In this paper, we propose a novel pilot-aided phase and channel estimation algorithm for coherent mode-division multiplexing multiple-input multiple-output free-space optical communication system. This algorithm enabl...
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In this paper, we propose a novel pilot-aided phase and channel estimation algorithm for coherent mode-division multiplexing multiple-input multiple-output free-space optical communication system. This algorithm enables the implementation of advanced multiple-input multiple-output decoders, leading to a significantly better bit error rate performance. This algorithm also supports phase-asynchronous light sources at each transmit and receive channel, significantly reducing the hardware requirements. Moreover, it has low computational complexity and Cram & eacute;r-Rao lower bound approaching estimation performance. In our proof-of-concept experiment, we employed 10 decorrelated channels to achieve a record-high 689.2 Gbit/s/wavelength line rate in strong turbulence, verifying the feasibility of our phase and channel estimation algorithm.
This paper presents a time-domain adaptive algorithm designed to eliminate harmonics in a multiple-input multiple-output (MIMO) system, taking into account its coupling characteristics. The algorithm is an improvement...
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This paper presents a time-domain adaptive algorithm designed to eliminate harmonics in a multiple-input multiple-output (MIMO) system, taking into account its coupling characteristics. The algorithm is an improvement over the X-filtered LMS (FxLMS) algorithm, and is specifically tailored to the triaxial vibration system. The proposed algorithm has been shown to achieve high convergence, even in the presence of identification errors, as confirmed through both theoretical derivation and numerical simulations. To validate the efficacy of the proposed MIMO harmonic cancellation algorithm, it was tested on a genuine triaxial vibration system. The experimental results clearly demonstrate that the algorithm effectively reduces the output harmonic disturbance of the three axes' frequency components.
It is well-known that the availability of transmit and receive arrays in colocated multiple-input multiple-output radar systems can be exploited to detect multiple targets, and estimate their range and angular coordin...
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It is well-known that the availability of transmit and receive arrays in colocated multiple-input multiple-output radar systems can be exploited to detect multiple targets, and estimate their range and angular coordinates. Unluckily, the accuracy achieved in the estimation of target parameters can be severely affected by hardware nonidealities. The impact of these nonidealities can be mitigated through the adoption of specific methods explicitly developed to estimate and compensate for them, i.e., briefly, of calibration methods. As far as we know, until now, most of the calibration techniques proposed in the technical literature for colocated multiple-input multiple-output radars are based on the idea of placing one or more reference targets in front of the considered radar device at perfectly known and fixed locations, and quantifying the difference between the expected radar image and the measured one. In this manuscript, two novel calibration methods are proposed. Both exploit the measurements captured by a colocated multiple-input multiple-output radar device at multiple positions;for this reason, the acquisition of such measurements involves the movement of the radar. The first one does not require any knowledge about the nature, number, position or radar cross section of the reference targets, provided that all these are in far-field;the second one, instead, needs a single reference target in near-field conditions, with the only constraints for it to be pointwise and isolated from stray targets in the range domain. This drastically simplifies the experimental setup to be employed for radar calibration. The proposed methods are tested on a commercial radar device and compared with a traditional method for radar calibration.
With the tremendous increase in wireless user traffic, investigation on the end-to-end reliability of wireless networks in practical conditions such as non-homogeneous fading channel conditions is becoming increasingl...
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With the tremendous increase in wireless user traffic, investigation on the end-to-end reliability of wireless networks in practical conditions such as non-homogeneous fading channel conditions is becoming increasingly widespread. Because they fit well to the experimental data, generalized channel fading distributions like kappa-mu, are well suited for modeling diverse fading channels. This paper analyzes the symbol error rate (SER) and outage probability (OP) performance of multiple-input multiple-output (MIMO) space-time block-code (STBC) selective decode and forward (S-DF) network over kappa-mu, fading channel conditions considering the additive white Gaussian noise (AWGN). First, the closed-form (CF) analytical expressions for the probability density function (PDF) and the cumulative distribution function (CDF) of the received signal-to-noise ratio (SNR) as well as its moment generating function (MGF) are derived. Second, the OP performance is then investigated for various values of the channel fading parameter and SNR regimes. The simulation findings show an increase in SER performance with an improved line-of-sight (LOS) component. Furthermore, the results show that the S-DF relaying systems can function properly even when there is no fading or LOS component. The OP has been increasing with the increase in the value of mu and kappa. In medium and high SNR regimes, simulation results exactly match with analytical results.
The identification capacity region of the compound broadcast channel is determined under an average error criterion, where the sender has no channel state information. We give single-letter identification capacity for...
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The identification capacity region of the compound broadcast channel is determined under an average error criterion, where the sender has no channel state information. We give single-letter identification capacity formulas for discrete channels and multiple-input multiple-output Gaussian channels under an average input constraint. The capacity theorems apply to general discrete memoryless broadcast channels. This is in contrast to the transmission setting, where the capacity is only known for special cases, notably the degraded broadcast channel and the multipleinputmultiple-output broadcast channel with private messages. Furthermore, the identification capacity region of the compound multiple-input multiple-output broadcast channel can be larger than the transmission capacity region. This is a departure from the single-user behavior of identification, since the identification capacity of a single-user channel equals the transmission capacity.
Inverse design has been applied to a variety of complex electromagnetic structures including multifunctional and multiple-input multiple-output (MIMO) devices, where analytical design methods are limiting. We have pre...
