• Title/Summary/Keyword: bit-error-rate(BER)

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The Performance Evaluation and Analysis of Next Generation Wireless LAN with OFDM (OFDM을 적용한 차세대 무선 LAN의 성능 평가 및 분석)

  • Han, Kyung-Su;Youn, Hee-Sang
    • Journal of Advanced Navigation Technology
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    • v.6 no.1
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    • pp.37-43
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    • 2002
  • This paper describes the performance evaluation and analysis of Wireless Local Area Network (W-LAN) in the 5 GHz ISM-band in compliance with IEEE 802.11a. At present, most W-LAN products are based on 2.4 GHz band, but low speed (11Mbps) has the limitation to serve systems demanding high-speed data transmission. To solve this problem, it is necessary to design next generation W-LAN system with 54Mbps in the 5GHz. It is sure that implementation of next generation W-LAN will bring competitive advantages. In particular, it will support telecommunications for high-speed mobile environments as well as for fixed places such as a school zone, a lecture room, a hospital and other premises. A few simulation methods are applied to more accurate and reliable performance analysis of next generation W-LAN. To verify if continuous data service is supported for a high-speed mobile notebook, multi-path fading channels between wireless Access Point (AP) and wireless Network Interface Card (NIC) are modeled. In addition, low interference is analyzed via convolutional codes and Orthogonal Frequency-Division Multiplexing (OFDM). Also, to obtain reliable Bit Error Rate (BER), a single tap Least Mean Square (LMS) equalizer is applied. Given the above simulation, next generation W-LAN is an ideal solution for continuous data transmission in high-speed mobile environments.

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Characterization of Electrical Crosstalk in 1.25 Gbps Optoelectrical Triplex Transceiver Module for Ethernet Passive Optical Networks (이더넷 광 네트워크 구현을 위한 1.25 Gbps 광전 트라이플렉스 트랜시버 모듈의 전기적 혼신의 분석)

  • Kim Sung-Il;Lee Hai-Young
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.3 s.333
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    • pp.25-34
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    • 2005
  • In this paper, we analyzed and measured the electrical crosstalk characteristics of a triplex transceiver module for ethernet Passive optical networks(EPONS). And we improved the electrical crosstalk levels using Dummy ground lines with signal lines. The triplex transceiver module consists of a laser diode as a transmitter, a digital photodetector as a digital data receiver, and a analog photodetector as a community antenna television signal receiver. And there are integrated on silicon substrate. The digital receiver and analog receiver sensitivity have to meet -24 dBm at $BER=10^{-l2}$ and -7.7 dBm at 44 dB SNR. And the electrical crosstalk levels have to maintain less than -86 dB from DC to 3 GHz. From analysis and measurement results, the proposed silicon substrate structure that contains the Dummy ground line with $100\;{\mu}m$ space from signal lines and separates 4 mm among devices respectively, is satisfied the electrical crosstalk level compared to simple structure. This proposed structure can be easily implemented with design convenience and greatly reduced the silicon substrate size about $50\%$.

A Study on the Improved Parity Check Receiver for the Extended m-sequence Based Multi-code Spread Spectrum System with Code Set Partitioning and Constant Amplitude Precoding (코드집합 분할 방식의 확장 m-시퀀스 기반 정진폭 멀티코드 대역확산 통신 시스템을 위한 개선된 패리티 검사 기반 수신기에 관한 연구)

  • Han, Jun-Sang;Kim, Dong-Joo;Kim, Myoung-Jin
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.49 no.8
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    • pp.1-11
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    • 2012
  • The multi-code spread spectrum communication system, which spreads data bit stream by multiplexing orthogonal codes, can transmit data in high rate. However it needs the high-cost good linear amplifier because of the multi-level output signal. In order to overcome this drawback several systems making the amplitude of output signal constant with Walsh codes have been proposed. Recently constant amplitude pre-coded multi-code spread spectrum systems using extended m-sequence have been proposed. In this paper we consider an extended m-sequence based constant amplitude multi-code spread spectrum system with code set partitioning. By grouping the orthogonal codes into 4 subsets, not only is the computational complexity of the transceiver reduced but BER performance also improves. It has been shown that parity checking on four detected codes at the receiver can correct code detection error and result in BER performance enhancement. In this paper we propose a improved parity check receiver. We carried out computer simulation to verify feasibility of the proposed algorithm.

