1999/4

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    2-D Motion Estimation of Video Sequences with Influnce of Zero-Mean Gaussian Noise
    (Společnost pro radioelektronické inženýrství, 1999-12) Usama, S.; Simak, B.; Klima, M.
    This paper presents the performance of four motion estimation algorithms with present of zero-mean Gaussian noise. The performance of full search (FS) algorithm, three-step search (TSS) algorithm, new three-step search (NTSS) algorithm, and four-step search (4SS) algorithm with influence of Gaussian noise has been described for three of famous video sequences. The critical signal-to-noise ratio (SNR) is introduced for each algorithm. The worst performance is often in case of full search algorithm (FS).
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    Neural Network Based Speech Enhancement
    (Společnost pro radioelektronické inženýrství, 1999-12) Tlucak, J.; Juhar, J.; Dobos, L.; Cizmar, A.
    This paper deals with methods of speech enhancement with particular focus on neural speech enhancement. Speech enhancement is concerned with the neural processing of noisy speech to improve the quality and intelligibility of the speech signal. The goal of this paper is to describe an experiment with implementation of two channel adaptive noise canceler via direct time domain mapping approach.
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    High-Level Analogue Fault Simulation Using Linear and Non-Linear Models
    (Společnost pro radioelektronické inženýrství, 1999-12) Bartsch, E. K.; Bell, I.
    A novel method for analogue high-level fault simulation (HLFS) using linear and non-linear high-level fault models is presented. Our approach uses automated fault model synthesis and automated model selection for fault simulation. A speed up compared with transistor-level fault simulation can be achieved, whilst retaining both behavioural and fault coverage accuracy. The suggested method was verified in detail using short faults in a 10k state variable bandpass filter.
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    An Effective Go-Back-N Automatic-Repeat-Request Scheme for Variable-Error-Rate Channels
    (Společnost pro radioelektronické inženýrství, 1999-12) Kosut, P.; Polec, J.; Diaz, P.; Menhart, P.
    In non stationary channels, error rates vary considerably. This paper proposes an effective go-back-N (GBN) Automatic-Repeat-Request (ARQ) scheme which estimates the channel state in a simple manner, and adaptively switches its operation mode. It provides higher throughput than other comparable ARQ schemes in conditions of Land-Mobile-Satellite (LMS) channel.
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    GSM Channel Equalization Algorithm - Modern DSP Coprocessor Approach
    (Společnost pro radioelektronické inženýrství, 1999-12) Drutarovsky, M.
    The paper presents basic equations of efficient GSM Viterbi equalizer algorithm based on approximation of GMSK modulation by linear superposition of amplitude modulated pulses. This approximation allows to use Ungerboeck form of channel equalizer with significantly reduced arithmetic complexity. Proposed algorithm can be effectively implemented on the Viterbi and Filter coprocessors of new Motorola DSP56305 digital signal processor. Short overview of coprocessor features related to the proposed algorithm is included.