Study of Power Control on Double-Weight Codes With an Arbitrary Maximum Cross-Correlation Value in Variable-QoS Optical CDMA

Abstract

In this paper, the use of power and weight control in multimedia, variable quality-of-services (QoS) incoherent optical code-division multiple-access (O-CDMA) systems in on-off keying is studied. An adjustable-power and variable-weight incoherent O-CDMA architecture is presented and the general performance model of 1-D and 2-D double-weight optical codes with an arbitrary maximum cross-correlation value λ <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</i> is formulated as functions of code weight and chip power. Our results show that the performance of double-weight codes can be fine-tuned by varying both code weight and power, and they play different roles in the QoS differentiation. From the numerical examples, we show that λ <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</i> =2 double-weight codes can perform as good as their λ <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</i> =1 counterparts and, at the same time, have the advantage of supporting more possible subscribers. This general analytical model is important for power-sensitive applications, such as in-service monitoring and fiber-fault surveillance in optical networks and sensor-identification in fiber-sensor systems with the use of optical codes.