Sung-Wan Yoon

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To set a valid communication channel between two endpoints employing different speech coders, decoder and encoder of each endpoint need to be placed in tandem. However, tandem coding is often associated with problems such as poor speech quality, high computational load, and additional transmission delay. In this paper, we propose an efficient transcoding(More)
A noise-robust pitch synchronous feature extraction algorithm for speaker recognition systems is proposed in this paper. Since the pitch synchronous algorithms utilize pitch information, which is meaningful only for periodic segments, we propose a new scheme to deal with non-periodic ones such as unvoiced and noise-corrupted. The experimental results show(More)
Dual-rate G.723.1 speech coder has been widely applied to real-time video and teleconferencing applications where reduced bandwidth and good voice quality is required. This paper presents an efficient implementation of G.723.1 speech coder. To simplify the excitation quantization procedure which is the most computationally demanding, we propose fast(More)
In this paper, an efficient transcoding algorithm between G.723.1 and AMR speech coders is proposed for providing interoperability between IP and mobile networks. Transcoding is completed through three processing steps: line spectral pair (LSP) conversion, pitch interval conversion, and fast adaptive-codebook search. For maintaining minimum distortion,(More)
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