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The authors investigated the spatial distribution of the vital sign on the human body using array antenna. We deployed the array antenna in front and back of the body, and used direction of arrival (DOA) estimation method. As a result, it was found a vital sign distribute intensely at left of the chest, which corresponds to the source location of cardiac impulse.
Toward 5G, LTE-Advanced specifies the key objective that the gigabit data rate for real-time video streaming can be transmitted under a high mobility scenario; thus, packet scheduling and radio resource management become the critical techniques that should be addressed effectively. Additionally, the mechanisms of relaying and the OFDMA coding have been certainly adopted in LTE-Advanced for the purposes...
In this paper, an improved and low-complexity signal detection approach for large-scale multiple-input multiple-output (MIMO) systems has been proposed. This approach utilizes the preconditioning technique to accelerate the conventional detection algorithm based on Gauss-Seidel (GS) iterative method, and achieves a detection performance close to the minimum mean square error (MMSE) detection algorithm...
By adopting multiple-input multiple-output (MIMO) technique, the spectral efficiency and data rate of wireless communication systems can be highly improved. To fully take the advantages of MIMO, belief prorogation (BP) detection methods are considered as a way in balancing the hardware complexity and error performance. Also with BP methods, polar code, which has been adopted by 3GPP eMBB control channel,...
As an alternative to classical multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM), MIMO-OFDM with index modulation (MIMO-OFDM-IM), which provides a flexible trade-off between spectral efficiency and error performance, has attracted considerable interest recently. However, in order to detect the active subcarrier indices and modulated symbols precisely, the receiver...
The scaling up of antennae and terminals in large-scale multiple-input multiple-output (MIMO) systems helps increase the spectral efficiency at the penalty of prohibitive computational complexity. In conventional linear detection such as the minimum mean square error (MMSE) signal detection, the high complexity is mainly caused by solving the inversion of random matrix, especially in large-scale MIMO...
Low-density parity-check (LDPC) coded massive multiple-input and multiple-output (MIMO) scheme is getting increasingly popular and sophisticated in today's wireless communication systems, since it can highly improve the spectral efficiency, data rates, and error performance. In this paper, a novel iterative detection and decoding (IDD) method for LDPC-coded massive MIMO systems is proposed. Based...
By combining the polarized modulation and the spatial modulation technique, dual-polarized spatial modulation (DPSM) has been recently proposed for MIMO transmission to improve the spectral efficiency and reduce the space occupancy. The performance of DPSM over correlated Rayleigh and Rice fading channels has been studied, showing that DPSM technique outperforms uni-polarized SM technique. For a general...
In the 3D massive MIMO system, both the transmitter encoding and the receiver signal detection require channel state information. The accuracy of channel state information will directly affect the overall performance of the system. Therefore, accurate channel estimation is the key to reliable communication in the 3D massive MIMO system. Due to the channel sparsity of 3D massive MIMO, existing works...
This paper extends previous work for extended target detection via Multiple Input Multiple Output (MIMO) bistatic radar using a compressed sensing (CS) approach by considering the detection of multiple fluctuating targets in the presence of transmit waveform dependent clutter. Detection waveforms and receiver filter are designed jointly using an algorithm that minimizes the mutual coherence of the...
The main objective of this paper is to develop an efficient satellite digital beam-forming (BF) method that can provide user specific desirable signal-to-interference-plus-noise ratio (SINR) or data rate for each user in each zone. And a massive multiple-input multiple-output (MIMO) communications system model and its favorable channel propagation condition are assumed (i.e., channel independence...
The stationarity region, i.e., the area in which the statistics of a propagation channel remain constant, is an important measure of the propagation channel, and essential for efficient system design. This paper presents what is to our knowledge the first extensive measurement campaign for measuring the stationarity region of MIMO mm-wave channels. Using a novel 28 GHz phased-array sounder with high...
Based on thorough analyses of adverse effects from nonlinear distortion caused by high power amplifiers (HPAs) with phase conversion in multiple-input multiple-output space-time block code (MIMO-STBC) systems, this work proposes a nonparametric phase estimation and compensation method for the received signal. Using the optimal feedforward blind estimation technique, the receive signal's rotated phase...
In this paper, we propose a compact frequency reconfigurable (FR) multiple-inputmultiple-output (MIMO) antenna in a overall size of 51 × 53 × 0.8 mms. The MIMO antenna consists of two symmetrical FR ones using two PIN diodes on ground plane and has a simple bias circuit without capacitor. By switching the PIN diodes, the FR MIMO antenna can operates in the three states covering bands of tte universal...
An RoF system using a quadrature-multiplexing technique is shown experimentally to improve the 3rd order SFDR by 2.7dB over an intrinsic optical link. As a result of orthogonality between quadrature sidebands, the system can support MIMO.
This paper considers a multiuser massive multiple-input multiple-output (MIMO) uplink transmission with the help of an Nr-antenna amplify-and-forward (AF) relay. Assume that the base station (BS) is equipped with a large array of Nd antennas but supported by a far smaller number, K, of radio-frequency (RF) chains, which greatly reduce hardware complexity and cost. A hybrid processing is proposed to...
In this paper, we consider a millimeter wave (mmWave) multiple-input multiple-output (MIMO) communication system with hybrid beamforming architecture. To search the optimal beam pair, the beam sweeping algorithm is complex and time-consuming in the case of initial access and beam switching. With the aim of improving the robustness, we propose a novel beam management scheme to quickly determine the...
In this work, we investigate the system model, key enabling technique, and the associated performance for an Nr × Nt dual polarized MIMO (DP-MIMO) based communication system, wherein only imperfect channel state information is available at the transmitter. The DP-MIMO channel involves the imperfect spatial fading and perfect polarization fading. At the transmitter, the precoding scheme based on oblique...
The performance of massive multiple-input multiple-output (MIMO) systems is heavily affected by pilot contamination. This paper considers the problem of pilot contamination in massive MIMO systems, and investigates the normalized mean square error (NMSE) of the minimum mean square error (MMSE) channel estimation algorithm in the presence of pilot contamination. An effective uplink training strategy...
In this paper, a novel orthogonal frequency division multiplexing (OFDM) modulation scheme based on discrete Hartley transform (DHT) combined with optical spatial modulation (OSM) is proposed for visible light communication (VLC) systems. In the proposed scheme, the function of the conventional discrete Fourier transform (DFT) is fulfilled by the DHT and real constellation schemes such as binary phase...
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