31-07-2013, 12:40 PM
Communication MIMO Wireless
[attachment=56860]
Introduction
The spread of telecommunication has led to a rapid change in the upcoming technologies relating communication. This spreading of technologies has led to a need of “MIMO (multiple input multiple output) wireless communication” which uses multiple transmit and receive antennas for communication.
In wireless communication systems we use different type of antenna technologies to transmit and receive message or data. MIMO is one of the smart antenna technologies used to transmit and receive message or data which uses multiple input and multiple output antennas to transmit and receive our message or data.
Theory
MIMO (multiple input multiple output) is a smart antenna technology used by many wireless systems now a days. In MIMO technology the system uses multiple antennas at the transmitter as well as at the receiver. This technology is used to reduce the errors and to optimize the data speed.MIMO (multiple input multiple output) technology created a breakthrough in the design of wireless communications systems, and is already used as a standard by several wireless systems.
In this project of MIMO we will discuss different encoders, decoders, modulation and demodulation schemes, channel effects, different types of channels .At encoders we will discuss different encoding schemes like space time block codes and trellis coding schemes .In encoders we will discuss Alamouti and Viterbi encoders. As we will be working on Alamouti encoders, so we will discuss Alamouti encoder in detail in the upcoming chapter of Alamouti Encoders.
We will take the data in the form of a signal or if we have data in the form of a bit stream. At the encoder the data is further encoded, this encoded data is then modulated here we will use QPSK modulation scheme. After modulation we will receive the modulated data affected by the channel effects. This data is then demodulated by the same scheme used at the modulation end which is QPSK. This demodulated data is then decoded by Alamouti or Viterbi decoder.
Main Technologies
“Arogyaswami Paulraj and Thomas Kailath proposed the concept of Spatial Multiplexing using MIMO in 1993. Their US Patent No. 5,345,599 issued 1994 on Spatial Multiplexing emphasized applications to wireless broadcast.[1] In 1996, Greg Raleigh and Gerard J. Foschini refine new approaches to MIMO technology, which considers a configuration where multiple transmit antennas are co-located at one transmitter to improve the link throughput effectively. [1] Bell Labs was the first to demonstrate a laboratory prototype ofspatial multiplexing (SM) in 1998, where spatial multiplexing is a principal technology to improve the performance of MIMO communication systems”.[1]
SISO
SISO is often refers to as “Single Input Single Output”, where SISO is the simplest antenna technology. In SISO wireless communications system it has a single transmitting antenna at the transmitter and a single receiving antenna at the receiver. For a clearer picture of SISO wireless communication you can refer to figure 1.1.
Smart antenna technology is used in order to minimize or eliminate problems caused by multipath wave propagation. The smart antenna technology is divided into three technologies known as SIMO “Single Input Multiple Output”, MISO Multiple Input Single Output”, and MIMO Multiple Input Multiple Output”.
MISO
MISO is often referring to as "Multiple Input Single Output", where MISO "Multiple Input Single Output" is a smart antenna technology. It consists of multiple antennas at the transmitter and a single antenna at a receiver.
MISO wireless communication system uses multiple transmit antennas and a single receive antenna to improve the transmission distance. MISO technology also has widespread applications in Digital Television, Wireless Local Area Networks (WLANs), Metropolitan Area Networks (MANs), and mobile communications. The antennas are combined to minimize errors and optimize data speed.
In digital communications systems such as wireless Internet, reduction in data speed and an increase in the number of errors is caused. MISO uses two or more antennas along with the transmission of multiple signals (one for each antenna) at the source, can reduce the trouble caused by multipath wave propagation. Figure 1.1 can be seen for a clearer picture of MISO wireless communication you can refer to.
[attachment=56860]
Introduction
The spread of telecommunication has led to a rapid change in the upcoming technologies relating communication. This spreading of technologies has led to a need of “MIMO (multiple input multiple output) wireless communication” which uses multiple transmit and receive antennas for communication.
In wireless communication systems we use different type of antenna technologies to transmit and receive message or data. MIMO is one of the smart antenna technologies used to transmit and receive message or data which uses multiple input and multiple output antennas to transmit and receive our message or data.
Theory
MIMO (multiple input multiple output) is a smart antenna technology used by many wireless systems now a days. In MIMO technology the system uses multiple antennas at the transmitter as well as at the receiver. This technology is used to reduce the errors and to optimize the data speed.MIMO (multiple input multiple output) technology created a breakthrough in the design of wireless communications systems, and is already used as a standard by several wireless systems.
In this project of MIMO we will discuss different encoders, decoders, modulation and demodulation schemes, channel effects, different types of channels .At encoders we will discuss different encoding schemes like space time block codes and trellis coding schemes .In encoders we will discuss Alamouti and Viterbi encoders. As we will be working on Alamouti encoders, so we will discuss Alamouti encoder in detail in the upcoming chapter of Alamouti Encoders.
We will take the data in the form of a signal or if we have data in the form of a bit stream. At the encoder the data is further encoded, this encoded data is then modulated here we will use QPSK modulation scheme. After modulation we will receive the modulated data affected by the channel effects. This data is then demodulated by the same scheme used at the modulation end which is QPSK. This demodulated data is then decoded by Alamouti or Viterbi decoder.
Main Technologies
“Arogyaswami Paulraj and Thomas Kailath proposed the concept of Spatial Multiplexing using MIMO in 1993. Their US Patent No. 5,345,599 issued 1994 on Spatial Multiplexing emphasized applications to wireless broadcast.[1] In 1996, Greg Raleigh and Gerard J. Foschini refine new approaches to MIMO technology, which considers a configuration where multiple transmit antennas are co-located at one transmitter to improve the link throughput effectively. [1] Bell Labs was the first to demonstrate a laboratory prototype ofspatial multiplexing (SM) in 1998, where spatial multiplexing is a principal technology to improve the performance of MIMO communication systems”.[1]
SISO
SISO is often refers to as “Single Input Single Output”, where SISO is the simplest antenna technology. In SISO wireless communications system it has a single transmitting antenna at the transmitter and a single receiving antenna at the receiver. For a clearer picture of SISO wireless communication you can refer to figure 1.1.
Smart antenna technology is used in order to minimize or eliminate problems caused by multipath wave propagation. The smart antenna technology is divided into three technologies known as SIMO “Single Input Multiple Output”, MISO Multiple Input Single Output”, and MIMO Multiple Input Multiple Output”.
MISO
MISO is often referring to as "Multiple Input Single Output", where MISO "Multiple Input Single Output" is a smart antenna technology. It consists of multiple antennas at the transmitter and a single antenna at a receiver.
MISO wireless communication system uses multiple transmit antennas and a single receive antenna to improve the transmission distance. MISO technology also has widespread applications in Digital Television, Wireless Local Area Networks (WLANs), Metropolitan Area Networks (MANs), and mobile communications. The antennas are combined to minimize errors and optimize data speed.
In digital communications systems such as wireless Internet, reduction in data speed and an increase in the number of errors is caused. MISO uses two or more antennas along with the transmission of multiple signals (one for each antenna) at the source, can reduce the trouble caused by multipath wave propagation. Figure 1.1 can be seen for a clearer picture of MISO wireless communication you can refer to.