Application of direct-sequence spread ALOHA communications system using a unified spread code to random access channel

Considering that the application of a direct-sequence slotted spread ALOHA communications system in the access/control channel is effective in systems with traffic channels operating in the CDMA mode, spread ALOHA communications is discussed in terms of the system configuration and throughput performance. The throughput performance of the spread ALOHA communications system using a unified spread code is derived by means of two methods. One is based on the simulation of the demodulation algorithm, and the other is based on an approximation by simple modeling. The modeling consists of two main conditions depending on the collision of packet signals. It becomes obvious from a quantitative evaluation that the approximated results coincide with the simulated results, and that the modeling is very effective in evaluating the system´s throughput performance