Simultaneous code-time access control in a MultiCode-CDMA network

Abstract

Existing MultiCode-CDMA MAC protocols do only single dimensional access control either in the code or time domain, and thus result in a complex optimization problem. In this paper, we propose a MAC protocol which can do simultaneous code-time access control to avoid the optimization problem, and to achieve better system utilisation. In order to do that, the proposed protocol decouples the function of transmission ordering from the function of packing all the scheduled transmissions in the resource space. As such, different transmission scheduling algorithms can be adopted without altering the protocol. A water filling approach is used for efficient transmission packing where each of the scheduled transmissions is treated as a rectangular capsule with an arbitrary size and the resource space is viewed as a water container. Simulation results indicate that the proposed protocol can achieve higher throughput compared to single dimensional access control protocols. Therefore, the proposed MAC protocol is a more efficient one.