Optimization of MQAM Modulation Schemes in Mobile Communications(Ⅰ)——Analysis of MQAM BER Performance in AGWN Channel Based on Signal Space

Based on signal space concepts, a transmission error code performance for MPSK, square MQAM and star MQAM modulation schemes on the AGWN channel is analyzed. The corresponding BER formulas and computer aided numeric results are also given. Therefore it provides a theoretical basis for choosing MQAM modulation schemes in mobile communications.     

Optimization of MQAM Modulation Schemes in Mobile Communications（I）—Analysis of MQAM BER Performance in AGWN Channel Based on Signal Space

Based on signal space concepts, a transmission error code performance for MPSK, square MQAM and star MQAM modulation schemes on the AGWN channel is analyzed.The corresponding BER formulas and computer aided numeric results are also given.Therefore it provides a theoretical basis for choosing MQAM modulation schemes in mobile communications.     

Optimization of MQAM Modulation Schemes in Mobile Communications（Ⅱ）—Analysis of MQAM BER Performance in Rayleigh Channel

The transmission error code performance of square MQAM and star MQAM modulation schemes for the AGWN Rayleigh fading channel is analyzed.The corresponding BERformulas and computer aided numeric results are given.Therefore it provides a theoretical basis for choosing MQAM modulation schemes in mobile communications.     

Chaos Synchronization on Parameters Adaptive Control for Chen Chaotic System

1　IntroductionThesynchronizationoftwononlineardynamicalsystemsisaphenomenonofimportanceinawiderangofappliedsciences,andhasbeenpaidmuchat tentiontoandinvestigatedinthe pasttwentyyears[1～ 1 3] .Recentlysecurecommunicationusingchaossynchronizationhasbeenpaidmuchattentiontoasoneoftheimportantpracticalapplicationsofchaos[1 4 ] .Themainideaisthatwhenaninforma tionsignalismaskedbythechaoticsignal,itcanbeeasilyrecoveredatthereceiverbymeansofchaossynchronization ,whileexternalattackisalmostim possibl…     

Parameter Optimization Based on GA and HFSS

A new project based on genetic algorithm (GA) and high frequency simulation software (HFSS) is proposed to optimize microwave passive devices effectively. This project is realized with a general program named as optimization program. The program is compiled by Matlab and the macro language of HFSS which is a fast and effective way to accomplish tasks. In the paper, two examples are used to show the pro/ect‘s feasibility.     

An Intrusion Detection System Model Based on Immune Principle and Performance Analysis

1　Introduction　 With the rapid development of Internet, network securityhas gotten the increasing focus of government, enterprise,even the individuals. But with the continuously spread ofnetwork application, attacks and destroys aiming at it in crease steadily also. Intrusion detection is a kind of networksecurity technique to detect any damage or attempt to tamperthe secrecy, integrality and usability of system. IntrusionDetection System (IDS) is an automated system for t…     

Adaptive Digital Audio Steganography Based on Integer Wavelet Transform

In this paper a novel method for digital audio steganography is presented where encrypted covert data is embedded into the coefficients of the host audio (cover signal) in the integer wavelet domain. The hearing threshold is calculated in the integer domain and this threshold is employed as the embedding threshold. The inverse integer wavelet transform is applied to the modified coefficients to form a new audio sequence (stego signal). The characteristics of this method are large payload, high audio quality and full recovery. This work was supported by Iranian Telecommunication Research Center (ITRC).     

Cross-layer in MIMO-OFDM System with Adaptive Modulation and Coding：Design and Analysis

The queuing performance of the cross-layer system with Space-time block code （STBC） over Multi- input-multi-output （MIMO） channel is analyzed. The Adaptive modulation and coding （AMC） in physical layer and finite length of buffer in data-link layer are combined with this model. A simple cross-layer design and the queue state process are proposed based on finite state 1V[arkov channel model~ which is to solve the service process. The proposed cross-layer design is also incorporated with STBC to further improve the system performance. Simulation results illustrate the dependence of system performance on various parameters, and quantify the performance gain due to cross-layer optimization. The adjustment of target packet loss rate of adaptive modulation coding in physi- cal layer can maximize average throughput of the system, meanwhile a significant improvement of the system perfor- mance is brought.     

