Preview

Mimo

Good Essays
Open Document
Open Document
544 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Mimo
MIMO IN WIRELESS COMMUNICATION

Wireless communication refers to the transfer of information between two or more points that are not physically connected. Distances between the two points can be short or as far as thousands or even millions of kilometers. Different ways can be used to establish wireless communication. Basically, antennas are used as transmitter and receiver in wireless communications like cellular telephones, satellite communications, radio broadcasting, etc. Despite many advantages of wireless communication there are many factors that affect the quality of wireless communication systems.
In urban and indoor environments, there are many obstacles between the clear line-of-sight (LOS) between transmitter and receiver. Instead the signal is reflected along multiple paths before finally being received. Each of these bounces can introduce phase shifts, time delays, attenuations, and distortions at the receivers. These destructively and constructively interfere with one another at receiving antenna degrading the quality of signal sent. Many researches have been done to mitigate this problem. One of the most prominent ways is to use MIMO techniques.
MIMO (Multiple Input and Multiple Output) is a technique in which multiple antennas are used both at the receiver and the transmitter for better communication performance.
In 1996, Greg Raleigh and Gerard J. Foschini refined new approaches to MIMO technology, considering a configuration where multiple transmit antennas are co-located at one transmitter to improve the link throughput effectively.
It is been said that MIMO offers significant increase in data throughput and quality without additional bandwidth or increased transmit power. It achieves this goal by spreading the same total transmit power over the antennas to achieve an array gain that improves the spectral efficiency (more bits per second per hertz of bandwidth) or to achieve a diversity gain that improves the link reliability. It

You May Also Find These Documents Helpful

  • Powerful Essays

    Sinemo

    • 5367 Words
    • 22 Pages

    This full text paper was peer reviewed at the direction of IEEE Communications Society subject matter experts for publication in the ICC 2007 proceedings.…

    • 5367 Words
    • 22 Pages
    Powerful Essays
  • Powerful Essays

    This full text paper was peer reviewed at the direction of IEEE Communications Society subject matter experts for publication in the IEEE ICC 2009 proceedings…

    • 4413 Words
    • 18 Pages
    Powerful Essays
  • Powerful Essays

    Wifi Technology

    • 1609 Words
    • 7 Pages

    Wi-Fi allows to connect to the internet from virtually anywhere at speeds of up to 54Mbps.The computers and handsets enabled with this technology use radio technologies based on the IEEE 802.11 standard to send and receive data anywhere within the range of a base station.…

    • 1609 Words
    • 7 Pages
    Powerful Essays
  • Powerful Essays

    (·)−1 is reserved for the matrix inverse and (·)H for Hermitian transposition. The estimated value of a variable a is…

    • 2012 Words
    • 9 Pages
    Powerful Essays
  • Powerful Essays

    Mimo

    • 4122 Words
    • 17 Pages

    Abstract— Multiple-input multiple-output (MIMO) wireless communication systems employ multiple transmit and multiple receive antennas to obtain significant improvement in channel capacity. However, the capacity is limited by the correlation of subchannels in non-ideal scattering environments. In this paper, we investigate MIMO systems that use antennas with dissimilar radiation patterns to introduce decorrelation, hence increasing channel capacity. We develop a ray tracing model that takes into account both the propagation channel and the transmit and receive antenna patterns. Using a computational electromagnetic simulator, we show that: (1) MIMO systems that exploit antenna pattern diversity allow for improvement over dual-polarized antenna systems; (2) The capacity increase of such MIMO systems depends on the characteristics of the scattering environment.…

    • 4122 Words
    • 17 Pages
    Powerful Essays
  • Good Essays

    When looking at radio applications, multiple-input and multiple-output (MIMO) is when multiple antennas are used at both the transmitter and receiver. This technology is useful in wireless applications because it significantly increases the data throughput and link range. The goal is to improve the wireless signal without requiring more bandwidth or power.…

    • 618 Words
    • 3 Pages
    Good Essays
  • Satisfactory Essays

    Mimo

    • 447 Words
    • 2 Pages

    The MIMO decoder implemented in this demo models a 4 transmit and 4 receive wireless system with BPSK modulation. The channel matrix G, whose elements Gij represents the amplitude distortion from the j-th transmit antenna to the i-th receive antenna, are real zero mean Gaussian variables with variance 1 per dimension. The channel matrix used in the demo is generated using the MATLAB® function randn() with a fixed seed initialized in the InitFcn Model callback function of the Model Properties.…

    • 447 Words
    • 2 Pages
    Satisfactory Essays
  • Powerful Essays

    tag to tag communication

    • 5352 Words
    • 22 Pages

    section”, IEEE Antennas and Propagation Society International Symposium, Jul. 1997, vol. 2, pp. 1172 - 1175…

