A novel packet scheduling scheme based on adaptive power/delay for efficient resource allocation in downlink CDMA systems

Abstract

A novel voice packet scheduling scheme named Modified Adaptive Priority Queuing (MAPQ) is proposed for CDMA downlinks. Closed-loop power control is employed to closely track fast fading, and provides power inputs for MAPQ. Estimation error is considered when measuring received pilots at mobile stations. An adaptive priority profile is defined in the scheme based on queuing delay and required transmission power, which borrows the idea of composite metric from wired systems. This definition ensures system capacity improvement, packet dropping rate reduction, and fairness. Users are allocated resources according to their priorities in a modified PQ fashion constrained by total power budget of base stations. Numerical results show distinct performance gains of the proposed scheme, comparing to the reference scheme.