A Throughput-Efficient and Channel-Adaptive Scheduling Scheme in Voice/Data DS-CDMA Networks with Transmission Power Constraints

LANGUAGE
English
SOURCE
to appear in Wiley Wireless Communications and Mobile Computing, Special Issue on Radio Resource Management for Wireless Internet, Oct. 2003
Published Date:2003-10-01
ABSTRACT
In a practical voice/data CDMA network, the constraint of transmission powers makes it necessary to transmit multiple data users in parallel in order to fully utilize system resource (power). How to choose those data users that should be transmitted simultaneously and allocate appropriate powers among them remains as an open issue. In this paper we prove that it is
optimal in the sense of maximum data throughput to select data users and allocate powers according to the descending order of their indexes of received power capability (IRPC). Here, IRPC is defined as the product of the transmission power upper bound and the channel gain. Based on this principle, a channel-adaptive scheduling scheme, Partially Descending IRPC (PDI) scheduling, is proposed to achieve efficient throughput performance for data traffic while maintaining certain fairness among different users. The efficiency and fairness of the PDI scheduling are verified by comparing with the conventional fair-sharing scheme and round-robin scheme through computer simulations. Numerical results also reveal the robustness of the new
scheme to the channel estimation errors.
KEYWORDS
CDMA, scheduling, throughput optimization, fading channel