Patent ID: 8565595
Filing Date: 2013-10-22
Classification: H04B

Abstract:
1. A method for optimizing a decision threshold of an optical receiver implemented with an apparatus which comprises a decision threshold adjusting unit, a pre-forward error correction bit error rate (pre-FEC BER) detecting unit, a decision threshold control unit and an optimal decision threshold determining unit, comprising the following steps of: A, the decision threshold control unit determining a maximum value and a minimum value of an adjustment range of the decision threshold and an adjustment step of the decision threshold, and transmitting a decision threshold adjusting instruction to the decision threshold adjusting unit; B, the decision threshold adjusting unit, when receiving the decision threshold adjusting instruction, adjusting within the adjustment range of the decision threshold a decision threshold value by adding the determined adjustment step of the decision threshold, and transmitting the adjusted decision threshold value to the pre-FEC BER detecting unit and feeding the adjusted decision threshold value back to the decision threshold control unit; C, the pre-FEC BER detecting unit, when receiving the adjusted decision threshold value, detecting a pre-FEC BER corresponding to the adjusted decision threshold value, and transmitting the pre-FEC BER corresponding to the adjusted decision threshold value to the decision threshold control unit; D, the decision threshold control unit transmitting the pre-FEC BER and the corresponding adjusted decision threshold value to the optimal decision threshold determining unit, judging whether the adjusted decision threshold value is greater than the maximum value of the adjustment range of the decision threshold; and, if not transmitting another decision threshold adjusting instruction to the decision threshold adjusting unit and returning to the step B; and if yes, transmitting an optimal decision threshold determining instruction to the optimal decision threshold determining unit and going to step E; E, the optimal decision threshold determining unit receiving pre-FEC BERs and corresponding decision threshold values sent by the decision threshold control unit more than one time, searching for a minimum value in the detected pre-FEC BERs when receiving the optimal decision threshold determining instruction, and setting a decision threshold value corresponding to the minimum value in the detected pre-FEC BERs as an optimal decision threshold value.