Using Speech Statistics to Achieve Flexibility and Spectral Efficiency in Wireless Communication Systems

Public demand for cellular telecommunications systems and services has increased at a speed far outstripping the capacity of present systems. Restrictions on the amount of available spectrum require that future systems provide significantly improved spectral efficiency. The next generation of cellular systems (called second generation systems) will offer improved spectral efficiency by using advanced voice encoding and RF modulation techniques, but these advanced techniques alone will be insufficient to provide enough capacity to meet all of the increased demand. Third generation systems are currently being proposed which will provide further spectral efficiency and flexibility by exploiting the silent periods inherent in speech communication. This paper examines various third generation systems and the techniques they will use to exploit the silence within speech.