Abstract magnified image This article reviews recent developments in nanowire‐based photovoltaics (PV) with an emphasis on III–V semiconductors including growth mechanisms, device fabrication and performance results. We first review the available nanowire methods followed by control of direction crystal structure. Important issues are reviewed, optical absorption, carrier collection, strain accommodation, design for high efficiency, tunnel junctions, Ohmic contact formation, passivation...

In multiple-input multiple-output (MIMO) multiuser detection theory, the QR decomposition of channel matrix H can be used to form back-cancellation detector. this paper, we propose an optimal decomposition, which call equal-diagonal or briefly QRS decomposition. We apply precoded successive-cancellation detection, where assume that both transmitter and receiver have perfect knowledge. show that, for any H, there exists a unitary precoder S, such HS=QR, nonzero diagonal entries upper...

In this paper, an exact asymptotic pairwise error probability (PEP) is derived for a half-duplex cooperative system employing amplify-and-forward (AF) protocol. When compared with the PEP of traditional multiple-input multiple-output (MIMO) system, "diversity gain" no longer just simple exponential function signal-to-noise ratio (SNR), rather, it involves logarithm SNR. The term diversity gain used to designate characteristic PEP. coding gain, on other hand, found similar that MIMO and...

For distance protection, the measurement accuracy at boundary of protective zone is most important issue to distinguish internal faults from external correctly. Since line parameters depend strongly on frequencies, in order obtain high accuracy, it should be considered during initial fault transients generally associated with plentiful harmonics. In this paper, a protection method considering frequency-dependent introduced into HVDC transmission lines. According transmission-line equations,...

In this paper, joint direction-of-departure (DOD) and direction-of-arrival (DOA) estimation for bistatic multiple-input-multi-output (MIMO) radar in an unknown spatially correlated noise environment is investigated. The signal model based on the assumption that waveforms are transmitted by two separated subarrays having M <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> sensors received N...

In conventional multi-input multioutput (MIMO) visible light communication (VLC) techniques such as repetition coding (RC), spatial multiplexing (SMP), and modulation (SM), the transmitted symbols through different light-emitting diodes located space are usually generated from unipolar pulse amplitude constellations independently. this letter, we propose a novel constellation design for MIMO indoor VLC systems, in which two spaces collaborate so closely that average optical power is...

This paper presents a method for jointly designing the transmitter-receiver pair in block-by-block communication system that employs (intrablock) decision feedback detection. We provide closed-form expressions pairs simultaneously minimize arithmetic mean squared error (MSE) at point (assuming perfect feedback), geometric MSE, and bit rate of uniformly bit-loaded moderate-to-high signal-to-noise ratios. Separate apply "zero-forcing" "minimum MSE" (MMSE) structures. In MMSE case, proposed...

In this paper, a general criterion for space-time block codes (STBC) to achieve full diversity with linear receiver is proposed wireless communication system having multiple transmitter and single antennas [multiple-input-single-output (MISO)]. Particularly, the STBC Toeplitz structure satisfies criterion, therefore, enables diversity. Further examination of reveals following important properties: (1) symbol transmission rate can be made approach unity; (2) applying code any signalling...

Subspace-based high-resolution algorithms for direction-of-arrival (DOA) estimation have been developed large-scale adaptive antenna arrays. However, its prerequisite step, namely, source enumeration, has not yet addressed. In this paper, a new approach is devised in the framework of Bayesian information criterion (BIC) to provide reliable detection signal number general asymptotic regime, where m, n → ∞ and m/n c ∈ (0, ∞), with m being numbers antennas snapshots, respectively. particular,...

To enable ultrareliable low-latency wireless communications required in the Industrial Internet of Things, this paper we develop an energy-based modulation [i.e., non-negative pulse amplitude (PAM)] constellation design framework for noncoherent detection massive single-input multiple-output (SIMO) systems. We consider that one single-antenna transmitter communicates to a receiver with large number antennas over Rayleigh fading channel, and decodes transmitted information at end every...

We present time-of-flight inelastic neutron scattering measurements at low temperature on powder samples of the magnetic pyrochlore oxides ${\mathrm{Tb}}_{2}{\mathrm{Ti}}_{2}{\mathrm{O}}_{7}$ and ${\mathrm{Tb}}_{2}{\mathrm{Sn}}_{2}{\mathrm{O}}_{7}$. These two materials possess related, but different ground states, with ${\mathrm{Tb}}_{2}{\mathrm{Sn}}_{2}{\mathrm{O}}_{7}$ displaying ``soft'' spin ice order below ${T}_{\mathrm{N}}\ensuremath{\sim}0.87$ K, while enters a hybrid, glassy state...

In this work, we consider the problem of joint sparse array antenna design and phase-only beampattern shaping with reconfigurability. Our objective is to reduce cost system for unmanned aerial vehicle (UAV) radar a large-aperture array. We formulate co-design as optimization angular response binary-like modulus constraints. To solve resultant NP-hard nonconvex problem, propose consensus alternating direction method multipliers (ADMM) based algorithm. This transforms original into...

In this paper we consider coherent flat fading wireless communication systems with multiple transmitter antennas and single receiver antenna (MISO). We propose a Toeplitz linear space time block code (STBC) that converts an original MISO channel into virtual inputs outputs (MIMO) channel. show our proposed has the following main features: (a) The symbol transmission rate is (T-M + 1)/T, where M number of T uses (T > M). (b) Linear receivers (zero-forcing minimum mean square error) can...

In this paper, the ergodic channel capacities are established for amplify-and-forward (AF) half-duplex cooperative systems, which consist of a source node, destination, and multiple-relay nodes. The relay nodes assist transmission from node to destination. Since matrices systems involve product Gaussian random variables, no longer Gaussian, approach in obtaining capacity conventional multiple-input-multiple-output (MIMO) channels (Telatar, 1999) is not applicable. By using novel approach, we...

In this paper, we investigate the design of energy-efficient space-time modulation for peak-limited MISO broadcast visible light communication (VLC) systems by cooperatively managing non-negative multiuser interference. We first characterize a constellation-optimal structure that maximizes worst-case minimum Euclidean distance all users general design. It turns out optimal constellation can be constructed via spatial repetition multidimensional in time dimension over ideal additive white...

This paper investigates the artificial noise (AN) aided physical layer security (PLS) for energy-based massive multi-input multi-output multi-access channels with finite-alphabet data inputs, where both legitimate base station (Bob) and passive eavesdropper (Eve) are equipped large antenna arrays each user has multiple antennas. For such system, main challenge is how to allocate power between transmitted constellation of finite size AN interference management PLS enhancement. To this end, we...

In this paper, we propose a new sparse coprime array design that achieves higher number of degrees-of-freedom for direction-of-arrival (DOA) estimation. The proposed completely avoids lag redundancies between the two constituting subarrays array, thus achieving maximum unique correlation lags under framework. As result, given same physical sensors, resolves more sources than other designs with enhanced DOA estimation performance. Simulation results demonstrate superior performance design.

We formulate the blind fractionally spaced equalization (FSE) problem as one that minimizes a piecewise linear convex function subject to some constraints on equalizer parameters. show this formulation achieves both interference removal and carrier phase recovery when input signal possesses certain quadrature amplitude modulation (QAM) type symmetry. A fast programming implementation is presented solve minimization problem. Computer simulation results indicate new programming-based FSE able...