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This paper presents a statistical block fading channel model for multiuser massive MIMO system. The proposed channel model acts as correlation based stochastic channel model (CBSCM) to simulate correlation in time/frequency and simultaneously captures spatial variations as geometry based stochastic channel model (GBSCM), using three controlling parameters: one parameter describes variation in channel...
We examine the deployment of a large multi-user multiple-input multiple-output (MIMO) system and the resulting Energy Efficiency (EE) considering a 2D rectangular array with increasing antenna elements within a fixed physical space. The resulting increasing mutual coupling and correlation among the base station (BS) antennas are incorporated by deriving a practical mutual coupling matrix which considers...
Non-contact devices for monitoring signs of life have attracted a lot of attention in recent years for applications in security, emergency and disaster situations. Current devices however, generally utilize bespoke active systems to transmit large bandwidth signals. In this paper, a real-time phase extraction method based on passive Wi-Fi radar is proposed for detecting the chest movements associated...
A general framework for the analysis of expected per-user signal-to-interference-plus-noise-ratio (SINR) of a multiuser multiple-input-multiple-output system is presented. Our analysis assumes spatially correlated Rayleigh fading channels with regularized zero-forcing precoding on the downlink. Unlike previous works, our analytical expressions are averaged over the eigenvalue densities of the complex...
For 5G it will be important to leverage the avail- able millimeter wave spectrum. Communication at high carrier frequencies requires antenna arrays at both the base and mobile station. A 1-bit analog to digital converter can effectively reduce the complexity and power consumption of the analog frontend. This is especially interesting in the context of large antenna arrays with a sizable signal bandwidth...
The recent hot research topic of a massive multiple-output (MIMO) has been primarily studied based on the assumption that channel vectors are asymptotically pairwise orthogonal. This condition is not exactly satisfied in practice. Correlation will occur among antenna elements at the base- station antenna array in a dense scattering environment, or in a LOS propagation condition. In this paper, by...
In this paper, a gradient descent method is used to build radar waveform sequences with good autocorrelation and/or cross-correlation. The approach we propose is based on the energy, a function that measures the sidelobe level of a sequence, and its gradient. Then, we extend and apply it to the optimization of the coherent MIMO (Multiple Input Multiple Output) ambiguity function. We suggest to look...
Improving antenna arrays characteristics such as power consumption, cost and complexity has gained wide attention in the context of cognitive radio networks. One antenna array configuration that offers great potential is the electronically-steerable parasitic array radiator (ESPAR) antenna. In this paper, we propose a transmitter patch ESPAR antenna system for underlay spectrum sharing in cognitive...
This paper summarizes the influence of many parameters on the keyhole probability of a 2×2 MIMO-OFDM train-to-wayside communications system on a tunnel. These parameters are the separation of the antennas within the array, polarization and the cross-section of the tunnel. Results in terms of capacity and keyhole probability are provided. Measurements were carried out on Metro de Madrid (Spain) on...
The noise correlation matrix and noise parameters are parameters of interest for antennas, and antenna arrays, particularly in the radio-astronomy context. For a passive network, such as an antenna, 2-port scattering parameters can be used to establish a noise correlation matrix and consequently the antenna noise parameters. In this paper we show how the 2-port scattering parameters of an antenna...
This paper presents a 3-D statistical channel model of the impulse response with small-scale spatially correlated random coefficients for multi-element transmitter and receiver antenna arrays, derived using the physically-based time cluster - spatial lobe (TCSL) clustering scheme. The small-scale properties of multipath amplitudes are modeled based on 28 GHz outdoor millimeter-wave small-scale local...
In this paper, minimum redundancy multiple-input multiple-output (MR-MIMO) arrays - a class of thinned antenna arrays - are discussed. The concepts of MR-MIMO array design and almost difference sets (ADSs) are introduced, and an analytical method based on ADSs is proposed for MR-MIMO array designs. This method can quickly determine the locations of MR-MIMO arrays and require little computational cost...
This paper explores optimal array beamforming for establishing secret encryption keys through bidirectional channel estimation in multipath propagation environments. The problem is cast as a convex optimization of the average secure key rate achieved in the presence of a passive eavesdropper, and the optimization is performed using semi-definite programming. Representative results demonstrate that,...
Advanced method of inner calibration of individual receive modules of active phased antenna arrays (APAA) in synthetic aperture radar (SAR) is discussed. This method allows fast and accuracy amplitude and phase characterization of every receive modules and uses pseudo-noise sequences as core of calibrating sequences system. Decorrelation method of cancelling mutual interference using simple matrix...
This paper focuses at the investigation of the degree of orthogonality of channels of multiple users in densely populated indoor and outdoor scenarios. For this purpose, a statistical millimeter wave (mmwave) MIMO channel simulator is carefully designed using state of the art channel models. At the mmwave frequencies, human/vehicular mobility around the mobile users may partially or completely block...
Channel estimation and beam training can be a source of significant overhead in establishing millimeter wave (mmWave) communication links, especially in high mobility applications like connected vehicles. In this paper, we highlight the opportunities and challenges associated with leveraging channel state information acquired at a lower frequency as a form of side information on a higher frequency...
Blockage by human body is a severe challenge to enabling robust 60 GHz directional links. Beam-steering may overcome this problem by electronically steering the signals, thus creating detour paths. However, effectiveness of beam-steering depends on the link's deployment location and the reflection characteristics of surrounding environment. An arbitrarily deployed link may suffer from complete black-out...
Massive MIMO is considered a key technology for the future wireless communication systems. The promising properties in terms of higher spectral and transmit-energy efficiency are brought by the large number of antennas at the base station(BS). As the number of antennas increases, the aperture of the BS antenna array may become much larger, as compared to today's antenna arrays. In this case, mobile...
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...
This paper presents a new design for a multiband sensing MIMO antenna system that can be used in cognitive radio communication for a mobile platform. The antenna system consists of two identical small-size multiband antennas with dimensions 29.5 × 17 × 5 mm3 and each of them is comprised of a driven strip monopole and a coupled parasitic shorted strip. These antennas are located diagonally to limit...
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