help.txt

A document and source code of Alamouti space time coding scheme

ALAMOUTI performs Monte-Carlo simulation and estimates Bit Error Rate 
(BER) of Alamouti Scheme [1] over Rayleigh channel. The scheme presumes 
2 transmit (Tx) and arbitrary number of receive (Rx) elements.  
If Rx=1 (one receive element) ALAMOUTI is transformed to the order 2 
transmit diversity scheme with Maximum Ratio Combining (MRC). The 
modulation format is MPSK with arbitrary order M which can be 
controlled by user.

The simulation parameters are entered using the built graphic user 
interface (GUI) and contains:

1. Number of pair symbols from both Tx elements to be transmitted: N. 
This number should be at least 10 times more that the expected 1/BER 
to provide low estimation error.

2. MPSK order  M, must be a power of 2.

3. Signal-to-Noise-Ratio (SNR) in dB as a ratio of the average received
power at one Rx element over the noise power at this element.

4. Number of transmit elements Tx=2 which cannot be changed by user.

5. Number of receive elements Rx, can be arbitrary.

The program does not check the format of the feeding parameters and 
does not produce any alert about incorrect values!

Pushbutton "Start" starts the simulation with desired parameters and 
plots the estimated BER vs. SNR. 

To allow efficient vector programming ALAMOUTI is an equivalent 
Alamouti Scheme [1] i.e. a simulation where the time 
epochs are hidden.

Reference:
[1] S. M. Alamouti, A Simple Transmit Diversity Technique for Wireless
Communications, IEEE Journal on Select Areas in Communications, vol. 
16, no. 8, Oct. 1998.

Acknowledgement:
To Dr. Sander Stepanov from Israel Institute of Technology (Technion) 
for helpful discussion and useful comments on Alamouti algorithm.

Author: G. Levin, July 2004.