20-09-2012, 05:30 PM
Mimo system with mmse equalization
[attachment=34210]
INTRODUCTION
Diversity plays an important role in improving the reliability of a message signal
It uses two or more communication channels with different characteristics as it combats fading and co-channel and avoid error bursts
Diversity coding techniques are used when there is no channel knowledge at the transmitter.
Multiple-input and multiple-output (MIMO) is the use of multiple antennas at both the transmitter and receiver to improve communication performance
In MIMO wireless communication, an equalizer is employed which is a network that makes an attempt to recover a signal that suffers with an Inter symbol Interference (ISI).
A MMSE equalization algorithm separates multiple transmitted sequences and minimize the ISI simultaneously.
MMSE EQUALIZATION
An approach which minimizes the mean square error (MSE),which is a common measure of estimator quality.
Its main feature is that it does not usually eliminate ISI completely but minimizes the total power of the noise and ISI components in the output.
The model under consideration is 2 transmit and 2 receive antennas assuming Rayleigh multipath channel and BPSK modulation.
Assumptions:
1. The channel is flat fading.
2. The channel experience by each transmit antenna is independent from the channel experienced by other transmit antennas.
3. For the transmit antenna to receive antenna, each transmitted symbol gets multiplied by a randomly varying complex number .
4. The channel experienced between each transmit to the receive antenna is independent and randomly varying in time.
5. On the receive antenna, the noise has the Gaussian probability density function.
6. The channel is known at the receiver.
Methodology:
Consider a transmission sequence, for example x1,x2,x3..xn.
In normal transmission, x1 is sent in the first time slot, x2 in the second time slot, and so on.
Group the symbols into groups of two. In the first time slot, send x1 and x2 from the first and second antenna. In second time slot, send x3 and x4 from the first and second antenna, and so on.
As two symbols are grouped and sent in one time slot, only (n/2) time slots are needed to complete the transmission i.e., data rate is doubled.
This forms the simple explanation of a probable MIMO transmission scheme with 2 transmit antennas and 2 receive antennas.
[attachment=34210]
INTRODUCTION
Diversity plays an important role in improving the reliability of a message signal
It uses two or more communication channels with different characteristics as it combats fading and co-channel and avoid error bursts
Diversity coding techniques are used when there is no channel knowledge at the transmitter.
Multiple-input and multiple-output (MIMO) is the use of multiple antennas at both the transmitter and receiver to improve communication performance
In MIMO wireless communication, an equalizer is employed which is a network that makes an attempt to recover a signal that suffers with an Inter symbol Interference (ISI).
A MMSE equalization algorithm separates multiple transmitted sequences and minimize the ISI simultaneously.
MMSE EQUALIZATION
An approach which minimizes the mean square error (MSE),which is a common measure of estimator quality.
Its main feature is that it does not usually eliminate ISI completely but minimizes the total power of the noise and ISI components in the output.
The model under consideration is 2 transmit and 2 receive antennas assuming Rayleigh multipath channel and BPSK modulation.
Assumptions:
1. The channel is flat fading.
2. The channel experience by each transmit antenna is independent from the channel experienced by other transmit antennas.
3. For the transmit antenna to receive antenna, each transmitted symbol gets multiplied by a randomly varying complex number .
4. The channel experienced between each transmit to the receive antenna is independent and randomly varying in time.
5. On the receive antenna, the noise has the Gaussian probability density function.
6. The channel is known at the receiver.
Methodology:
Consider a transmission sequence, for example x1,x2,x3..xn.
In normal transmission, x1 is sent in the first time slot, x2 in the second time slot, and so on.
Group the symbols into groups of two. In the first time slot, send x1 and x2 from the first and second antenna. In second time slot, send x3 and x4 from the first and second antenna, and so on.
As two symbols are grouped and sent in one time slot, only (n/2) time slots are needed to complete the transmission i.e., data rate is doubled.
This forms the simple explanation of a probable MIMO transmission scheme with 2 transmit antennas and 2 receive antennas.