Abstract:
The present invention relates to a synchronization method of a femtocell base station and a femtocell base station using the same. More specifically, the invention relates to a synchronization method of a femtocell base station and a femtocell base station using the same, wherein the femtocell base station, using a femtocell for an indoor or shadow area of an existing cell, receives a preamble signal and adjusts downlink synchronization based on the preamble signal; transmits a ranging signal to a macrocell base station and receives uplink synchronization information as a result of the transmission of the ranging signal so as to ensure the uplink synchronization of a terminal; and eliminates interference from an undesirable signal by maintaining orthogonality between subcarriers while using the same or different subcarriers of which the frequency band is the same as that of a macrocell. For this purpose, the invention provides a synchronization method of a femtocell base station which comprises the steps of: enabling the femtocell base station to adjust time synchronization to a preamble signal when the femtocell base station receives the preamble signal from a macrocell base station in an OFDMA (Orthogonal Frequency Division Multiple Access) communication system where the femtocell exists in a macrocell; and transmitting a symbol to a terminal which belongs to the femtocell in order to ensure the time synchronization of the femtocell base station.
Abstract:
The present invention relates to an adaptive transmitting device using limited feedback information in a mobile communication system, and a method thereof. According to an exemplary embodiment of the present invention, when the base station transmits a pilot signal to the terminal, the terminal generates channel information by using the pilot signal, generates additional channel information from the channel information, and transmits the channel information and the additional channel information to the base station. The base station determines band allocation, power allocation, and modulation methods for each use by using received feedback information, and transmits modulated traffic data to the terminal according to the determined methods.
Abstract:
The present invention relates to a mobile communication system, and to a method for managing terminal paging in the system. A paging method of a terminal is characterized by comprising the steps of: receiving, from a base station, both a local counter value for synchronization with the base station and a local ID that the base station has allocated to the terminal; synchronizing the base station and the counter using the local counter value so as to enter an idle state; and checking the local counter and a paging trigger message contained in the subframe corresponding to the local ID. According to the present invention, local IDs are each allocated to the respective multiple MTC terminals, and therefore trigger periods can be efficiently managed in a network. Further, the multiple MTC terminals can be grouped using the allocated local IDs, thus achieving advantages of an increased number of MTC terminals which can be managed in the network.
Abstract:
The present invention relates to an adaptive transmitting device using limited feedback information in a mobile communication system, and a method thereof. According to an exemplary embodiment of the present invention, when the base station transmits a pilot signal to the terminal, the terminal generates channel information by using the pilot signal, generates additional channel information from the channel information, and transmits the channel information and the additional channel information to the base station. The base station determines band allocation, power allocation, and modulation methods for each use by using received feedback information, and transmits modulated traffic data to the terminal according to the determined methods.
Abstract:
Disclosed are an adaptive pilot symbol assignment method that flexibly controls the number of transmit antennas according to each user's moving speed, channel status, or user request, and assigns proper pilot symbols in the downlink of an OFDMA (Orthogonal Frequency Division Multiplexing Access) based cellular system; and a sub-carrier allocation method for high-speed mobile that allocates some sub-carriers to assign proper pilot symbols for ultrahigh-speed mobile users, and the rest of the sub-carriers to the other users to assign proper pilot symbols to the users, on the assumption that the ultrahigh-speed mobile users have a traffic volume almost insignificant to the whole traffic volume.
Abstract:
The present invention relates to a bumper lower stiffener formed at the lower portion of the front bumper of a vehicle and a manufacturing method thereof. More specifically, the present invention relates to a bumper lower stiffener manufactured using a steel pipe formed by hot pressing and a manufacturing method thereof. The present invention provides a method for manufacturing the horizontal member of the bumper lower stiffener, which includes a cutting step of cutting a steel pipe added with quenching elements at a predetermined length; a heat treatment step of heating the cut steel pipe at a molding temperature; a hot pressing step of hot-pressing the heated steel pipe with press molds into the shape of the horizontal member having plane surface sections at the both sides thereof; and a cooling step of rapidly cooling the formed horizontal member in the state that the press molds are closed.
Abstract:
The present invention relates to a mutant HIV-1 (Human immunodeficiency virus-1) protease capable of effectively enhancing cell-mediated immune responses to DNA vaccination, and use of a nucleic acid encoding the same as a vaccine adjuvant. The mutant HIV-1 protease according to the present invention has inactivated or attenuated proteolytic activity, while retaining chaperone-like activity. When the mutant HIV-1 protease is used together with a DNA vaccine against the HIV-1 envelope protein or the HPV antigen (E6 or E7), cell-mediated immune responses can be effectively enhanced for the prevention or treatment of AIDS or cervical cancer.
Abstract:
Disclosed is a random access data transmission system and method using OFDMA. The system includes a scheduling ID into an access grant on a preamble for a random access, and transmits it together with an acknowledgment or a non-acknowledgment of the preamble, a base station uses the scheduling ID to notify the mobile station of a random access data transmittable time and a data transmission channel through a control channel, and the mobile station transmits a preamble in advance. After receiving a transmission assignment instruction corresponding to a scheduling ID through the control channel, the mobile station transmits random access data through an assigned channel.
Abstract:
Disclosed is a downlink signal configuring method and device, and synchronization and cell search method and device using the same in a mobile communication system. A downlink frame has plural symbols into which pilot subcarriers are distributively arranged with respect to time and frequency axes. Initial symbol synchronization and initial frequency synchronization are estimated by using a position at which autocorrelation of a cyclic prefix of a downlink signal and a valid symbol of the downlink is maximized, and cell search and integer-times frequency synchronization are estimated by using pilot subcarriers included in the estimated symbol. Fine symbol synchronization, fine frequency synchronization, and downlink frame synchronization is estimated by using an estimated cell search result. Downlink frequency and time tracking is performed, cell tracking is performed by using a position set of pilot subcarriers inserted into the downlink frame, fine symbol synchronization tracking and fine frequency synchronization tracking are repeated by using the pilot subcarriers to perform the frequency and time tracking of the downlink frame.
Abstract:
Disclosed are an adaptive pilot symbol assignment method that flexibly controls the number of transmit antennas according to each user's moving speed, channel status, or user request, and assigns proper pilot symbols in the downlink of an OFDMA (Orthogonal Frequency Division Multiplexing Access) based cellular system; and a sub-carrier allocation method for high-speed mobile that allocates some sub-carriers to assign proper pilot symbols for ultrahigh-speed mobile users, and the rest of the sub-carriers to the other users to assign proper pilot symbols to the users, on the assumption that the ultrahigh-speed mobile users have a traffic volume almost insignificant to the whole traffic volume.