Abstract: A method, an apparatus, and a computer-readable medium may be described in the present disclosure. The apparatus may be a user equipment. The apparatus may determine whether a number of unsuccessful repetitions associated with performance of a first type of scanning exceeds a repetition threshold. The apparatus may perform a second type of beam scanning based on the determination that the number of unsuccessful repetitions exceeded the repetition threshold.

Abstract: A communications system for a vehicle includes an antenna mounted on a vehicle and configured to communicate with a plurality of remote units. A diagnostic controller is configured to detect obstacles or damage to the antenna. The diagnostic controller is configured to receive remote messages, measure a receive signal strength of the remote messages, and determine a ratio of low receive signal strength sample messages to total sample messages. The diagnostics controller is further configured to trigger a diagnostic output to the vehicle when the ratio is greater than a predetermined threshold.

Abstract: In an exemplary embodiment, a phased array antenna comprises multiple subcircuits in communication with multiple radiating elements. The radio frequency signals are independently adjusted for both polarization control and beam steering. In a receive embodiment, multiple RF signals of various polarizations are received and combined into at least one receive beam output. In a transmit embodiment, at least one transmit beam input is divided and transmitted through multiple radiating elements, with the transmitted beams having various polarizations. In an exemplary embodiment, the phased array antenna provides multi-beam formation over multiple operating frequency bands. The wideband nature of the active components allows for operation over multiple frequency bands simultaneously.

Abstract: A first communication device receives a plurality of training signals from a second communication device via a communication channel. The first communication device determines, based on the plurality of training signals, a channel matrix corresponding to the communication channel, and determines, based the channel matrix and without decomposing a steering matrix, compressed feedback to be provided to the second communication device. The first communication device transmits the compressed feedback to the second communication device to enable the second communication device to steer at least one subsequent transmission to the first communication device.

Abstract: A method and apparatus for determining a vertical beam for reception are disclosed herein. A method in a wireless transmit/receive unit (WTRU) includes that the WTRU may receive a broadcast message from an evolved Node B (eNB) that includes information associated with a plurality of beam reference signals, wherein the information includes at least one set of Physical Random Access Control Channel (PRACH) resources associated with each of the plurality of beam reference signals. Further, the WTRU may measure reference signals transmitted on each of the plurality of beam reference signals. Then, the WTRU may select a beam reference signal from among the plurality of beam reference signals. In addition, the WTRU may transmit a PRACH preamble in a set of resources associated with the selected beam reference signal. The WTRU may then receive further communications from the eNB.

Abstract: The invention relates to a method for radio communication using a plurality of antennas, and to an apparatus for radio communication using a plurality of antennas. An apparatus for radio communication of the invention comprises: 4 antennas; a radio device; an antenna tuning apparatus having 2 antenna ports and 2 radio ports; a switching unit comprising 4 input ports each coupled to one of the antennas through a feeder, and 2 output ports, the switching unit operating in an active configuration in which it provides a path between any one of the output ports and one of the input ports, the active configuration being determined by a configuration instruction generated by the radio device; and a tuning control unit, the tuning control unit receiving a tuning instruction generated by the radio device, the tuning control unit delivering a plurality of tuning control signals to the antenna tuning apparatus.

Abstract: The present invention is a method for interference and noise reduction in systems with two signals paths and a phase filter, primarily applicable in telecommunications receiving systems with two antennas, radiolocation, measuring and medical equipments and other fields where there is a need to reduce undesired signals with different phases or amplitudes. The phase filter have two signals paths, where the input signals x and y are supplied to the voltage adders SX and SY, at the output of which output signals x? and y? are achieved. The differential output signals w2 and w2? are also supplied to these voltage adders. The differential outputs signals w2 and w2? are obtained by means of one or two power combiners by comparing the voltages received at the output of these power combiners to the average voltages on inputs. Signals supplied to inputs of power combiners are derived from a combination of input signals x and y and difference of voltages between these signals.

Abstract: A communication system is used to receive information from mobile sources. The system includes a plurality of antennas including multiple disjoint sets of multiple antennas configured to receive signals from the multiple mobile sources. At least a subset of the antennas have coverage areas that overlap with antennas in another set of the multiple disjoint sets of multiple antennas. The communication system also includes multiple receivers and multiple signal paths including one signal path for each set of multiple antennas. Each signal path is configured to provide outputs from a corresponding set of multiple antennas of the multiple disjoint sets of antennas to each of the multiple receivers. Each of the receivers choose to output information from one or more of the signal paths based on one or more characteristics of the signals received from the signal paths.

