Nippon Telegraph and Telephone Corporation

Doohwan Lee

Hirofumi Sasaki

Hiroyuki Shiba

Hiroyuki Fukumoto

Takana Kaho

Takashi Shimizu

Kazuhiro Uehara

Kazunori Akabane

Yo Yamaguchi

Takayuki Yamada

Yasunori Yagi

An OAM multiplexing communication system uses one or more OAM modes and multiplexes signals of one or more sequences for each OAM mode. A transmitting station includes a transmitting antenna using an M-UCA, and an OAM mode generation unit that simultaneously generates one or more OAM modes from each UCA. A receiving station includes a receiving antenna equivalent to the M-UCA, an OAM mode separation unit that separates signals received by each UCA for each OAM mode, and a received signal processing unit that estimates channel information for each OAM mode and performs an equalization process for each OAM mode by using a receiving weight calculated from the channel information. The received signal processing unit is configured to estimate, for each OAM mode, channel information of another OAM mode causing interference and calculate the receiving weight of a subject OAM mode by using the channel information of the subject OAM mode and said another OAM mode.

Oam multiplexing communication system and inter-mode interference elimination method

In an OAM multiplexing communication system in which an M-UCA is provided in each of a transmitting station and a receiving station, signals in a plurality of OAM modes are generated and transmitted from each UCA of the transmitting station, signals in the plurality of OAM modes are received and demultiplexed by each UCA of the transmitting station, and streams of the number of UCAs&#xd7;the number of OAM modes are subjected to spatial multiplex transmission, in which the transmitting station includes a signal processing unit generating the streams to be transmitted in the plurality of OAM modes from each of the UCAs of the M-UCA, and the receiving station includes a signal processing unit receiving the signals in the plurality of OAM modes demultiplexed by each of the UCAs of the M-UCA, and demultiplexes the received signals for each stream from signals in an identical OAM mode.

OAM multiplexing communication system and OAM multiplexing communication method

A wireless communication device includes a plurality of antenna elements; a modulation unit modulating signals including data in a plurality of first OAM modes having different real number values; a calculation unit calculating factors indicating weights corresponding to each of the signals in the plurality of first OAM modes modulated by the modulation unit for each of the plurality of antenna elements, based on information indicating a wireless environment of a counter wireless communication device that is a transmission destination of the data; and a transmission processing unit multiplexing each of the signals in the plurality of first OAM modes for each of the plurality of antenna elements by using the factors, and outputting the signals obtained through multiplexing for each of the plurality of antenna elements to each of the plurality of antenna elements.

Wireless communication device and wireless communication method

A transmitting station includes a plurality of transmitting weight multiplication units multiplying each of the transmission signal sequences by a transmitting weight, to be converted into Msignals corresponding to UCAs forming an M-UCA so as to output the converted signals, and Mtransmitting OAM mode generation units inputting the signals corresponding to the UCAs and performing DFT on the input signals, so as to output to the corresponding UCA; and a receiving station includes Mreceiving OAM mode demultiplex units inputting signals from each of the UCAs forming the M-UCA and performing IDFT on the input signals, so as to output by each of received signal sequences, and a plurality of receiving weight multiplication units multiplying for each of them by a receiving weight, so as to demultiplex the spatially multiplexed received signal sequences and to output them in which interference between spatially multiplexed OAM modes is suppressed.

OAM multiplexing communication system and inter-mode interference elimination method

A circuit includes a first input and output terminals to which a current, a voltage, or an electromagnetic wave (referred to as 'current or the like' below) is applied, a second input and output terminals to which the current or the like is applied, a first board including a matrix circuit which is formed by a first line and includes a 90-degree hybrid circuit and a delay line, the first line in which one end is connected to the first input and output terminals and a tip of the other end is opened, a second board including a second line in which one end is connected to the second input and output terminals, and a tip of the other end is opened, and a shielding plate including an opening portion.

Circuit and wireless device

In an OAM multiplexing communication system that subjects a plurality of signal sequences to multiplex transmission by using an OAM mode, a transmitting station includes a transmitting antenna using an M-UCA formed of a plurality of UCAs, and a unit performing basis transformation in each of the rotational direction dimension and a diameter direction dimension in a polar coordinate system having a center of UCAs as an origin, and subjecting the plurality of signal sequences to multiplex transmission for each complex mode formed by a combination of different bases in each dimension. A receiving station includes a receiving antenna using an M-UCA, and a unit receiving a signal subjected to multiplex transmission from the transmitting station, performing basis transformation in each of the rotational direction dimension and the diameter direction dimension by using the received signal, and demultiplexing the plurality of signal sequences subjected to the multiplex transmission.

An antenna displacement correction method for an OAM multiplexing communication system includes: a step of estimating a displacement amount by evaluating an evaluation function defined such that a theoretical channel response between a transmitting antenna and a receiving antenna matches a measured channel response estimated in a receiving station by using a known signal transmitted from a transmitting station, wherein the theoretical channel response has, as a parameter, the displacement amount indicating an amount of displacement of a reference axis predefined for each of the transmitting antenna and the receiving antenna from a predetermined position with respect to a desired relative positional relationship between the transmitting antenna and the receiving antenna; and a step of correcting a displacement of each of the transmitting antenna and the receiving antenna according to the estimated displacement amount.

Antenna displacement correction method and device for OAM multiplexing communication system

An OAM multiplexing communication system multiplexes signals of one or more sequences for each OAM mode. A transmitting station includes a transmitting antenna using an M-UCA, and an OAM mode generation unit that simultaneously generates one or more OAM modes from each UCA. A receiving station includes a receiving antenna equivalent to the M-UCA, an OAM mode separation unit that separates signals received by each UCA for each OAM mode, and a channel estimation/interference compensation unit that compensates for inter-mode interference between the OAM modes by using a weight. The channel estimation/interference compensation unit selects, for each OAM mode, signals of a subject mode and an adjacent mode from among the signals of the OAM modes separated by the OAM mode separation unit, and compensates for the inter-mode interference by multiplying an approximate weight calculated by using channel matrixes of the subject mode and the adjacent mode.

OAM multiplexing communication system and inter-mode interference compensation method

An OAM multiplexing transmission device includes a unit generating each of the transmission streams in a baseband (BB), in which a channel estimation signal sequence is disposed before a transmission target data signal sequence, and a CP having a predetermined length is disposed in the first half of the channel estimation signal sequence, the channel estimation signal sequence is time-shifted with a channel estimation signal sequence (a basic channel estimation signal sequence) having a predetermined length and a zero correlation, by a predetermined shift value for each of the transmission streams; a unit converting a baseband signal sequence of the generated transmission streams to frequency conversion into RF band, or converting into IF band and then converting into the RF band; and a unit converting a plurality of the frequency-converted transmission streams into a plurality of OAM mode signals having different orders, and multiplexing spatially by using the UCA.

OAM multiplexing communication system, OAM multiplexing transmission device, OAM multiplexing receiving device, and OAM multiplexing communication method

A receiver includes a local signal generator, a power phase adjuster, and a frequency converter so as to perform frequency conversion on signals included in a plurality of radio frequency bands. The local signal generator supplies a plurality of local signals. The power phase adjuster adjusts local signals in terms of signal power or relative phases. The frequency converter performs frequency conversion on radio frequency bands by use of local signals adjusted with the power phase adjuster, thus sorting them in a desired frequency range.

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Yokosuka, Japan

Doohwan Lee