• Title/Summary/Keyword: BER Performance

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BER Performance of DS/CDMA-BPSK Systemin 3-State Land Mobile Satellite fading Channel (3-상태 육상이동위성 페이딩 채널에서 DS/CDMA-BPSK 시스템의 오율 성능)

  • Cho, Sung-Eon;Cho, Kyung-Ryong;Yeo, Hyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.3 no.4
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    • pp.795-804
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    • 1999
  • The increasing number of users of mobile communication systems and the corresponding need for increased system capacity require the use of a modulation scheme which is both power and spectrally efficient. In this paper, we numerically calculate the BER performance of DS/CDMA-BPSK system in different fading channel (Rayleigh, Rician, Shadow Rician). Also, we calculate BER performance and the channel capacity of DS/CDMA-BPSK system which is constant or nearly constant envelopes in 3-state fading channel model. The Shadow Rician fading model described in this paper apply the parameters of the Canadian Mobile Satellite (MSAT). And we assume that the 3-state fading channel model is consist of Rayleigh fading state, Rician fading state, and shadow Rician fading state. This model can be used as a basis for the simulation of the land mobile satellite channel. The dynamic 3-state fading channel model is considered corresponding to different environments and the transitions between these environments. From the numerically calculate results, the DS/CDMA-BPSK system with MUI-20, PG-511 can not achieve the BER performance ($P_b\leq10^{-5}$). And the channel capacity did not meet the system requirement. Also, we know that the BER performance is depend m the occupancy probability of radio channel and the degree of shadow. From the results, we how that during shadowed time intervals it is necessary to use some form of error control coding and receiver diversity in order to support reliable data communication.

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An OFDM Receiver Scheme for Multipath Environment with Delay Profile over the Guard Interval (가드인터벌을 초월하는 지연프로필의 멀티패스채널에 적합한 OFDM수신시스템)

  • 주창복
    • Journal of the Institute of Convergence Signal Processing
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    • v.4 no.4
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    • pp.66-72
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    • 2003
  • In the present paper some fundamentals about exceeding the guard interval of an OFDM system is going to discuss and will introduce method to cancel a ISI and ICI effects. In this paper, the performance characteristics of robust OFDM receiving system algorithm that is composed of a channel estimator using recursive least square(RLS) algorithm in time domain and of a ISI and ICI replica and subtracter using the channel coefficients are presented. By computer simulation method, the effect of suppression of ISI and ICI is demonstrated and compared the BER performance with a conventional 1-tap equalized system. Especially the presented scheme improves the BER performance at low SNRs more or so compared with the conventional one-tap equalized receiving configuration.

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Improving the Base-Layer BER performance at AT-DMB using a Channel Estimation (AT-DMB 시스템에서 채널추정을 이용한 기본계층 수신 성능 향상기법)

  • Bang, Keuk-Joon
    • 전자공학회논문지 IE
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    • v.49 no.2
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    • pp.46-51
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    • 2012
  • Transmit signal of Enhancement Layer in AT-DMB system is received by Coherent Detection, but in Base Layer of AT-DMB, a differential modulation and demodulation is adopted, same as the T-DMB. Especially for the coherent dectection of enhancement layer in AT-DMB system, a channel estimation must be employed. In this paper, I will show that the BER performance of Base-Layer in AT-DMB system will be improved by using the channel estimation information. The suggested method is focusing the constallations after Equalizaing to the nearlest ${\pi}$/4-shift DQPSK constallation points. Simulation results show that for the non-coding environment, the BER performance of AWGN channel, about 2-dB gain can be achieved at $10^{-4}BER$.

Performance Evaluation of VHF Digital Link Mode 3 System (VHF Digital Link 모드 3 시스템의 성능 평가)

  • Bae, Joong-Won;Nam, Gi-Wook;Kwak, Jae-Min;Park, Ki-Sik;Cho, Sung-Eon
    • Journal of Advanced Navigation Technology
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    • v.9 no.2
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    • pp.156-163
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    • 2005
  • In this paper, we analyzed the performance of VDL mode 3 system model whose specification is defined by ICAO(International Civil Aviation Organization). For performance evaluation, we obtained BER(Bit Error Rate), transmission delay time, burst retransmission rate and throughput. From the analysis result, we could explicitly define relationships among BER, transmission delay time, throughput and burst restransmission rate. In addition, it became known that V/D retransmission rate and throughput are closely related in down link channel.

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Effects of Multione Interference on the Spectrum-Overlapped DS/SFH-SSMA System (스펙트럼 겹침이 있는 DS/SFH-SSMA 시스템의 다중톤 영향 분석)

  • Park, Jeong-Min;Ryu, Ho-Jin;Kim, Kie-Keun;Ryu, Heung-Gyoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.3
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    • pp.446-450
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    • 2001
  • Performance of spectrum-overlapped BPSK DS/SFH-SSMA communication system is considered in MAI and MTI channel. SSMA system is studied that the frequency spectrums of DS spread signals are overlapped. The increase of overlapping makes ACI and processing gain larger simultaneously. Therefore, BER performance can be optimized by controlling the amount of overlapping. BER equation are derived far the overlapping BPSK DS/SFH-SSMA communication system in multitone interference channel. From the numerical analyses and the simulation results, it can be concluded that the BER performance is considerably improved in optimized overlapping system.

