Fiber enabled optical wireless communication system and method

Patent metadata

Field	Value
Publication number	US-12418341-B2
Application number	US-202217962558-A
Country	US
Kind code	B2
Filing date	Oct 10, 2022
Priority date	Apr 10, 2020
Publication date	Sep 16, 2025
Grant date	Sep 16, 2025

Abstract

A fiber enabled optical wireless communication (FE-OWC) system and method is provided. An optical antenna composed of an optical fiber transceiving port array and a lens or a reflecting mirror is used to generate optical beams in different directions, such that full-beam coverage of a communication area is implemented. The optical antenna is connected to an optical chain by an optical fiber, the optical chain realizes mutual conversion of an optical signal and an electrical signal, and a baseband signal processing unit which is in electrical signal connection with the optical chain realizes user scheduling, transceiving signal processing, etc. Multi-user multiple-input multiple-output (MIMO) or massive MIMO or beam division multiple access optical wireless communication between a base station and user terminals is implemented by using the optical beams. The FE-OWC system and method may support ultra-high-rate user data transmission and system throughput, and have a low complexity.

First claim

What is claimed is:

1. A fiber enabled optical wireless communication (FE-OWC) method, wherein the FE-OWC method, based on an FE-OWC system, calculates a link budget of a single link transmission and establishes a channel model of an electrical signal transmission between transceiving ends;
wherein a base station and a user terminal of the FE-OWC system are both configured with an FE-OWC apparatus, wherein one of multi-user MIMO or massive MIMO or beam division multiple access (BDMA) optical wireless communication between the base station and the user terminal is implemented;
wherein the FE-OWC apparatus comprises an optical antenna and one or more optical chains;
wherein the optical antenna comprises an optical fiber transceiving port array and a lens or a reflecting mirror, wherein an optical fiber transceiving port of the optical fiber transceiving port array comprises an optical fiber port and a micro-lens, and to expand an angular range of optical signals, the micro-lens is arranged adjacent to the optical fiber port, wherein the optical signals are transmitted and received by the optical fiber port;
in a process of transmitting a first optical signal of the optical signals, the first optical signal is transmitted by a single optical fiber port of the optical fiber transceiving port array, and then the optical signal is refracted by the micro-lens to generate a first optical beam of optical beams; the first optical beam is further refracted by the lens or reflected by the reflecting mirror, resulting the first optical beam being transmitted in a direction and having a predetermined angular range; wherein the optical beams are refracted or reflected to different directions, and wherein the optical beams are transmitted by different optical fiber transceiving ports of the optical fiber transceiving port array;
in a process of receiving a second optical signal, the optical beams are received from different directions and are refracted by the lens or reflected by the reflecting mirror, then the micro-lens refracts a second optical beam of the optical beams within a predetermined angular range into the second optical signal received by a corresponding optical fiber port of the optical fiber transceiving port array, wherein different optical fiber transceiving ports of the optical fiber transceiving port array receive the optical signals from different directions; and
the optical fiber transceiving port array and the lens or the reflecting mirror are configured to generate the optical beams in different directions, different optical beams cover different areas, and all the optical beams cover a communication area, wherein all the optical beams are generated by the optical fiber transceiving port array, such that a full-beam coverage of the communication area is implemented;

wherein the optical antenna is configured to transmit and receive the optical signals and the optical beams to and from different directions; the optical antenna is connected to the optical chains by an optical fiber directly, or the optical antenna is connected to the optical chains by an optical switching unit; the optical chains are configured to implement a mutual conversion between an optical signal and an electrical signal; and a first single FE-OWC apparatus communicates with a second single FE-OWC apparatus or a set of FE-OWC apparatuses;

wherein the link budget comprises an electro-optic conversion at a transmitting end, an optical wireless channel gain, an optical-electro conversion at a receiving end, and an electrical noise at the receiving end; an electro-optic conversion part at the transmitting end establishes a relationship between an optical power and an input electrical signal based on an optical-electro property of an electro-optic conversion device, wherein the optical power is output by the transmitting end; the optical wireless channel gain is a wireless channel gain between an optical fiber transceiving port at the transmitting end and an optical fiber transceiving port at the receiving end; an optical-electro conversion part at the receiving end considers two processes of the receiving optical signal being amplified by a first optical amplifier and detected by a photodetector, and establishes a conversion relationship between an input optical signal and an output electrical signal at the receiving end; the electrical noise at the receiving end comprises an electrical noise introduced by a second optical amplifier and the photodetector, and a relationship between signal power and noise power in an electrical signal received by a single link is established; based on a single link budget, a complete channel model for transmitting the electrical signal from the transmitting end to the receiving end is established; and based on the channel model, the multi-user MIMO or massive MIMO or BDMA optical wireless communication method is implemented between a base station and user terminals.

2. The FE-OWC method according to claim 1 , wherein the optical wireless channel gain describes a channel gain of an optical wireless transmission from the transmitting end to the receiving end, and the optical wireless channel gain comprises four parts: a beam modeling at the transmitting end, a channel gain of a free space transmission, a ratio of a receiving power of the optical fiber transceiving port at the receiving end, and a coupling efficiency of the optical fiber port; the beam modeling at the transmitting end describes an optical intensity distribution of a single beam, wherein the single beam is generated by the light, the light is transmitted by the optical fiber transceiving port after being refracted by the lens or reflected by the reflecting mirror, and as a number of optical fiber transceiving ports at the transmitting end increases, the optical intensities from a single optical fiber transceiving port to different user terminals are asymptotically orthogonal; the channel gain of the free space transmission considers a transmission process of the optical beam from the transmitting end to the receiving end through a free space, and the channel gain of the free space transmission is inversely proportional to a square of a transmission distance; the ratio of the receiving power of the optical fiber transceiving port at the receiving end describes a ratio of the optical power received by the single optical fiber transceiving port to a total receiving power of a user, and the ratio is proportional to a common area of an receiving light projection and the optical fiber transceiving port on a receiving plane; and the coupling efficiency of the optical fiber port is a ratio where a receiving light at the optical fiber port is coupled into the optical fiber, and the coupling efficiency of the optical fiber port is proportional to the common area of an angular range of an incident light at the optical fiber port and a receiving angle of the optical fiber port.

3. The FE-OWC method according to claim 1 , wherein the FE-OWC method is the multi-user MIMO or massive MIMO optical wireless communication method implemented based on the FE-OWC system, and a communication process comprises the following steps:
a synchronization, wherein the base station broadcasts a downlink synchronization signal, and the user terminals establish and maintain the synchronization with the base station according to the received signal;
a channel sounding, wherein the user terminal transmits an uplink sounding signal, and the base station estimates channel information of each user terminal based on the received sounding signal;
a downlink transmission, wherein the base station uses the channel information of each user terminal and a low rank property of a channel to perform a precoding transmission and simultaneously transmits signals of all the user terminals, wherein the signals of all the user terminals comprise pilot si

Assignees

• Univ Southeast

Inventors

• Gao Xiqi
• Sun Chen
• Wang Jiaheng

Classifications

• H04B10/40

  Transceivers · CPC title

• H04B10/516

  Details of coding or modulation · CPC title

• H04B10/503

  Laser transmitters · CPC title

• H04J14/0202

  Arrangements therefor · CPC title

• H04B10/116 Primary

  Visible light communication · CPC title