A Performance Analysis of DF-DPD and DPD-RGPR (DF-DPD와 DPD-RGPR에 대한 성능 분석)

  • Jeong, Jin-Doo;Jin, Yong-Sun;Chong, Jong-Wha
    • 전자공학회논문지 IE
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    • v.47 no.4
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    • pp.39-47
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    • 2010
  • This paper proposes a numerical analysis to prove that the performance of the differential phase detections (DPDs) with the decision feedback, such as the decision feedback DPD (DF-DPD) and the DPD with recursively generated phase reference (DPD-RGPR), approach the performance of the coherent detection with differential decoding. The conventional differential phase detection for M-ary DPSK can make the receiver architecture simple, while it can make the bit-error rate (BER) performance poor because of the previous noisy phase as a reference phase. To improve the BER performance of the conventional differential detection, multiple symbol differential detection methods, including DF-DPD and DPD-RGPR, have been proposed. However, the studies on the analysis and on the comparison of these methods have been little performed. Then, this paper mathematically intends to analyze and compare the performance of the DPDs with the decision feedback. The analysis results show that the DPDs with the decision feedback can have the performance equal to that of the coherent detection with differential decoding and be available for the noncoherent detection in the improved performance. Considering the hardware complexity, the DPD RGPR with the simple detection process by using the recursively generated phase reference can be more simply implemented than the DF-DPD based on the architecture whose complexity increases according to the increasing detection length.

Design and Analysis of 4D-8PSK-TCM System Considering the Nonlinear HPA Environment (비선형 HPA 환경을 고려한 4D-8PSK-TCM 시스템의 설계 및 분석)

  • An, Changyoung;Ryu, Sang-Burm;Lee, Sang-Gyu;Ryu, Heung-Gyoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.4
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    • pp.299-307
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    • 2018
  • Considering a nonlinear high power amplifier(HPA) and a predistorter, we have designed a four-dimensional 8-ary phase shift keying trellis-coded modulation(4D-8PSK-TCM) system, which is recommended for X-band satellite communications. Subsequently, we have evaluated and analyzed the spectrum, constellation characteristics, and BER performance of the system. In satellite communications, owing to the limited power, nonlinear characteristics that determine the operating point of the HPA must be analyzed because the HPA consumes high power. We herein report the design of the 4D-8PSK-TCM system, with efficiencies of 2 and 2.25 bits/channel-symbol. The simulation results confirmed that a 0.35 roll-off value is effective, considering the low peak-to-average power ratio(PAPR) characteristic and the narrow occupation bandwidth of the spectrum. It also confirmed that approximately 15~20 dB of output backoff(OBO) value is required at the HPA when the predistorter is not used, and approximately 1 dB of the OBO value is required when the predistorter is used.

Performance Analysis of MVDR and RLS Beamforming Using Systolic Array Structure (시스토릭 어레이 구조를 갖는 최소분산 비왜곡응답 및 최소자승 회귀 빔형성기법 성능 분석)

  • 이호중;서상우;이원철
    • The Journal of the Acoustical Society of Korea
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    • v.22 no.1
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    • pp.1-6
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    • 2003
  • This paper analyses the performance of either the minimum variance distortionless response (MVDR) or the recursive least square (RLS) beamformer structured on the systolic array. Provided that the snapshot vector including the desired user's signal and the interferences with the noise is received at the array antenna. In order to improve the quality of received signal, MVDR or RLS algorithm can be utilized to update the beamformer weights recursively. Furthermore to increase the channel capacity, by the usage of the above schemes, the effect of the spatial filtering can be obtained which constructively combining multipath components corresponding to the desired user whereas the multiple access interferences (MAI) is nulled out on spatial domain. This paper introduces the MVDR and RLS beamformer structured on systolic array conducting the spatial filtering, and its performance under the multipath fading channel in the presence of multiple access interferences will be analyzed. To show the superior spatial filtering performances of the proposed scheme employing the systolic way structured beamformer, the computer simulations are carried out. And the validity of practical deployment of the proposed scheme will be confirmed throughout showing the BER behaviors and the beampatterns.

