Essay:

Essay details:

  • Subject area(s): Media
  • Price: Free download
  • Published on: 15th October 2019
  • File format: Text
  • Number of pages: 2

Text preview of this essay:

This page is a preview - download the full version of this essay above.

1.1 Overview

The tremendous boom in the electronics and wireless communication industry has lead to on-the-move internet capability and cheaply available wireless devices. Advance makes use of of images and videos have increased the data transfer by a lot of folds. This has set the have to of efficient and reliable communication techniques with data rates. To cater to these needs recent advances in the field of wireless communications has led to some remarkable breakthrough in the region of multiuser space-time wireless communications.

The advance of the multiple-input multiple-output (MIMO) wireless scheme shows tremendous potential to relieve the bottleneck of wireless data transmission. MIMO offers an increase in traffic capacity for future cellular systems, to handle the commission of internet-intensive applications. MIMO communication scheme use multiple antennas at the transmitter and the receiver that create virtual spatial sub-channels, over which multiple data streams can be transmitted. Each sub-channel uses the exact same frequency, and the transmission occurs separately. In fact MIMO scheme can be consider as an extension of smart antenna system, a favorite technique, dating back several decades, for improving link reliability through the use of antenna array beam forming [1]. Further even the future 4G wireless networks will combine the powerful technologies of MIMO, adaptive and reconfigurable systems (software radio) and wireless entrance technologies such as used for example orthogonal frequency division multiple access (OFDMA) and multiple-carrier code division multiple access (MC-CDMA)  [2].

This paper presents a plan of unequal power allocation scheme for transmissions of digital images over a MIMO scheme. The proposed scheme employs the usage of OFDM and chaotic communication to transmit the input images from different transmit antennas using unequal transmit power of the MIMO scheme.

1.2 Wireless Communication

A wireless network is any variety of networks that uses wireless knowledge connections for connecting network nodes.

Wireless networking could be a methodology by that home, telecommunications networks and enterprise (business) installations avoid the pricey method of introducing cables into a building, or as a affiliation between numerous instrumentation locations. Wireless telecommunications networks are usually enforced and administered exploitation radio communication. This implementation takes place at the physical level (layer) of the OSI model network structure.

Examples of wireless networks include cell phone networks, Wi-Fi local networks and terrestrial microwave networks.

Fig. 1(a): Wireless network

1.2.1 Wireless links

• Terrestrial microwave communication uses Earth-based transmitters and receivers resembling satellite dishes. Terrestrial microwaves area unit within the low-gigahertz vary, that limits all communications to line-of-sight. Booster’s area unit spaced roughly forty eight clicks (30 mi) apart.

• Communications satellites via microwave radio waves, that don't seem to be deflected by the Earth's atmosphere. The satellites square measure stationed in house, usually in orbit thirty-five, 400 km (22,000 mi) on top of the equator. These Earth-orbiting systems square measure capable of receiving and relaying voice, data, and television signals.

• Cellular and PCS systems use many radio communications technologies. The systems divide the region coated into multiple geographic areas. Every space incorporates a low-power transmitter or radio relay antenna device to relay calls from one space to consecutive space.

• Radio and spread spectrum technologies wireless local area networks use a high-frequency radio technology almost like digital cellular and a low-frequency radio technology. Wireless LANs use unfolds spectrum technology to modify communication between multiple devices during a restricted space. IEEE 802.11 defines a typical flavor of open-standards wireless radio-wave technology referred to as wireless fidelity.

• Free-space optical communication uses visible or invisible lightweight for communications. In most cases, line-of-sight propagation is employed, that limits the physical positioning of act devices.

2.1.3 Types of wireless networks

• Wireless personal area networks (WPANs) interconnect devices among a comparatively tiny space, which is usually among a human reach. As an example, each Bluetooth radio and invisible infrared radiation provides a WPAN for interconnecting a receiver to a laptop computer. Zip Bee conjointly supports WPAN applications. Wi-Fi PANs are getting commonplace (2010) as instrumentality designers begin to integrate Wi-Fi into a spread of client electronic devices. Intel "My Wi-Fi" and Windows seven "virtual Wi-Fi" capabilities have created Wi-Fi PANs less complicated and easier to line up and tack.

