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We consider the downlink multi-user multi-cell massive MIMO systems, assuming that the number of antennas at base station (BS) and the number of users are large. Our system model accounts for channel estimation, pilot contamination, and uniformly random user location distribution. We derive the approximation of area spectral efficiency (ASE) with regularized zero-forcing (RZF) precoding technique...
In this paper, We present a MIMO bezel antenna design composed by a seamless double metal ring structure. The MIMO antenna mainly operates in the loop mode and can cover the majority of globe cellular bands. Good efficiencies (>-4dB) and a low envelope correlation coefficient (<0.5) are achieved, which ensure a good MIMO performance of our proposed antenna. Moreover, our antenna also performance...
This paper mainly focuses on the investigation of the body loss of beamforming mode in LTE MIMO mobile terminals with CTIA user effects. The research of the body loss and radiation efficiency is carried out over different phase differences between two ports of each MIMO antenna. During studies, four kinds of typical LTE MIMO antennas are used, namely, collocated ground free (GF), parallel GF, parallel...
Massive Multiple-Input Multiple-Output (MIMO) antenna arrays are being studied for 5G due to their ability to focus energy towards desired receiver, reducing interference to other users, giving rise to higher spectral and energy efficiencies. Conventional analysis assumes that the large scale fading component of the channel model is constant across the entire Massive MIMO antenna array. However, when...
Few technologies have achieved such worldwide success as mobile communications technology has over the last several decades. Mobile wireless communication is still evolving at a fast pace and continues to create new possibilities for daily application. As demand for more energy-efficient and faster mobile computing power grows, so does the need for transmission at high data rates, driven by users'...
The past decades' phenomenal and rapid growth in cell phone use and, more recently, in smartphone adoption is apparent to everyone. What has not be so clearly articulated is that underlying this growth is a larger growth in the demand for smartphone filters and duplexers. As a result of fourth-generation longterm evolution wireless technology (4G)-and in light of coming fifth-generation (5G) requirements-the...
In this paper, a non-stationary geometry-based scattering model for street wideband multi-input multi-output (MIMO) vehicle-to-vehicle (V2V) fading channel is proposed. It is assumed that the static scatterers on the both roadside are uniformly distributed on time-varying ellipses, and the mobile scatterers are uniformly distributed in time-varying segment of the road. To avoid complicated procedure...
With the rapid growth of global mobile data transmission, the conventional multiple-input multiple-output (MIMO) systems are not able to accommodate the increasing data demand. The massive MIMO has been proposed as one of the key technologies for the next generation wireless communication systems. Compared to the conventional MIMO systems, massive MIMO systems are advantaged in energy and spectral...
Multiuser multiple-input multiple-output (MU-MIMO) transmission technique based on orthogonal frequency division multiplexing (OFDM) system has been received great deal of attention in recent years due to its potential higher spectral efficiency. However, because of the coarse knowledge of channel state information at the transmitter (CSIT), co-scheduled mobile users may suffer large residual multiuser...
This paper considers millimeter-wave access network systems using a hybrid beamforming structure, which is a combination of digital and analog beamformers. To multiplex mobile stations in the frequency domain along with the space and time domain improves a system capacity for the following reasons: it exploits frequency diversity, accommodates mobile stations that can only use a limited bandwidth...
The most up-to-date application and many numbers of users need higher access speeds and lower latency of wireless communication. As a result, mobile companies need more capacity and higher efficiency to give the high quality service to the customers. LTE has been designed to get broader channels up to 20MHz, with low latency and packet optimized radio access technology. The peak data rate envisaged...
A novel design of a compact antenna array for MIMO (multiple input multiple output) communication systems is introduced for mobile applications, which require in particular a low profile of the antennas. The proposed antenna array can be integrated at the contour of mobile terminals. The antenna array operates in two frequency bands around 2.45 GHz and 5.5 GHz, corresponding to the WLAN (wireless...
This paper presents a polarization-controlled MIMO antenna to realize ultra high-speed and high-capacity mobile communications. The proposed antenna is comprised of three orthogonal dipoles, which can be controlled using a weight function created based on the variation of cross polarization power ratio (XPR) and the antenna inclination angle. By adjusting a phase shift between the antenna elements...
In this paper, a geometrical approach is presented to estimate locations of the last hop of multipath based on measurement data. Statistic characteristics of last hops can be used to generate spatially consistent channels which are required for 5G channel modelling. The measurement was conducted with a 28GHz wideband channel sounder in urban street environments. Results show that most last hops are...
A channel prediction based space-time code selection technique for multiple input-single output systems is proposed. This transmit antenna diversity technique selects both the space-time code and the number of transmitter antennas using estimated and predicted channel state information. Linear channel prediction, designed to be optimal in the mean-square sense, has been used. Simulation results show...
Analog network coding has been successfully employed in conventional two way relaying systems. However, analog two way relaying is successful when the two sender and destination nodes are symmetric. In practical cellular-based mobile communication systems of the likes of Long Term Evolution (LTE), the system is composed of several powerful base-stations and low power users' equipment. Applying classical...
The evolution to ever higher radio bandwidths and the massive introduction of new services and technologies in 5G networks, along with their challenging requirements in the time and frequency domain will warrant revisiting the present CPRI fronthaul approach.
Achieving an increase in the spectral efficiency (SE) has always been a major driver in the design of communication systems. The use of MIMO techniques in mobile communications has achieved significant benefits in improving the system throughput. The basic underlying concept of MIMO is to exploit the signal and channel characteristics to eliminate interference between multiple transmissions. Departing...
The next generation of digital terrestrial broadcasting systems using dual-polarized SDM-MIMO technology is under development. The reception deteriorates under an AWGN channel when the XPD for the SDM-MIMO system is low. We describe a method for inter-polarization spreading in the SDM-MIMO transmission system that compensates for the deterioration and our investigation of the reception in a computer...
Cloud-RAN is a novel architecture for LTE networks, where antennas with only limited processing capabilities are deployed in the field and all baseband and higher layer processing of the base stations is pooled in a central office. It has been shown that the centralization leads to multiplexing gains for signal processing hardware. When a system is able to efficiently cope with overload of the compute...
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