Abstract: A radar device includes a RF signal source, two or more antenna interface units, a feed network, and a control unit. The RF signal source is arranged to provide a RF signal; each of the antenna interface units includes an antenna port and one of the following: an amplifier and a mixer; the feed network includes two or more buffers, each buffer has an active and an inactive state; the control unit is arranged to generate or receive a selection signal which specifies none, one, or more of the antenna interface units as active antenna interface units and the remaining antenna interface units as inactive antenna interface units; the control unit is arranged to activate and deactivate the buffers in dependence on the selection signal so as to feed the RF signal to the none, one, or more active antenna interface units and not to the inactive antenna interface units.

Abstract: It is presented a method for determining how to combine received signals from a plurality of antennas in an antenna set. The method is performed in a network node and comprises the steps of: determining for each evaluation sector whether it is better to perform intra-sector IRC on received signals for all antennas of the evaluation sector than refraining from performing IRC; for each evaluation sector, when it is better to perform intra-sector IRC, forming a single antenna part; for each evaluation sector, when it is better to refrain from performing IRC on any of the received signals for the antennas, forming a separate antenna part for each antenna; determining for a sector group whether it is better to perform inter-sector IRC on all its antennas or to keep the previously formed antenna parts; forming a single combined antenna part for the sector group when it is better to perform IRC on the at least two evaluation sectors of the sector group.

Abstract: Disclosed are a distributed multi-cell multi-user beamforming method, a transmitter and a relevant system. In the distributed beamforming method in the embodiments of the present invention, beamforming coordinated calculation is performed by a plurality of transmitters, and an interference matrix among the transmitters is used to perform an iterative operation on a beamforming vector corresponding to the data which is to be sent to each user over each sub-channel of this cell, so that the interference dimension of each user over each sub-channel of the transmitters is compressed into a subspace as small as possible.

Abstract: A distributed spectrum analyzer and a method of spectrum analysis applying same. The spectrum analyzer adopts a separate design. A radio frequency receiver receives a signal, performs frequency conversion processing and AD conversion on the received signal, and sends the converted digital signal to a host. In such a structure, by a digital optical module, the radio frequency receiver is connected to a corresponding digital optical module on the host through an optical fiber, so as to implement a bidirectional data transmission. The host performs general control of the system as well as signal processing and spectrum analysis. Therefore, a multi-interface design is applied to the host of the spectrum analyzer, so as to support simultaneous access and control for a plurality of radio frequency receivers, thereby conveniently implementing multi-port measurement extension.

Abstract: A method and apparatus for transmitting and receiving a signal of Random Access Channel (RACH) in a wireless communication system using beamforming are provided. The reception method includes receiving the signal through each transmission beam of a transmitter from a transmitter, transmitted in each transmission beam by the transmitter, the signal including as many repeated symbols as a total number of reception beams of a receiver, and detecting symbols by switching to reception beams corresponding to the symbols included in the signal during reception of the signal.

Abstract: Methods and systems are described for determining and transmitting at least one orthogonal frequency division multiplexing (OFDM) symbol that may comprise data associated with multiple nodes such as a first node and a second node. Each OFDM symbol may be determined using weights, time-frequency channels, and/or tones that are determined based at least in part on transmissions from the first node and the second node.

Abstract: A mobile station performs a method for random access in a wireless network. The method includes receiving, from a base station, information regarding a configuration of at least one receive beam of the base station to receive a random access signal. The method also includes configuring at least one transmit beam for a transmission of the random access signal based on the configuration information from the base station. The method further includes transmitting the random access signal to the base station on the at least one transmit beam.

Abstract: Optical fiber-based wireless systems and related components and methods are disclosed. The systems support radio frequency (RF) communications with clients over optical fiber, including Radio-over-Fiber (RoF) communications. The systems may be provided as part of an indoor distributed antenna system (IDAS) to provide wireless communication services to clients inside a building or other facility. The communications can be distributed between a head end unit (HEU) that receives carrier signals from one or more service or carrier providers and converts the signals to RoF signals for distribution over optical fibers to end points, which may be remote antenna units (RAUs). In one embodiment, calibration of communication downlinks and communication uplinks is performed to compensate for signal strength losses in the system.

