Simulation of a Multiple Input Multiple Output (MIMO) system using various Space Time Coding (STC) techniques in LabVIEW
(Undergraduation Major Project Thesis)

Click Here to view the top level graphical user interface of the MIMO Simulation Model.

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Download the stand-alone software developed as a part of the undergraduate thesis.

Required: LabVIEW Runtime Engine 2009 or later

MIMO Simulation Model.rar
Size : 2.351 Kb
Type : rar

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Browsing Archive: March, 2009

Alamouti Encoding with RX Diversity (MRC), BER Curves

Posted by Ujjval Shah on Saturday, March 28, 2009, In : Simulation

The following result is for Alamouti Encoding with RX diversity using Maximal Ratio Combining technique at the Recevier

Following curves are the expected theoretical curves for various different TX and RX antennas.

The dotted curve for Na=4 is the curve to be compared with the above simulated curve.

Following is a quick comparison of all the three curves simulated till now:

RX Diversity

Posted by Ujjval Shah on Saturday, March 28, 2009, In : Theory

RX Diversity means to have multiple antennas at the receiver.

There are basically three types of method to obtain RX Diversity:

Selection Combining (SC): Here the receiver selects the best branch of all the receiver antennas and decodes the signal coming from that antenna. It is suboptimal and doesnt utilizes the energy of the signals from the other antennas.
Maximal Ratio Combining (MRC): Here, the limitation of the SC technique is removed. In MRC, signals from all the antennas are weighted app...

UpConversion DownConversion Effect

Posted by Ujjval Shah on Tuesday, March 24, 2009, In : Simulation

How does the inclusion of upconversion and downconversion affect the simulation results and upto what extent do they affect?

As of now it is observed that for a set of same given symbol rate, samples per symbol, no of message symbols and other parameters the BER curves for the simulation using upconversion and downconversion and the one without using them are almost the same.

BER Curves for Alamouti scheme, high symbol rate

Posted by Ujjval Shah on Tuesday, March 24, 2009, In : Simulation

As mentioned in previous posts, those curves were plotted at a symbol rate varying from 2-10Hz.

The published ones are plotted at 2bits/sec ie 1symbol/sec for QPSK.

In all the curves shown till now, none of them match exactly to the published ones.

However it is observed that as the symbol rate is gradually increased, the simulated curve tends to become more and more similar to the published ones.

Consider following values:

symbol rate =500

no of samples per symbol =8

no of symbols =5k

doppler ...

BER Curves for Alamouti scheme, smoothed out

Posted by Ujjval Shah on Wednesday, March 18, 2009, In : Simulation

The BER curves in the previous posts were plotted with the Fading and AWGN profile varying with each iteration and Eb/No value. Hence the graph had abrupt changes when the channel used to suddenly dive deep blotting out the signal, thus making the comparison for various Eb/No value difficult. Moreover a number of iterations had to be taken and mean was required to find out to get the most suitable reading; this resulted into lot of compuatational time.

Hence to avoid this a constant fading pro...

BER Curves for Alamouti scheme

Posted by Ujjval Shah on Monday, March 16, 2009, In : Simulation

The BER curves donot follow exactly as per the ones published in the book i am referring to, however they do resemble them. moreover the performance after using alamouti scheme does increases but not significantly as per the book. i have attached the pics of simulated curves. they were taken with 3.5K no of symbols, 10Hz symbol rate, 1 Hz doppler spread, 8 samples per symbol and mean of 20 iterations per SNR value. These values gives a very good result but the time taken for it outrageously l...

Alamouti Encoding-Decoding 2

Posted by Ujjval Shah on Sunday, March 8, 2009, In : Simulation

The simulation is complete.

As discussed in previous post, the entire simulation of a siso and mimo (with alamouti scheme) has been done.

Entire simulation is done for QAM Modulation. But the same can be realised for other modulation schemes too as only the values of the complex symbols (values I and Q) are going to change with modulation scheme and the Alamouti encoding remaining constant.

Two major impairments are included in the simulation- The Additive White Guassian Noise (AWGN) and Rayleig...

Alamouti Encoding-Decoding

Posted by Ujjval Shah on Sunday, March 1, 2009, In : Query/Problem/Solution

Previously, i had already developed a code to encode complex constellation symbols into alamouti codes for two transmit antennas.

For the decoding process at the receiver (only one antenna currently) i am using the maximum likelihood receiver (mlr) algorithm for finding the original transmitted symbols. To find the advantage of using alamouti code i am comparing it with a siso transmission system. in this case i am using the QAM transreceiver example provided by NI. however besides the given A...