• Title/Summary/Keyword: dual-mode blind equalization

Search Result 15, Processing Time 0.022 seconds

Convergence Characteristics of the Normalized Blind Equalization Algorithm

  • Lee, Gwang-Seok
    • Journal of information and communication convergence engineering
    • /
    • v.8 no.2
    • /
    • pp.136-139
    • /
    • 2010
  • We derived Stop-and-go normalized DD, dual-mode normalized Sato, dual-mode NCMA blind equalization algorithm for complex data in this research. And then, the convergence characteristics of the proposed SG-NDD, dual-mode NSato blind equalization algorithms are compared with those of SG-DD, dual-mode Sato algorithms. In general, the normalized blind equalization algorithms have better convergence characteristics than the conventional algorithms.

A new dual-mode blind equalization algorithm combining carrier phase recovery (반송파 위상 복원을 결합한 새로운 이중모드 블라인드 등화 알고리즘)

  • 오길남;진용옥
    • Journal of the Korean Institute of Telematics and Electronics A
    • /
    • v.32A no.5
    • /
    • pp.14-23
    • /
    • 1995
  • A new dual-mode algorithm for blind equalization of quadrature amplitude modulation (QAM) signals is proposed. To solve the problem that the constant modulus algorithm (CMA) converges to the constellation with the arbitrary phase rotation, with the modification of the CMA, the proposed algorithm accomplishes blind equalization and carrier phase recovery simultaneously. In addition, the dual-mode algorithm combining the modified constant modulus algorithm (MCMA) with decision-directed (DD) algorithm achieves the performance enhancement of blind convergence speed and steady-state residual ISI. So we can refer the proposed algorithm to as a scheme for joint blind equalization and carrier phase recovery. Simulation results for i.i.d. input signals confirm that the dual-mode algorithm results in faster convergence speed, samller residual ISI, and better carrier phase recovery than those of the CMA and DD algorithm without any significant increase in computational complexity.

  • PDF

A study on normalize dblind equalization algorithms (정규화된 블라인드 등화 알고리즘에 관한 연구)

  • Jang, Gi-Won;Huh, Chang-Won;Yoon, Tae-Sung;Ha, Pan-Bong;Huh, Young
    • Proceedings of the IEEK Conference
    • /
    • 1998.06a
    • /
    • pp.627-630
    • /
    • 1998
  • In this study, we derived stop-and-go normalized DD, dual-mode normalized sato, dual-mode NCMA blind equalization algorithm for complex data. and then, the convergence characteristics of the proposed SG-NDD, dual-mode NSato blind equalization algorithms are compared with those of SG-DD, dual-mode sato algorithm. In genral, the normalized blind equalization algorithms have better convergence characteristics than the conventional algorithms.

  • PDF

Dual-mode Blind Equalization Algorithm for QAM Demodulation (QAM 복조용 이중 모드 채널 등화 알고리즘)

  • Ryu, Seok-Kyu;Hwang, Hu-Mor;Song, Jin-Ho
    • Proceedings of the KIEE Conference
    • /
    • 1999.07g
    • /
    • pp.3209-3211
    • /
    • 1999
  • We propose a robust Dual-Mode blind equalization algorithm based on Quadrant-partitioned Constant Modulus Algorithm (QCMA) and Modified Constant Modulus Algorithm(MCMA) for QAM demodulation and its performance evaluated. The proposed algorithm show that the stability in setting 2d range and the faster convergence accomplished to conventional Dual-Mode algorithm.

  • PDF

A Stop-and-Go Dual-Mode Modified Constant Modulus Algorithm for Adaptive Blind Equalization of High-Order QAM Signals (고밀도 광 기록 채널을 위한 터보 코드와 터보 등화기를 연접한 데이터 복호 방법)

  • 임창현;김기윤;김동규;최형진
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.25 no.6B
    • /
    • pp.1074-1081
    • /
    • 2000
  • In this paper, in order to speed up the convergence process and improve the steady mean square error simultaneously, we propose the Stop-and-Go Dual Mode Modified Constant Modulus Algorithm(SAG DM MCMA) for adaptive blind channel equalization of high order QAM. The proposed algorithm is a hybrid scheme of the Modified CMA that treat error signals with real and imaginary components of the equalizer output, the concept of dual mode CMA, and Stop-and-Go algorithm. As a result it can prevent blind equalization from converging to incorrect direction and simultaneously operates reliably for tap weight adaptation. We demonstrate via simulation that the proposed algorithm achieves lower steady state mean square error and residual ISI than the conventional algorithms under high order QAM signals and severe channel environment.

