and syst...
Analysis and experimental evaluation of rate adaptation with transmit buffer information
In hardware, packet loss may happen due to overflow at a finite-depth transmit buffer in addition to the packet corruption in the channel. To reduce such losses and further improve spectral efficiency via rate selection, we exploit either statistical or instantaneous knowledge of transmit buffer occupancy and source packet distribution in IEEE 802.11-based systems, which have highly variable fr...


Fuzzy Based Congestion Control for Wireless Multimedia Sensor Networks
Congestion is a challenging problem for sensor networks because it causes the waste ofcommunication and reduces energy efficiency. Compared to traditional wireless sensor networks, theprobability of congestion occurrence in wireless multimedia sensor networks is higher due to thehigh volume of data arising from multimedia streaming. In this article, problems for multimediatransmission over wire...
A Multiobjective Optimization Approach for Optimal Link Adaptation of OFDM-Based Cognitive Radio Systems with Imperfect Spectrum Sensing
This paper adopts a multiobjective optimization (MOOP) approach to investigate the optimal link adaptation problem of orthogonal frequency division multiplexing (OFDM)-based cognitive radio (CR) systems, where secondary users (SUs) can opportunistically access the spectrum of primary users (PUs). For such a scenario, we solve the problem of jointly maximizing the CR system throughput and minimi...


Comparison of Channel State Acquisition Schemes in Cognitive Radio Environment
We compare the capacity of two most popular methods for acquiring the state of the spectrum in cognitive radio technology: geolocation-database-based schemes and spectrum-sensing-based schemes. For the comparison, we use a new Hidden Markov Chain based channel model, because recent measurements show that a conventional two-state model, which has been widely used, is not appropriate for modeling...
Performance of Rayleigh-Product MIMO Channels with Linear Receivers
This paper presents an analytical investigation on the performance of Rayleigh-product MIMO channels with linear minimum mean-square-error (MMSE) or zero-forcing (ZF) receivers. For MMSE receivers, exact closed-form expressions for the ergodic sum-rate of the system are derived. In addition, simplified expressions are obtained for the key parameters dictating the sum-rate performance of the sys...

Channel and Energy Modeling for Self-Contained Wireless Sensor Networks in Oil Reservoirs
The real-time and in-situ monitoring capability in oil reservoirs is highly desired to increase the current recovery factor of crude oil and natural gas. To this end, the wireless sensor networks (WSNs) are envisioned to be deployed deep inside oil reservoirs to collect and report the physical and chemical information in real time. However, none of the existing wireless communication and networ...
Uplink Interference Management for Coexisting MIMO Femtocell and Macrocell Networks: An Interference Alignment Approach
This paper considers uplink interference management for two-tier cellular systems by way of Interference Alignment (IA). In order to manage the uplink interference caused by macrocell users at the femtocell base stations (FBS), cooperation between macrocell users with the closest femtocell base stations is proposed with the goal of aligning the received signals of macrocell users in the same su...

Invertible Subset LDPC Code for PAPR Reduction in OFDM Systems with Low Complexity
In this paper, we introduce a new family of low-density parity-check (LDPC) codes, called as invertible subset LDPC (IS-LDPC) code, for peak-to-average power ratio (PAPR) reduction in OFDM systems with low complexity. An IS-LDPC code has a number of disjoint invertible subsets, and each invertible subset can be independently inverted to generate other valid codewords of the LDPC code. To constr...
Asymptotic Studies for the Impact of Antenna Selection on Secure Two-Way Relaying Communications with Artificial Noise
In this paper, we consider a two-way relaying scenario with one pair of source nodes, one relay and one eavesdropper. All nodes are equipped with multiple antennas, and we study the impact of antenna selection on such a secure communication scenario. Three transmission schemes with different tradeoff between secure performance and complexity are investigated respectively. Particularly, when ant...

Multi-Channel Sensing and Access Game: Bayesian Social Learning with Negative Network Externality
In a distributed cognitive radio network, due to negative network externality, rational secondary users tend to avoid accessing the same vacant primary channels with others. Moreover, they usually need to make their channel access decisions in a sequential manner to avoid collisions. The characteristic of negative network externality and the structure of sequential decision making make the mult...
Minimum Energy Data Transmission for Wireless Networked Control Systems
The communication protocol design for wireless networked control systems brings the additional challenge of providing the guaranteed stability of the closed-loop control system compared to traditional wireless sensor networks. In this paper, we provide a framework for the joint optimization of controller and communication systems encompassing efficient abstractions of both systems. The objectiv...
Cooperative Networks with Amplify-and-Forward Multiple-Full-Duplex Relays
In this paper, we present a cooperative system with amplify-and-forward (AF) multiple-full-duplex relays (FDRs) that receives and transmits signals simultaneously. In the first, we propose a new concept of delayed M-FDR relaying (M-D-FDR) scheme being able to achieve the full spatial diversity. At this time, we consider each delayed FDR receives a signal from source, adjacent relays and its del...
Capacity Loss Due to Polarization-Mismatch and Space-Correlation on MISO Channel
This paper analyzes the effects of polarization-mismatch and space-correlation to a multiple-input and single-output (MISO) channel which is observable in the near future cellular communications environments such as large-scale antenna arrays and small cells. The analysis is based on a polarization-mismatched and space-correlated MISO channel which is modeled from the conventional dual-polarize...