• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9A
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• pp.917-923
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• 2008

The D-STTD system obtains the diversity gain through the STTD scheme and the Multiplexing gain through parallel structure of the encoder using the STTD scheme known Alamouti Code. We are difficult to use Combining scheme of the STTD scheme for the D-STTD detection in the decoder because the D-STTD system transmits mutually different data in each other STTD encoder for multiplexing gain. Therefore, in this paper we combine the D-STTD system with Linear algorithm, SIC algorithm and OSIC algorithm known multiplexing detection scheme based on MMSE scheme and compare the performance of each system. And we propose the detection scheme of the D-STTD using MAP Algorithm and analyze the performance of each system. The simulation results show that the detector using iterative algorithm has better performance than Linear MMSE Detector. Especially, we show that the detector using MAP algorithm outperforms conventional detector.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.9
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• pp.8-12
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• 2008

In this paper, we proposes a D-STTD(Double-Space Time Transmit Diversity) communication system with AMC scheme and analyzes its performance using simulation experiments. The AMC scheme selects an optimal channel coding rate and modulation scheme based on the channel response data for signal transmission, creating a balance between error rate and throughput to improve the overall system throughput and transmission quality. The D-STTD scheme complements the conventional STTD(Space Time Transmit Diversity) scheme, yielding about twice the throughput. The simulation results show that the probability of selecting a high MCS(Modulation and Coding Scheme) level increased as the SNR(Signal to Noise Ratio) improved. Furthermore, the D-STTD communication system with AMC scheme provided a more uniform throughput distribution throughout the entire SNR range compared to its counterpart which did not apply AMC scheme. Also, the maximum throughput of the D-STTD communication system with AMC scheme was twice that of a conventional AMC communication system or a STTD communication system with AMC scheme.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.3
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• pp.411-416
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• 2003

In this paper, We analysed performance of adaptive modulation system with STTD. Transmission error of system is increased by ISI according to delay wave in wireless channel environment. Therefore, We analysed performance that it is applied adaptive modulation system with STTD to reduce ISI's effect. As a results, Data transmission of high speedㆍhigh quality could know possible by applying adaptive modulation system with STTD. Because of selected high modulation mode in low SNR.

• Journal of information and communication convergence engineering
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• v.7 no.2
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• pp.235-240
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• 2009

This paper combines various detection techniques and analyzes their performances in detecting the transmission information of the D-STTD scheme that uses, in parallel, the STTD scheme known as the Alamouti code. The D-STTD scheme adopts one of the STTD schemes for transmission to acquire diverse effects and uses another form of STTD for multiplexing effects. Due to the multiplexing effect that transmits different data, it is difficult to apply D-STTD to the conventional STTD combining technique. This paper combines the D-STTD system with linear algorithm, SIC algorithm and OSIC algorithm known as multiplexing detection scheme based on MMSE scheme. And we propose the detection scheme of the D-STTD using MAP algorithm and analyze the performance of each system. The simulation results showed that the detector using iterative algorithm has better performance than Linear MMSE Detector. Especially, we can show that the detector using MAP algorithm outperforms conventional detector.

• Journal of the Korea Society of Computer and Information
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• v.11 no.2 s.40
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• pp.201-211
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• 2006

The standardization of third Generation Partnership Project(3GPP) has been performed in of order to support interactive multimedia services under mobile environments. In this 3GPP, transmit diversity solutions are applied to increase the available diversity effectively using 2 or more antennas. In this paper, we analyzer the performances on STTD(Space Time Transmit Diversity) technique and its modified techniques such as STTD-OTD, CL-STTD, and 4TX-STTD out of open loop transmit diversities that the standardization of 3GPP has released. We also propose the open loop transmitter and receiver diversities to add the receiver diversity. We analyze and discuss the performance of the proposed techniques and using the Matlab simulation under the flat fading channel environment.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.87-90
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• 2004

This paper proposes 4-STTD(4${\times}$l) technique for the shake of application of W-CDMA which expand Alamouti STTD(2${\times}$l) technique. As the result of analyzing 4-STTD(4${\times}$l) technique proposed in this paper, we can see improvement of quality by approximately 2.2 dB rather than Alamouti STTD(2${\times}$l) technique

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.551-555
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• 2003

본 논문에서는 이동 멀티미디어 통신을 위해 송신 다이버시티 STTD(Space Time Transmit Diversity)기법을 적용하였을 경우 발생하는 송신 안테나 상호간의 간섭을 제거 하기 위해 새로운 수신기를 제안하고 이를 적용한 DS-CDMA/QPSK STTD 시스템의 성능을 모의실험으로 확인하였다. 모의실험 결과 제안된 수신기를 적용한 시스템의 성능이 0.5∼2 dB 정도의 성능 개선이 있음을 알수 있었다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.138-141
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• 2003

본 논문에서는 STTD(space Time Transmit diversify)를 적용한 적응변조 시스템의 성능을 분석하였다. 무선채널 환경에서는 지연파에 의한 ISI(Intersymbol interference)간섭으로 인해 전송 오율을 증가시키게 된다. 따라서, ISI간섭의 영향을 줄이기 위해 STTD를 적용함으로써 적응변조시스템의 성능개선 정도를 분석하였다. 결과에 의하면, STTD를 적용함에 따라 더 낮은 SNR에서도 변조 다치수가 높은 변조 모드를 선택함으로써 고속ㆍ고품질의 데이터 전송이 가능함을 알 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.8
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• pp.1301-1307
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• 2018

Objective: This study was conducted to determine the apparent and standardized total tract digestibility (ATTD and STTD) of phosphorus (P) in corn, soybean meal (SBM), and canola meal (CM), and additivity of values for ATTD and STTD of P in corn, SBM, and CM in diets fed to growing pigs. Methods: Thirty-six growing barrows (initial body weight of $21.6{\pm}1.7kg$) were placed in metabolism crates and allotted to a completely randomized design with 6 diets and 6 pigs per diet. Six diets were formulated using corn, SBM or CM as the sole source of P, or corn and SBM, or corn and CM, or corn, SBM, and CM as the P source in each diet, respectively. Fecal samples were collected for 5 d following a 7 d adaptation period to the diets. Results: Values for ATTD and STTD of P in corn, SBM, and CM in growing pigs were 33.12% and 37.76%, 50.19% and 56.62%, 34.93% and 39.45%, respectively. The ATTD and STTD of P in SBM were greater (p<0.05) than those in corn and CM. However, there were no differences in the ATTD or STTD of P between corn and CM. The determined STTD of P in the mixture of corn and SBM, corn and CM, and corn, SBM, and CM is not different from the calculated STTD values. Conclusion: Values for STTD of P in corn, SBM, and CM are additive in their mixture fed to growing pigs.

• Journal of electromagnetic engineering and science
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• v.3 no.2
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• pp.99-103
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• 2003

For mobile multimedia systems that equip transmit diversity for a forward channel, it is well known that the Tx diversity technique is appropriate for high rate mobile multimedia communications. In this paper, we propose a STTD (Space Time Transmit Diversity) receiver, which incorporates the design of the Tx diversity receiver without the mutual interference of antenna by using a CCI cancellation technique. The new STTD receiver is simulated and its performance is analyzed in a DS-CDMA/QPSK. Adopting the proposed STTD receiver at $10^{-2}$TEX>∼$10^{-4}$TEX> in bit error rate, SNR of 0.5 ㏈∼2 ㏈ performance improvement in AWGN and Rayleigh fading environments has been achieved.