提出了一种复用技术——正交波形复用(OGDM)，并将其应用于无源光网络(PON)系统中作为上行信号传输。在本方法中，对于N个光网络单元(ONU)端的PON系统，先将N个ONU端信号分别通过强度调制或无载波调幅调相(CAP)技术，调制到N个两两相互正交电波形上，使“1”码对应有波形，“0”码对应无波形，然后再将各路不同的波形信号分别调制到每个ONU用户的激光器上，这些激光器的波长可以是同一个波长；通过光分配网络(ODN)单元合路后上行传输到光线路终端(OLT)端，在OLT端采用相关接收的方法，把接收到的信号和OLT端的本地正交波形作相关运算，利用正交波形的正交性来区分不同ONU端的用户信息。仿真显示在理想情况下，32路ONU信号当采用外调制方式时，每路单独占用10 Gb/s，总带宽为320 Gb/s,可以传输20 km。

A multiplexing technique named orthogonal waveform (graph) division multiplexing (OGDM) and its application on the upstream data transmission in passive optical access networks (PON) are proposed. N mutually orthogonal electrical waveforms are assigned to N optical network units (ONU). For intensity modulator, ONU′s code “1” means orthogonal electrical waveform and code “0” means no waveform. Those electrical orthogonal waveforms are modulated on lasers with the same wavelength and then are combined at optical distribution network (ODN) to be transmitted to optical line terminal (OLT) in a single fiber. At OLT, the mixed signals can be separated by using correlative demodulation method. Stimulation results show that, under external modulation, the transmission distance reaches 20 km with 320 Gb/s data transmission rates in ideal situation.