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The multiple input multiple output (MIMO) sensor utilized for human detection by channel state information in a MIMO propagation channel has been proposed. In this paper, we evaluate the estimation of the detection of the person and the approximate direction of arrival (DoA) of the person using a correlation function with only 2 by 2 MEMO configuration. We focus on the DoA estimation of the human...
As a technique for improving the transmission rate within a limited frequency band, Multiuser MIMO (MU-MIMO), which realizes MIMO transmission with multiple user terminals, has been attracted much attention. However, it is not possible to communicate with the users that exceed the number of base station (BS) antennas in the MU-MIMO transmission. We have proposed a method by using non orthogonal multiple...
This paper proposes a collision detection scheme in asynchronous multiuser-multiple input multiple-output (MU-MIMO) transmission and self-interference cancellation. We assume that asynchronous MU-MIMO which realizes the efficient transmission and other antennas can receive preamble signals while the transmission is employed with antennas which are used in asynchronous MU-MIMO. The self-interference...
Massive MIMO transmission has been attracted much attention as one of key technologies in next-generation mobile communication system, because it enables improvement in service area and interference mitigation by simple signal processing. Multi-beam massive MIMO configuration has proposed that utilizes the beam selection with high power in analog part and blind algorithm such as constant modulus algorithm...
Massive MIMO enables the improvement on the transmission rate without increasing the burden on the signal processing by employing a large number of antennas at a base station (BS). However, it is reported that CSI estimation itself has a large overhead when considering massive MIMO. The authors have proposed analog-digital hybrid massive MIMO configuration which eliminates CSI estimation itself by...
Multiuser multiple-input multiple-output (MU-MIMO) has been much attracted much attention for improving the spectral efficiency within a limited frequency band. However, it is not possible to communicate with the users that exceed the number of base station (BS) antennas in the MU-MIMO transmission. We have proposed a method by using non orthogonal multiple access (NOMA) and Zero Forcing (ZF) at the...
Multiple Input Multiple Output (MIMO) sensor, which is utilized for intruder detection by channel state information (CSI) in MIMO propagation channel, has been proposed. We have focused on wide range human detection in indoor scenario by applying array antenna with wide element spacing in the horizontal place at transmit and receive antennas. On the other hand, human detection with limited range such...
The Multiuser Multiple-Input Multiple-Output (MU-MIMO) has been much attracted much attention for improving the spectral efficiency within a limited frequency band. The MU-MIMO techniques have been introduced in the standardization of IEEE802.11ac and LTE-Advanced. However, it is not possible to communicate with the users that exceed the number of base station (BS) antennas in the MU-MIMO transmission...
We are focusing our research on indoor positioning technology; specifically, a type that uses Visible Light Communication (VLC); modulatable LED lights transmit data at 9600 bps, using 4 Pulse Position Modulation (4PPM), while a fish-eye lens-equipped camera receives the light signal over a 160-degree field-of-view. This type of lighting requires neither additional space nor-power. We assigned a unique...
We have proposed a method which realizes collision detection by utilizing 2-by-2 multi-input multi-output (MIMO) transmission in wireless LAN systems. We assume the collision due to multiple short preamble signals. In the proposed method, We utilize a fact that the short preamble signal is transmitted from only first antenna. Then, an access point (AP) can detect interference signals by using a second...
The downlink non orthogonal multiple access (NOMA) was proposed by using successive interference cancellation (SIC) at the receiver that enables communication with the terminal over the number of base station antennas. Furthermore, technique using both random beamforming and SIC was proposed. In this paper, we propose the spatial multiplexing for multiple users exceeding degree of freedom at the base...
Multiuser MIMO (MU-MIMO) improves the system channel capacity by employing the transmission between a base station (BS) and multiple user terminals (UTs). Block Diagonalization (BD) has been proposed as a practical algorithm in MU-MIMO broadcast channel. However, when the number of transmit antennas is equals to the total number of received antennas, the transmission rate by the BD algorithm is decreased...
Intruder detection method by using time variant Multiple Input Multiple Output (MIMO) channels was proposed (MIMO sensor). It was verified that the antenna height and element spacing suitable for the MIMO sensor by the measurement. It was also shown that 2 × 2 MIMO sensor obtains the higher detection performance compared to 1 × 4 SIMO sensor. However, we conducted only the measurement when considering...
This paper proposes an interference detection method in MIMO transmission, which utilizes periodical preamble signals in a frequency domain. The signals are mapped in only several subcarriers in short preamble signals of IEEE802.11 based OFDM signals and the signal in a frequency domain is transformed by IFFT at the transmitter. We assume the collision due to multiple short preamble signals. In the...
This paper proposes novel antenna arrangements which improve the channel capacity for 4×4 multiple-input multiple-output (MIMO) system in line-of-sight (LOS) environment. It is shown that the channel matrix is unitary matrix by the proposed antenna arrangement and the high channel capacity is obtained by the proposed antenna arrangement with directional antennas even if the multipath signals in indoor...
We propose a method for determining the indoor position based on a Visible Light Communication (VLC) system that uses a high-speed fish-eye lens-equipped camera. In VLC, lights are used as data transmitters and users can receive location information using a receiving device. Since the lights are configured to meet a pre-determined illumination level, the system requires neither space nor additional...
Concept of very large MIMO (VL-MIMO) has recently been proposed. In this paper, basic performance of VL-MIMO is investigated when considering the small cell such as phantomcell. An optimal radio frequency which is suitable VL-MIMO is evaluated when changing the cell size in the phantomcell. Moreover, it is shown that the channel capacity by Maximum Ratio Combining is compared with that by Zero Forcing...
Multi-user MIMO (MU-MIMO) improves the system channel capacity by employing the transmission between a base station and multiple user terminals (UT). Block Diagonalization (BD) has been proposed in order to realize MU-MIMO broadcast. The BD algorithm cancels inter-user interference by creating the weights so that the channel matrixes for the other users are set to be zero matrixes. However, when the...
This paper proposes an interference detection method in MIMO transmission, which utilizes periodical preamble signals in a frequency domain. In this paper, we assume the collision between the short preamble signal in WLAN system and interfering signal like a microwave oven. In the propose method, second antenna receives the signals while first antenna transmits the preamble signals. Hence, the interference...
In the short range MIMO transmission, an optimal element spacing, which maximizes the channel capacity, exists, when the transmit distance between the transmitter and receiver is given. We focus on that the weight by a zero forcing (ZF) at the optimal element spacing can be realized by using 90-degree phase shifters and dividers because the matrix of weight by the ZF at the optimal element spacing...
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