Research on Threshold Adjustment Algorithm in Adaptive Modulation and Coding

1Introduction AMCisoneofthekeytechniquesinHSDPA[1].AMChasbeenofinterestasanefficientwaytoincrease thethroughputof3Gwirelesscommunicationsystems.ThecoreideaofAMCistodynamicallychangethe MCSinsubsequentframeswiththeobjectiveofmaxi mizingthespectralefficienc…     

Cost–Performance Analysis and Optimization of Fuel-Burning Thermoelectric Power Generators

Energy cost analysis and optimization of thermoelectric (TE) power generators burning fossil fuel show a lower initial cost compared with commercialized micro gas turbines but higher operating cost per energy due to moderate efficiency. The quantitative benefit of the thermoelectric system on a price-per-energy ($/J) basis lies in its scalability, especially at a smaller scale (<10 kW), where mechanical thermodynamic systems are inefficient. This study is based on propane as a chemical energy source for combustion. The produced heat generates electric power. Unlike waste heat recovery systems, the maximum power output from the TE generator is not necessarily equal to the economic optimum (lowest $/kWh). The lowest cost is achieved when the TE module is optimized between the maximum power output and the maximum efficiency, dependent on the fuel price and operation time duration. The initial investment ($/W) for TE systems is much lower than for micro gas turbines when considering a low fractional area for the TE elements, e.g., 5% to 10% inside the module. Although the initial cost of the TE system is much less, the micro gas turbine has a lower energy price for longer-term operation due to its higher efficiency. For very long-term operation, operating cost dominates, thus efficiency and material ZT become the key cost factors.     

Design and Realization of Software for Guard Against DDoS Based on Self-Similar and Optimization Filter

1IntroductionWith the development of network,security of net-work is more and more serious[1]flooding-based Dis-tributed Denial-of-Service(DDoS)attack presents avery serious threat to the stability of the internet[2~3].The detection of DoS/DDoS attack mai…     

A Novel Pulse Design Based on Hermite Functions for UWB Communications

1IntroductionUltra-Wide Band(UWB)technology is foreseen as apossible solution for future short-range high-data-ratewireless communications.Unlike the conventional carrier-based wireless communication systems,a carrier-freeUWB radio system usually transmit…     

Production Planning Based on BOM Optimization

According to a prototype enterprise, a rulebased Bill of Materials （BOM） structure is designed in order to get optimal design and management of product BOM. The constraint rules and optional objects for product data structure optimization are considered by associating customer demands with product BOM. Furthermore, the functional model of production planning system for assembling enterprise is given based on customization and BOM optimization.     

Performance Analysis of Tags Collection Time on A New Architecture of 2.4 GHz Embedded Active RFID System for Indoor and Outdoor Tracking and Monitoring Applications Based on IEEE 802.15.4 Standard

This paper focuses on the analysis of tags collection time of 2.4 GHz embedded active Radio Frequency Identification (RFID) system for indoor and outdoor real-time tracking and monitoring applications based on IEEE 802.15.4 standard. The main novelty of the system is the implementation of the communication method in order to provide Machine to Machine (M2M) communication and automated switching mechanism between indoor and outdoor location by utilizing active RFID, Wireless Sensor Network (WSN), Global Positioning System (GPS) and mobile communication on a single platform. In this work, GPS receiver covers outdoor location tracking, while active RFID provides identification and Receive Signal Strength Indicator (RSSI) reading for each tag holder to cover indoor location tracking especially near or inside building where location information is not detected by GPS. Several experiments were conducted on three different RFID tags which were active RFID tag embedded with GPS and GSM (ERFIDG2), active RFID tag embedded with GPS (ERFIDG) and standalone RFID tag communicating with the same active RFID reader. The experiment was done to evaluate the communication performance of the active RFID in terms of tags collection time using Transparent (AT) and Application Programming Interface (API) mode. The experiment was extended to measure tags collection time in single hop and multi hops communication for Tag Talk First (TTF) and Reader Talk First (RTF) protocols. The results show that the proposed active RFID system (ERFIDG2) is better than the standalone and ERFIDG systems. The in-depth research done in this work is to study the experience and identify the challenges that will be faced in the development and implementation of a wireless RFID-based system for tracking and monitoring applications.     

