Sk Telecom Company, Ltd.

Airpoint Co., Ltd.

Jong-Tae Ihm

Young-Lak Kim

Hyun-Wook Kim

Nam-Gun Kim

Sung-Ho Shin

Sung-min Cho

Sang-shin Lee

Seong-Soo Park

Joo-Sik Lee

Sung-Jun Baik

Dong-Hahk Lee

Seong-Keun Kim

Duk-Kyung Kim

Byung-Suk Lee

Ra-Mi Lee

Jae-Hwang Yu

Sung-Youl Park

Gyeong-Ho Choi

Disclosed is a method and system for estimating an adaptive joint channel in a CDMA system based on TDD. The method includes the steps of a) receiving activity information of a mobile terminal; b) parsing the activity information, and transmitting a midamble sequence to the mobile terminal when a result of the parsing shows that the mobile terminal is in an ON state; c) conducting adaptive joint channel estimation by using the midamble sequence in the mobile terminal; and d) conducting adaptive joint detection by using a channel impulse response of the mobile terminal, obtained as a result of conducting the adaptive joint channel estimation. The method and system decreases the complexity in channel estimation and additionally increases the accuracy of channel estimation by reducing transmission power consumption and eliminating unnecessary interference.

Method and system for estimating adaptive combined channel in CDMA system based on time division duplex system

Disclosed herein is a mobile communication terminal and handover method therefor, which enable handover of a mobile communication terminal that is using a packet data service or is in a dormant state in a mobile communication network in which asynchronous and synchronous networks coexist. In the handover method, if a channel is assigned between a mobile communication terminal and a synchronous mobile communication system in response to a request from an asynchronous mobile communication system as a mobile communication terminal using packet data service in the asynchronous mobile communication system moves into an area of the synchronous mobile communication system, call setup is performed. A node B of the asynchronous communication releases a connection to the mobile communication system and assigns a new mobile IP to the mobile communication terminal, thus providing continuous packet data service to the mobile communication terminal.

System for packet data service in the mixed network of asynchronous communication network and synchronous communication network and hand-over method thereof

The handover method includes the steps of the base stations of the synchronous mobile communication network transmitting dummy pilot signals for the asynchronous mobile communication network, the mobile communication terminal, for which call connection with the asynchronous mobile communication network is performed through the asynchronous wireless device, determining whether the dummy pilot signals for the asynchronous mobile communication network have been received through the asynchronous wireless device; the mobile communication terminal requesting handover from the asynchronous mobile communication network if it is determined that the dummy pilot signals for the asynchronous mobile communication network have been received; and the asynchronous mobile communication network determining that handover is possible, notifying the mobile communication terminal of the determination that handover is possible, and the asynchronous mobile communication network requesting handover to the synchronous mobile communication network, thus performing handover.

Hand over method for dual band/dual mode mobile communication terminal

Disclosed herein is a handover method for a mobile communication terminal in a mobile communication network in which an asynchronous network and a synchronous network coexist. In the present invention, as a mobile communication terminal, which is making a call through an asynchronous mobile communication system, moves into the area of a synchronous mobile communication system, and thus a handover event occurs, the establishment of a call with a synchronous mobile communication system is performed by the automatic call termination or origination of the mobile communication terminal while a connection between the asynchronous modem unit of the mobile communication terminal and the asynchronous mobile communication system is maintained, and then the connection with the asynchronous mobile communication system is released. Accordingly, a call interruption can be prevented at the time of handover between heterogeneous networks.

Method for hand-over in the mixed network asynchronous communication network and synchronous communication network

Disclosed herein is a radio frequency (RF) repeater comprising an analog signal processing unit and a digital signal processing unit, wherein the analog signal processing unit includes a filtering unit; an amplification unit on receiving side; a frequency conversion unit on receiving side; a frequency conversion unit on transmitting side; and an amplification unit on transmitting side, and the digital signal processing unit includes a receiving signal detection unit; the automatic gain control unit; a feedback signal detection unit; a feedback signal combining unit; a feedback signal elimination unit; an automatic delay control unit; and the control unit. According to the RF repeater and repeating method, installation cost is reduced, limitations in output magnitude and installation are overcome, and ensuring high output power characteristics.

Radio repeater for mobile communication system and repeating method using the same

The present invention relates to a method of controlling a mobile communication terminal and mobile communication system therefor. In the mobile communication terminal control method, a synchronous base station of a synchronous area placed at the boundary region of an asynchronous area transmits a dummy pilot signal at the same frequency as that of a signal used in the asynchronous mobile communication system and drives a synchronous modem unit of the mobile communication terminal moving from the asynchronous area to the synchronous area. A handover cell is constructed at the boundary between synchronous and asynchronous areas, and a handover base station in the handover cell transmits a signal including system information at the same frequency as that of a signal used in the asynchronous mobile communication system, thus driving the synchronous modem unit of the mobile communication terminal entering the handover cell.

