• Title/Summary/Keyword: Log MMSE

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The study of paralytic side functional recovery on hemiplegia (편마비 환자의 환측 기능회복을 위한 연구)

  • Kim, Chi-Hyok;Cho, Young-Ha;Kim, Yong-Kwon
    • Journal of Korean Physical Therapy Science
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    • v.9 no.2
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    • pp.7-16
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    • 2002
  • This study was conducted to assess the changes in the functional levels of affected upper extremities after treating hemiplegic patients by applying constraint-induced movement therapy(CIMT). The subjects were selected from 20 hemiplegic patients with scores of 25 or more in Mini Mental State Examination(MMSE-k), transferred to the departments of physical therapy in two university hospitals in Busan from December, 2001 to march, 2002, and were divided into two groups. Eleven subjects with fixing unaffected arms by CIMT were assigned to the experimental patient group and the other 9 patients to control group without fixing unaffected arms. The function of upper arms for both groups were evaluated by using Actual Amount of Use Test(AAUT) and Motor Active Log(MAL) before and after physical therapy. The malts were as follows: The recovery rates of upper extremity by AOU(Activity of Use) and QOM(Quality of Movement) were 23.9% and 27.3% for CIMT treated group, and by 8.3% and 4.6% for the control group on the average, respectively, in AAUT after physical therapy, showing statistically significant differences between two groups. And in MAL, the average recovery rates were 27.3% by AOU and 22.6% by QOM for CIMT treated group while 3.1% by both AOU and QOM for the control group, and were significantly different between twogroups.

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Multi-Stage Turbo Equalization for MIMO Systems with Hybrid ARQ

  • Park, Sangjoon;Choi, Sooyong
    • Journal of Communications and Networks
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    • v.18 no.3
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    • pp.333-339
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    • 2016
  • A multi-stage turbo equalization scheme based on the bit-level combining (BLC) is proposed for multiple-input multiple-output (MIMO) systems with hybrid automatic repeat request (HARQ). In the proposed multi-stage turbo equalization scheme, the minimum mean-square-error equalizer at each iteration calculates the extrinsic log-likelihood ratios for the transmitted bits in a subpacket and the subpackets are sequentially replaced at each iteration according to the HARQ rounds of received subpackets. Therefore, a number of iterations are executed for different subpackets received at several HARQ rounds, and the transmitted bits received at the previous HARQ rounds as well as the current HARQ round can be estimated from the combined information up to the current HARQ round. In addition, the proposed multi-stage turbo equalization scheme has the same computational complexity as the conventional bit-level combining based turbo equalization scheme. Simulation results show that the proposed multi-stage turbo equalization scheme outperforms the conventional BLC based turbo equalization scheme for MIMO systems with HARQ.

Implementation of Chip and Algorithm of a Speech Enhancement for an Automatic Speech Recognition Applied to Telematics Device (텔레메틱스 단말용 음성 인식을 위한 음성향상 알고리듬 및 칩 구현)

  • Kim, Hyoung-Gook
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.7 no.5
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    • pp.90-96
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    • 2008
  • This paper presents an algorithm of a single chip acoustic speech enhancement for telematics device. The algorithm consists of two stages, i.e. noise reduction and echo cancellation. An adaptive filter based on cross spectral estimation is used to cancel echo. The external background noise is eliminated and the clear speech is estimated by using MMSE log-spectral magnitude estimation. To be suitable for use in consumer electronics, we also design a low cost, high speed and flexible hardware architecture. The performance of the proposed speech enhancement algorithms were measured both by the signal-to-noise ratio(SNR) and recognition accuracy of an automatic speech recognition(ASR) and yields better results compared with the conventional methods.

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Low complexity ordered successive interference cancelation detection algorithm for uplink MIMO SC-FDMA system

  • Nalamani G. Praveena;Kandasamy Selvaraj;David Judson;Mahalingam Anandaraj
    • ETRI Journal
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    • v.45 no.5
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    • pp.899-909
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    • 2023
  • In mobile communication, the most exploratory technology of fifth generation is massive multiple input multiple output (MIMO). The minimum mean square error and zero forcing based linear detectors are used in multiuser detection for MIMO single-carrier frequency division multiple access (SCFDMA). When the received signal is detected and regularization sequence is joined in the equalization of spectral null amplification, these schemes experience an error performance and the signal detection assesses an inversion of a matrix computation that grows into complexity. Ordered successive interference cancelation (OSIC) detection is considered for MIMO SC-FDMA, which uses a posteriori information to eradicate these problems in a realistic environment. To cancel the interference, sorting is preferred based on signal-to-noise ratio and log-likelihood ratio. The distinctiveness of the methodology is to predict the symbol with the lowest error probability. The proposed work is compared with the existing methods, and simulation results prove that the defined algorithm outperforms conventional detection methods and accomplishes better performance with lower complication.

A QOC Signal Detection Method for Spatially Multiplexed MIMO Systems (공간다중화 MIMO 시스템을 위한 QOC 신호검출 기법)

  • Im, Tae-Ho;Kim, Jae-Kwon;Cho, Yong-Soo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.9C
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    • pp.771-777
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    • 2010
  • This paper proposes a new signal detection method, called QR-OSIC with Candidates (QOC) method, for spatially multiplexed multiple input multiple output (MIMO) systems. By using the ordered successive interference cancellation (OSIC) algorithm and the maximum likelihood (ML) metric, the proposed method achieves near-ML performance without requiring a large number of candidates. Although the proposed method can be used for both hard and soft decoding systems, it is especially useful for soft decoding systems since the LLR values for all the bits can be efficiently computed without using LLR estimation. The proposed method is also suitable for VLSI implementation since it leads to fixed throughput system.