Multirate subband coding applied to digital speech interpolation
A statistical analysis is presented of a digital speech interpolation (DSI) system using multirate subband coding. The authors estimate the level of speech quality and grade of service that can be provided by such a system, given values of various system parameters. The analysis uses birth-death models for the arrival and departure of calls and talkspurts, and considers a strategy for allocating bandwidth among the ports of the system that takes advantage of the properties of the multirate subband coder. A simulation model is used to estimate values of certain performance parameters that are difficult to obtain analytically. The bandwidth allocation strategy ensures that all traffic offered to the DSI system is carried, with neither blocking nor freezeout. An example is considered that demonstrates the systems' increased efficiency without quality loss
