Short Time DFTコンパンダのフェージング雑音抑圧効果

Abstract

Signals transmitted over poor radio channels are interfered by fading noise to be degraded in speech quality. The short time DFT (ST DFT) compander has successfully excluded envelope detection owing to employing concept of instantaneous spectrum instead of employing approximated AM demodulation in realizing the envelope detectors. This ST DFT compander is able to reduce fading noise to improve speech quality over poor radio channels without any distortions. The ST DFT compander is discussed in this paper to optimize their structures and is also discussed to be sufficient in noise reduction both from theoretical analysis and computer simulations.