• Korean Journal of Optics and Photonics
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• 제14권5호
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• pp.491-497
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• 2003

In this paper, an optical encryption system using binary key code based on the joint transform correlator (JTC) is considered. The binary key code is synthesized by using a design technique of the pixel-oriented Computer Generated Holograms (CGHs). The independence and efficiency of the binary encryption key are investigated through computer simulation. To test the efficiency of the encryption system using binary key code, a holographic encryption system is constructed, and the experimental results prove that our holographic encryption system has high ability.

• ETRI Journal
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• 제28권2호
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• pp.227-230
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• 2006

There has been a growing need for increased capacity in cellular systems. This has resulted in the adoption of the code division multiple access (CDMA) system as a multiple channel access method. Thus, it is important to obtain the phase offsets of binary codes in the CDMA system because distinct phase offsets of the same code are used to distinguish signals received at the mobile station from different base stations. This letter proposes an efficient algorithm to compute the phase offset of a binary code in the CDMA system through the use of the basic facts of number theory and a new notion of the subcodes of a given code. We also formulate the algorithm in a compact form.

• Proceedings of the IEEK Conference
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(1)
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• pp.13-16
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• 2002

In this paper, we propose adaptive despreading receiver for multi-code PW-CDMA system with binary-level clipping. The distortion due to clipping the multi-level signal causes the performance degradation. Adaptive despreading alleviates the effect of clipping. It is shown that the proposed adaptive despreading receiver achieves smaller BER than conventional despreading receiver for multi-code PW-CDMA system with binary-level clipping.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제19권10호
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• pp.1065-1074
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• 2008

T-DMB(Terrestrial Digital Multimedia Broadcasting) system, is based on the Eureka-147 standard, provides various multimedia data services. However T-DMB system needs upgrades for more various services and better services. Therefore, we proposed advanced T-DMB system using unequal error protection system and hierarchical modulation in this paper while maintaing backward compatibility. And we simulated various bit split methods and double binary turbo code of DVB-RCS standard as method of LP data stream for additional service of advanced T-DMB. As the simulation results, double binary turbo code of proposed advanced T-DMB system have each coding gain of over 2 dB compared to conventional T-DMB.

• Journal of the Korean Institute of Telematics and Electronics
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• 제23권3호
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• pp.309-316
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• 1986

A concatenated coding system using a binary code as the inner code and a nonbinary code as the outer code has been constructed for the purpose of error correction. The complexity of a conventional coding system grows exponentially as the code length of a block code becomes longer. To reduce the complexity for ling code, an effective communication system has been proposed by cascading two codes-binary and norbinary codes. Using a parallel-to-serial circuit and a serial-to-parallel circuit, the concatenated coding system has been designed and constructed by empolying a (7,3) burst error correcting code as the inner code and a (7,3) Reed-Solomon code as the outer code. This system has been simulated and tested using a micro-computer. For the (49,9) concatenated coding system, the error probability of the channel has been evaluated and compared to different coding systems.

• Proceedings of the IEEK Conference
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.11-14
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• 1998

This paper introuces a new efficient method of synchronization acquisition which is the most important element in DS-CDMA system using the phase offset of binary code. This approach uses the binary code function which can easily estimate the phase offset from the received spreading waveforms which respect to the receiver-stored replica of the spreading code. This paper proposes the initial acquisition model with repeat error control device that is good for perfomance. The hardware is implemented by TMS320c30

• The Journal of Korean Institute of Communications and Information Sciences
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• 제33권12C호
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• pp.997-1005
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• 2008

In this paper, we proposed advanced T-DMB system which is based on Eureka-147 using UEP coding methods and hiererchical modulation for providing additional services while maintaining BER performance. We simulated the proposed advanced T-DMB system using unequal l6QAM modulation scheme combined with various bit split methods and coding methods such as double binary turbo code of DVB-RCS standard and LDPC code of DVB-S2 standard. In the simulation results, double binary turbo code and LDPC code of proposed advanced T-DMB system have coding gain of 2dB and 3.5dB compared to conventional T-DMB system respectively.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• 제10권1호
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• pp.39-50
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• 2010

In this paper, we analyze and simulate the performance of a tactics mobile communication system based on ultra wide band (UWB) in multi-user interference (MUI) environments. This system adopts a double binary turbo code for forward error correction (FEC). Wireless channel is modeled a modified Saleh and Valenzuela (SV) model. We employ a space time block coding (STBC) scheme for enhancing system performance. System performance is evaluated in terms of bit error probability. From the simulation results, it is confirmed that the tactics mobile communication system based on UWB, which is encoded with the double binary turbo code, can achieve a remarkable coding gain with reasonable encoding and decoding complexity in multi-user interference environments. It is also known that the bit error probability performance of the tactics mobile communication system based on UWB can be substantially improved by increasing the number of iterations in the decoding process for a fixed cod rate. Besides, we can demonstrate that the double binary turbo coding scheme is very effective for increasing the number of simultaneous users for a given bit error probability requirement.

• The Journal of Information Technology
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• 제6권1호
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• pp.71-84
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• 2003

In this paper, it is presented the efficient system for data recognition using the proposed binary code images. The proposed algorithm finds the position of binary image. Through the process of the block region classification, it is classified each block with the edge region using the value of gray level only. Each block region is divided horizontal and vertical edge region. If horizontal edge region blocks are classified over six blocks in any region, the proposed algorithm should search the vertical edge region in the start point of the horizontal edge region. If vertical edge region blocks were found over ten blocks in vertical region, the code image would found. Practical code region is acquired from the rate of the total edge region that is computed from the binary image that is processed with the average value. In case of the wrong rate, it is restarted the code search in the point after start point and the total process is followed. It has a short time than the before process time because it had classified block information. The block processing is faster thant the total process. The proposed system acquires the image from the digital camera and makes binary image from the acquired image. Finally, the proposed system extracts various characters from the binary image.

• Journal of the Korea Society of Computer and Information
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• 제12권1호
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• pp.155-160
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• 2007

Because output of multi-code CDMA system adapted high speed data transmission becoming multi-level system use linear amplifier in output stage and complex output signal. Therefore, Multi-Code CDMA system has shortcoming of high price, high complexity etc.. Binary CDMA technology that allow fetters in existing CDMA technology to supplement this shortcoming proposed. In binary CDMA system When correlator process high speed data, bottle-neck phenomenon is happened on synchronization acquisition process, it is very important parameter. Because existent correlator must there be advantage that power consumption is small but flow addition of several stages to receive correlation's value, the processing speed has disadvantage because the operation amount is much. Therefore in this paper, proposed correlator has characteristic such as data is able to high speed processing, chip area is independent and power consumption is constant in structure in binary CDMA system.