Beam domain optical wireless communication method and system

Patent metadata

Field	Value
Publication number	US-11139908-B2
Application number	US-201716302676-A
Country	US
Kind code	B2
Filing date	Sep 22, 2017
Priority date	Sep 15, 2017
Publication date	Oct 5, 2021
Grant date	Oct 5, 2021

Abstract

The invention discloses a beam domain optical wireless communication method and system. A base station is equipped with an array of optical transceiver ports or transmitter/receiver ports and a lens, each optical transceiver port forms a beam with centralized energy through the lens, and the base station generates beams in different directions by using the optical transceiver port array and the lens, thereby realizing multi-beam coverage or large-scale beam coverage in a communication region. The base station transmits/receives signals of multiple or a large number of user terminals by using channel state information of each user terminal, and different optical transceiver ports transmit/receive signals in different directions, thereby realizing simultaneous communication and bidirectional communication between the base station and different user terminals.

First claim

What is claimed is:

1. A transmitting method of beam domain optical wireless communication, the method comprising:
equipping a base station or a transmitting device of the beam domain optical wireless communication with an optical transmitter unit array and a lens,
transmitting the optical signal by each optical transmitter unit in the optical transmitter unit array forming a beam in some direction through the lens,
transmitting the optical signals by different optical transmitter units forming beams in different directions through the lens,
forming beam coverage by the base station or the transmitting device in a communication scope thereof by using the optical transmitter unit array and the lens,
covering different regions by different beams, and
communicating the base station or the transmitting device simultaneously with each user terminal or receiving device in the beam domain,
wherein the optical transmitter unit is a light-emitting diode or a laser diode, and different optical transmitter units are separated from each other by using a photoresist or reflective material to construct the optical transmitter unit array, and a square array or a circular array is used as the optical transmitter unit array.

2. The transmitting method of beam domain optical wireless communication according to claim 1 , wherein the base station or the transmitting device is equipped with single or multiple lenses; when the single lens is arranged, the optical transmitter unit array is arranged on the focal plane of the lens, the optical signal transmitted by each optical transmitter unit is refracted to some direction through the lens, thereby having an energy centralization feature depending on the transmitting angle, so as to form one beam; when the multiple lenses are arranged, each lens covers one or multiple optical transmitter units, the optical transmitter unit corresponding to each lens is arranged on the focal plane of the lens, the optical signal transmitted by each optical transmitter unit forms one beam through the lens, or the optical signals transmitted by the multiple optical transmitter units corresponding to one lens form one beam through the lens.

3. The transmitting method of beam domain optical wireless communication according to claim 1 , wherein the optical wireless communication is implemented in the beam domain, which comprises beam domain optical downlink transmission; the beam domain optical downlink transmission comprises that the base station or the transmitting device generates the transmitting signal by using channel state information of each user terminal or receiving device, different optical transmitter units in the same optical transmitter unit array transmit different signals, then the optical transmitter unit array transmits the signals to different user terminals or receiving devices simultaneously.

4. The transmitting method of beam domain optical wireless communication according to claim 3 , wherein in the beam domain optical downlink transmission, when the base station or the transmitting device generates the transmitting signal by using the channel state information of each user terminal or receiving device, a linear precoding beam domain transmission based on maximum ratio transmission or regularized zero forcing, or a beam division multiple access downlink transmission is used.

5. The transmitting method of beam domain optical wireless communication according to claim 4 , wherein the beam division multiple access downlink transmission comprises that the base station or the transmitting device conducts user scheduling and beam allocation according to the channel state information of each user terminal or receiving device, selects multiple user terminals or receiving devices capable of communicating by using the same time-frequency resource, allocates non-overlapping beam sets to the user terminals or the receiving devices that are communicated simultaneously, and the base station or the transmitting device transmits pilot signals and data signals to the user terminal or the receiving device on the beam allocated to each user terminal or receiving device.

6. A receiving method of beam domain optical wireless communication based on the transmitting method of claim 1 , wherein the user terminal or the receiving device receives the signal transmitted in the beam domain by the base station or the transmitting device through a transmission channel, and the user terminal or the receiving device estimates channel information according to a received pilot signal, and detect the data signal by using the channel state information.

7. The receiving method of beam domain optical wireless communication according to claim 6 , wherein the user terminal or the receiving device is equipped with an optical receiving device, the optical receiving device is a single optical receiver unit, or is composed of the optical receiver unit array and the lens; when the optical receiving device is the single optical receiver unit, the optical receiving device receives the transmitting signal from one base station or transmitting device; and when the optical receiving device is composed of the optical receiver unit array and the lens, the optical receiving device receives the transmitting signals from single or multiple base stations or transmitting devices at different positions, and the lens refracts optical signals in different directions to different optical receiver units.

8. The receiving method of beam domain optical wireless communication according to claim 6 , wherein the channel state information is the path gain of all the beams transmitted by the base station or the transmitting device to the user terminal or the receiving device; when a linear precoding beam domain transmission based on maximum ratio transmission or regularized zero forcing is used, the channel state information is the equivalent channel gain of each data stream in the precoding domain; and when a beam division multiple access downlink transmission is used, the channel state information comprises the channel gain from the beam or beam set allocated for each user terminal or receiving device at the base station or the transmitting device to the user terminal or the receiving device.

9. The receiving method of beam domain optical wireless communication according to claim 6 , wherein the receiving process comprises signal detection and decoding, and recovery of original transmitting signals.

10. A beam domain optical wireless communication system, wherein comprising the transmitting device at the base station and the receiving device at the user side;
at the base station side, the transmitting device comprising:
an optical transmitter unit array, configured to transmit optical signals of different beams in downlink transmission, wherein each optical transmitter unit independently transmits the optical signal;
a lens module, wherein the lens module is a single lens or a lens set of multiple lenses, configured to refract the optical signals transmitted by different optical transmitter unit to different directions to form different beams; and
a downlink transmitting signal generator, configured to generate signals transmitted to different user terminal or receiving devices; and
at the user terminal side, the optical receiving device comprising:
an optical receiver, configured to receive a downlink optical signal transmitted by the base station or transmitting device;
a channel estimator, configured to estimate channel state information according to a received pilot signal; and
a signal detector, configured to detect the received data signal.

11. The beam domain optical wireless communication system according to claim 10 , wherein th

Assignees

• Univ Southeast

Inventors

• Gao Xiqi
• Sun Chen
• Wang Wenjin
• You Li
• Lu Anan
• Zhong Wen

Classifications

• H04B7/0695

  using beam selection · CPC title

• H04W72/046

  the resource being in the space domain, e.g. beams · CPC title

• H04L5/0005

  Time-frequency · CPC title

• H04B10/50

  Transmitters · CPC title

• H04B10/11

  Arrangements specific to free-space transmission, i.e. transmission through air or vacuum · CPC title