AN ADAPTIVE MULTI-RATE VOCODER

Tactical communications, as they currently exist, stress the available channel bandwidth to support the enormous amount of information that is communicated. To ase the burden on the communication channel, the amount of data being exchanged must be reduced. In speech communications, there iare many techniques implemented which compress a voice signal into a data stream; various speech encoding algorithms offer different advantages with respect to alternative performance cirteria. The proposed Adaptive Multi-Rate Vocoder (AMRAV) architecture allows dynamic selection of the best communication strategy from a list of predefined techniques; in certain scenarios in which the grade or rate of service can be controlled, the source coding strategy can be chosen automatically. The objective of the Phase I program is to refine the baseline set of candidate algorithms (presented in this proposal) and demonstrate the feasibility of the architecture by implementing a subset of the final AMRAV system to be constructed under the Phase II effort. A system breadboard will be constructed and tested during the Phase I effort to demonstrate the feasibility of the system. This will ideally position Nova for Phase II of this program which will culminate with the delivery of several AMRAVE engineering units.