Title:
OPTICAL HETERODYNE RECEIVER
Document Type and Number:
Japanese Patent JPH06209288
Kind Code:
A
Abstract:
PURPOSE: To reduce the sensitivity loss of a receiver due to phase deviation by controlling the intermediate frequency of the receiver by a controller so as to meet a specific condition. CONSTITUTION: A signal from a local oscillator 2 is superposed on a reception signal S of an optical signal encoded to a binary code by phase difference keying of a carrier frequency signal to form an intermediate frequency signal UZF through a photo detector 4 and an amplifier 5, and a frequency ωZF of the signal UZF is doubled by discriminators 7 and 8, and the frequency of the oscillator 2 is adjusted from an ideal target value 2ωZF to a target value ωZFr of phase deviation Δϕ by a controller 9. When this target value 2ωZFr is selected so as to meet the condition of formula I where (r) equals an odd number of -1, +1, and so on, and T is the duration of a bit of the signal S, the degradation in sensitivity of the receiver due to phase deviation is suppressed.
Inventors:
RAINHORUTO NOE
Application Number:
JP25005693A
Publication Date:
July 26, 1994
Filing Date:
September 10, 1993
Export Citation:
Assignee:
SIEMENS AG
International Classes:
H04B10/60; H04L27/22; (IPC1-7): H04B10/04; H04B10/06; H04L27/22
Attorney, Agent or Firm:
Tomimura Kiyoshi
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