This paper presents an experimental evaluation of open-loop precoding MIMO (multipleinputmultipleoutput) using a testbed targeted at IMT-Advanced systems. Open-loop MIMO is realized by applying Rotational OFDM (R-O...
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ISBN:
(纸本)9781424426430
This paper presents an experimental evaluation of open-loop precoding MIMO (multipleinputmultipleoutput) using a testbed targeted at IMT-Advanced systems. Open-loop MIMO is realized by applying Rotational OFDM (R-OFDM), that is previously proposed by authors, to MIMO transmission. MIMO R-OFDM is more robust with respect to correlated channels than conventional open-loop MIMO-OFDM, because it optimizes the distances between the constellation points using simple phase rotation. The angle of phase rotation depends on the modulation orders and coding rate, hence the receiver does not need to feed the CSI (Channel State Information) back to the transmitter. In this paper, MIMO R-OFDM is implemented in a testbed targeted at IMT-Advanced systems, it is then evaluated experimentally and by computer simulations. The results of the evaluation reveal that MIMO R-OFDM is effective in correlated channels, and the gain in terms of the CIR (Carrier to Interference Ratio) with respect to conventional MIMO OFDM to achieve PER (Packet Error Rate) = 0.01 is about 1.5 dB when MIMO R-OFDM is used in correlated channels.
In this paper, a stub-loaded 2-port MIMO antenna is introduced for applications across the n77 (3.30-4.20 GHz), n78 (3.30-3.80 GHz), n79 (4.40-5.00 GHz), Wi-Fi-5 (5.15-5.85 GHz), and 7-7.83 GHz bands. It comprises a m...
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ISBN:
(纸本)9798350391558;9798350379990
In this paper, a stub-loaded 2-port MIMO antenna is introduced for applications across the n77 (3.30-4.20 GHz), n78 (3.30-3.80 GHz), n79 (4.40-5.00 GHz), Wi-Fi-5 (5.15-5.85 GHz), and 7-7.83 GHz bands. It comprises a microstrip line feed, a two-port stub-loaded MIMO antenna, and an FSS (frequency selective surface) filter. The antenna designed with dimensions of 37.5 x 32 mm(2) on an FR-4 epoxy substrate PCB with a thickness of 1.6 mm. The FSS structure contains 16 circular vertex square- shaped unit cells arranged in a 4x4 array, with a size of 50 x 50 x 1.6 mm(3), and due to stub and FSS loading, gain, bandwidth, and isolation improved significantly. The design process utilizes the ANSYS HFSS tool, and the antenna operates within the frequency ranges of 3.36-5.76 GHz and 7-7.83 GHz. Moreover, the isolation value achieves a minimum of -18 dB and -15 dB for nearly simulated and measured results across the entire band. Peak gain reaches a maximum of 6 dBi and a minimum of 3.35 dBi due to FSS loading. Radiation patterns exhibit high directivity at lower and higher frequencies and nearly omnidirectional behavior at middle frequencies, attributed to the passband filter characteristics of the FSS. The MIMO diversity parameters ECC and CCL are verified to be within acceptable limits. This innovative antenna can envisaged for sub-6 GHz band 5G applications.
Dynamic spectrum sharing in cognitive radio networks is an open research issue. This paper propose, a limited feedback opportunistic spectrum sharing (LFOSS) technique for heterogeneous multiple-input multiple-output ...
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ISBN:
(纸本)9783037851036
Dynamic spectrum sharing in cognitive radio networks is an open research issue. This paper propose, a limited feedback opportunistic spectrum sharing (LFOSS) technique for heterogeneous multiple-input multiple-output (MIMO) uplink system based on the concept learning automata. Simulation results show that our proposed algorithm can substantially improve the average mutual information of each secondary user under the interference temperature constraint and the maximum data substream constraint compared to the random selection scheme.
Grant-free non-orthogonal multiple access (GF-NOMA) based on multiple-input multiple-output (MIMO) has attracted much attention as a promising technique to support massive connectivity and bursty data transmission in ...
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ISBN:
(纸本)9798350387414
Grant-free non-orthogonal multiple access (GF-NOMA) based on multiple-input multiple-output (MIMO) has attracted much attention as a promising technique to support massive connectivity and bursty data transmission in massive machine-type communication. In this paper, we propose two compressed sensing based multiuser detection (MUD) algorithms for the MIMO-enabled GF-NOMA system. First, the spatially enhanced variational Bayesian inference (SE-VBI) algorithm is developed for MUD by exploiting the Gaussian mixture prior and diversity combining technique. Then, by applying the covariance-free (CoFe) strategy to the SE-VBI framework to estimate the diagonal elements of the posterior covariance, we propose a low-complexity MUD method named SE-CoFe-VBI. In particular, the proposed algorithms integrate the multivariate nature of the transmitted signal, i.e., discreteness, sparsity, and spatial correlation. Simulation results show that the proposed algorithms offer improved detection performance over the state-of-the-art spatially enhanced sparse Bayesian learning method.
This paper presents an area- and energy-efficient 4-lane far-end crosstalk (FEXT) cancellation wireline transceiver (TRX) with a multiple-input multiple-output (MIMO) discrete multitone (DMT) modulation. The channel e...
