Liang-Yu Yen

ZigBee(2.4G) wireless sensor network application on indoor intrusion detection

In this paper, it discusses and performs lab experiment of detecting LQI value from ZigBee wireless sensor network and from the variation of LQI values to determine is there any intrusion. In closed and no one existence indoor area it has a steady LQI value while it changes when someone intrudes into the area. An intrusion detection system is developed by using the variation in LQI values. After the system is validated we further develop an in house intrusion monitor system that when someone intrudes into the house the system will alarm or send a message to the house owners cell phone to alarm the house has been intruded so as to attain the in house security protection effect.

Applying Genetic Algorithms to the Data Traffic Scheduling and Performance Analysis of a Long-Term Evolution System

In this study it develops a superior transmission resource allocation method by using genetic algorithm. The convergence properties of genetic algorithm are employed to increase the transmission resource use efficiency of a base (station) to allow users to access wider bandwidth and to improve the system throughput and packet service rate. In this paper, it also studies the genetic algorithm convergent phenomena. The calculated system convergent time is significantly less than that of a long term evolution (LTE) frame duration. Finally, the system performances with and without implementing the genetic algorithm in resource allocations are simulated; their performances are compared to study the effectiveness of using the genetic algorithm in resource allocation.

A method of measuring sleep quality by using PPG

Modern life is more busy than previous, after a busy day of work, sleep quality at night has become an important part of the next day that can working smoothly. With the development of wearable devices, people must go to the medical center to spend a whole day for sleep diagnosis in the past day, but now they have opportunity achieve a simple sleep quality measurement by using wearable devices.

A method of measurement sleep quality by using EEG

Due to the pressure of modern life and work, resulting in poor quality of sleep, insomnia and other issues, in order to find suitable for daily life can get sleep quality approach to further analysis to improve sleep quality. This paper contained a Bluetooth device through a single conductive layer measured by EEG brainwave of slow-wave signals to judge the quality of sleep during sleep. This paper use wearable module DAQ100 to measure the sleep cycle α, β, θ, δ four single conductive layer, and transmit this date to the cloud to do data analysis by Bluetooth device, to improve the sleep quality.

2.4-GHz (ZigBee) Indoor Intrusion Detection

In this era of the Internet of Things, many studies have proposed and implemented smart home technologies. This paper proposes a technique that involves using link quality index level variations among end devices to detect intrusion and an algorithm for estimating the possible intruder location. The IEEE 802.15.4 ZigBee technique was adopted as the platform for the wireless sensing technology used.

HARQ performance analysis of a long-term evolution system

This study investigated an existing cellular wireless communication system and found that the system performance was severely limited by co-channel interferences (CCI) within the cell and from users of other cells. Therefore, in addition to simulating the shadow fading and path loss models caused by the attenuation of wide-range signals and the Rayleigh fading caused by the attenuation of short-range signals required for general channel exploration, a co-channel interference model was also constructed. Finally, a structured simulation method is presented in the Conclusion section.

Carrier frequency offset detection using hierarchical modulations for OFDM communications

In this study, we used hierarchical modulation technology to estimate the carrier frequency offset (CFO) caused by the Doppler effect. In this study, we transformed modulation within orthogonal frequency-division multiplexing into hierarchical modulation. We estimated the extent of the Doppler effect using the hierarchical modulation characteristic that the bit error rate (BER) of each level varies for differing CFO. The design developed in this study estimates the CFO and conducts hierarchical modulation of pilot signals. The receiving end estimates the CFO based on the characteristic that the BER of each level has different error rates at various CFO degrees. The simulation result showed that the actual BER was higher than the mathematically analyzed BER for each level, which resulted in overestimated CFO degrees or extents.

The study of multiwall carbon nanotubes light reflectivity

In this paper we study the light reflectivity of multiwall carbon nanotubes (MWCNTs) in the wavelength of range 1150nm–1755 nm, it reveals from our measurements that when the multiwall carbon nanotubes are pattern-grown its return loss is linear inversely proportional to the nanotubes grown height and with this characteristics the pattern-grown CNTs can be utilized as a good optical attenuator. However for nanotubes when it is fabricated in high density but pattern-less it has greater than 45 dB return loss, this is equivalent to have less than 0.56% reflectivity; it has high absorption effect and consequently can be utilized as a black body absorber.

An uplink pilot design for IEEE802.16m

This paper provides some design considerations of pilot structure for 1-antenna and 2-antenna IEEE802.16m. Space-Zone (SP-Zone) and Mobility-Zone (MB-Zone) concepts are introduced to use different numbers of subcarriers and symbols between pilots according to the radio environment and mobile speed to improve the system performance comparing with the conventional fixed number of subcarriers and symbols between pilots.

Study On Key Technology For Encryption And Security System In Wireless Communication Network

A novel secure encryption using the recieved signal strength indicator (RSSI) has been proposed in this paper. RSSI signals are time variant and irregular, especially in more complicated environment. Changes of RSSI can generate a nonperiodical random number, and an attacker will hardly predict this number. Furthermore, we use this option, open cryptography algorithm, and rapid stream ciphers to construct an efficient encryption system for wireless communication network. Keywords-Encryption, Security system,