Proposed optical random access CDMA protocol with stop & wait ARQ

Abstract

A new random access protocol for optical code division multiple access (CDMA) communication systems is proposed. Stop & wait automatic repeat request (ARQ) is implemented at the optical link layer. A detailed state diagram and a mathematical model based on the equilibrium point analysis (EPA) technique are presented. Several performance measures are evaluated under different network parameters. In our numerical calculations both chip-level and correlation models have been adopted at the receiver side. Furthermore, the effect of thermal noise is studied. We also compare the performance of the proposed protocol to that of the round robin receiver/transmitter (R/sup 3/T) protocol which is based on a go back-n technique. We prove by numerical analysis that the proposed protocol is less complex and significantly outperforms the R/sup 3/T protocol. Our results also reveal that the performance of the proposed protocol with correlation receivers is competitive to that of the R/sup 3/T protocol with chip-level receivers, which reduces the overall system cost.