29 December, 2015

The project may use mathematical derivation to analysis the procedure and result of positioning system based on TDOA technology. Thus, I have used the Matlab to simulate the procedure in 2D environment.

First, this matlab code is used to generate two random number form 0 to 200. Then, "sensor" coordinate will get those two random number for the x and y axis value respectively. Then, it will simulate TDOA system and calculate the output target coordinate after TDOA calculation.

Where "sensor" is the initial value generate before and "OUT" is the output value after TDOA calculation estimation. From the above result, TDOA system find the target in a very close range.
Later, I will generate the result value many times and compare them in order to get the error range.

6 October 2015

After the Seminar on Turnitin, I have learnt how to avoid running into plagiarism issues in my FYP written report.
And I recognized that I have to borrow some books for my FYP research.

I have borrowed a book called Ground- Based wireless positioning.
This book provides the techniques of wireless positioning, which include Time difference of arrival.
I have learnt the theory of positioning systems. I learnt the limitation and error of the positioning system based on TDOA. In this book, it gave the 3-dimension approach to calculate the corresponding position of the target.

29 September 2015

Principle of TDOA
In time different of arrival, at the beginning, all base stations are synchronized. 

There are three access points (AP1, AP2, AP3), when a client transmits a signal like a sound wave, each of access points will produce a time of arrival measurement. 

Equations of TDOA can be obtained.

In the above equations, AP1(x1,y1), AP2(x2,y2), AP3(x3,y3)

Each TDOA equation is a hyperbola, so the target location can be located as the intersection point of equations.    

11 September 2015

After a briefing session at 10 Step, Dr. Martin Chow has gave the general information about the final year project topic (Time Difference of Arrival )

Time Difference of Arrival (TDOA) is a measurement positioning system by determining time difference between base stations in order to find target location.