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Performance of M-ary OSTBC MIMO System (M-ary OSTBC MIMO 시스템의 성능 연구)

  • Hong, Young-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.9
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    • pp.6269-6273
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    • 2015
  • Performance of the Alamouti algorithm based M-ary $2{\times}N$ OSTBC(Orthogonal Space Time Block Coded) MIMO(Multi Input Multi Output) system has been simulated varying two main parameters - the number of constellation(M), and the number of receiving antennas(N). Computer simulation has also been carried out using Matlab software for performance comparison between $2{\times}N$ MIMO and MRC(Maximal Ratio Combining) diversity antenna system to evaluate the degree of enhancement achieved through the use of Alamouti $2{\times}N$ MIMO. Under 10 dB EbNo QPSK scenario, $2{\times}1$ MIMO brought 4.2 dB BER improvement over single antenna system and $2{\times}2$ MIMO resulted in 7.4 dB BER improvement over $1{\times}2$ MRC.

Performance Analysis of UWA Communication System by Diversity in UWA Channel (수중 음향 다중 경로 채널에서 수중 음향 통신 시스템 성능 분석)

  • Lee, Hojun;Kang, Jiwoong;Ahn, Jongmin;Chung, Jaehak
    • The Journal of the Convergence on Culture Technology
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    • v.3 no.4
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    • pp.191-198
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    • 2017
  • In this paper, we compare the transmission performance of Code Division Multiple Access (CDMA) and Orthogonal Frequency Division Multiplexing (OFDM) under long duration multipath channel environments. This paper generates underwater channels through Bellhop based on the underwater environmental data of the west sea. BER performance of CDMA and OFDM are analyzed through various underwater channels based on the channels. Computer simulations result show that CDMA has better performance than OFDM when multipath delay time of underwater channel is shorter than spreading factor (SF). However, OFDM has better BER performance than CDMA as multi-path delay time increases.

PAPR Reduction Method in Multi-Code CDMA System (다중 코드 CDMA 시스템에서 PAPR저감 기법)

  • 이강미;김상우;유흥균
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.7
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    • pp.685-691
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    • 2004
  • In this paper, we propose the hybrid methods of SLM(selected mapping) and predistortion, and PTS(partial transmit sequence) and predistortion to reduce PAPR(peak to average power ratio) and to decrease the nonlinear distortion of the nonlinear HPA(high power amplifier) in the multi-code CDMA(code division multiple access) system. The phase rotation factors are transmitted as side information in PTS and SLM methods play an important role in the BER performance. So, we present the theoretical BER equation when the errors of side information are considered in the multi-code CDMA communication system. Simulation results show that PAPR is reduced and nonlinear distortion is compensated by hybrid methods. Therefore BER performance is enhanced.

An Effective Clipped Companding Scheme for PAPR Reduction of OFDM Signals (OFDM 신호의 PAPR 감소를 위한 효과적인 Clipped Companding 기법)

  • Kim, Jae-Woon;Shin, Yo-An
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.10C
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    • pp.1010-1018
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    • 2007
  • In this paper, we propose a companding scheme to effectively reduce PAPR (Peak-to-Average Power Ratio) of the OFDM (Orthogonal frequency Division Multiplexing) signals. The proposed scheme is basically based on the companding scheme to consider both complexity and Bit Error Rate (BER) performance, and composed of the clipping followed by the companding scheme. In the first step of the proposed scheme, some of peak signals which do not influence the BER even without them, are clipped. In the second step, the proposed scheme utilizes the ${\mu}-law$ companding to effectively reduce the PAPR. Simulation results show that the proposed clipped companding scheme can provide more PAPR reduction without degradation of the BER performance, as compare to the conventional ${\mu}-law$ companding.

Generalized BER Performance Analysis for Uniform M-PSK with I/Q Phase Unbalance (I/Q 위상 불균형을 고려한 Uniform M-PSK의 일반화된 BER 성능 분석)

  • Lee Jae-Yoon;Yoon Dong-Weon;Hyun Kwang-Min;Park Sang-Kyu
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.3C
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    • pp.237-244
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    • 2006
  • I/Q phase unbalance caused by non-ideal circuit components is inevitable physical phenomenons and leads to performance degradation when we implement a practical coherent M-ary phase shift keying(M-PSK) demodulator. In this paper, we present an exact and general expression involving two-dimensional Gaussian Q-functions for the bit error rate(BER) of uniform M-PSK with I/Q phase unbalance over an additive white Gaussian noise(AWGN) channel. First we derive a BER expression for the k-th bit of 8, 16-PSK signal constellations when Gray code bit mapping is employed. Then, from the derived k-th bit BER expression, we present the exact and general average BER expression for M-PSK with I/Q phase unbalance. This result can readily be applied to numerical evaluation for various cases of practical interest in an I/Q unbalanced M-PSK system, because the one- and two-dimensional Gaussian Q-functions can be easily and directly computed using commonly available mathematical software tools.