광대역 신호전송을 위한 Digital ADM에 관한 연구

Study on the Digital ADM for Expanding the Frequency Range

電話信號에 대하여 syllabic companding 과 비슷한 變形된 ADM을 論하였다. 入力과 歸還回路를 포함한 大部分의 回路에 digital 技法을 사용함으로 DM의 IC化가 용이 하게 된다. 廣帶域 ADM의 slope over load 最適化, 安定化, SNR에 對하여 解析하였고 實驗 結果 周波數帶域이 改善됨을 確認하였다.

Adaptive version of the delta modulator that is akin to wyllabic companding for telephony is described. A digital technique is used to sense the slope of the input signal and to control the amplitude of the pulses supplied to the RC network in the feed back loop. Thus the development was stimulated by the suitability of delta modulator for low-cost integrated circuits. Analysis are made of the optimum overload characteristics, stability, SNR for improving the frequency range and these results have been esperimentally verfied.