• Title/Summary/Keyword: bit error rate

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Robust TCP algorithm against the burst error in wireless Internet (버스트 에러에 강인한 TCP 알고리즘)

  • 박종훈;배세인;유명식
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.6B
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    • pp.548-553
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    • 2004
  • Due to the recent advance in wireless communication technology, it is now more demanding to enjoy the high quality of service in the wireless Internal. TCP, which many Internet applications depend on for the end-to-end transport service, is optimized for the wired environment. Consequently, TCP suffers from severe performance degradation in the wireless environment where the bit error rate is relatively high and the burst errors frequently take place. In this paper, we propose a Robust TCP algorithm, which can effectively react against the burst error and significantly improve the TCP performance in wireless Internet. It is shown through the simulations that the Robust TCP performs well in the wireless environment, especially under the burst error condition.

Approximate Minimum BER Power Allocation of MIMO Spatial Multiplexing Relay Systems (다중 안테나 공간 다중화 릴레이 시스템을 위한 근사 최소 비트 오율 전력 할당 방법)

  • Hwang, Kyu-Ho;Choi, Soo-Yong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.4A
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    • pp.337-344
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    • 2011
  • In this paper, a multiple-input and multiple-output (MIMO) spatial multiplexing (SM) relay system is studied in a bit error rate (BER) sense, where every node is deployed with multiple antennas. In order to efficiently use the limited power resource, it is essential to optimally allocate the power to nodes and antennas. In this context, the power allocation (PA) algorithm based on minimum BER (MBER) for a MIMO SM relay system is proposed, which is derived by direct minimization of the average BER, and divided into inter-node and inter-antenna PA algorithm. The proposed scheme outperforms the conventional equal power allocation (EPA) algorithm without extra power consumption.

A Study on the Capacity Enhancement of HDR-WPAN System (HDR-WPAN 시스템의 용량증대 방안 연구)

  • Kang Chul-Gyu;Oh Yong-Taek;Kim Jae-Young;Cho Sung-Eon;Oh Chang-Heon
    • Journal of Digital Contents Society
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    • v.5 no.4
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    • pp.306-310
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    • 2004
  • In this paper, we proposed a capacity enhancement method using TCM-128QAM modulation and bandwidth extension of 25MHz in HDR-WPAN (high data rate wireless personal area network) system. In case using TCM-128 QAM modulation scheme, we can obtain maximum 66Mbps transmission rate in bandwidth of 15MHz. If extend bandwidth by 25MHz and roll-off coefficient ${\alpha}=0.35$, we can obtain maximum 110Mbps transmission rate. These results are confirmed through PSD(power spectrum density) analysis and BER (bit error rate) performance.

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Adaptive Watermarking Method using Watermark Detection Rate (워터마크 검출율에 기반한 적응적 워터마킹 방법)

  • An, Il-Young
    • The Journal of the Korea institute of electronic communication sciences
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    • v.5 no.5
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    • pp.465-470
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    • 2010
  • This paper proposes an adaptive video watermarking algorithm according to bit detection rate of watermark in MPEG2 system. The watermark strength is adaptively applied as BER(bit error rate) of watermark extracted from decoded frame for motion compensation. Watermark insertion uses a frequency spread spectrum method. A realtime watermark extraction is done directly in the DCT domain during MPEG decoding. The experimental simulations show that PSNR(peak signal to noise ratio) results 31.5dB for a fixed watermark strength and 33.dB for an adaptive watermark strength. Also average BER is 0.126 and less than 0.2 avaliable value.

Investigation of Relation between EFTB Test and RF Conductive Immunity Test Using BER and Baseband Signal

  • Kuwabara, Nobuo;Irie, Yasuhiro;Hirasawa, Norihito;Akiyama, Yoshiharu
    • Journal of electromagnetic engineering and science
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    • v.11 no.4
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    • pp.274-281
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    • 2011
  • High-speed telecommunication systems are influenced by electromagnetic environments because they need a wide bandwidth to transmit signals. Immunity tests of telecommunication equipment are effective for improving its immunity to electromagnetic environments. However, immunity tests are expensive to carry out because there are several different tests. The correlation among the tests should therefore be examined in order to reduce the kinds of tests that are necessary. This paper investigates the correlation between the electrical fast transient/burst (EFTB) test and the radio frequency (RF) conductive immunity test. Imitation equipment was constructed with a balun, and a baseband signal was transmitted from the associated equipment to the imitation equipment. Then, disturbances were applied to the equipment, and the telecommunication quality was evaluated by using the bit error rate (BER). The results from the EFTB test indicated that the BER was less than $6{\times}10^{-5}$ and the value was independent of the peak value. The results from the RF conductive immunity test indicated that the BER was affected by the longitudinal conversion loss (LCL).

