• Title, Summary, Keyword: PSAM

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Developing the Test Module of PSAM for $Hipass^{PLUS}$ Card System (하이패스플러스카드 시스템을 위한 PSAM 시험 모듈 개발)

  • Lee Ki-Han;Suh Hyun Kyo;Yoo Chang Hee;Lee Seung-Hwan
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.2 no.2
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    • pp.73-84
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    • 2003
  • Due to the problems of existing prepaid plastic card issued by Korea Highway Company, the prepaid electronic payment system using a smart card, called HipassPLUS Card, was developed to overcome the Problems. PSAM is one of the main component of the systea which can retrieve the value from HipassPLUS card, transmit the transaction data to CSAM, and store the accumulated account lists. For the safety of the elecoonic payment system, the functions of PSAM should be faultless. This paper developed a test module including the test method, the test checklist, and the test procedure. The test module examines the functionality and security of the payment mechanism to insure that the value stored in HipassPLUS card can be raid to PSAM by the merchants and the standardized SAM. The test module also inspects the transmission mechanism to send and store the transaction data kom PShM to CSAM correctly and safely. Ihe module is designed to test the standard items using the test checklists for PSAM. The test items and the test checklists of PShM was selected under the provision of the specification of Korea Highway Company and ISO standard. Ihe evaluation on PSAM using the test module indicates that PSAM satisfies the evaluation criteria on the quality characteristics of the functionality, security, and compatibility.

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Performance of SFBC OFDM Transmission Systems Using PSAM Technique (PSAM 방식의 SFBC OFDM 전송 시스템의 성능)

  • Choi, Seung-Kuk
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.5
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    • pp.1031-1037
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    • 2011
  • Pilot symbol assisted modulation (PSAM) can be used for the channel estimation in orthogonal frequency division multiplexing (OFDM) transmission systems. However, imperfect channel estimates in PSAM systems degrade the bit error rate (BER) performance. I derive the BER of PSAM OFDM systems over time dispersive fading channels. The BER performance of OFDM systems with SFBC antenna diversity are analyzed, where data is transmitted over time and frequency selective Rayleigh fading channel. The performance of this PSAM SFBC OFDM systems, gauged by the average bit error rate, is analyzed considering the channel estimation error.

Gaussian Interpolation GPSAM Method to Overcome Fast Fading in High Speed Mobile Environments (고속 모바일 환경에서 fast 페이딩 극복을 위한 가우시안 보간 GPSAM 기법)

  • Kim, Jeong-Su
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.7
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    • pp.3482-3486
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    • 2013
  • In the case of the Pilot Symbol Assisted Modulation (PSAM) method predicting and compensating amplitude and phases caused on fading channels, there can be severe performance deterioration by Doppler spread on fast fading channels. In this paper, the fading compensation method suggested so as to improve occurring problems as well as analyze them. Doppler spread is the major cause of the bit error rate(BER) performance deterioration. Compared to the existing PSAM method, the more performance deterioration occurs, the larger Doppler spread appears but performance shows well its less $10^{-2}BER$ performance than the existing PSAM method in the suggested method whereas the existing PSAM method has about $10^{-1}BER$ its considerable performance deterioration that caused by Doppler spread within a symbol cycle with the level of delay wave interference.

Two-Dimensional Pilot Symbol Assisted Channel Estimation for OFDM Systems over Frequency Selective Rayleigh Fading Channel (주파수 선택적 레일리 페이딩 채널에서 OFDM 시스템을 위한 2-D PSA에 의한 채널 추정)

  • 이병로
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • pp.336-340
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    • 2001
  • In this paper we analyze the performance of 2-D PSAM for wireless OFDM systems. We apply the analysis of single-carrier PSAM to the 2-D time-frequency lattice of OFDM. To estimate channel fading, we use interpolation filter which minimizes the average power of error as compensation method and analyze the affects on the system performance of the pilot symbol pattern on the 2-D tine-frequency lattice. Finally according to the CP and the Doppler frequency, we analyze the performance of 2-D PSA-16QAM for OFDM systems over frequency selective Rayleigh fading channel model.

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Two-Dimensional Pilot Symbol Aided Channel Estimation for OFDM Systems over Frequency Selective Rayleigh Fading Channel (주파수 선택적 레일리 페이딩 채널에서 2-D PSA OFDM 시스템의 채널 추정)

  • 이병로
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.6
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    • pp.1050-1055
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    • 2001
  • In this paper we analyze the performance of 2-D PSAM for wireless OFDM systems. We apply the analysis of single-carrier PSAM to the 2-D time-frequency lattice of OFDM. To estimate channel fading, we use interpolation filter which minimizes the average power of error as compensation method and analyze the affects on the system performance of the pilot symbol pattern on the 2-D time-frequency lattice. Finally according to the CP and the Doppler frequency, we analyze the performance of 2-D PSA-16QAM for OFDM systems over frequency selective Rayleigh fading channel model.