Abstract: An angle diversity receiving device performs angle diversity reception by configuring branches of angle diversity in accordance with received signals of an array antenna, the angle diversity receiving device being provided with: a plurality of phased array synthesizing unit that generates a received signal of a branch by performing phased array synthesis for the received signals of a plurality of antenna elements included in the array antenna; and a correlation control unit that outputs a correlation value for the received signals of two branches; wherein the phased array synthesizing unit controls the angular difference in the orientations of the branches for which the correlation value was computed so that the correlation value decreases.

Abstract: A receiving apparatus for communication area evaluation includes a receiving unit configured to receive a first signal transmitted from a base station; a delay profile calculation unit configured to calculate a downlink delay profile based on the first signal; and an estimated value calculation unit configured to calculate an estimated cyclic prefix length based on the calculated downlink delay profile.

Abstract: A data communication network to transmit and/or receive data using soft-decision information is provided. A target access point in a data communication network may compute soft-decision information with respect to information bits corresponding to a transmission symbol, and transmit the computed soft-decision information to a destination device or an access point connected to the destination device. The destination device or the access point connected to the destination device may combine soft-decision information of a plurality of access points, and detect information bits based on the combined soft-decision information.

Abstract: A device is provided for use of an antennal base formed of two antennas which pick up the emissions present and produce two radioelectric signals S1 and S2. These two signals are used to produce at least one intermediate-frequency signal Fl by demodulation of one of the two signals by the other (autotransposition). The demodulation is carried out by firstly transposing one of the signals, S1 for example, around a given frequency F1, the signal S2 being preserved around its initial central frequency F0. Thus, whatever the central frequency F0 of the emission picked up by the antennas, the demodulation produces a signal of central frequency F1, thereafter demodulated into a given intermediate frequency Fl by a local oscillator of constant frequency F2=F1+Fl. The device is applied to the production of a device for detecting emissions and for characterizing the emissions picked up.

Abstract: Methods and apparatus for implementing a wireless communication transceiver having receive path performance diversity. The transceiver implements a plurality of signal paths that can be configured as diversity receive paths. Each of the plurality of signal paths includes a distinct RF filter. Each RF filter can be configured to provide a distinct jammer rejection profile. Each receive path also includes a jammer detector, that can be a multiple level jammer detector. Each jammer detector operates to control a level of processing gain applied to the signals in its receive path. The multiple gain scaled receive signals can be combined in a coherent combiner before being routed for further processing.

Abstract: A combination of antennas to be used is selected based on a distance between a plurality of antennas or the polarization direction of a radio signal to be transmitted/received.

Abstract: A mobile communication method according to the present invention includes the steps of: (A) notifying, from a first radio base station (MBS) to a second radio base station (FBS), scheduling information including information specifying a radio resource for a control channel through which a first mobile station (MUE) that is in communication in a first cell under the control of the first radio base station (MBS) transmits downlink control information or uplink control information, when the first radio base station (MBS) assigns the radio resource; and (B) assigning, at the second radio base station (FBS), a radio resource for a control channel through which a second mobile station that is in communication in a second cell under the control of the second radio base station (FBS) transmits downlink control information or uplink control information based on the scheduling information.

Abstract: A propagation channel estimation unit estimates a propagation channel estimation value. A symbol replica generation unit generates a symbol replica that is modulated symbol of a demodulated information. A signal extraction unit extracts, in an arbitrary time duration, each subcarrier component of a received signal in which an interference signal was removed, the extraction being made based on the propagation channel estimation value and the symbol replica. A demodulator demodulates a signal of each subcarrier component in the received signal, the demodulation being made based on signal during the time duration extracted by the signal extraction unit.

Abstract: A hybrid combining method in a receiver is provided, and the method includes that wideband combining, e.g. using a maximum ratio combining (MRC) or an interference rejection combing (IRC) process, to combine signals distributed over a first plurality of subcarrier frequencies from antennas in the same polarization direction is performed, resulting in a combined signal for each polarization direction that is distributed over a smaller number of subcarrier frequencies, then a two-port narrowband IRC is done of these wideband combined signals for the two polarization directions, resulting in a diversity combined signal.

Abstract: A wireless communication device (100) carries out diversity reception and a noise cancellation process, and a signal combining section (combining circuit (123)) combines a plurality of received signals in a case where the diversity reception is carried out and combines a received signal and a noise signal in the noise cancellation process.

