Efficiency Of MIMO System Research Articles

Research of antenna complexes using chiral metamaterials and fractal geometry of radiators for MIMO systems

This article is devoted to the study of the possibilities of increasing spectral efficiency in MIMO systems by using antennas with substrates of biisotropic and bianisotropic chiral metamaterials and various types of fractal emitters, in particular, fractal structures in the form of a Sierpinski triangle, Koch and Gilbert curves, as well as a dipole triangular antenna of complex configuration FRM. The spectral efficiency was calculated by using one of the variations of the Shannon formula, which includes a complete matrix of Z-parameters. In turn, this matrix was determined using the software package of electrodynamic modeling. It is shown that the use of such antennas with the fractal geometry of the emitters located on chiral substrates reduces the mutual influence between the emitters, and, in turn, increases the spectral efficiency in several frequency ranges compared to traditional solutions.

Invited Paper: Antenna selection in energy efficient MIMO systems: A survey

With the explosive growth and need for high-speed wireless communications, more and more energy is consumed to support the required quality of service. Therefore, energy efficient or green communication has become a very hot topic under the ground of limited energy resource and environmentally friendly transmission schemes. MIMO technique is capable of reducing the transmission power thanks to its diversity and multiplexing gain. Moreover, antenna selection (AS) is an alternative to extract many of the benefits in MIMO systems with a reduced cost of complexity and power. Although many works including several survey papers have investigated AS in MIMO systems, the goal of these works is only the capacity maximization or error rate minimization, which fails to guarantee the optimality of the energy efficiency in MIMO systems. In this paper, we overview the state of the art in the AS schemes in energy efficient MIMO systems, the goal of which is to optimize the energy efficiency of the whole system. Specifically, we introduce energy efficient AS in point-to-point MIMO, cooperative MIMO, multiuser MIMO and largescale MIMO systems, respectively. Several challenging and practical issues in this area are also addressed.

Spectral Efficiency in MIMO Systems Using Space and Pattern Diversities Under Compactness Constraints

The aim of this paper is to evaluate the performance of multiple-input-multiple-output (MIMO) systems using multimode patch antennas as basic elements. The focus is compactness in the antenna design and suitability for being deployed in relatively small terminals. To this purpose, the performance in terms of spectral efficiency of a MIMO system with small multimode patch antennas on the terminal side is presented. We assume no knowledge of the channel at the transmitter and perfect channel knowledge at the receiver. Several multielement multimode-antenna scenarios are compared to alternative scenarios with single-mode antennas.

Compact Multimode Patch Antennas for MIMO Applications [Wireless Corner

This work presents the design of compact multimode patch antennas for application in medium-size MIMO terminals combining spatial and radiation-pattern diversity. This design was inspired by previous work, which proposed the use of patch antennas providing two services at two frequency bands that required different radiation patterns. These precedents are briefly reviewed, before extending the concept of the dual-pattern two-frequency case to one in which diversity is demanded at a single frequency. A design with three modes at a single frequency is also accomplished. Some prototypes have been manufactured and measured. An example of the advantages of using these multimode antennas in terms of spectral efficiency in MIMO systems is also included. The key aspect of this work is the use of short-circuited ring patch (SCRP) antennas.