INTERFEROMETRIC NOISE IN OPTICAL CODE MULTIPLE ACCESS SYSTEMS

光码分多址（OCDMA）是一种能够支持突发、可变数据速率业务的系统方法，同时减少了网络管理开销。光码分多址系统在物理层上的性能受到多种噪声源的限制，其中多址干扰（MAI）和干涉差拍噪声更为关键。当具有相同（或名义上相同）频率的不同光信号同时入射到同一检测器上时，会出现干涉差拍噪声（BN）。由于平方律接收器特性，归因于BN的光电流比归因于单独的串扰信号的入射光（强度总和）功率的光电流大得多，从而产生比预期的更严重的性能劣化。有许多研究在估计不同的OCDMA系统的性能时考虑了差拍噪声：频率编码（FE-CDMA）、跳频（FH-CDMA）、相干复用（CM-CDMA）、序列反转键控（SIK-CDMA）和2-D TW-CDMA。该旅行补助金旨在使两个备受尊敬的研究小组之间建立有意义的互动，以开始实验性地验证BN在代表性OCDMA网络场景中的影响。合作的结果将是非常宝贵的，作为一个理论框架的开发投入，以模拟更广泛的实现，包括其他物理层的损害。

Optical code-division multiple access (OCDMA) is a system approach able to support bursty, variable data rate traffic with a reduced network management overhead. The performance of OCDMA systems at the physical level is limited by a combination of noise sources, the more critical being multiple access interference (MAI) and interferometric beat noise. Interferometric beat noise (BN) occurs when different optical signals with identical (or nominally the same) frequencies are incident simultaneously on the same detector. Due to the square law receiver characteristic, the photocurrent attributed to BN is much greater than that owing to the incident optical (sum of intensities) power of the crosstalk signal alone, producing more severe performance degradation than otherwise would be expected. There are many studies that have considered beat noise in estimating performance of different OCDMA systems; frequency encoding (FE-CDMA), frequency hopping (FH-CDMA), coherence multiplexing (CM-CDMA), sequence-inversion-keyed (SIK-CDMA) and 2-D TW-CDMA. This travel grant aims to enable the establishment of meaningful interaction between two well respected research groupings to begin to experimentally characterise the effect of BN in representative OCDMA network scenarios. The output of the collaboration will be invaluable as input to the development of a theoretical framework to model more extensive implementations incorporating other physical layer impairments.