A rate adaptive transmission scheme for MIMO systems, which can transmit a variable number of data symbol streams, provide transmit diversity for each data symbol stream, and fully utilize the total transmit power of the system and the full power of each antenna. In one method, at least one data symbol stream is received for transmission from a plurality of antennas. Each data symbol stream is scaled with a respective weight corresponding to the amount of transmit power allocated to that stream. The scaled data symbol stream(s) are multiplied with a transmit basis matrix to provide a plurality of transmit symbol streams for the plurality of antennas. The transmit basis matrix (e.g., a Walsh-Hadamard matrix or a DFT matrix) is defined such that each data symbol stream is transmitted from all antennas and each transmit symbol stream is transmitted at (or near) the full power for the associated antenna.

Rate adaptive transmission scheme for MIMO systems

A device for wirelessly communicating between one or more mobile communication devices over a wireless network. A primary mobile communication device is configured to establish one or more connections to one or more secondary mobile communication devices. The primary mobile communication device is further configured to establish a first connection and a second connection to at least one of the secondary mobile communication devices. The first connection is a Bluetooth (BT) connection and the second connection is a Wireless Fidelity (WiFi) connection. The primary mobile device is also configured to establish a third connection to another secondary mobile communication device wherein the third connection is a WiFi connection. Additionally, the primary mobile communication device is configured to simultaneously maintain the BT connection and the WiFi connections during the bi-directional transmission of data between the primary mobile communication device and the secondary mobile communication devices.

Simultaneously maintaining bluetooth and 802.11 connections to increase data throughput

Disclosed is a method for configuring transmission antenna groups in a mobile communication system with multiple transmission antennas and multiple reception antennas. The method includes the steps of: receiving a first matrix having a size of ‘N t ×N t ’, which corresponds to N t number of transmission antennas, fedback from the mobile terminal, generating combinations of sub-matrixes of the first matrix corresponding to N r number of reception antennas, and calculating sums of maximum eigenvalues; determining combinations of the sub-matrixes having a maximum value from among the calculated sums of eigenvalues to be transmission antenna groups for the N t number of transmission antennas; and transmitting different relevant symbols from each other through the transmission antenna groups.

Method for grouping transmission antennas in mobile communication system including multiple transmission/reception antennas

This paper presents wireless OAM (orbital angular momentum) and OAM-MIMO (multi-input and multi-output) multiplexing in a 28 GHz frequency band. We have implemented transmission (Tx) and reception (Rx) antennas consisting of multiple uniform circular arrays (UCAs) to confirm the feasibility. Each UCA can concurrently transmit or receive five OAM mode signals (0, ±1, ±2). Using implemented antennas, we rectified mode-selective Rx SNR degradation caused by the inherent nature of OAM beams. With a combination of antenna selection and receiver diversity we have achieved a 45 Gbps transmission rate using five OAM modes. We also experimentally demonstrated the effectiveness of the OAM-MIMO multiplexing by using a total of eleven OAM modes (three OAM 0 modes and two sets of OAM ±1 and ±2 modes). Experimental results reached a new milestone in point-to-point transmission rates by achieving 100 Gbps at 10 m transmission distance.

An Experimental Demonstration of 28 GHz Band Wireless OAM-MIMO (Orbital Angular Momentum Multi-Input and Multi-Output) Multiplexing

A radar sensing system for a vehicle includes transmit and receive pipelines. The transmit pipeline includes transmitters able to transmit radio signals. The receive pipeline includes receivers able to receive signals. The received signals are transmitted signals that are reflected from an object. The transmit pipeline phase modulates the signals before transmission, as defined by a first binary sequence. The receive pipeline comprises an analog to digital converter (ADC) for sampling the received signals. The transmit pipeline includes a pseudorandom binary sequence (PRBS) generator for outputting a second binary sequence of bits with an equal probability of 1 and 0. The first binary sequence is defined by least significant bit (LSB) outputs from the ADC and the second binary sequence of bits. The first binary sequence comprises a truly random unbiased sequence of bits with an equal probability of 1 and 0.

