Performance analysis of DS unslotted packet radio networks with given auto- and crosscorrelation sidelobes

The paper is concerned with the performance analysis of multiple-access DS unslotted ALOHA systems with fix packet length in synchronous (chip slotted) channels with single spreading code or CDMA coding. In contrast with previous work the present authors focus on the performance analysis of a system that can have given auto- and crosscorrelation sidelobes between the spreading codes. They present a novel approach based on the multivariable probability generator function of the level of interferences which facilitates the calculation of packet error probability for different systems without error correcting codes. In the paper the lower bound of the throughput is calculated. And its asymptotic behaviour is considered, when the length of the DS code goes to infinity. Generally the chip spread ALOHA model is analyzed, but the results can be used in the case of bit spread ALOHA systems