• Wireless local area network (WLAN) links 2 or a lot of devices over a brief distance employing a wireless distribution methodology, sometimes providing a affiliation through AN access purpose for web access. The utilization of spread-spectrum or OFDM technologies might permit users to maneuver around inside {a local an space a neighborhood} coverage area, and still stay connected to the network.

The transceiver, sometimes called an access point, broadcasts and receives signals to and from the surrounding computers and passes data back and forth between the wireless computers and the cabled network.

These wireless LANs use small wall-mounted transceivers to connect to the wired network. Figure 1.2 shows a wireless connection between a laptop computer and a LAN. The transceivers establish radio contact with portable networked devices. Note that this is not a true wireless LAN, because it uses a wall-mounted transceiver to connect to a standard, cabled LAN.

 Fig. 1(b): Wireless portable computer connecting to a cabled network access point

• Wireless wide area networks (Wwan’s) are wireless networks that usually cowl massive areas, like between neighboring cities and cities, or town and suburban area. These networks are often accustomed connect branch offices of business or as a public web access system. The wireless connections between access purposes are typically purpose to point microwave links victimization parabolic dishes on the two. 4 GHz band, instead of unidirectional antennas used with smaller networks. A typical system contains base station gateways, access points and wireless bridging relays. Different configurations are meshes systems wherever every access purpose acts as a relay conjointly. Once combined with renewable energy systems like photo-voltaic star panels or wind systems they'll be stand alone systems.

• Wireless metropolitan area networks (Wman’s) area unit a sort of wireless network that connects many wireless LANs. Technologies Wireless technologies for mobile commerce can be roughly categorized into mobile client devices for interactivity (or m-commerce terminals) and communications infrastructure.

1.3 Problem Description

The aim is to address the tradeoff between the power consumption and the quality of service in wireless media systems. Digital images are attractive data types with widespread range of use and many users are interested to make it secure. Transmission of images over varying channel conditions using single OFDM transmitter with limited power resources are used. The chaotic encoder ensures secure image transmission. The channel distortion is been reduced as multiple transmitters are used.

1.4 Thesis Objective

Since the last decade the study of the joint transmission and coding schemes has attracted many effort and made great progresses. However, the research interest is still growing.

• The emergence of recent chaotic system model is one of the finest outcomes of these efforts in the area.

• Chaotic systems provide rich mechanism for signal design and generation, with potential applications to communications and signal processing.

• This project work combines the two technologies of MIMO and Chaotic Communication to provide secure & reliable image transfer with minimum power.

• This work presents an unequal power allocation scheme for the transmission of compressed images over MIMO systems over a noisy channel.

• The proposed system employs OFDM and chaotic encoder schemes.

• The input is passed through chaotic encoder and OFDM transmitter and is transmitted using MIMO configuration. At the receiving end reverse is followed and then the mean of the received image is calculated to give the output image.

• The chaotic encoder ensures secure image transmission and the use of two separate transmitters reduces the channel distortion.

• The proposed system is tested using various images. The results show that the proposed system has less delay and less BER for a given SNR as compared to a system employing only single OFDM transmitter.

1.5 Organization of Thesis

The layout of the dissertation is as follows:

Chapter 1: Introduction describes the introduction of Wireless Communication, its Feature, Application, and Technology, Digital images, its Processing, Tasks, and statement of the Problem.

Chapter 2: Literature Survey describes related techniques and literature review along with various algorithms proposed by several researches is also discussed.

Chapter 3: Analysis of Unequal Power Allocation describes MIMO, MIMO functions, chaotic communication and OFDM.

Chapter 4: Proposed Work this chapter deals with the Problem statement with exiting system, and proposed solution. It also describes the techniques of our work.

Chapter 5: Simulation and results Analysis this chapter give analysis of obtained in our work and analysis is in terms of SNR and BER.

Chapter 6: Conclusion and Future Work discusses conclusion of the work with to the future different schemes and techniques.

...(download the rest of the essay above)

About this essay:

This essay was submitted to us by a student in order to help you with your studies.

If you use part of this page in your own work, you need to provide a citation, as follows:

Essay Sauce, . Available from:< https://www.essaysauce.com/essays/media/2015-11-19-1447914904.php > [Accessed 02.12.21].