Abstract: A multi-tuner apparatus comprises a splitter (S) for received RF signals. The splitter has a splitter output (U) for connection to a plurality of tuners. To reduce signal degradation and dissipation the output impedance of the splitter output is substantially lower than the input impedance of each of the tuners.

Abstract: A down-converter for receiving a multiband radio frequency signal (RF) and a local oscillator signal comprises a frequency divider and a heterodyne receive chain. The frequency divider is configured to divide the local oscillator signal and provide different divided local oscillator signals. The heterodyne receive chain comprises a first stage mixer and second stage mixers. The first stage mixer is configured to mix the multiband radio frequency signal and either the local oscillator signal or a divided local oscillator signal to generate a first intermediate frequency signal. Each second stage mixer is configured to mix the first intermediate signal and a divided local oscillator signal to generate second intermediate frequency signals that each represent a band from the multiband radio frequency signal. The frequency divider is configured to provide a different divided local oscillator signal to each of the second stage mixers.

Abstract: A combination of antennas to be used is selected based on a distance between a plurality of antennas or the polarization direction of a radio signal to be transmitted/received.

Abstract: Methods and systems consistent with this invention receive a plurality of transmitted signals in a receiver having a plurality of receive elements, wherein each transmitted signal has a different spatial location. Such methods and systems receive the plurality of transmitted signals at the plurality of receive elements to form a plurality of receive element signals, form a combined signal derived from the plurality of receive element signals, and detect each of the plurality of transmitted signals from the combined signal by its different spatial location. To achieve this, methods and systems consistent with this invention generate a plurality of arbitrary phase modulation signals, and phase modulate each of the plurality of receive element signals with a different one of the phase modulation signals to form a plurality of phase modulated signals.

Abstract: According to one embodiment, a mobile wireless terminal, which makes a wireless communication with a base station accommodated in a network, includes a receiver, a communication module, and a controller. The receiver is configured to receive and frequency-convert a wireless signal transmitted from the base station, and to detect a beacon signal transmitted from the base station based on a reception signal obtained by the frequency conversion. The communication module is configured to receive a wireless signal transmitted from the base station, to acquire identification information of the base station by decoding a reception signal obtained from the wireless signal, and to communicate with the base station. The controller is configured to activate the communication module in accordance with a reception result of the beacon signal by the receiver, and to control the communication module to acquire identification information from the base station.

Abstract: A collaborative MIMO method using a sounding channel in a multi-cell environment is disclosed. The method includes acquiring, by a first base station providing a service for a first cell, first CSI of a first downlink channel between the first base station and a mobile station, transmitting, to a second base station, a signal including information requesting that the second base station providing a service for a second cell acquire second CSI of a second downlink channel between the second base station and the mobile station, and acquiring, by the second base station, the second CSI. The mobile station is served by the first base station.

Abstract: Techniques to calibrate downlink and uplink channels to account for differences in the frequency responses of transmit and receive chains are described. In one embodiment, pilots are transmitted on downlink and uplink channels and used to derive estimates of the downlink and uplink channel responses, respectively. Sets of correction factors are then determined based on estimates of downlink and uplink channel responses. A calibrated downlink channel is formed using a first set of correction factors for the downlink channel, and a calibrated uplink channel is formed using a second set of correction factors for the uplink channel. The first and second sets of correction factors may be determined using a matrix-ratio computation or a minimum mean square error computation. The calibration may be performed in real-time based on over-the-air transmission. Other aspects, embodiments, and features are also claimed and described.

Abstract: A device previously configured as a registrar and that has established an independent ad-hoc network is automatically discovered by another device also previously configured as a registrar. To form an ad-hoc wireless network between these two devices, each device periodically enters a scanning mode to scan for and intercept beacons transmitted by the other device. Upon such interception, one of the devices becomes an enrollee in accordance with a predefined condition and in response to a user selected option. Subsequently, the enrollee modifies its beacons to include an attribute, such as the MAC address, associated with the other device. After intercepting the modified beacon, the remaining registrar prompts it user to decide whether to allow the enrollee to join the registrar's network. If the user responds affirmatively, a handshake is performed between the two devices and a subsequent attempt is made by the enrollee to join the registrar's network.

