IEEE Consumer Electronics Magazine - March 2018 - 77

Table 2. The summary of results on different hand gestures.
Gestures

Average

Maximum

Minimum

Pattern
Observed

1) No gesture

−17.5~−18.5

−15

−23

2) Hand is horizontal

−18~−19

−15

−23

3) Hand is vertical

−19~−21

−17

−31

condition changes from no gesture to the hand
being vertical.

4) Hand moves toward
the receiver

−19~−22.5

−15

−31

▼▼An interval of 0.5 s between two maximum RSSI

Notes
▼▼No specific patterns in the waveforms.
▼▼The signal strengths become weaker when the

values.

▼▼It has a relatively short period of frequently chang-

ing RSSI values at the end.

5) Hand moves away
from the receiver

−19~−22

−15

−31

Swipe

▼▼It has a relatively long period of frequently chang-

▼▼Certain patterns in the waveforms are observed.
▼▼All swipes are rectangular pulses between −17 dBm

ing RSSI values at the end.

and −21 dBm.

▼▼Cannot distinguish between the different directions.

6) Swipe up

−18~−20

−15

−27

7) Swipe down

−17.8~−20

−15

−27

▼▼Certain patterns in the waveforms are observed.
▼▼All swipes are rectangular pulses between −17 dBm

8) Swipe left

−18~−20

−15

−27

9) Swipe right

−19~−20

−15

−27

10) Turn key

−18~−19

−15

−27

11) Clap

−21~−25

−15

−33

▼▼Strong up-and-down waves between a maximum

12) "Come here"

−19~−20

−17

−31

▼▼Clear peaks and through at a minimum of −31 dBm

13) V-shape

−19.5~−20.5

−17

−29

▼▼No specific patterns in the waveforms.

14) Open and close

−19~−20.5

−15

−31

▼▼No specific patterns in the waveforms.

and −21 dBm.

▼▼Cannot distinguish between the different directions.
▼▼Long, narrow, and downward cones are observed

only in some of the testing cases.

−19 dBm and a minimum −31 dBm are observed.
are observed.

Under the condition of no gesture, the average of the signal
strength of the RSSI was −18.5 dBm; the maximum was
−15 dBm; and the minimum was −23 dBm. Although there
is no conspicuous pattern shown in this waveform, the
average, minimum, and maximum values of the signal
strength of the RSSI in the no-gesture condition were much
lower than those of the conditions with gestures, as shown
in Figure 2.

(dBm)

GESTURE 1: NO GESTURE

-15
-16
-17
-18
-19
-20
-21
-22
-23
-24
-25

0.5

1.5

GESTURE 2: A HAND STAYS HORIZONTAL
When a hand stayed horizontal in front of the receiver, no
conspicuous pattern was found in the waveform. The average,
minimum, and maximum RSSI values were similar to the
RSSI values in the no-gesture condition. Thus, this gesture
cannot be easily recognized.

GESTURE 3: A HAND STAYS VERTICAL
("STOP" GESTURE)
When a hand remained vertical in front of the receiver, the
average, maximum, and minimum RSSI values were −21
dBm, −17 dBm, and −31 dBm, respectively. Although there
was no conspicuous pattern shown in this waveform, the
three values were within a range that was different from those
that were obtained using other gestures.

2.5 3
Time (s)

3.5

4.5

FIGURE 2. The RSSI change over time with no gesture.

GESTURE 4: A HAND MOVES TOWARD THE RECEIVER
When a hand moved toward the receiver, the following pattern was observed in the result waveform: there was an interval of roughly 0.5 s between two maximum values and a
frequent change of RSSI values at the end in most of the tested files, as can be seen in Figure 3.

GESTURE 5: A HAND MOVES AWAY
FROM THE RECEIVER
When a hand was moving away from the receiver, the average, maximum, and minimum RSSI values were −20.5 dBm,
−15 dBm, and −31 dBm, respectively. The following pattern
MARCH 2018

IEEE Consumer Electronics Magazine

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