| 摘要 |
<p>A receiver node includes an optical amplifier optically coupled to the input of a receiving device such as a PIN photodiode. A controller inputs received power level values from the receiver to perform gain control. The input signal of an optical receiving device is pre-amplified by an optical amplifier such that the amplified signal is within a dynamic range of the receiving device. Upon the occurrence of a LOS (loss of signal) event, the controller sets the gain to a Home Gain value. Thus, when the signal is re-established, a strong signal will not be over amplified and damage the receiver. Gain control is re-established when the LOS event is over. Various methods are used to declare LOS including comparing the received power level or commanded pump power against a threshold. The LOS declaration may also be received from an external device or service channel. Windows are utilized to trigger the gain control algorithm such that when the received power level is inside a first window the gain control is turned off. When the received power level is outside the second window, the gain control is turned on.</p> |
