• Title/Summary/Keyword: Probability of Symbol Error Rate

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Channel estimation of OFDM System using Matching Pursuit method (Matching Pursuit 방식을 이용한 OFDM 시스템의 채널 추정)

  • Choi Jae Hwan;Lim Chae Hyun;Han Dong Seog;Yoon Dae Jung
    • Journal of Broadcast Engineering
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    • v.10 no.2
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    • pp.166-173
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    • 2005
  • In this paper, we propose a mobile channel estimation algorithm using matching pursuit algorithm for orthogonal frequency division multiplexing (OFDM) systems. Least square (LS) algorithm, which is used as a conventional channel estimation algorithm for OFDM systems, has error probability of channel estimation affected by effects of noise. By estimating the channel of sparse type, the proposed algorithm reduces effects of noise during time intervals that multi-path signal doesn't exist. The proposed algorithm estimates a mobile receivingchannel using pilot information transmitted consequently. We compare performance of the proposed algorithm with the LS algorithm by measuring symbol error rate with 64QAM under a mobile multi-path fading channel model.

Performance of Radio Communication DS/CDMA System with Diversity Technique and BCH Coding under Impulsive Noise and Nakagami Fading (임펄스 잡음과 나카가미 페이딩이 존재할 때 다이버시티 기법과 오류정정 부호를 이용한 무선통신 DS/CDMA 시스템의 오율 특성)

  • 김지웅;강희조;이권현
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.10 no.4
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    • pp.539-549
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    • 1999
  • In this paper, the bit error rare (BER) performance of DS/CDMA DQPSK communication system in the presence of multi access interference, impulsive noise and Nakagami fading is investigated. The DS/CDMA DQPSK communication system adopts Maximum Ratio Combining (MRC) diversity reception and error correcting BCH code technique to enhance system performance. Using the derived error probability equation, the error rate performance of DS/CDMA DQPSK communication system has been evaluated and shown in figures to discuss as a function of impulsive index(A), Gaussian noise to impulsive noise power ratio($\Gamma$'), multi access interference(Κ), Nakagami fading parameter(m), the number of diversity branch (L), the number of error correction symbol (t), PN code sequence length(N) and $E_b/N_0$. The error performance of DS/CDMA-MDPSK signals improve by adopting MRC diversity and BCH(15,7) coding technique in the environment of impulsive noise plus Nagakami fading. From the results, we known that proposed system is affected by multi access interference, impulsive noise and Nakagami fading in radio communication system environment. Also, BER performance of DS/CDMA DQPSK communication system cam be improved increasing either the power of desired signal or the value of Gaussian noise to impulsive noise power ratio. And BCH(15,7) code technique is more effective to restrain the affection of multi access, interference, impulsive noise and Nakagami fading in DS/CDMA DQPSK communication system than MRC diversity reception technique.

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Error Performance Analysis of Trellis Coded QPSK Signal with Reed-Solomon Coding and MRC Diversity Reception in Micro-Cellular System (마이크로 셀룰러 시스템에서 MRC 다이버시티와 Reed-Solomon 부호를 적용한 Trellis Coded QPSK 신호의 오율 해석)

  • 노재성;김영철;박기식;조성언;조성준
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.9 no.4
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    • pp.427-438
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    • 1998
  • The bit error rate(BER) performance of Trellis Coded QPSK signal in the presence of cochannel interference (CCI) and Rician fading is investigated. The trellis coded QPSK system adopts Maximum Ratio Combining (MRC) diversity reception and Reed-Solomon code to enhance system performance. Using the derived error probability equation, the error performance of trellis coded QPSK system has been evaluated and shown in figures to discuss as a function of signal power to noise power ratio (SNR), signal power to interference power ratio(SIR), direct to indirect signal power ratio ($K_R$), the number of diversity branch (M), the frame length of Reed-Solomon code (n), the number of error correction symbol (t), and the number of state of trellis encoder. From the results, we know that proposed system is affected by cochannel interference and fading in microcell environment. Also, BER performance of Trellis Coded QPSK system can be improved as increasing either the power of desired signal or the value of SIR. And the BER floor in microcellular system is caused by the cochannel interference and it occurs at high BER when SIR is low. And Reed-Solomon code (n=15, t=2) is more effective to restrain the affection of CCI and fading than MRC diversity reception (M=2).

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Collision Performance Improvement in Orthogonal Code Hopping Multiplexing Systems Using Multiple Antennas (다중 안테나를 이용한 직교 부호 도약 다중화 시스템의 성능향상)

  • Jung, Bang-Chul;Lee, Woo-Jae;Park, Yeoun-Sik;Jeon, Seong-Keun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.10
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    • pp.2100-2112
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    • 2011
  • An orthogonal code hopping multiplexing (OCHM) technique has been proposed for accommodating a large number of users with low channel activities than the number of orthogonal codewords through statistical multiplexing in downlink cellular systems. In this paper, a multiple input multiple output (MIMO) antenna based OCHM system is proposed to improve the performance. Each modulated symbol is repeated N times and the N repeated symbols are transmitted simultaneously using N transmit antennas. Through repetitions, the effect of perforations that the OCHM system experiences is decentralized among the repeated symbols and the full perforation probability is significantly reduced. Each receiver detect the transmitted signal using its pre-assigned code hopping pattern. Simulation results show that the proposed scheme saves the required energy for a given frame error rate (FER).

Structure Detection of Transmission Frame Based on Accumulated Correlation for DVB-S2 System (DVB-S2 시스템에서 상관 누적을 이용한 전송프레임 구조 검출)

  • Jeon, Hanik;Oh, Deock-Gil
    • Journal of Satellite, Information and Communications
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    • v.10 no.2
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    • pp.109-114
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    • 2015
  • Frame synchronization is achieved by correlation between received symbols and a preamble pattern which is periodically appended at a frame header. In this paper, we deal with a frame detection method complaint with satellite-based DVB-S2 system. In DVB-S2, frame synchronization is performed under the low signal-to-noise ratio(SNR), a large frequency offset which can be up to 20% of a symbol transmission rate and unknown modulation schemes ranging from QPSK to 32-APSK. In this environment, we propose a method combining differential correlation based on SOF and PLSC with an accumulated correlation method for the detection of frame structures. In addition, detection performances about mean acquisition time(MAT) and detection error probability are evaluated via computer simulations.