Method and apparatus for evaluating digital transmission systems
AssigneeLeader Electronics Corporation
InventorGenichi Imamura
Life of this patent
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Abstract
An evaluator for evaluating a digital transmission system is provided which comprises a signal power decrease detector and a system margin evaluator. The signal power decrease detector receives a digital signal which has been transmitted through the transmission medium of a transmission system so as to generate a signal power decrease signal. The system margin evaluator evaluates the system margin of the transmission system in response to the signal power decrease signal. The system margin of the digital transmission system can be evaluated in a simple and convenient manner.
Claims32
An evaluation method for evaluating a system margin of a digital transmission system, the method comprising:
- a) receiving a digital signal transmitted through said digital transmission system;
- b) detecting a decrease in signal power of said transmitted digital signal, detection of the signal power decrease comprising:
- i. extracting, from said transmitted digital signal, components within a predetermined frequency band, the extracted components forming an extracted output;
- ii. detecting a magnitude of power of said extracted output, the detected magnitude forming a detected output;
- and
- iii. detecting a difference between said detected output and a predetermined reference value, the detected difference corresponding to said detected signal power decrease;
- and
- c) generating an indication relating to the system margin of said transmission system based on the detected signal power decrease.
An evaluation apparatus for evaluating a system margin of a digital transmission system comprising:
- a) an input terminal for receiving a digital signal transmitted through said transmission system;
- b) a signal power decrease detecting means for detecting a decrease in signal power of said transmitted digital signal received at said input terminal, said signal power decrease detecting means comprising:
- i. extracting means for extracting, from said transmitted digital signal received at said input terminal, frequency components within a predetermined frequency band to form an extracted output, said predetermined frequency band including at least a frequency band within which said digital signal is most strongly affected by said transmission system during transmission of said digital signal through said transmission system;
- ii. detecting means, coupled to said extracting means, for receiving said extracted output from said extracting means and for detecting a magnitude of power of said extracted output, the detected magnitude represented as a detected output;
- and
- iii. difference detecting means, coupled to said detecting means, for receiving said detected output and for detecting a difference between said detected output and a predetermined reference value, the detected difference corresponding to said detected signal power decrease;
- and
- c) an evaluator means for generating an indication relating to the system margin of said transmission system based on the detected signal power decrease.
Dependencies are inferred from the claim text.