Interference Alignment in 2-user X Channel System with Orthogonal and quasi-orthogonal Space-time Block Codes (직교 및 준직교 시공간 블록 부호를 통한 2-사용자 X 채널에서의 간섭정렬)

  • Mohaisen, Islam;Lee, Saet-byeol;Mohaisen, Manar;Elaydi, Hatem
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.8
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    • pp.1785-1796
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    • 2015
  • In this paper, we investigate achieving the full diversity order and power gains in case of using OSTBCs and quasi-OSBCs in the x channel system with interference alignment with more than 2 antennas at each terminal. A slight degradation is remarked in the case of quasi-OSTBCs. In terms of receiver structure, we show that due to the favorable structure of the channel matrices, the simple zero-forcing receiver achieves the full diversity order, while the interference cancellation receiver leads to degradations in performance. As compared to the conventional scheme, simulation results demonstrate that our proposed schemes achieve 14dB and 16.5dB of gain at a target bit error rate (BER) of 10-4 in the case of OSTBCs with 3 and 4 antennas at each terminal, respectively, while achieving the same spectral efficiency. Also, a gain of 10dB is achieved at the same target BER in the case of quasi-OSTBC with 4 antennas at each terminal.

Improvement of Received Optical Power Sensitivity in Asymmetric 2.5Gbps/1.2Gbps Passive Optical Network with Inverse Return to Zero(RZ) coded Downstream and NRZ upstream re-modulation (역 RZ 부호로 코딩된 하향신호의 재변조를 이용한 비대칭 2.5Gbps/622Mbps 수동 광가입자 망에서의 수신 감도의 개선)

  • Park, Sang-Jo
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.3
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    • pp.65-72
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    • 2010
  • We propose the asymmetric 2.5Gbps/622Mbps PON(Passive Optical Network) in order to reduce the bandwith of filter at receiver with inverse RZ(Return to Zero) code coded downstream and NRZ(Non Return to Zero) upstream re-modulation. I theoretically analyze BER(Bit Error Rate) performance and the power sensitivity with the optimal threshold level by performing simulation with MATLAB according to the types of downstream data. The results have shown that the optimal threshold level at the optical receiver could be saturated at 0.33 as the optical received power increase more than -26dBm to keep $10^{-12}$ of BER to a minimum. Also the power sensitivity is more improved by about 3dB by fixing the threshold level at 0.33 than the conventional receiver. The proposed system can be a useful technology for optical access networks with asymmetric upstream and downstream data rates because the optical receiver can be used without controlling threshold levels and that does not require a light source in optical network unit (ONU) and its control circuits in the optical line termination (OLT).

Impact of Group Delay in RF BPF on Impulse Radio Systems (임펄스 라디오 시스템에서 RF 대역 통과 필터의 군지연 영향 분석)

  • Myoung Seong-Sik;Kwon Bong-Su;Kim Young-Hwan;Yook Jong-Gwan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.4 s.95
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    • pp.380-388
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    • 2005
  • This paper presents analysis results of the effects of RF filter characteristics on the system performance of impulse radio. The impulse radio system transmits modulated pulses having very short time duration and information can be extracted in receiver side based on cross-correlation between received and transmitted pulses. Accordingly, the pulse distortion due to in-band group delay variation can cause serious system performance degradation. In general, RF bandpass filters inevitably cause group delay difference to the signal passing through the filter which is proportional to its skirt characteristic due to its resonance phenomenon. For time as well as frequency domain analysis, small signal scattering parameter $S_{21}$ and its Fourier transform are used to characterize output pulse waveform under the condition that the input and output ports are matched. The output pulse waveform of the filter is predicted based on convolution integral between input pulse and filter transfer function, and resulting BER performances in the BPM and PPM based impulse radio system are calculated.

Optical Transceiver Module for Next-generation Automotive Optical Network, MOST1000 (차세대 자동차 광네트워크 MOST1000 용 광트랜시버 모듈)

  • Kim, Gye Won;Hwang, Sung Hwan;Lee, Woo-Jin;Kim, Myoung Jin;Jung, Eun Joo;An, Jong Bea;Kim, Jin Hyeok;Moon, Jong Ha;Rho, Byung Sup
    • Korean Journal of Optics and Photonics
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    • v.24 no.4
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    • pp.196-200
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    • 2013
  • Heretofore, it was enough that most of optical transceiver modules for automotive networks have the performance of data rate from 10 Mbps to 150 Mbps. As the required data rate in automotive infotainment systems has recently been increasing, the development of a new optical transceiver having high speed data rate over 1Gbps is now required. Therefore, we suggested a next-generation bi-directional optical transceiver module using vertical cavity surface emitting laser technology and plastic clad fiber technology, for the next-generation automotive optical network, MOST1000. We fabricated the high-speed and compact optical transceiver having 1 Gbps data rate and -22 dBm sensitivity satisfying bit error rate $10^{-12}$.