Abstract: A method and apparatus of a portable terminal estimate a step length of a pedestrian. An accelerometer detects acceleration caused by a movement of the portable terminal as a pedestrian carrying the portable terminal walks. A gyroscope detects angular velocity caused by the movement of the portable terminal as the pedestrian walks. A controller determines a magnitude of a swinging motion of the portable terminal by using at least one of the detected acceleration and angular velocity, determines that the portable terminal makes the swinging motion when the magnitude of the swinging motion is equal to or greater than a predetermined value, determines a carrying position of the portable terminal in the pedestrian's body by using at least one of the detected acceleration and angular velocity, and estimates a step length of the pedestrian according to the determined carrying position of the portable terminal.

Abstract: Walking status estimation in a portable terminal includes a method for estimating walking status. The method includes setting an observation using an estimated temporary step length, an acceleration variance, and a step frequency. The method also includes generating an observed probability vector comprising probabilities per walking status according to the observation. The method further includes determining final probabilities per walking status by multiplying the observed probability vector by at least one of an initial probability matrix and one or more status transition probability vectors. The method still further includes determining a walking status having the greatest final probability as a final walking status.

Abstract: A method and system for estimating a step length in a pedestrian navigation system is provided. The method of estimating a step length in a pedestrian navigation system includes calculating a walking frequency and an acceleration variance of a pedestrian by using acceleration data acquired from an acceleration sensor, calculating a walking distance of the pedestrian by using GPS data acquired from a GPS receiver, and estimating a step length of the pedestrian by using the calculated walking frequency, acceleration variance, and walking distance.