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ISBN:
(纸本)9781733509671;9798350362978
Inverse design has been applied to a variety of complex electromagnetic structures including multifunctional and multiple-input multiple-output (MIMO) devices, where analytical design methods are limiting. We have previously reported on the inverse design of single-input, single-output Perfectly-Matched Metamaterials (PMMs). PMMs are inhomogeneous, anisotropic 2D metamaterials composed of unit cells that remain impedance-matched to each other and the surroundings under all excitations. PMMs rely primarily on refractive effects and exhibit broadband operation. This work presents the inverse design of a compact MIMO device based on PMMs: a 2D beamformer with prescribed amplitude and phase profiles that exhibits zero scan loss.
This letter experimentally demonstrated the performance improvement of orbital-angular-momentum (OAM) based 2 x 2 MIMO communication by using the diversity of different OAM modes. The OAM antenna we used is an eight-a...
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This letter experimentally demonstrated the performance improvement of orbital-angular-momentum (OAM) based 2 x 2 MIMO communication by using the diversity of different OAM modes. The OAM antenna we used is an eight-arm Archimedean spiral antenna (ASA) capable of generating multiple high-quality OAM vortex waves individually or two types of two-mode mixed vortex waves simultaneously. Both of the two cases are investigated for MIMO communication by evaluating the throughput performance. For MIMO with two OAM modes (generated by two ASAs separately), the throughput improves upon traditional MIMO by up to 30.50%, while for MIMO with two-mode mixed vortex waves (generated by one ASA), 6.59% throughput improvement is obtained.
multiple-input multiple-outputs (MIMOs) have eminent quality in maximizing the throughput of wireless communication models. In MIMO, the antenna arrays can be utilized for fulfilling the needs of 5G by utilizing vario...
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multiple-input multiple-outputs (MIMOs) have eminent quality in maximizing the throughput of wireless communication models. In MIMO, the antenna arrays can be utilized for fulfilling the needs of 5G by utilizing various spatial signatures of users. Even though 5G communication is imminent, there exist issues, like network interference that arise due to reused frequency spectrum resources. This delving presents an optimized deep model for suppressing interference occurring in the Rayleigh channel in the multiple-user MIMO (MU-MIMO) model. Here, an MU-MIMO model is employed with correlated interference wherein there exist various users around the base station (BS) with several antennas at the transmitter and receiver. Here, a deep neuro-fuzzy network (DNFN) is used to upgrade the performance of detectors underneath correlated interference. Here, the model comprises zero forcing-maximum likelihood detection (ZF-MLD) that assists to generate an initial estimate of broadcasted signals in a particular time slot. The DNFN is used to capture latent correlation among several symbols. Here, the DNFN training is performed using developed autoregressive Henry gas spider monkey optimization (RHGSMO), which is the combination of conditional autoregressive value at risk (CAViaR), Henry gas solubility optimization (HGSO), and spider monkey optimization (SMO). With the lowest symbol error rate (SER), bit error rate (BER), and signal to interference and noise ratio (SINR), the suggested RHGSMO-based DNFN performed better than existing approaches.
A nonlinear adaptive multiple-input multiple-output (NAMIMO) controller is designed to control a super capacitor compensation inverter. The proposed controller effectively suppresses the effects of impact loads from n...
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A nonlinear adaptive multiple-input multiple-output (NAMIMO) controller is designed to control a super capacitor compensation inverter. The proposed controller effectively suppresses the effects of impact loads from natural gas generation systems. In this paper, the transient current model of the compensation system is transformed into the power model using transient power theory, and then a direct power control algorithm with a vector control strategy is designed based on the whole power model. The proposed strategy can not only effectively suppress the impact of impact loads on the system but also maintain the stability of the microgrid to a certain extent. Meanwhile, the PLL control structure is replaced by an adaptive algorithm, which not only solves the system instability problem but also improves the dynamic response of the compensation system. In addition, the functional advantages, the frequency is bounded and stable throughout the whole process, and this differential frequency modulation allows the compensation system to exit the compensation smoothly. Finally, the simulation and experimental results on a 600 kW natural gas generator demonstrate that the proposed compensation strategy and control algorithm can effectively suppress the impact load effects.
This paper proposes two flexible ultra-wideband (UWB) multiple-input multiple-output (MIMO) slot antennas with connected ground and high isolation. Two MIMO antennas consist of two parallel slot antenna elements with ...
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This paper proposes two flexible ultra-wideband (UWB) multiple-input multiple-output (MIMO) slot antennas with connected ground and high isolation. Two MIMO antennas consist of two parallel slot antenna elements with coplanar waveguide feeds and ground. The antennas are etched on the liquid crystal polymer substrate and have the consistent sizes of 30 x 56 x 0.1 mm(3). The first UWB-MIMO antenna can cover 3-13 GHz. By adding a U-shaped slot on the first antenna, a second UWB-MIMO antenna with a notch-band is designed, which can work in 3.2-13 GHz and filter the wireless fidelity frequency band (5-6 GHz). High isolation better than 20 dB is obtained by adding fence-shaped branches. In addition, the performance of the flexible MIMO antenna is analyzed, including diversity performance parameters such as envelope correlation coefficient, diversity gain, gain, and total active reflection coefficient. The proposed UWB-MIMO antenna can be applied in internet of things and wireless body area network frequency bands.
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