Apparatus and method for estimating direction of radio frequency signal

1. An apparatus for estimating a direction of an RF signal, comprising:

an antenna for receiving an RF signal;

an electronic compass for, as a pointing direction of the antenna is varied, generating information about pointing directions and pointing angles corresponding to variations in the pointing direction of the antenna;

a control unit for determining received signal strength indicator (RSSI) values at respective pointing angles of the antenna based on a received signal of the antenna and information of the electronic compass depending on the variations in the pointing direction of the antenna, extracting a maximum RSSI value from the RSSI values at the respective pointing angles, and storing the maximum RSSI value and a pointing direction corresponding to the maximum RSSI value;

a display unit for displaying the RSSI values at the respective pointing angles and a trajectory of the RSSI values at the respective pointing angles under control of the control unit, and

a mode setting unit for setting a start and an end of a mode in which an arrival direction of the RF signal is estimated,

wherein the control unit is operated depending on settings by the mode setting unit.

2. The apparatus of claim 1 , wherein the display unit displays the RSSI values at the respective pointing angles in a form of one or more of numerals, a bar graph, and polar coordinates.

3. The apparatus of claim 1 , wherein the display unit displays a pointing line indicating a pointing direction depending on movement of the antenna in a polar coordinate system.

4. The apparatus of claim 1 , wherein the display unit is configured to, if the mode in which the arrival direction of the RF signal is estimated ends, display a trajectory of the RSSI values at the respective pointing angles obtained for a measurement time and a pointing line indicating a direction of the maximum RSSI value in a polar coordinate system.

5. The apparatus of claim 1 , wherein the control unit is connected to a spectrum analyzer for receiving a received signal of the antenna through a cable and is configured to receive a plurality of RSSI values at each pointing angle from the spectrum analyzer, calculate an average of the RSSI values at the corresponding pointing angle, and determine the average to be an RSSI value at the corresponding pointing angle.

6. The apparatus of claim 5 , wherein the cable comprises a cable body, an RF connector installed in one side of the cable body and configured to perform impedance matching with impedance of the antenna, and a data communication connector installed on one side of the cable body separately from the RF connector.

7. The apparatus of claim 1 , wherein the antenna is implemented as a uni-directional antenna.

8. An apparatus for estimating a direction of an RF signal, comprising:

an antenna for receiving an RF signal;

an electronic compass for, as a pointing direction of the antenna is varied, generating information about pointing directions and pointing angles corresponding to variations in the pointing direction of the antenna;

a digital signal processing unit for receiving the RF signal from the antenna and calculating a RSSI value corresponding to the RF signal;

a control unit for determining RSSI (Received Signal Strength Indicator) values at respective pointing angles of the antenna corresponding to the variations in the pointing direction of the antenna based on the RSSI value from the digital signal processing unit and information of the electronic compass, extracting a maximum RSSI value from the RSSI values at the respective pointing angles, and storing the maximum RSSI value and a pointing direction corresponding to the maximum RSSI value;

a display unit for displaying the RSSI values at the respective pointing angles and a trajectory of the RSSI values at the respective pointing angles under control of the control unit, and

a mode setting unit for setting a start and an end of a mode in which an arrival direction of the RF signal is estimated,

wherein the control unit is operated depending on settlings by the mode settings unit.

9. The apparatus of claim 8 , wherein the control unit receives a plurality of RSSI values at each pointing angle from the digital signal processing unit, calculates an average of the RSSI values at the corresponding pointing angle, and determines the calculated average to be an RSSI value at the corresponding pointing angle.

10. The apparatus of claim 8 , wherein the display unit displays the RSSI values at the respective pointing angles in a form of one or more of numerals, a bar graph, and polar coordinate plot.

11. The apparatus of claim 8 , wherein the display unit displays a pointing line indicating a pointing direction depending on movement of the antenna in a polar coordinate system.

12. The apparatus of claim 8 , wherein the display unit is configured to, if the mode in which the arrival direction of the RF signal is estimated ends, display a trajectory of the RSSI values at the respective pointing angles obtained for a measurement time and a pointing line indicating a direction of the maximum RSSI value in a polar coordinate system.

13. A method of estimating a direction of an RF signal, comprising:

determining, by a control unit, RSSI (Received Signal Strength Indicator) values at respective pointing angles of an antenna, based on a received signal of the antenna and information of an electronic compass related to a pointing direction and a pointing angle of the antenna;

extracting, by the control unit, a maximum RSSI value from the RSSI values at the respective pointing angles, and storing the maximum RSSI value and a pointing direction corresponding to the maximum RSSI value; and

displaying, by a display unit, the RSSI values at the respective pointing angles and a trajectory of the RSSI values at the respective pointing angles,

wherein the determining RSSI values at respective pointing angles of an antenna comprises:

calculating an average of a plurality of RSSI values generated at each pointing angle of the antenna; and

determining the calculated average to be an RSSI value at the corresponding pointing angle.

14. The method of claim 13 , wherein the displaying is configured to display the RSSI values at the respective pointing angles in a form of one or more of numerals, a bar graph, and polar coordinates.

15. The method of claim 13 , wherein the displaying is configured to display a pointing line indicating a pointing direction depending on movement of the antenna in a polar coordinate system.

16. The method of claim 13 , wherein the displaying is configured to display a trajectory of the RSSI values at the respective pointing angles obtained for a measurement time and a pointing line indicating a direction of the maximum RSSI value in a polar coordinate system.