BER Performance of Spatial Modulation in Uplink Multi-User Environment (상향 링크 다중 사용자 환경에서 공간 변조의 BER 성능)

  • Kim, Jin Kwan;Hyun, Kwangmin;Park, Sang Kyu
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.24 no.9
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    • pp.922-927
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    • 2013
  • In this paper, we evaluate the performance of up-link multi-user MIMO systems with SM. The receiver demodulates the received signal using ML method determines the signal which seems to be the most probable after comparing the received signal and all transmitted signal candidates. When transmitting with the same data rate, the SM method shows better performance of bit error rate(BER) than that of the space shift keying(SSK) of the previously proposed multi-user system.

Continuous Multiple Phase Differential Detection of Trellis-coded MDPSK-OFDM (연속적인 다중 위상 검출을 이용한 트렐리스 부호화된 MDPSK-OFDM)

  • 안필승;김한종;김종일
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.05a
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    • pp.568-573
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    • 2002
  • In this paper, the Viterbi decoder containing new branch metrics of the squared Euclidean distance with multiple order phase differences is introduced in order to improve the bit error rate (BER) in the differential detection of the trellis-coded MDPSK-OFDM. The proposed Viterbi decoder is conceptually same as the Continuous multiple phase differential detection method that uses the branch metric with multiple phase differences. Also, we describe the Viterbi algorithm in order to use this branch metrics. Our study shows that such a Viterbi decoder improves BER performance without sacrificing bandwidth and power efficiency Also. the proposed algorithm ran be used in the single carrier modulation.

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BER Derivation of M-PSK ModulationTechnique for Single and Multiple Racian Fading Channel (단일 및 다중 라이시안 페이딩 채널에서 M-PSK 변조기술에서의 BER 유도)

  • Alam, S.M. Shamsul;Choi, Goang-Seog
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.49 no.4
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    • pp.34-40
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    • 2012
  • In wireless communication system, fading is an unavoidable problem. Hence, errors in form of BER are introduced with the transmitted signal. It is necessary to recognize the behavior of these errors in different fading channels. To obtain the mathematical solution for the average bit error rate(BER) of coherent MPSK, some techniques are presented. In this paper, the impact of diversity is also analyzed over slow and flat Rician fading channel. In here, the value of modulation index, M is varied and the effects of its variation are also depicted. So, these performance curves with different diversity values and fading parameter are useful to design and evaluate the radio channel for faithful communication system.

Performance of Equalizer Schemes in Power Line Communication Systems for Automatic Metering Reading (자동 원격검침을 위한 전력선 통신 시스템에서의 등화 기법 연구)

  • Kim, Yo-cheol;Bae, Jung-Nam;Kim, Jin-Young
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.11 no.1
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    • pp.29-34
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    • 2011
  • In this paper, we propose and analyze the equalizer schemes, zero-forcing (ZF) and minimum mean square error (MMSE) in power line communication (PLC) system for automatic meter reading (AMR). For efficient implementation of AMR system with PLC, effects of impulsive noise and multipath channel should be mitigated. To overcome these effects, the above equalizer schemes are employed. System performance is evaluated in term of bit error rate. From simulation results, it is confirmed that the equalizer can significantly improve bit error rate (BER) performance in PLC system, and MMSE equalizer provides better performance than ZF scheme. The results of this paper can be applied to AMR system as well as various smart grid services using PLC.

A Comparative Study on Interference-Limited Two-Way Transmission Protocols

  • Xia, Xiaochen;Zhang, Dongmei;Xu, Kui;Xu, Youyun
    • Journal of Communications and Networks
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    • v.18 no.3
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    • pp.351-363
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    • 2016
  • This paper investigates the performance of interference-limited two-way transmission protocols in the Rayleigh fading channels. New lower bound of outage probability and approximate expression of bit error rate (BER) for three-phase two-way relaying (3P-TWR) protocol are derived in closed-form. These expressions are valid for arbitrary signal-to-noise ratio values, numbers of co-channel interferers and amajority of modulation formats employed in the practical system. Then a comparative study is developed for the performance of three two-way transmission protocols, i.e., direct transmission (DT) protocol, two-phase two-way relaying (2P-TWR) protocol and 3P-TWR protocol based on the asymptotic expressions of outage probability and BER. On the basis of the theoretical results, the thresholds on the strength (variance) of direct channel and target rate for the relative performance of different protocols are obtained and the effect of interferences at the terminal and relay on the relative performance is analyzed. The results present key insights on how to choose proper two-way transmission protocol with the knowledge of fading channels, required date rate and modulation format to optimize the system performance in the practical interference-limited scenarios. Simulation results are presented to validate the theoretical analysis.