Method for controlling multi-mode multi-band mobile communication terminal for hand-over between asynchronous communication network and synchronous communication network and mobile communication system therefor

The present invention relates to a dual band/dual mode mobile communication terminal, which can perform stable roaming between synchronous and asynchronous mobile communication networks. The mobile communication terminal of the present invention includes an antenna (), an asynchronous RF device (), a synchronous RF device (), and a common module (). The antenna () transmits/receives radio waves to/from an asynchronous mobile communication network () and a synchronous mobile communication network (). The asynchronous RF device () performs asynchronous communication with the asynchronous mobile communication network () through the antenna (). The synchronous RF device () performs synchronous communication with the synchronous mobile communication network () through the antenna (). The common module () provides common resources at the time of wirelessly communicating with the synchronous and asynchronous mobile communication networks through the synchronous and asynchronous RF devices.

Dual band/dual mode mobile communication terminal and control method thereof

Disclosed herein is a mobile communication terminal and handover method therefor, which enable handover of a mobile communication terminal that is using a packet data service or is in a dormant state in a mobile communication network in which asynchronous and synchronous networks coexist. In the handover method, if a channel is assigned between a mobile communication terminal and a synchronous mobile communication system in response to a request from an asynchronous mobile communication system as a mobile communication terminal using packet data service in the asynchronous mobile communication system moves into an area of the synchronous mobile communication system, call setup is performed. A node B of the asynchronous mobile communication releases a connection to the mobile communication system and assigns a new mobile IP to the mobile communication terminal, thus providing continuous packet data service to the mobile communication terminal.

The present invention relates to a handover method for a dual band/dual mode mobile communication terminal between a synchronous mobile communication network and an asynchronous mobile communication network. The method includes the first step of the main processor setting an initial mobile communication network connection to the asynchronous mobile communication network and connecting to the asynchronous mobile communication network when power is applied; the second step of activating the synchronous RF device and setting up a connection to the synchronous mobile communication network when the intensity of a signal from the asynchronous mobile communication network is equal to or lower than a first predetermined reference value; the third step of determining whether the intensity of a signal from the asynchronous mobile communication network is equal to or lower than a second predetermined reference value previously set for the handover; the fourth step of activating the connection to the synchronous mobile communication network set up at the second step if the intensity of the signal from the asynchronous mobile communication network is determined to be equal to or lower than the second predetermined reference value at the third step; and the fifth step of releasing the connection to the asynchronous mobile communication network.

In the handover method, a radio network controller periodically measures the wireless environment of a mobile communication terminal, determines whether handover is required, and informs the asynchronous mobile switching center of the asynchronous communication system that the handover is required. The asynchronous mobile switching center requests the handover and a synchronous mobile switching center assigns a forward channel to the mobile communication terminal. The mobile communication terminal prepares for communication with a synchronous mobile communication system according to the direction of the asynchronous mobile switching center, and causes a backward channel with respect to the synchronous communication system to be assigned to the mobile communication terminal. The synchronous mobile switching center informs the asynchronous mobile switching center that handover has been completed, and causes a connection between the asynchronous mobile switching center and the radio network controller to be released.

Method for handover between asynchronous communication network and synchronous communication network

In the present invention, as a mobile communication terminal, which is using service in the area of an asynchronous mobile communication system, detects signals from a synchronous mobile communication system, the mobile communication terminal repeatedly performs a process of examining whether, in a predetermined time, signals from the asynchronous mobile communication system have been detected a designated number of times, and measuring the intensity of the signals. When the number of times that the intensity of signals from the asynchronous mobile communication system is smaller than a designated number of times, or no signals from the asynchronous mobile communication system are detected, within the predetermined time, it is determined whether to perform handover of the mobile communication terminal.

Method of hand-over in the mixed network of asynchronous communication network and synchronous communication network

Disclosed herein is a mobile communication terminal and handover method therefor. In the mobile communication system, a Gateway GPRS Support Node (GGSN) of the asynchronous network is connected to a Packet Data Service Node (PDSN) of the synchronous network. Accordingly, as a mobile communication terminal, using packet data service in the asynchronous mobile communication system, moves into an area of a synchronous mobile communication system, the synchronous mobile communication system sets control signals and traffic to transmit packet data in response to a request from the asynchronous mobile communication system. Further, if forward and reverse channels are assigned between the mobile communication terminal and the synchronous mobile communication system, call setup is performed to provide the packet data service, and then a node B of the asynchronous mobile communication system releases the connection to the mobile communication terminal.

Growing community of inventors

Seongnam-si, South Korea

Jong-Tae Ihm