Method and apparatus for non-calibrated automatic frequency correction of a portable terminal
An apparatus and method for non-calibrated Automatic Frequency Correction (AFC) of a portable terminal are provided. The method includes identifying, by the portable terminal, signal strengths of signals received from neighboring base stations of a cell in which the portable terminal is currently located; searching for a frequency burst serving that provides synchronization acquisition information for synchronization with a base station; determining to perform the AFC according to a result of the searching for the frequency burst; and storing AFC data extracted through the AFC.
1. A method for non-calibrated Automatic Frequency Correction (AFC) in a portable terminal, the method comprising:
searching for a frequency burst that provides synchronization acquisition information for synchronization with a base station;
performing a non-calibrated AFC when no frequency burst is found; and
storing AFC data extracted through the non-calibrated AFC.
2. The method of claim 1 , wherein a strength of a signal received from a serving base station is identified through the non-calibrated AFC, and the non-calibrated AFC is performed when the identified strength of the signal pertains to an electric field which meets a network selection condition, prior to a network being selected.
3. The method as claimed in claim 1 , wherein the non-calibrated AFC is performed by plus/minus(+/−)-crossing an AFC Digital-to-Analog Converter (DAC) value.
4. The method of claim 1 , wherein searching for the frequency burst is performed in a physical layer that is interface between the portable terminal and transmission data.
5. The method of claim 1 , wherein searching for the frequency burst is performed before a camping-on by the portable terminal.
6. The method of claim 1 , further comprising:
sorting out the signals received from the neighboring base stations in an ascending order of the signal strengths;
selecting a neighboring base station whose signal strength is highest as a serving base station; and
receiving a base station identification code by requesting a frequency correction channel for frequency synchronization and a synchronization channel for time synchronization from the serving base station.
7. The method of claim 1 , wherein when a serving base station changes, the stored AFC data is used for frequency synchronization with the changed serving base station.
8. An apparatus for non-calibrated Automatic Frequency Correction (AFC) in a portable terminal, the apparatus comprising:
a wireless communication unit for communicating with a base station;
a control unit for searching for a frequency burst that provides synchronization acquisition information to perform the non-calibrated AFC when no frequency burst is found, and storing AFC data extracted through the non-calibrated AFC; and
a Radio Frequency (RF) correction unit for generating a control signal for performing the non-calibrated AFC under the control of the control unit.
9. The apparatus of claim 8 , wherein the control unit identifies a strength of a signal received from a serving base station, and performs the non-calibrated AFC, when the identified signal strength pertains to an electric field that meets a network selection condition, prior to a network being selected.
10. The apparatus of claim 8 , wherein the control unit performs the non-calibrated Automatic Frequency Correction (AFC) by plus/minus(+/−)-crossing an AFC Digital-to-Analog Converter (DAC) value.
11. The apparatus of claim 8 , wherein the control unit searches for the frequency burst before a camping-on by the portable terminal.
12. The apparatus of claim 8 , wherein the control unit sorts out the signals received from the neighboring base stations in an ascending order of the signal strengths, selects a neighboring base station whose signal strength is highest as a serving base station, and receives a base station identification code by requesting a frequency correction channel for frequency synchronization and a synchronization channel for time synchronization from the serving base station.
13. The apparatus of claim 8 , wherein the control unit performs a controlling operation so that when a serving base station changes, the stored AFC data is used for frequency synchronization with the changed serving base station.