Performance Analysis of Transmission Probability Control Scheme in Slotted ALOHA CDMA Networks

This paper proposes a dynamic packet transmission probability control scheme in slotted CDMA system. In slotted CDMA system, multiple access interference is the major factor of unsuccessful packet transmissions. In order to obtain the optimal system throughput, the number of simultaneously transmitted packets should be kept at a proper level. In the proposed scheme, the base station calculates the packet transmission probability based on the offered load and then broadcasts it. Mobile stations, which have a packet to send, attempt to transmit with the received probability. Numerical analysis and simulation results show that the proposed scheme can offer better system throughput than the conventional one, and furthermore can guarantee a good fairness among all mobile stations regardless of the offered load.