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Multiple input, Multiple output space time spreading (MIMO STS) system is a scheme which can provide full diversity gain without extra resource requirements. However, its performance degrades significantly when multiple access interference (MAI) occurs. In order to mitigate MAI effects, we propose a criterion to build a promising set of combination of spreading sequences for users. Simulation results...
Massive multi-input multi-output (MIMO) system adopting large amount of antennas is a promising technique to improve spectral efficiency and energy efficiency for next generation wireless communication systems. However, the power consumptions of the radio frequency (RF) chains can be huge, which poses great challenges. In this paper, we consider the problem of transmit RF chain configuration with...
This paper focus on Space-Shift-Keying (SSK) modulation with polarization diversity for multiple-input multiple-output (MIMO) channels. The proposed scheme make use of dual polarized antenna array in SSK-MIMO wireless system to improve the system performance under LOS channel conditions, where high correlation is accounted between the wireless links. The main motivation behind the proposed scheme...
In this paper, we have analyzed the spatial correlation statistics of different antenna polarization setups for uniform linear and circular antenna arrays. We have compared correlation statistics of different MIMO orders. We are motivated to understand pair-by-pair correlation behavior of MIMO channel as it plays a vital role in defining the channel spectral efficiency. We have further evaluated the...
The paper proposes the MIMO waveforms consisted of Doppler-offset orthogonal complementary codes (DO-OCC) for realizing high update rate MIMO system. The DO-OCC waveforms have low cross-correlation among multiplexed waves and low autocorrelation peak side-lobe level (PSL) even in a channel fluctuation condition. Computer simulation and experimental measurements have been done for verification. Consequently,...
Singular-value decomposition (SVD)-based multiple-input multiple-output (MIMO) systems have attracted a lot of attention in the wireless community where the whole MIMO channel is decomposed into a number of unequally weighted independent single-input single-output (SISO) channels. The unequal weighting of the SISO channels has led to intensive research on bit- and power allocation even in MIMO channel...
The goal of the study presented in this paper is to investigate the performance of a new transmission strategy for MIMO-WCDMA networks operating in spatial multiplexing transmission mode, based on Principal Component Analysis (PCA) at the reception. In this context, all individual multipath components are first processed by a space — time RAKE receiver, and then PCA is employed on the received data...
In this paper, we investigate the performance of the point-to-point multiple-input-multiple-output (MIMO) systems in the presence of a large but finite numbers of antennas at the transmitters and/or receivers. Considering the cases with and without hybrid automatic repeat request (HARQ) feedback, we determine the minimum numbers of the transmit/receive antennas which are required to satisfy different...
The influence mechanism of antenna polarization on channel response is studied, and a modified multiple-input multiple-output (MIMO) channel model including polarization effect is constructed. Some new exact expressions of signal power and spatial correlation coefficient are derived, which include the effect of polarization. The MIMO channel capacity with polarization in different conditions is also...
In this paper, we propose a frequency coding waveform with segment linear frequency modulation (LFM) signal for the multiple-input multiple-output (MIMO) radar. This new waveform is modified from the discrete frequency coding waveform with LFM (DFC-LFM) by changing the subpulse from the LFM signal to segment LFM and extending the contiguous waveform to a pulse train. Compared to the existing frequency...
Space hopping is a transmission scheme that emits wireless signals by rapidly switching transmit antennas according to the space hopping pattern. This paper proposes a transmission focusing based space hopping technique which aims at improving communication security by exploiting spatial resources sufficiently. More specifically, the legitimate user first transmits a training signal. Then the transmitter...
The novelty of Multiple-Input Multiple-Output (MIMO) radar can effectively improve radar system performance by utilizing the multi-antennas and orthogonal signals. While the traditional single sequence can't keep the complete orthogonality (the sidelobes of the auto-correlation and cross-correlation function equal to zero at all delays). The expression of ambiguity function of complete complementary...
Coincidence imaging radar (CIR) can achieve super-resolution in real aperture staring radar imagery by employing temporal-spatial independent array detecting (TSIAD) signals. The characteristics of TSIAD signals are determined by the random signal waveform and the array geometry, and the imaging performance is influenced by the relative imaging position with respect to the antenna array. In this paper,...
We consider in this work the Distributed Channel State Information (DCSI) Broadcast Channel (BC) setting, in which the various Transmitters (TXs) compute elements of the precoder based on their individual estimates of the global multiuser channel matrix. Previous works relative to the DCSI setting assume the estimation errors at different TXs to be uncorrelated, while we consider in contrast in this...
This paper proposes an open-loop correlation reduction precoding scheme for overloaded multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. In overloaded MIMO-OFDM systems, frequency diversity through joint maximum likelihood (ML) decoding suppresses performance degradation owing to spatial signal multiplexing. However, on a line-of-sight (LOS) channel,...
The performance of an underlay cognitive (secondary) dual-hop relaying system with multiple antennas and hardware impairments at each transceiver is investigated. In particular, the outage probability of the end-to-end (e2e) communication is derived in closed-form, when transmit antenna selection with maximum ratio combining (TAS/MRC) is established in each hop. The practical scenario of spatial correlation...
Spatial Modulation is a new transmission mode which increases spectral efficiency by employing information-driven transmit antenna selection. This performance is realized at a reduced hardware complexity and cost because only a single radio-frequency transmit chain is necessary. A measurement campaign is performed to assess the characteristics of spatial modulation over a body-centric communication...
Multiple-input multiple-output (MIMO) systems can provide a noticeable improvement in channel performance. Nevertheless some perturbances affect the capability of this technique to get the expected improvement. Due to the use of multiple antennas at the same front-end and their close spacing the so called antennas correlation effect appears. Antennas correlation can drastically affect the channel...
This work studies the dependency of MIMO performance figures on two characteristic multipath cluster parameters, the innercluster Angular Spread of Arrival (ASA) and the number of clusters. Both these parameters play a vital role in geometric based stochastic channel models as from the WINNER or COST families. Our motivation to the study these parameters is two-fold. First, we study their impact on...
In this paper, a novel Ultra-Wideband and High-Frequency (UWHF) channel modeling is proposed for the next generation wireless communications e.g., 5G. The novel channel modeling is proposed based on the Ultra-Wideband (UWB) channel model and channel measurement results at high-frequency (28GHz and 73GHz) in real scenarios. In specific, the novel channel modeling method aims at accurately describing...
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