Abstract: An apparatus for calculating receive parameters for an MIMO system including a plurality of individual transmission sections, a transmission section having a transmit circuit adjustable by a transmit parameter, and a plurality of individual users, a user having a receive circuit being adjustable by a receive parameter, includes a calculator for calculating a receive parameter for a first selected data stream for a first user of the plurality of users using a channel information for a transmission channel between the user and a first individual transmit section, to which the user is associated, and for calculating a receive parameter for a second selected data stream for a second user of the plurality of users associated with a second different individual transmission section using channel information between the first user and the second transmission section the second user is associated with, or using the calculated receive parameter for the first user.

Abstract: A system for routing short message service (SMS) messages to endpoints in a contact center includes a first node for receiving SMS message streams from multiple sources operating variant protocols and for multiplexing the multiple streams into a single message stream following a universal protocol, a media gateway server connected to the first node for receiving the single message stream and for forwarding individual ones of the messages therein to individual ones of a plurality of connected servers, and a router connected to at least one of the connected servers for routing individual messages represented therein to individual ones of a plurality of network-supported endpoint devices.

Abstract: The specification and drawings present a new method, apparatus and software related product for antenna clustering for multi-antenna aperture selection (MAAS), e.g., in LTE wireless systems, using multi-core DSP processing with sub-optimum selection of N out of M of antenna signals and minimizing the performance degradation due to the sub-optimal antenna/antenna signal selection. Assigning each DSP core (machine) to N/K antennas (i.e., to antenna signals) having a similar property (e.g., polarization) and a same tier, the selection of N out of M using a predefined criterion (e.g., best SINR) is reduced to selecting N/K out of M/K which reduces the computation complexity by a factor of K, where K is a number of the DSP cores.

Abstract: A central office node using beam patterns and antenna polarizations, a remote node, and a wireless communication method between the nodes. The central office node includes: a first antenna array with first polarization attributes; a second antenna array with second polarization attributes; and a transmitter unit configured to transmit data to a plurality of remote nodes using beam patterns generated during beamforming and the polarization of the first and second antenna arrays.

Abstract: Disclosed is a wireless receiving apparatus, whereby inter-antenna interference can be reduced without inducing an increase of a mounting area due to an increase of the number of antennas, and the number of RFIC input terminals, circuit scale and power consumption can be reduced. In the wireless receiving apparatus (100), when a receiving antenna (110-1) and a down-converter (130) are connected with a multiplexer (120) therebetween, a capacity control unit (190-2) controls the capacity value of the capacity-variable parasitic element (180-2) connected to the receiving antenna (110-2) such that the communication capacity of the receiving antenna (110-1) is maximum.

Abstract: An FM receiver includes a receiving unit that receives a signal from a broadcasting station and outputs a receiving signal, an equalizer that equalizes the receiving signal by using a calculated weight, and obtains an equalized output signal, a demodulator that demodulates the equalized output signal to reproduce the signal from the broadcasting station, a detection unit that observes size of the calculated weight to detect a capture state with respect to an undesired broadcasting station and generates a capture detection signal, and a weight setting unit that sets the calculated weight with respect to the equalizer at a steady state, and sets a specific weight for temporarily setting the equalizer in a through state when the capture detection signal is generated.

Abstract: A power control method in a mobile station having at least two antennas. The mobile station operates in a receive-diversity state in which the mobile station wirelessly receives communications with multiple antennas. The mobile station determines a relative gain of operating in the receive-diversity state versus operating in a non-receive-diversity state in which the mobile station wirelessly receives communications with one antenna rather than with multiple antennas. The mobile station uses the determined gain as a basis to set one or more power characteristic(s). The one or more power characteristic(s) may include (i) an initial power control setpoint for use by the mobile station to evaluate strength of received transmissions and (ii) an initial power level at which a remote entity transmits to the mobile station.

Abstract: An antenna assembly for receiving the GPS signals in a global positioning system (GPS) receiver module automatically orients the antenna to better receive the GPS signals. The antenna is oriented by a positioner (e.g., a counterweight) that automatically rotates a frame on which the antenna is mounted. The GPS receiver module may also include multiple antennas oriented in different directions to maintain good reception of the GPS signals in any position. The multiple antennas are oriented in a manner so that the poor reception range an antenna is covered by other antennas. Signals from multiple antennas may be combined or chosen for processing by a GPS processor. Also, multiple GPS receiver modules may be deployed in close proximity so that wireless communication between the GPS receiver modules may be established.