Multiuser–Multipath Detection in IDMA Based HetNet: An Adaptive Cyclic Interleaving Approach

In this paper, we introduce a method of user loading for interleave division multiple access (IDMA) based two-tier Heterogeneous network (HetNet) to achieve improved performance in terms of lower bit-error rate (BER) for active micro-cell users present in the coverage area of a macro-cell base station (BS). Based on the fading scenario, the proposed method adjusts the load distribution among the macro-cell BS and the participating micro-cell BSs in the HetNet structure to guarantee relatively low BER to the mobile users. In this study, we propose a HetNet employing an adaptive cyclic interleaving technique at the IDMA transmitter and a multiuser–multipath (MUMP) detector at the receiver to support load distribution. With the aid of cyclic interleaving, MUMP detector resolves each received multipath component through multipath detection rather than conventional single path detection. Then, via theoretical study and extensive simulations, first, we demonstrate how the cyclic interleaving mechanism introduced in IDMA transmitter exploits the diversity property of the maximal-length sequence (m-sequence). Next, the superiority of the MUMP detector over single path detectors in multipath Rayleigh fading channel is shown and also the effect of equal-gain combining (EGC) and maximal-ratio combining (MRC) schemes in system performance is analysed for different BS load distribution in IDMA based HetNet.     

Globally Exponential Synchronization and Parameter Regulation for Coupled Chaotic System via Adaptive Control

Based on Lyapunov stability theory,an adaptive controller is designed for a class of chaotic systems. Globally exponential synchronization and parameter regulation for couple chaotic systems can be carried out simultaneously. The controller and the regulating law of parameters are directly constructed by analytic formula. Simulation results with some chaotic systems show the effectiveness of the proposed controller.     

Modeling and Stability Analysis for Non-linear Network Control System Based on T-S Fuzzy Model

Based on the T -S fuzzy model, this paper presents a new model of non -linear network control system with stochastic transfer delay. Sufficient criterion is proposed to guarantee globally asymptotically stability of this two - levels T - S fuzzy model. Also a T - S fuzzy observer of NCS is designed base on this two - levels T - S fuzzy model. All these results present a new approach for networked control system analysis and design.     

Performance Analysis of Combined mMCSK–mMFSK Modulation in AWGN and Rayleigh Fading Channel

As there are many use cases considered for robotics communications, the data rate variation may be very large. Some sensor applications may require very low data rate, telemetry data may require low-to-medium data rates and e.g. video application will require high data rates. On the other hand, robots may have to operate in very difficult radio propagation environments such as nuclear power plants or industrial facilities. To combat difficult propagation characteristics, an often used and well known mechanism is to use spread spectrum signal structures. Thus in this paper a novel modulation method is considered which offers the inherent signal structure and processing opportunities of spread spectrum signal and at the same time offers an easy mechanism to adapt the data rate from low to high depending on the requirement at hand thus addressing two important communication requirements for robotics. The introduction of $m$ MFSK generated the idea of applying the given approach to other modulation methods. To further enlarge the modulation alphabet sizes (with the price of larger spectrum usage) it was realized that combining the $m$ MFSK and $m$ MCSK would be an interesting choice. The $m$ MCSK– $m$ MFSK modulation is hence considered. A method to analyze this two-component modulation is developed and the performance analyses give results for $m$ MCSK– $m$ MFSK modulation in AWGN and flat Rayleigh fading channels for both coherent and non-coherent receivers. The performance was also assessed with orthogonal and non-orthogonal code constructs for coherent receiver.     

Synchronization and Parameters Identification of Chaotic Systems via Adaptive Control

Based on Lyapunov stability theory, a novel adaptive controller is designed for a class of chaotic systems. The parameters identification and synchronization of chaotic systems can be carried out simultaneously. The controller and the updating law of parameters identification are directly constructed by analytic formula. Simulation results with Chen‘s system and Roessler system show the effectiveness of the proposed controller.     

Performance Analysis of Anti-Interference Wireless Packet Networks for LEO Micro-Satellite with Adaptive Nulling Antenna Array

1Introduction LEOMicro Satellitesatelliteisespeciallyusefulfor wide areadistributeddatacollectionincasesofmarine exploration,geologicalorecologicalsurveillance,etc.,andforalternatetemporarymobiledatacommunications inspecialcircumstances.Arandomaccesspacke…