Patent ID: 11936429
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A wireless transmission system comprising:
an accommodation station transmission unit configured to modulate light based on an RF signal to generate an optical signal and output the generated optical signal; and
a base station transmission unit configured to receive the optical signal output by the accommodation station transmission unit,
wherein the base station transmission unit includes:
an optical demultiplexer including a plurality of output ports assigned to a plurality of wavelengths of the light, the optical demultiplexer being configured to receive, from an input port, the optical signal output by the accommodation station transmission unit, demultiplex the received optical signal for each of the plurality of wavelengths, and output the demultiplexed optical signal from the output port corresponding to the wavelength,
a plurality of photoelectric converters, each of which is connected to each of the plurality of output ports of the optical demultiplexer, the plurality of photoelectric converters being configured to convert the optical signal output by the optical demultiplexer into an electrical signal to demodulate the RF signal and output the demodulated RF signal,
a matrix operation unit including a plurality of first ports and a plurality of second ports, the matrix operation unit being configured to perform, using each of the plurality of first ports as a reference port, on a plurality of signals received by a plurality of the reference ports, a BFN matrix operation of making a phase change that is different for a position of the reference port and the phase change that causes phases of signals output by the plurality of second ports to have a linear inclination, each of the plurality of first ports being connected to an output of each of the plurality of photoelectric converters to receive the RF signal output by each of the photoelectric converters connected to each of the plurality of first port, and
a plurality of transmission antennas, each of which is connected to each of the plurality of second ports of the matrix operation unit, the plurality of transmission antennas being configured to form a plurality of transmission beams in different directions for each of the wavelengths through emission of the RF signal output by each of the second ports after the BFN matrix operation.