Abstract: Provided is a technology for increasing accuracy of position estimation by estimating a position of a signal source based on an error due to altitudes of a sensor and a signal source and an error due to a pitch of an aircraft as well as an error due to curvature of the earth. At this time, a position estimation method may include receiving measurement data from a plurality of sensors, estimating first position data of the signal source based on the measurement data, identifying an altitude error of the first position data, and estimating second position data that is data obtained by correcting the first position data based on the altitude error.

Abstract: Provided is a method and apparatus for reducing the number of times of measurements in a mobile communication terminal. According to the method, a signal receive level (“Srxlev”) and a signal quality (“Squal”) of a serving cell in an idle state are measured. When the serving-cell selection condition is not satisfied or an adjacent-cell measurement condition is satisfied as a result of the measurement, it is determined whether the number of times of cell reselections reaches a critical value. When the number of times of cell reselections reaches the critical value, the number of times of cell reselection is initialized to a value smaller than the critical value and the mobile terminal returns to an idle state. When the number of times of cell reselections does not reach the critical value, an adjacent-cell measurement for the cell reselection is performed. Therefore, unnecessary quiescent current consumption is reduced and a quiescent current performance is improved.

Abstract: An apparatus and a method for improving the performance of an error correction code in response to the influence of error propagation are disclosed.

Abstract: Provided is a method and apparatus for reducing the number of times of measurements in a mobile communication terminal. According to the method, a signal receive level (“Srxlev”) and a signal quality (“Squal”) of a serving cell in an idle state are measured. When the serving-cell selection condition is not satisfied or an adjacent-cell measurement condition is satisfied as a result of the measurement, it is determined whether the number of times of cell reselections reaches a critical value. When the number of times of cell reselections reaches the critical value, the number of times of cell reselection is initialized to a value smaller than the critical value and the mobile terminal returns to an idle state. When the number of times of cell reselections does not reach the critical value, an adjacent-cell measurement for the cell reselection is performed. Therefore, unnecessary quiescent current consumption is reduced and a quiescent current performance is improved.

Abstract: An apparatus and a method for cell search for transmitting an emergency call in a dual mode terminal supporting a Global System for Mobile communication (GSM) and a Universal Mobile Telecommunication System (UMTS) are provided. A cell search for transmitting the emergency call is performed for all networks even though the network mode set by the user is different from the network installed in the region where the mobile communication terminal is located.

Abstract: An apparatus and method for transmitting control information in a mobile communication system are disclosed. The apparatus and method include selecting a pilot signal having different predetermined pilot patterns according to whether the data are received and the data contain an error, and inserting the selected pilot signal into a pilot field of a dedicated physical channel frame as control information and transmitting the dedicated physical channel frame.

Abstract: An apparatus and a method for transmitting control information in a mobile communication system are disclosed. In a mobile communication system including a transmitter for transmitting data and a receiver for receiving the data, when transmitting information regarding whether the data have been received, the receiver generates identifiers having different signs according to whether received data contain an error, adds the generated identifiers to a physical channel, and transmits the physical channel. The transmitter detects a sign corresponding to an existence or absence of an error from the information regarding whether or not the data have been received, detects transmission error for the data according to the detected sign, and determines whether the data are retransmitted according to a result of the detection.