    • 5352 Words
    • 22 Pages
    Powerful Essays
  • Powerful Essays

    LTE technology

    • 802 Words
    • 4 Pages

    we analyze the deployed Releases of Long Term Evolution (LTE) technology, their advantages and drawbacks. Based on the existing Releases, from 5 to 10 [1, 2], we put a question on how to integrate the advanced LTE technology and multiple-input-multiple-output (MIMO) system for multi-user (MU) multiple access deployment, which we call the Advanced LTE Release 10/MIMO network. We analyze this integrated network in order to increase the communication capacity. We take into account multi-parametric stochastic approach that combines the statistical description of the terrain and the built-up overlay with description of the signal intensity spatial distribution, taking into account the channel multipath effects from various natural and artificial obstructions located in the urban scene. The Rician K-parameter is used for multiplicative noise description, as a ratio of the coherent and incoherent components of the signal intensity [3]. Using the K-factor spatial distribution depending of the features of built-up terrain, an information data stream both for MIMO correlated antennas (the good case) and uncorrelated MIMO antennas (the worst case), as well as the capacity and spectral efficiency are predicted,…

    • 802 Words
    • 4 Pages
    Powerful Essays
  • Powerful Essays

    Mimo System

    • 16933 Words
    • 68 Pages

    - multiple-output (MIMO) systems are a natural extension of developments in antenna array communication. While the advantages of multiple receive antennas, such as gain and spatial diversity, have been known and exploited for some time [1, 2, 3], the use of transmit diversity has only been investigated recently [4, 5]. The advantages of MIMO communication, which exploits the physical channel between many transmit and receive antennas, are currently receiving significant attention [6–9]. While the channel can be so nonstationary that it cannot be estimated in any useful sense [10], in this article we assume the channel is quasistatic. MIMO systems provide a number of advantages over single-antenna-to-single-antenna communication. Sensitivity to fading is reduced by the spatial diversity provided by multiple spatial paths. Under certain environmental conditions, the power requirements associated with high spectral-efficiency communication can be…

    • 16933 Words
    • 68 Pages
    Powerful Essays
  • Good Essays

    Transmit Diversity

    • 7383 Words
    • 30 Pages

    So far we have investigated the use of antenna arrays in interference cancellation and for receive diversity. This final chapter takes a broad view of the use of antenna arrays in wireless communications. In particular, we will investigate the capacity of systems using multiple transmit and/or multiple receive antennas. This provides a fundamental limit on the data throughput in multipleinput multiple-output (MIMO) systems. We will also develop the use of transmit diversity, i.e., the use of multiple transmit antennas to achieve reliability (just as earlier we used multiple receive antennas to achieve reliability via receive diversity). The basis for receive diversity is that each element in the receive array receives an independent copy of the same signal. The probability that all signals are in deep fade simultaneously is then significantly reduced. In modelling a wireless communication system one can imagine that this capability would be very useful on transmit as well. This is especially true because, at least in the near term, the growth in wireless communications will be asymmetric internet traffic. A lot more data would be flowing from the base station to the mobile device that is, say, asking for a webpage, but is receiving all the multimedia in that webpage. Due to space considerations, it is more likely that the base station antenna comprises multiple elements while the mobile device has only one or two. In addition to providing diversity, intuitively having multiple transmit/receive antennas should allow us to transmit data faster, i.e., increase data throughput. The information theoretic analysis in this chapter will formalize this notion. We will also introduce a multiplexing scheme, transmitting multiple data streams to a single user with multiple transmit and receive antennas. This chapter is organized as follows. Section 2 then presents a theoretical analysis of the capacity of MIMO systems. The…

    • 7383 Words
    • 30 Pages
    Good Essays
  • Powerful Essays

    OFDM Simulation and Analysis

    • 4216 Words
    • 17 Pages

    [6] Y. S. Cho, J. Kim, W. Yang and C. G. Kang, MIMO-OFDM Wireless Communication with…

    • 4216 Words
    • 17 Pages
    Powerful Essays
  • Better Essays

    Free Space Path Loss Model

    • 1173 Words
    • 5 Pages

    Path loss models play a vital role in planning of wireless communication systems. They represent a set of mathematical equations and algorithms that are used for radio signal propagation prediction in certain areas. Propagation path loss models are used for calculation of electromagnetic field strength for the purpose of wireless network planning during preliminary deployment. Path loss model describes the signal attenuation from transmitter to receiver antenna as a function of distance, carrier frequency, antenna heights and other significant parameters like terrain profile (urban, suburban and rural). In this section various path loss models are discussed.…

    • 1173 Words
    • 5 Pages
    Better Essays
  • Powerful Essays

    Wireless Communications

    • 4981 Words
    • 20 Pages

    In this paper we will look at the following technologies used to provide wireless communication:…

    • 4981 Words
    • 20 Pages
    Powerful Essays
  • Good Essays

    – - Beamforming: spatial focusing of correlated signals – - Rx/Tx diversity: combining of decorrelated signals – - MIMO: increasing spectral efficiency/ data rates…

    • 1099 Words
    • 5 Pages
    Good Essays