Patent ID: 8989575
Filing Date: 2015-03-24
Classification: H04B

Abstract:
1. A signal detection method, comprising: receiving, by a frequency mixer, wavelength division multiplexing signals and a local oscillator signal, wherein a wavelength of the local oscillator signal and a wavelength of a target signal in the wavelength division multiplexing signals are the same; performing, by the frequency mixer, interference on the wavelength division multiplexing signals through the local oscillator signal to obtain a coherent signal formed by the local oscillator signal and the target signal; sending the coherent signal to a transimpedance amplifier for amplification to obtain a voltage signal, and then sending the voltage signal to a variable-gain amplifier; and obtaining power of the target signal according to a feedback voltage signal of an output end of the variable-gain amplifier and a formula wherein S is the power of the target signal, P is the power amplitude of the voltage signal, Lo is a power value of the local oscillator signal, and Va is the gain of the transimpedance amplifier.