Abstract: A system and a closed form method of optimizing a set of receive beamformers' weights, each feeding one of N multi-layer MIMO receiving system wherein the beamformers have a pool of M receive antennas wherein M is greater than N.

Abstract: In an exemplary embodiment, a phased array antenna comprises multiple subcircuits in communication with multiple radiating elements. The radio frequency signals are adjusted for both polarization control and beam steering. In a receive embodiment, multiple RF signals are received and combined into at least one receive beam output. In a transmit embodiment, at least one transmit beam input is divided and transmitted through multiple radiating elements. In an exemplary embodiment, the phased array antenna provides multi-beam formation over multiple operating frequency bands. The wideband nature of the active components allows for operation over multiple frequency bands simultaneously. Furthermore, the antenna polarization may be static or dynamically controlled at the subarray or radiating element level.

Abstract: An active channelized antenna system includes an antenna array operable over a multi-octave frequency band to provide one or more antenna output signals. An electronics module includes multiplexer circuitry responsive to the one or more antenna output signals configured to divide an input signal spectrum into a plurality of frequency band components each of less than an octave bandwidth. The electronics module includes a plurality of amplifiers each of less than an octave bandwidth to provide an amplified component signal for a respective frequency band. Combiner circuitry included with the electronics module is configured to combine the amplified frequency band components into a composite signal. A transmission medium such as a coaxial cable, fiber optic line or free space, is configured to transmit the composite signal to a remotely located receiver system. The antenna system may be employed as a repeater system.

Abstract: A beamforming network includes a plurality of signal conditioning devices in signal communication with each other, wherein each of the signal conditioning devices receives an input signal, conditions the input signal by independently and selectively adjusting at least one of a time delay, a phase, and an amplitude of the input signal, and transmits an output signal to at least one of another of the signal conditioning devices, an antenna, and a load.

Abstract: An RF transceiver front-end includes receiver and transmitter front-ends. The receiver front-end includes 1st and 2nd antennas, a ninety degree phase shift module and an LNA module. The 1st and 2nd antennas receive inbound RF signals and provide a first directional circular polarization. The ninety degree phase shift module phase shifts the RF signals received by the 2nd antenna. The LNA module amplifies the RF signals received by the 1st antenna and the shifted RF signals. The transmitter front-end includes a PA module and 3rd and 4th antennas, which provide a second directional circular polarization. The PA module amplifies outbound RF signals to produce amplified outbound RF signals and amplified orthogonal outbound RF signals. The 3rd antenna transmits the amplified outbound RF signals and the 4th antenna transmits the amplified orthogonal outbound RF signals.

Abstract: Use of an antennal base formed of two antennas which pick up the emissions present and produce two radioelectric signals S1 and S2. These two signals are used to produce at least one intermediate-frequency signal Fl by demodulation of one of the two signals by the other (autotransposition). The demodulation is carried out by firstly transposing one of the signals, S1 for example, around a given frequency F1, the signal S2 being preserved around its initial central frequency F0. Thus, whatever the central frequency F0 of the emission picked up by the antennas, the demodulation produces a signal of central frequency F1, thereafter demodulated into a given intermediate frequency Fl by means of a local oscillator of constant frequency F2=F1+Fl. The device is applied to the production of a device for detecting emissions and for characterizing the emissions picked up.

Abstract: An apparatus includes a transceiver configured to transmit wireless signals to and receive wireless signals from wireless nodes associated with an industrial process. The apparatus also includes a controller configured to initiate transmission of the wireless signals and to process data contained in the received wireless signals. The transceiver includes a diversity receiver configured to process the wireless signals from the wireless nodes. The transceiver may be further configured to perform beam-shaping in order to transmit a directional beam to at least one of the wireless nodes. Also, the controller may be configured to perform spatial routing by identifying a target of a wireless transmission and to initiate transmission of the directional beam towards a known or estimated location associated with the identified target.

Abstract: A PDMA terminal (1000) establishes communication by forming a plurality of spatial paths to another single radio apparatus. A plurality of antennas constituting an array antenna are divided into a plurality of subarrays corresponding to the plurality of spatial paths respectively. An adaptive array processing unit (USP) can perform an adaptive array processing for each of the plurality of subarrays. A memory (MMU) stores in advance information on the number of antennas associated with the number of spatial paths that can be formed by the array antenna. A control unit (CNP) controls a processing to transmit possible multiplicity information to another radio apparatus at a prescribed timing.