• Review of KIISC
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• v.2 no.4
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• pp.75-90
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• 1992

본고는 아날로그 음성, 비디오 및 오디오 신호의 비화방식에 대한 연구로써 정보의 대부분을 구성하고 있는 음성, 그리고 앞으로 요구가 증가될 것으로 예견되는 위성 TV 및 CATV의 비디오와 오디오의 아날로그 비화방식의 종류 및 각각의 알고리즘에 대해 고찰하였다.

• The Journal of the Acoustical Society of Korea
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• v.16 no.2
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• pp.80-88
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• 1997

In this paper, the implementation of audio/data processor using ETRI DSP to support analog mode in digital/analog dual mode mobile phone is presented. Audio/data processor performs the wideband data processing, audio signal processing, demodulation function, and data rate conversion when it is operated in analog mode. These functions are programmed in assembly language, and then loaded to ETRI DSP together with vocoder program for the digital mode operation. This is a very efficient implementation of the dual mode cellular phone ASIC since the vocoder for the digital mode and audio/data processor for the analog mode are programmed together in the same hardware.

• Journal of Korean Electronics
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• v.2 no.7
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• pp.52-53
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• 1982

• The Magazine of the IEIE
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• v.31 no.6
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• pp.75-95
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• 2004

기존의 아날로그 오디오에 비해 향상된 음질과 넓은 대역폭을 갖는 디지털 오디오는 CD나 DVD 등을 비롯하여, 고선명 TV, 디지털 오디오 방송(DAB) 등 가정용 엔터테인먼트 시스템에서부터, 포터블 오디오 재생기, 이동통신 단말기 등 개인 휴대 장치에 이르기까지 그 응용분야가 다양하다.(중략)

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.63-68
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• 2016

Audio mixer is an electronic device which performs a mixing of multiple audio signals. Digital mixer having various functions and scalability is spreaded thanks to advanced DSP and IT technology. However, digital mixer is more vulnerable to stability comparing to conventional analog mixer in the digital error or software error sense because its control is executed by SW. To solve this problem, in this paper, we propose a multi-channel digital analog hybrid mixer scheme, digital mixer error detection mechanism and malfunctioning switching technique. Also we develop the audio mixer having digital-analog hybrid structure. By simulation, we can sense the error of digital mixer except power loss in a 120ms, change into analog mixer mode automatically and provide continuous broadcasting function without mixer function loss.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.1199-1202
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• 1998

4채널 입력으로부터 입력되는 오디오를 압축,복원,저장, 전송하는 ㅅ스템을 설계한다. 이러한 시스템은 보안 시스템 중에서 특정 센서로부터 alarm 신호를 디지털 데이터로 변환한 후, 압축시켜 저장하고 동시에 압축된 오디오 데이터를 비디오 데이터와 통합하여 하나의 스트림으로 만들어 통신망으로 보내주는 시스템에 적용된다. 이러한 시스템의 구조를 간단히 설명하면 아날로그 음성 신호를 디지털 음성 data로 변환하기 위해 OKI사의 MSM 7570L-91이라는 ADPCM codec을 사용하였고 ADPCMcodec을 거쳐 나온 ADPCM 데이터를 64Mbyte SDRAM에 저장하였다가 FIFO를 거쳐서 통신망으로 전송을 한다. 복원은 SDRAM에 저장된 ADPCM 데이터를 MSM 7570L-01을 거쳐 아날로그 신호로 변환한 후 엠프를 거쳐 스피커로 출력을 하게 된다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1997.11a
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• pp.95-99
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• 1997

본 논문에서는 TI사의 범용 DSP인 TMS320C31을 이용하여 48KHz의 표본화주파수를 지원하고 20비트의 해상도를 갖는 방송용 디지털 오디오 믹서 시스템을 구현하였다. 전체 시스템은 4부분의 모듈로 구성된다. 아날로그 및 AES/EBU 디지털 포맷의 오디오 데이터를 입력받는 입력 모듈과 믹싱을 위한 믹싱 모듈, 처리된 데이터를 아날로그 및 디지털 포맷으로 출력하는 출력 모듈, 그리고 전체 시스템을 제어하는 제어 모듈로 구성된다.

• The Journal of the Acoustical Society of Korea
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• v.24 no.7
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• pp.387-394
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• 2005

In this paper, we propose a new transmission technique of audio signals for the serial connection of the speakers of multiple-channel audio systems. Analog audio signals from a multi-channel audio system are converted into digital signals with signal processing steps and transferred to each speaker through a serial line. The signal processing steps contain data compression and packet generation in association with audio signal characteristics. Each speaker gets its corresponding digital audio signals from the transmitted packets and converts the signals into analog audio signals to make sounds with the speaker All the proposed functions in this paper are modeled in VHDL. implemented with FPGA chips, and tested for actual multi-channel audio systems.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.7
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• pp.44-51
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• 2008

A stereo audio digital-to-analog converter (DAC) with a power amplifier using asymmetric pulse-width modulation (PWM) is presented. To adopt class-D amplifier mainly used in high-power audio appliances for head-phones application, this work analyzes the noise caused by the inter-channel interference during the integration and optimizes the design of the sigma-delta modulator to decrease the performance degradation caused by the noise. The asymmetric PWM is implemented to reduce switching noise and power loss generated from the power amplifier. This proposed architecture is fabricated in 0.13-mm CMOS technology. The proposed audio DAC including the power amplifier with single-ended output achieves a dynamic range (DR) of 95-dB dissipating 4.4-mW.

• The Journal of the Acoustical Society of Korea
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• v.26 no.6
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• pp.269-275
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• 2007

Pervasive Multi-channel audio systems are being realized due to advances in digital technology. This paper proposes an efficient system that serially connects individual speakers with bidirectional digital communication capability by means of SoC design. In particular, each speaker can identify the bit stream assigned to the speaker and convert it into analog audio. Furthermore, the speaker can self-diagnose the speaker functionality by utilizing the designed capability to measure frequencies of various square wave test signals. The proposed system running on 200MHz clock yielded restoration of analog output signal with latency of only $500{\mu}s$ compared to directly driving the speakers in a traditional way.