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ISBN:
(纸本)9798350330991;9798350331004
This paper presents an area- and energy-efficient 4-lane far-end crosstalk (FEXT) cancellation wireline transceiver (TRX) with a multiple-input multiple-output (MIMO) discrete multitone (DMT) modulation. The channel estimation (CHEST) is an essential block for DMT TRX to find the MIMO equalizer coefficients at the receiver (RX) side. However, due to the high computational complexity, the matrix inversion in CHEST hinders the generalization to larger MIMO, such as 4x4, considering circuit implementation. In this work, we show that CHEST can be effectively approximated to an element-wise reciprocal instead of an inversion when some properties of the wireline channels are used as constraints. This approximation also simplifies the MIMO equalizer circuit and realizes a decentralized MIMO. Simulation results demonstrated that the FEXT noise from adjacent lanes is sufficiently canceled out even with our approximated CHEST and MIMO equalizer, achieving a symbol error rate (SER) of 2E-4 for communicating over a channel exhibiting insertion loss (IL) of 16 dB and 17 dB of IL-to-crosstalk ratio at Nyquist, while showing SER of 1e-1 when the FEXT is not canceled.
Several applications need imaging sensors for environmental monitoring which can continuously observe an area in a 24/7 mode independently from the weather and other atmospheric obscuration like dust and smoke. Imagin...
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ISBN:
(纸本)9781424495665
Several applications need imaging sensors for environmental monitoring which can continuously observe an area in a 24/7 mode independently from the weather and other atmospheric obscuration like dust and smoke. Imaging MIMO radar fulfills these requirements and enables the opportunity of low-cost and robust imaging systems by synthesizing many virtual antennas out of just a few real ones. MIRA-CLE is a fully configurable and expandable experimental MIMO radar in Ka-band while MIRA-CLE X works in X-band and is intended to be a low-cost experimental system for long range applications. This paper presents both MIMO radar systems and shows and discusses first imaging results of MIRA-CLE X.
This paper studies the performance of transmit antenna selection algorithms in spatially correlated fading MEMO channels. The antenna subset is selected based on maximizing the channel capacity. A novel method is prop...
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ISBN:
(纸本)9781424436927
This paper studies the performance of transmit antenna selection algorithms in spatially correlated fading MEMO channels. The antenna subset is selected based on maximizing the channel capacity. A novel method is proposed to select the optimum set of transmit antennas based on the upper bound on the mean channel capacity. The proposed method based only on the fading correlation and not the instantaneous channel realization. And also its computational complexity is low and tends to be realized. The simulation results show that antenna selection of transmitter can increase the channel capacity of MIMO system by 1 bit/s in a flat fading environment with a rank deficient channel.
A novel scheme of the Frequency-Modulated Continuous-Wave Synthetic Aperture Radar (FMCW SAR) with multiple orthogonal transmitted waveforms is introduced in this paper. Based on the Interleaved Orthogonal Frequency D...
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ISBN:
(纸本)9781479921867
A novel scheme of the Frequency-Modulated Continuous-Wave Synthetic Aperture Radar (FMCW SAR) with multiple orthogonal transmitted waveforms is introduced in this paper. Based on the Interleaved Orthogonal Frequency Division multiplex (I-OFDM) principle, the transmit waveform successfully combines the advantages of the linear frequency modulated waveform and the OFDM waveform. This maintains FMCW SAR system smart and miniature, with lower cross correlation and higher coherence. Instead of band pass filter for traditional frequency division waveform, the division of the novel waveform is performed efficiently by the demodulation using discrete Fourier transform. At last, to verify the novel scheme, a simulation of imaging of one point is performed with two transmit waveform.
This paper analyzes the reception performance of the double space-time transmit diversity (DSTTD) with spatial modulation (SM) in vehicle-to-vehicle (V2V) channel. The DSTTD-SM scheme improves the performance of spect...
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ISBN:
(纸本)9781467388016
This paper analyzes the reception performance of the double space-time transmit diversity (DSTTD) with spatial modulation (SM) in vehicle-to-vehicle (V2V) channel. The DSTTD-SM scheme improves the performance of spectral efficiency and reception in V2V environments. The conventional multi-input multi-output (MIMO) schemes are also analyzed in the view of the antenna correlated channel and the spectral efficiency. And the simulation results shows DSTTD-SM scheme has better performance than conventional MIMO schemes in V2V channels which have Rician channel properties with correlation between transmit antennas and Doppler effects.
Visible light communication (VLC) is a promising technique in future networks due to its advantages of high data rate and licensed-free spectrum. In this paper, we apply the non-orthogonal multiple access (NOMA) techn...
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ISBN:
(纸本)9781728111902
Visible light communication (VLC) is a promising technique in future networks due to its advantages of high data rate and licensed-free spectrum. In this paper, we apply the non-orthogonal multiple access (NOMA) technique to improve the achievable sum rate of multipleinputmultiple-output (MIMO)-based multi-user visible light communication (VLC) systems. To ensure efficient and low complexity power allocation in indoor MIMO-NOMA-based VLC systems, a normalized gain difference power allocation (NGDPA) method is first proposed by exploiting users' channel conditions. We investigate the performance of an indoor 2x2 MIMO-NOMA based multi-user VLC system through numerical simulations. The obtained results show that the achievable sum rate of the 2x2 MIMO-VLC system can be significantly improved by employing NOMA with the proposed NGDPA method. It is demonstrated that NOMA with NGDPA achieves a sum rate improvement of up to 29.1% compared with NOMA with the gain ratio power allocation method in the 2 x 2 MIMO-VLC system with three users.
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