Throughput maximization in multimedia TDMA/CDMA systems

Abstract

In recent mobile communications, many applications using a terminal as a host of multimedia transmissions through a wireless channel have been introduced. With these advances, resource allocation of the uplink has become an important factor for quality and efficiency purposes. In this work, two classes of transmissions that have different criteria of QoS (Quality of Service) are considered. One is represented by a real-time media (voice or video) transmission which is intolerant of delay but can stand some amount of errors, and the other is a data transmission which sets importance on high throughput (error-free information rate) at the cost of delay caused by retransmissions. The optimum set of power levels, transmission rates, packet length, and Eb/No are investigated to maximize the total throughput of data transmissions, subject to required QoS constraints on media transmissions in a dual-class wireless system. Considering the number of data transmissions in one snapshot of time as a controllable variable, the optimum number of data transmissions is also determined, and the hybrid TDMA/CDMA mode is shown to be the most efficient way to maximize the total throughput.