  • PDF

Performance Evaluation of a Dual-Mode Blind Equalization Algorithm Using the Size of Decision-Directed Error Signal for High-Order QAM Signals (고차 QAM 신호에 대한 결정 지향 오차 신호의 크기 값을 이용한 이중 모드 블라인드 등화 알고리즘의 성능 분석)

  • Jeong, Young-Hwa
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.16 no.3
    • /
    • pp.89-95
    • /
    • 2016
  • In this paper, we propose a dual-mode blind equalization algorithm that two of the blind equalization algorithm using the size of the decision-directed error signal is automatically switched. The proposed algorithm has a faster convergence speed due to operation of the MSAGF-SMMA with large fixed step-size mainly in the initial equalization. After the equalization has been made to some extent, the proposed algorithm has a smaller residual error in the steady- state by operation of the MSAGF-SMMA with a variable step-size mainly. The variable step-size is determined by multiplying the size of the decision-directed error signal of a fixed step-size. In this paper, we analyze the performance of the proposed algorithm. The computer simulation results demonstrate that the proposed algorithm has a significantly improved performance in terms of a residual inter-symbol interference and residual error in the steady-state compared with the MMA, SMMA, and MSAGF-SMMA.

Triple-mode Blind Equalization Algorithm for QAM Demodulation (QAM 복조용 삼중 모드 채널 등화 알고리즘)

  • Wui, Jung-Hwa;Hwang, Hu-Mor
    • Proceedings of the KIEE Conference
    • /
    • 1999.07g
    • /
    • pp.3138-3140
    • /
    • 1999
  • We propose a robust blind equalization algorithm based on dual-mode algorithm which incorporates a stop-and-go technique. The constant modulus algorithm(CMA) exhibits very slow convergence when applied to QAM signals and generates phase error. We show that convergence properties of the dual-mode MCMA can be significantly improved by simply adding a stop-and-go technique. To speed up the convergence rate, the TMA-MCMA operates in triple mode that is based on the dual-mode of the MCMA incorporated with the tap-updating control modes of the SGA.

  • PDF

Blind Equalization of Digital Television Broadcasting Signals in Dynamic Multipath Channels (다이내믹 다중경로 채널에서의 디지털 텔레비전 방송 신호에 대한 블라인드 등화)

  • 오길남
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.41 no.5
    • /
    • pp.269-274
    • /
    • 2004
  • In this paper, proposed is the dual-mode algorithm of blind decision feedback equalizer (DFE) for digital terrestrial television signals. According to channel impairments, the proposed dual-mode algorithm for blind DFE operates in decision-directed mode or in blind mode of operation. The error signals being used in tap update of the equalizer are generated in the best mode of operations, so that the confidence of equalizer tap coefficient update is more accurate. As a result, it is possible to track the channel characteristics variations by automatic switching over between two modes of operations. For 8-level vestigial sideband modulated digital television signals, the mean square errors and symbol error rates of the proposed algorithm are compared with those of conventional methods. And the usability of the proposed scheme is assessed by computer simulations under various static and dynamic multipath channel environments.

Adaptive blind equalization algorithm with dual-mode (이중 모드를 가지는 적응 블라인드 등화 알고리즘)

  • 정영화;진용옥
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.22 no.9
    • /
    • pp.2005-2013
    • /
    • 1997
  • The MCMA adaptive blind equalization algorithm has a excellent phase correction capabilities in addition to channel amplitude equalization, but has an inevitable error by mismatching between the original constellation points in arriving at the perfect equalization since unique new type constellation points are used as desired response instead of original constellation points and follows the slow convergence speed of CMA. In this paper, We propose an adaptive blind equalization algorithm with dual-mode, which has decision regions. Inside the decision regions, it operates as considering the moudlus of original data symbol point and outside the decision region, it operates as considerin gthe modulus of new constellation points. The proposed algorithm has a lower error in the steady state and rapid convergence speed toward steady state using the original data symbol points instead of new constellation points in the decision regions. From computer simulation, we confirm that the propposed algorithm has the performance superiority in residual ISI, convergence speed compared with the cnventional adaptive blind equalization algorithms, CMA, MCMA, Stop-and-Go algorithm.

  • PDF

Robust Blind Equalization Algorithms and Its Application to 8-VSB Receiver (강인한 자력복구 채널등화 알고리즘 및 8-VSB 수신시스템에의 응용)

  • Park, Kyung-Do;Hwang, Hu-Mor
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.48 no.8
    • /
    • pp.1037-1045
    • /
    • 1999
  • We propose two new classes of robust blind equalization algorithms against abrupt changes of channel conditions, which we call a triple-mode algorithm(TMA) and an automatic switch-over algorithm(ASA). The conventional DMGSA exhibits slow convergence rates due to the incorrect equalizer tap-updating process under the severe channel conditions. In order to speed up the convergence process, the TMA operates in triple-mode that is based on the dual-mode of the DMGSA incorporated with the tap-updating control modes of the SGA as well as the MSGA. Without resorting to the decision region for selecting the operation mode in the TMA, the ASA automatically switches the blind mode to the smoother conventional decision-directed mode. The ASA uses the error functional that is the weighted sum of the Generalized Sato error and the decision-directed error, where the weights correspond to the channel conditions. Test results on 16-QAM and 8-VSB datas confirm that the TMA and the ASA perform well under the sudden changes of channel conditions.

  • PDF