Envelope detection in strict sense and its application to syllabic companders

Syllabic companders are one of the important functional devices which prevents speech quality degradation due to fading by using the transmission power of finite radio resources effectively. Conventional companders suffer from distortions because of the use of approximate envelope detection in the AM demodulators. It is shown by the way of strict sense envelope detection (SSEd) employing the concept of instantaneous spectrum based on short time DFT can be adopted for the realization of ideal syllabic companders. SSEd companders are also verified to be free from any distortions through analysis and computer simulations both for single and dual tone signals