Presented by: Dorathy Abonyi

1. T0PIC:
DIRECTION OF ARRIVAL (DOA)
ESTIMATION WITH TWO
ELEMENT ANTENNAS

2. FORMAT OF PRESENTATION
• OVERVIEW
• SIMULATION OF TWO ELEMENT RADIATION PATTERN
• PATTERN SELECTION
• NODE SIMULATION ( RANDOMLY SCARTERED PLOTS)
• RSS CALCULATION (TWO RAY MODEL)
• SIMULATION RESULT ANALYSIS
• DOA ESTIMATION
• END

3. OVERVIEW
• MOBILE UNITS ARE RANDOMLY LOCATED.
• A MOBILE BTS IS COSTLY TO SET UP
• IN SOME CASES A SMALLER CELL IS NEEDED WITHIN
A MICROCELL FOR GOOD QOS.
• THERE IS NEED TO IDENTIFY THE OPTIMUM
LOCATION FOR A BTS BEFORE IMPLIMENTATION
• THERE IS NEED TO KNOW LOCATION OF HIGH
CONCENTRATION OF MOBILE USERS FOR CELL SETUP.

4. SIMULATION OF TWO ELEMENT
RADIATION PATTERN
• BACKGROUND MATHEMATICS
The output signal from antenna array with
progressive phase shift between the antennas
is given by:

5. 2
1.5
1
0.5
30
180 0
210
60
240
90
270
120
300
150
330
Radiation pattern for [0,0] phases
2
1.5
1
0.5
30
180 0
210
60
240
90
270
120
300
150
330
Radiation pattern for [0,110] phases
2
1.5
1
0.5
30
180 0
210
60
240
90
270
120
300
150
330
Radiation pattern for [110,0] phases
2
1.5
1
0.5
30
180 0
210
60
240
90
270
120
300
150
330
Radiation pattern for [0,180] phases

6. RADIATION PATTERN FOR 120 DEGREE
COVERAGE
Radiation pattern of four selected phase groups
2
1.5
1
0.5
30
180 0
210
60
240
90
270
120
300
150
330

7. PATTERNS ANGLE OF
MAXIMUM
RADIATION
P1 0-180 LEFT & RIGHT
P2 190 – 540 RIGHT
P3 190 – 540 LEFT
P4 550 - 600 LEFT & RIGHT

8. NODE GENERATION
450
400
350
300
250
200
150
100
50
0
Plot1
-250 -200 -150 -100 -50 0 50 100 150 200 250
y axis
x axis
y(i) d(i)
x(i)

9. TWO RAY MODEL

10. I x y d
RSS(dB
m) theta1
1 -119 186 220.8 -82.0 57
2 -186 60 195.4 -79.9 18
3 205 441 **486.3 -95.7 65
4 35 27 44.2 -54.1 38
5 -122 163 203.6 -80.6 53
6 149 7 149.2 -75.2 3
7 -211 78 225.0 -82.3 20
8 69 338 345.0 -89.7 78
9 69 208 219.1 -81.9 72
10 22 136 137.8 -73.8 81

11. Simulation result for Isotropic nodes
Nodes x d(m) RSS(dBm)
ANGLE
OFF
BROAD
SIDE P1(dBd) P2(dBd) P3(dBd) P4(dBd)
1 0 320.0 -95.6 0 3.01 0.46 0.46 -156.60
2 68 249.4 -91.3 16 2.59 2.32 -5.07 -0.76
3 -91 335.6 -96.5 16 2.59 -5.07 2.32 -0.76
4 42 112.2 -77.4 22 2.21 2.67 -29.08 0.45
5 -158 425.4 -100.6 22 2.21 -29.08 2.67 0.45
6 164 330.6 -96.2 30 1.51 2.93 -4.09 1.51
7 -121 243.2 -90.9 30 1.51 -4.09 2.93 1.51
8 92 129.4 -79.9 45 -0.52 2.97 -0.01 2.53

12. RESULT ANALYSIS
• It can be deduced that a pattern with highest RSS
value, a value closer to zero has the most likelihood of
having the node at its region. For instance, node 1 is
most likely to be located within the region of PI left or
right while node 6 will most likely be located within the
region of P2.
• It can also be noticed that patterns P2 and P3 are
symmetrical, while one has maximum reception in one
direction, the other one has maximum in the opposite
direction.
• Pattern 4 gives the same gain for the same angle in
both left and right as seen in node 6 and 7.

13. DIRECTION OF ARRIVAL ESTIMATION
• DOA of node 8 can be predicted if the angle
and distance is not known by determining the
pattern with the highest RSS value.
• In this case P2 which is under the range 19 to
540 is the highest.
• P4 is the second highest meaning node 8 is
closer to p4 than it is to p1
• 350 coverage of P2 can be halved in favour of
P4 to give 17.50 + 190 = 36.50.

14. • Difference between the RSS values of P4 and
P1 is 0.44
• Their percentage difference is 8%
• The coverage range of P2 between 19 and 540
is 350, therefore 8% of 350 gives 2.80.
• This further narrows down the location of
node 8 to 39.3 - 540. In this way, the location
of each node can be determined.
• From table, node 8 is located at 450 off
broadside
• More research needed for a narrower
estimate.

15. FOR FURTHER DETAILS
CONTACT ME
@
ujuejikeme@yahoo.com

16. THANKS