Adaptive Control and Testing System for an Adaptive Receiver

Patent metadata

Field	Value
Publication number	US-2025279798-A1
Application number	US-202519212151-A
Country	US
Kind code	A1
Filing date	May 19, 2025
Priority date	Jan 10, 2022
Publication date	Sep 4, 2025
Grant date	—

Abstract

An adaptive receiver comprising a current buffer, an inverter that receives input from the current buffer, an average current control loop that feeds back from the inverter to the current buffer, a variable gain circuit that receives input from the inverter, a differential voltage amplifier that receives input from the variable gain circuit, an automatic gain control loop that feeds back from the differential voltage amplifier to the inverter and variable gain circuit, and a differential buffer that receives input from the differential amplifier.

First claim

What is claimed is:

1 . An optical test system that comprises:
a transmitter system configured to transmit modulated coherent optical signals modulated based upon radio frequency signals that encode test data; a propagation medium simulator configured to:
receive the modulated coherent optical signals from the transmitter system;
change a set of optical attributes for the modulated coherent optical signals to model propagation of the modulated coherent optical signals through a propagation environment to form varied modulated coherent optical signals; and
output the varied modulated coherent optical signals; and
an optical receiver system configured to:
receive the varied modulated coherent optical signals from the propagation medium simulator; and
recover the radio frequency signals that encode the test data from the varied modulated coherent optical signals in a manner that adjusts for changes in the varied modulated coherent optical signals caused by a variation in a set of optical attributes in the varied modulated coherent optical signals generated by the propagation medium simulator; and
an analog to digital system configured to extract the test data from the radio frequency signals, and outputs recovered data.

2 . The optical test system of claim 1 , further comprising an analyzer configured to compare the test data with the recovered data and form a comparison.

3 . The optical test system of claim 1 , further comprising a fiber simulator configured to change the set of optical attributes to model propagation of the modulated coherent optical signals through a set of optical fibers.

4 . The optical test system of claim 1 , wherein the optical receiver system comprises:
an optical receiver that receives the varied modulated coherent optical signals and generates an input current using the varied modulated coherent optical signals.

5 . The optical test system of claim 1 , wherein the optical receiver system comprises:
an optical receiver configured to receive the varied modulated coherent optical signals and generates an input current using the varied modulated coherent optical signals; and an adaptive receiver configured to receive the input current and recovers the radio frequency signals that encode the test data from the varied modulated coherent optical signals in the manner that adjusts for changes in the varied modulated coherent optical signals caused by the variation in a received varied optical intensity generated by the propagation medium simulator, extracts the test data from the radio frequency signals, and outputs the recovered data.

6 . The optical test system of claim 5 , wherein the optical receiver comprises:
an optical amplifier that receives the varied modulated coherent optical signals and amplifies the varied modulated coherent optical signals to form amplified modulated coherent optical signals; an optical bandpass filter that receives the amplified modulated coherent optical signals and filters the amplified modulated coherent optical signals to form band limited modulated coherent optical signals; and a photodiode system that receives the band limited modulated coherent optical signals and generates the input current in response to receiving the band limited modulated coherent optical signals.

7 . The optical test system of claim 5 , wherein the optical receiver comprises:
an optical amplifier that receives the varied modulated coherent optical signals and amplifies the varied modulated coherent optical signals to form amplified modulated coherent optical signals; and an optical bandpass filter that receives the amplified modulated coherent optical signals and filters the amplified modulated coherent optical signals to form band limited modulated coherent optical signals.

8 . The optical test system of claim 5 , wherein the optical receiver comprises:
an optical amplifier that receives the varied modulated coherent optical signals and amplifies the varied modulated coherent optical signals to form amplified modulated coherent optical signals; an optical bandpass filter that receives the amplified modulated coherent optical signals and filters the amplified modulated coherent optical signals to form band limited modulated coherent optical signals; a fiber simulator that receives the band limited modulated coherent optical signals and adjust a set of optical attributes for band limited modulated coherent optical signals that simulates change in the set of optical attributes for the band limited modulated coherent optical signals to model propagation of the band limited modulated coherent optical signals through an optical fiber to form simulated optical signals; and a photodiode system that receives simulated optical signal and generates the input current in response to the simulated optical signals.

9 . The optical test system of claim 1 , wherein the optical receiver system comprises:
an optical amplifier that amplifies the varied modulated coherent optical signals to form amplified modulated coherent optical signals; and an optical bandpass filter receives the amplified modulated coherent optical signals from an output of the amplifier and outputs a filtered modulated coherent optical signals within a frequency range, wherein a fiber simulator receives the filtered modulated coherent optical signals within the frequency range output from the optical bandpass filter.

10 . The optical test system of claim 1 , wherein the optical receiver system comprises:
an optical amplifier that amplifies the varied modulated coherent optical signals to form amplified modulated coherent optical signals; an optical bandpass filter receives the amplified modulated coherent optical signals from an output of the amplifier and outputs a filtered modulated coherent optical signals within a frequency range, wherein a fiber simulator receives the filtered modulated coherent optical signals within the frequency range output from the optical bandpass filter; a photodiode that receives the filtered modulated coherent optical signals within the frequency range and outputs an input current; and an adaptive receiver that receives the input current from the photodiode, recovers the radio frequency signals that encode the test data from the input current in a manner that adjusts for changes in the varied modulated coherent optical signals caused by variation in received optical intensity caused by propagation medium simulator, and outputs the radio frequency signals that encode the test data.

11 . The optical test system of claim 1 , wherein the optical receiver system comprises:
an optical amplifier that amplifies the varied modulated coherent optical signals to form amplified modulated coherent optical signals; an optical bandpass filter receives the amplified modulated coherent optical signals from an output of the amplifier and outputs a filtered modulated coherent optical signals within a frequency range, wherein a fiber simulator receives the filtered modulated coherent optical signals within the frequency range output from the optical bandpass filter; a photodiode that receives the filtered modulated coherent optical signals within the frequency range and outputs an input current; an adaptive receiver that receives the input current from the photodiode, recovers the radio frequency signals that encode the test data from the input current in a manner that adjusts for changes in the varied modulated coherent optical signals caused by variation in received optical intensity caused by propagation medium simulator, and outputs the radio frequency signals encoding the test data; and an analog to digital converter that receives the radio

Assignees

• Boeing Co
• California Inst Of Techn

Inventors

• Hunt Jeffrey H
• Aghlmand Fatemeh
• Emami Azita

Classifications

• H04B10/616

  Details of the electronic signal processing in coherent optical receivers · CPC title

• H04B10/27

  Arrangements for networking · CPC title

• H04B10/6165

  Estimation of the phase of the received optical signal, phase error estimation or phase error correction · CPC title

• H04B10/6164

  Estimation or correction of the frequency offset between the received optical signal and the optical local oscillator · CPC title

• H04B1/18

  Input circuits, e.g. for coupling to an antenna or a transmission line (coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H) · CPC title