Random optical codes used in optical networks

An analysis of a simple way to design generalised optical orthogonal codes to be used in optical code-division multiple-access systems is presented. They are random optical codes (ROCs). This novel family is especially suitable for optical networks with a large number of channels, low bit rate requirements, energy limitations and packed data. For example, sensor networks need these requirements. An application in an intra-spacecraft telecommand and telemeasurement (TC/TM) optical wireless network is also described. ROCs are selected randomly from all possible rearrangements. However, its probability of error is adequate in many useful parameter ranges. Moreover, ROCs present features not found in other families of codes such as huge cardinality and parameter adaptation to the system necessities. Here, the main contribution is to present a method to optimise the values of the parameters. Furthermore, the optimal weight of the codes is found, given two out of the other set of parameters, that is, the length, the number of users and the probability of error. In addition, a comparison between the length and the power consumption of ROCs and prime codes is also developed.