Apparatus and method for upstream transmission in a coherent pon

A method, comprising:

• configuring a first operation parameter of a first laser to be a reference value, such that the emission frequency of the first laser is aligned to a frequency of a downstream signal;
• determining a target value of the first operation parameter of the first laser based on a deviation between the target value and the reference value, and the reference value of the first operation parameter;
• configuring the first operation parameter of the first laser to be the target value, such that the emission frequency of the first laser aligned to a frequency for an upstream signal;
• transmitting upstream signals to the OLT by modulating the output of the first laser.

A non-transitory computer readable medium storing instructions. which when executed by at least one processor, cause an apparatus to perform at least the following:

• configuring a first operation parameter of a first laser to be a reference value, such that the emission frequency of the first laser is aligned to a frequency of a downstream signal;
• determining a target value of the first operation parameter of the first laser based on a deviation between the target value and the reference value, and the reference value of the first operation parameter;
• configuring the first operation parameter of the first laser to be the target value, such that the emission frequency of the first laser is aligned to a frequency for an upstream signal;
• transmitting upstream signals to the OLT by modulating the output of the first laser.