Vehicular radar sensing system utilizing high rate true random number generator

A calibration apparatus for an array of antenna elements. The apparatus includes a plurality of first antenna elements in the array of antenna elements, and a calibration signal supplier for supplying a calibration signal to a second antenna element near at least two first antenna elements, or a coupler connected to the first antenna element. The calibration apparatus further includes a section which obtains a relative phase fluctuation between the antenna elements based on the calibration signal received by the plurality of antenna elements and user signals received respectively by the antenna elements. The calibration apparatus further includes a calibration factor supplier which obtains a relative amplitude fluctuation between the antenna elements of the array antenna based on the calibration signals received by at least first antenna elements and the user signals received respectively by the antenna elements, and a beam former which calibrates the user signals received respectively by the antenna elements using the relative phase fluctuation and the relative amplitude fluctuation.

Apparatus and method for calibrating array antenna

Disclosed is a radio communication system for performing MIMO transmission including: a first radio communication apparatus including an array antenna in which a plurality of first antennas each having two orthogonally polarized wave characteristics are arranged in an array configuration at predetermined intervals; and a second radio communication apparatus including a plurality of second antennas each having a polarized wave characteristic which are intermediate in angle between the two orthogonally polarized wave characteristics, the plurality of second antennas being arranged at predetermined interval, wherein the first radio communication apparatus forms a directional beam using the array antenna and performs the MIMO transmission using the two orthogonally polarized wave characteristics. The array antenna may be formed by using a plurality of antennas having a right-handed circularly polarized wave characteristic and a left-handed circularly polarized wave characteristic.

Radio communication system and radio communication apparatus

Provided is an antenna orientation adjustment assistance device that allows any worker to rapidly and accurately install an antenna device. An antenna device (100) is tentatively installed. In addition, a camera (200) is attached to the antenna device (100). In addition, the antenna orientation adjustment assistance device is provided with: a received signal strength detection unit (420) which detects received signal strength of radio waves received at an antenna unit (110); a position calculation unit (414) which, using an image captured with the camera (200) relatively fixed with respect to the antenna unit (110), calculates a relative angle position of the antenna unit (110); and a signal strength recording unit (430) which records the relative angle position of the antenna unit (110) and the signal strength at the time of the relative angle position in association with each other.

Antenna orientation adjustment assistance device and antenna device installation method

This paper presents the development of prototype radio equipment for orbital angular momentum (OAM) mode and polarization multiplexing transmission in E-band, as well as the results of a field trial using the prototype. The equipment consists of a radio frequency unit (RF UNIT) and a base-band unit (BB UNIT). The RF UNIT has a uniform circular array with eight elements and E-band frequency converters for each element. The BB UNIT for the transmitter has OAM mode multiplexers and digital modulators, and one of the receivers has an adaptive OAM mode de-multiplexer and digital demodulators which can operate in real-time. Sixteen multiplexing transmissions (eight OAM modes and two polarizations) over a link distance of 40 m with 256 QAM and spectral efficiency of 85.7 bps/Hz have been achieved.

40 M Transmission of OAM Mode and Polarization Multiplexing in E-Band

A method for estimating an arrival direction of a desired wave in which the arrival direction of the desired wave can be estimated even in case of existence of a multiple reflection wave. An identical signal series is repetitively transmitted two or more times from a transmitting side. The transmitted signal series is received by an array antenna having a plurality of element antennas on a receiving side. When the signal is received by each of the element antennas, cross-correlation is calculated between the signal series corresponding to the different repetition of the signal transmission from the transmitting side. Then, a MUSIC algorithm or an ESPRIT algorithm using the cross-correlation matrix is applied to estimate the arrival direction of the desired wave.

Masashi Hirabe

Papers

Apparatus and method for calibrating array antenna

Radio communication system and radio communication apparatus

Antenna orientation adjustment assistance device and antenna device installation method

40 M Transmission of OAM Mode and Polarization Multiplexing in E-Band

Method for estimating arrival direction of desired wave