Minimizing power consumption of source encoding and radio transmission in multiuser CDMA systems
Xiaoan Lu · 2005
Summary form only given. We investigate the power consumed by multiple mobile terminals transmitting compressed source signals to a base station in a CDMA cellular system. The aim is to minimize total power consumption (the sum of power consumed by source compression and radio transmission) at the terminals by simultaneously adjusting the operating parameters of the source coder and the transmitter. We find that in general the complexity of source compression should increase with increasing distance between a terminal and the base station. However, the exact configuration of the source coder and the transmitter depends on the interaction of all N terminals. The optimum operating points of the terminals are contained in N nonlinear equations. We use the example of a transform coder processing signals from a Gauss-Markov source to explore the advantages of an adaptive system over a system with fixed operating parameters. We also argue how our analytical framework can be applied to a variety of source coders.