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A Research on Multiple PS QAM for Channel Compensation in Frequency-Selective Rayleigh Fading Channels (주파수 선택적 Rayleigh 페이딩 채널에서 고차 PS QAM 채널 보상에 대한 연구)

  • Kim, Jeong-Su
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.7
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    • pp.79-84
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    • 2013
  • In this paper, the method of multiple PS(pilot symbol) QAM channel compensation is suggested in order to analyze and improve occurring problems in case of delay waves in Frequency-Selective Rayleigh fading channels through Pilot Symbol Assisted Modulation(PSAM) which is a method predicting and compensating fading information, using Pilot Symbol in flat fading channels. This suggested method shows stable improvement in its performance even though it is effected by the level of delay on delay waves while the existing PSAM method has severe malfunction with a small amount of level of delay on delay waves regardless of signal-to-noise ratio(SNR).

Performance Improvement of PSAM Channel Estimation Method for OFDM Systems over Frequency-Selective Channel (주파수 선택적 채널에서의 OFDM 시스템을 위한 PSAM 채널 추정 기법의 성능 개선)

  • Kim, Young-Soo;Bae, Jeong-Gook
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.2
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    • pp.235-243
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    • 2012
  • In this paper, we propose a method to improve performance of pilot symbol assisted modulation(PSAM) channel estimation method for OFDM systems over frequency selective channel. When channel values are estimated, the low pilot density used for channel estimation increases not only the effective data rate but also power efficiency. Thus, the lower pilot density which is used for channel estimation is better for OFDM system. At first, we estimate the channel values which are located at the middle of adjacent pilots, and then all of the possible channel values are estiamted by using original pilot values and previously estimated pilot values. Furthermore, the error of estimated channel values is reduced by introducing guard interval which is designed acccording to maximum channel delay. Performance achieved with the proposed method is illustrated by simulation experiments in comparison with the existing methods in terms of mean squared error(MSE).

Robust Channel Estimation Method for OFDM Systems with Mobile Speed (이동성에 강건한 OFDM 시스템을 위한 채널추정기법)

  • 문홍진;조주필
    • Journal of Korea Multimedia Society
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    • v.5 no.4
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    • pp.450-457
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    • 2002
  • Conventional channel estimation methods for OFDM system have not the robust characteristics relating to various mobile speed. To solve this drawback in conventional methods, we propose the channel estimation method for OFDM, which has a good performance and computational complexity in consideration of other methods. Proposed method uses a block frame structure within a whole channel in contrast with conventional methods such as PSAM and ESAE. This concept prevents overall performance from diverging or showing a poor one. The analytical results demonstrate the proposed method outperforms PSAM and ESAE in terms of MSE and BER performance under all Rayleigh fading environment. Considering the simulation performance and computational complexity, proposed method shows better characteristics than conventional methods for OFDM and has not an error floor even in a severe Rayleigh fading environment.

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An Improved Rayleigh Fading Compensation Algorithm with Modified Sinc Interpolation (수정된 Sinc 보간법을 이용한 새로운 Rayleigh 페이딩 보상 알고리즘)

  • 이창재
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.10A
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    • pp.1492-1498
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    • 2000
  • Pilot symbol aided modulation (PSAM) using the conventional sinc interpolation (CSI) achieves nearly the same BER performance as Caver' optimal Wiener interpolation but with much less complexity. The CSI, however, has to use a non-rectangular window function that is applied to the sinc function to smooth out the abrupt truncation of rectangular window. In this paper, we propose the modified sinc interpolation (MSI). With the weighting factor the MSI scheme with no window has almost the same BER performance as the CSI scheme using window, In addition, if we use the MSI with a window its BER performance gets close to that of the theoretical one. We assume the multicarrier QAM system and an optimal frame structure for performance evaluation.

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Performance Evaluation of QAM System in Faded Digital Wireless Communication Environments (디지탈무선통신 방식에서 페이딩의 영향을 고려한 QAM 방식의 성능평가)

  • 임성준;유흥균
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.8 no.6
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    • pp.568-580
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    • 1997
  • In this paper we evaluate the performances of two types of 16-QAM system such as square QAM and star QAM. First we analyze the performances of QAM systems under AWGN(adaptive white Gaussian noise) and afterward analyze the performances under fading environments. The performances of QAM systems in case of using the PSAM(Pilot Symbol Assisted Modulation) are finally evaluated under fading environments. In conclusion, the Square QAM's performance is better than star QAM in AWGN. But the performances of the both QAM systems are very poor under the fading environments. QAM performance using the PSAM system is verified to be improved in that case, and the star QAM's performance is better than square QAM.

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