Jae-Sang Cha

Implementation of Orthogonal Frequency Division Multiplexing Modem Using Radix-N Pipeline Fast Fourier Transform(FFT) Processor

In this paper, a new Radix-N pipeline fast Fourier transform (FFT) processor for the implementation of IEEE 802.11a baseband orthogonal frequency division multiplexing (OFDM) modem for wireless local area network (WLAN) is proposed. The newly proposed scheme has a simple control structure and multiplication block is designed based on canonic signed digit (CSD) with N/4 twiddle factors, which enables both hardware complexity and power consumption to be reduced as about less 33% and 66% respectively than the conventional Radix-4 pipeline and Radix-2 pipeline structures. In order to verify the real time operation, the IEEE802.11a baseband OFDM test-bed with the newly proposed Radix-N pipeline FFT processor is implemented using field programmable gate array (FPGA) devices.

New ternary spreading codes with zero-correlation duration for approximately synchronized CDMA

In this paper, ternary ZCD (zero-correlation duration) sequences are proposed as the new spreading codes. Novel ternary ZCD sequences sets are generated by carrying out a chip-shift operation of the ternary preferred pairs (TPP) with ZCD of (0.75 N-1) chips. Proposed ternary ZCD sequences have superior family size than the binary ZCD sequences and they are effective for approximately synchronized (AS) CDMA.

A Study on the A·R type Monitoring Technique using QR-code and Environment Monitoring Sensor Based on Smart Device

The applications of augmented reality technology is increasing in the several field by IT convergence and we find augmented reality application easily in the smart device application area. And then, to attempt to use augmented reality technology in advantage, exhibitions and performances was activated. However, it less than other fields of augmented reality technology expertise yet. Among them services to Use in fusion with monitoring are lacking. In this paper, we proposed the augmented reality monitoring technology based on smart device. It is able to incorporate QR-code which is already building for the purpose of advertising promotional materials with augmented reality technology in many areas. Therefore, it is able to utilize unattended building or automation equipment facilities using QR-code and environmental monitoring sensor in the industry.

A Study of Watermarking Data Transmission Scheme for BPSK-OFDM Based LED Communication System

In this paper, BPSK-OFDM-based LED communication systems are applied to watermarking techniques, were studied on how to transfer the additional information data with at the same time as the transfer of LED communication data. For watermarking kasami code was used as spreading codes, and spread additional data is controlled by small signal level to be BPSK-OFDM does not affect the optical signal. BPSK-OFDM is added to an optical signal is transmitted. The performance of the spreading code as a kasami code is autocorrelation of the noise-free environment, under the noise environment was confirmed by autocorrelation. BPSK-OFDM-based LED communication system has been applied proposed technique throughout the simulation in analyzed to BER of BPSK-OFDM DER performance and watermark signal level according to signal size level of data. That was availability confirmed for watermarking data transmit techniques data as being analysis detection performance of watermarking information using LED communication according to the code.

New Partial Correlation-type Matched Filter for Zero Correlation Duration Sequence and its Advanced Television Systems Committee-Digital Television Application

In this paper, we propose a new transmitter identification (TxID) sequence without any inter code interference (ICI) or multi-path interference (MPI) and truncation error. Moreover, we design a new TxID sequence based efficient matched filter (MF) architecture with new partial correlation structure. Using variable simulation and digital hardware implementation with field-programmable gate array (FPGA; XC2V3000), we verified the availability and superiority of proposed algorithm and architectures. The proposed TxID sequence and new partial correlation-type MF can be widely used in the advanced single frequency network (SFN) of advanced television system committee-digital television (ATSC-DTV).

A Study of VLC Channel Modeling using user Location Environment

In this paper, channel modeling and analysis of wireless visible light communication(VLC) were studied in indoor circumstance. Photons emitted from LED straightly moved and navigated within indoor, after that a part of photons reached on PD via LOS(Line Of Sight) or NLOS(None Line Of Sight). These received signals had characteristics of delay profile and attenuation, which was multiple-path fading. In this paper, computer simulation of VLC channel was executed under the condition that two LEDs were used for transmitter and three PDs were located at different positions of the 20*8*2.3m sized indoor. BER performance simulation was excuted based on the characteristics of each VLC channel.

LED-QR Authentication Technology for Access Control and Security

There are several possible places which are accessible in many buildings and facilities, various types of systems have been utilized such as access control or surveillance depending on the purpose. Especially if security is important, it must go through the various authentication procedures when people can access. Until now many access control systems have been proposed and developed, they are applied and utilized to companies which security is needed. However, as time passes the problems with existing access control systems occur or the vulnerabilities related to access control are reported, as technology advances. The solution to this, we propose authentication technology related to access control using LED-QR tag.

POSE-VIWEPOINT ADAPTIVE OBJECT TRACKING VIA ONLINE LEARNING APPROACH

In this paper, we propose an effective tracking algorithm with an appearance model based on features extracted from a video frame with posture variation and camera view point adaptation by employing the non-adaptive random projections that preserve the structure of the image feature space of objects. The existing online tracking algorithms update models with features from recent video frames and the numerous issues remain to be addressed despite on the improvement in tracking. The data-dependent adaptive appearance models often encounter the drift problems because the online algorithms does not get the required amount of data for online learning. So, we propose an effective tracking algorithm with an appearance model based on features extracted from a video frame.

A Study for Protocol for Heterogeneous Interface in Sensor Networks within Water Restore Facilities

Currently, the management system of wastewater treatment facility has magnified due to the stringent regulations for the protection of the environment. However, wastewater treatment system is insufficient in wastewater quality monitoring technology in specialized. Above all it aim one-to-one data transmission instead of one-to-n data transmission through sensor and network. And then, it lack compatibility toward communication system between different. Mainly it has observed detecting system of manual system. In this paper, we studied protocol technology about efficient data transmission between sensor and integration interface of water quality detecting interface for automated sensor network integration interface in water restoration facility. Therefore, we proved the possibility of efficient data transmission from communication system of different type through monitoring implementation of sensor network integration interface.

OFDM System for Wireless-PAN related short distance Maritime Data Communication

Orthogonal Frequency Division Multiplexing (OFDM) has been focused on as 4th generation communication method for realization of Ubiquitous Network in land mobile communications services, and has been a standard technology of Wireless Local Area Network (WLAN) for a High Date Rate communication. And in maritime data communication using high frequency (HF) band, 32-point FFT OFDM system is recommended by International Telecommunication Union (ITU). Maritime communication should be kept on connecting when maritime accident or the maritime disaster happen. Therefore, main device FFT should be operated with low power consumption. In this paper we propose a low power 32-point FFT algorithm using radix-2 and radix-4 for low power operation. The proposed algorithm was designed using VHSIC hardware description language (VHDL), and it was confirmed that the output value of Spartan-3 field-programmable gate array (FPGA) board corresponded to the output value calculated using Matlab. The proposed 32-point FFT algorithm will be useful as a leading technology in a HF maritime data communication.