• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.3
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• pp.319-328
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• 1999

It is necessary to devise the method for increasing bandwidth efficiency in order to provide the high speed mobile multi-media communication services with CDMA under the limited radio bandwidth resources. In this paper the structure for transmitting the high speed data at the half bandwidth of the required bandwidth using the symmetry property of the IFFT output of the binary input MC-CDMA, which enables the time scaling method utilized, is proposed. The processing gain is increased 4 times than the DS-CDMA and its performance is evaluated as better than DS-CDMA with rake receivers under the Rayleigh fading channel and same bandwidth per one channel.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.5
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• pp.111-124
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• 2010

AMI (Advanced Metering Infrastructure) is a core infrastructure of Smart Grid, and is promoting in various country. Wireless network is considered for cost savings and operational efficiencies in AMI. But various security problems are expected in wireless networks of AMI, so we should solve these problems. In this paper, we suggest a wireless network of AMI by using Binary CDMA and security countermeasures of AMI wireless network. Proposed security architecture is using BSIM (Binary Subscriber Identity Module) to perform user authentication and key agreement for the encryption and decryption over radio network to reduce security threats.

• Proceedings of the IEEK Conference
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• 2002.06a
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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.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.1
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• pp.51-61
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• 2010

Koinonia system is designed to fully utilize the advantage of Binary CDMA so as to guarantee QoS in wireless networks. In this paper, we propose the new network structure based on this system and refer to it as BLAN(Binary CDMA LAN). Although BLAN is similar structure to IEEE 802.11 WLAN, it will ensure the fast handover and QoS. We also propose the AKA(Authentication and Key Agreement) protocol and Reauthentication protocol to be used for communication in BLAN. These protocols are securely and efficiently designed using the user identity module to support the more powerful authentication. Hence, BLAN, including the proposed protocols, will support the high mobility and security. In conclusion, we expect that BLAN can be applied to future infrastructure on special environment, and it can be helpful showing the new network model which alternate WLAN.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.4
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• pp.149-154
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• 2004

In this paper, Interference-Cancelled CDMA system using binary ZCD spreading codes is introduced. Proposed Interference-Cancelled CDMA system can be usefully used for the intra-cellular Interference-Cancelled wireless communication systems. Binary ZCD spreading code sets have various sequence period and family sizes and the ZCD properties of them are very effective for Interference-cancelled CDMA Systems. In this paper, we mathematically analyzed the system performance of our proposed Interference-Cancelled CDMA system in the AWGN channel and various interference environments such as MAI and MPI. Furthermore, using the BER performance simulation we certify the available interference cancellation properties of the proposed system.

• Journal of Advanced Navigation Technology
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• v.15 no.5
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• pp.735-741
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• 2011

In this paper, we have analyzed the effect of SNR estimation error on the BER performance of MMSE-DFE in high-speed binary CDMA system. Since MMSE equalization algorithm requires the SNR value of input signal, it should be estimated using CAZAC sequence in preamble. However, when AWGN and ISI exist simultaneously, it is impossible to estimate the exact SNR value of input signal and thereby equalizer's performance may be deteriorated. The simulation results can be used as a guideline for selection of SNR estimation algorithm for MMSE-DFE design.

• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.434-437
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• 2010

본 논문에서는 현재 연구 개발이 활발히 진행되고 있는 공공 무선망 서비스 제공을 위한 Binary CDMA기술이 적용된 Guardian 모뎀 칩셋에 대하여 알아 본 후, 무선 데이터 전송 시험을 통해 데이터 율과 SNR, BER, PER에 대한 성능을 분석한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10A
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• pp.1494-1500
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• 1999

In order to provide high speed multimedia data rate service, Multi-Code CDMA has been proposed which converts high speed serial data stream into N parallel low speed data streams with orthogonal PN codes for spreading. However this signal has multi level and causes interferences to be increased at the neighboring cell boundary in the reverse link. Therefore in order to solve the above mentioned problem, M/B-MC/CDMA, in which multi level signal is converted to binary level signal using M/B conversion, is proposed and the performance is compared with MC-CDMA.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2001.06a
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• pp.9-12
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• 2001

In DS/CDMA system the number of output signal levels increases as multi-channel signals are summed, hence the power amplifier with high linearity is required. PW/CDMA is a transmission technique that performs pulse width modulation on the multilevel signal synthesized from multiple channel data. In PW/CDMA system the signal level is maintained to be binary, hence the modulation and demodulation circuits become simple. In this paper we derive the probability of bit error of the PW/CDMA system in AWGN environment. The results are compared with DS/CDMA system and are verified through the computer simulations.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.3 no.1
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• pp.56-74
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• 2004

본 논문에서는 기존의 여러 가지 무선 홈 네트워크에 대해 개괄하고 새로운 표준인 Binary CDMA (Code Division Multiple Access)를 이용한 Koinonia 시스템을 제안한다. 제안된 시스템은 멀티 코드 CDMA 시스템을 고속의 멀티미디어 전송을 위해 변형한 형태이다. 멀티코드 사용 시 송신 신호 파형이 멀티 레벨로 나타나게 되어 시스템의 구조가 복잡해지고 가격이 비싸지는 단점이 존재한다. 이러한 기술적 문제점을 해결하기 위해 멀티레벨의 신호를 부호화 블록을 통해 정진폭으로 변환해 전송한다. 이를 통해서 복잡한 멀티 레벨의 신호가 간단히 나타나므로 전송되는 신호의 파형이 간단히 표현되어지고 수신기의 구조가 간단해진다. 그리고, 제안된 시스템은 멀티 코드 방식을 기반으로 하기 때문에 디지털 가전기기나 3세대 이동통신과, WPAN과 관련된 무선 네트워크 응용과 같은 미래의 고속의 무선 멀티미디어 서비스를 지원하기에 적합하다.