Abstract: There is provided a method of switching a zone through which services are provided to subscriber stations (SS) in an environment using an FRF-1 zone and an FRF-3 zone based on traffic load of each zone in order to reduce the inter-cell interference in 802.16/WiBro systems. The service zone switching method based on load considering inter-cell interference in 802.

Abstract: Disclosed is a system and a method for collecting various road traffic information, road image information, and position information of a position information generation device carried by an object, the position of which is to be tracked, by interworking with an information provision means and using the collected information to provide service subscribers with real-time traffic information, traffic prediction, or position information of the object via wireless Internet, satellite broadcasting, DMB, or cable data broadcasting. The system and method can provide detailed traffic information service regarding a specific region or location on a nationwide scale, predict traffic to properly deal with it, and easily provide position information of an object to be tracked.

Abstract: A method and apparatus of allocating downlink power in a radio access station system are disclosed. The method of allocating transmission power to a plurality of terminals in a radio access station system according to the present invention includes (A-1) calculating an allocation power for the respective terminals based on downlink quality information of the respective terminals; (A-2) calculating a minimum requirement power for the respective terminals based on the downlink quality information; and (A-3) allocating the transmission power by distributing part of excess power of a first terminal group having the allocation power higher than the minimum requirement power to the second terminal group having the allocation power lower than the minimum requirement power, and the part of excess power is a sum of insufficient power of the second terminal group. As a result, the loss of the quantity of service transmission of the radio access station is reduced and service areas can be expanded.

Abstract: A method and apparatus for Automatic Repeat reQuest (ARQ) feedback in a wireless communication system. The ARQ feedback method includes checking whether feedback transmission on received ARQ blocks with a Cumulative ACK type is possible, and performing ARQ feedback transmission with the Cumulative ACK type when the feedback transmission with the Cumulative ACK type is possible; calculating the number of blocks to be transmitted feedback with a Cumulative ACK with Block Sequence ACK type and the number of blocks to be transmitted feedback with a Cumulative with Selective ACK type, when the feedback transmission with the Cumulative ACK type is not possible; selecting a feedback type by comparing the number of blocks to be transmitted between the Cumulative ACK with Block with Block Sequence ACK type and the Cumulative with Selective ACK type; and performing ARQ feedback with the selected feedback type.

Abstract: Disclosed is an apparatus and a method for implementing efficient redundancy and an expanded service coverage in a Radio Access Station (RAS) system. In the RAS system, if the main processor unit generates switching control signals in response to the sensed failures on sensing a failure in any of the channel cards and the transceivers or a failure in any of the high-power amplifiers, all supporting M (i.e., the number of FAs equal to or more than three) and K (i.e., the number of sectors equal to or more than three), between the transceivers and the predetermined Time Division Duplex (TDD) switches connected to the antennas, the RF switch unit switches a path based on the generated switching control signals so as to substitute the failed module either by one additional redundancy transceiver per M and K or by one additional redundancy high-power amplifier per M and K. As a result, an efficient N+1 redundancy structure is embodied.

Abstract: Disclosed is an apparatus and a method for generating a local signal and a Radio Access Station (RAS) using the same in a wireless telecommunication system. The apparatus includes: an Intermediate Frequency (IF) local unit for generating an IF local signal; and a Radio Frequency (RF) local unit for generating an RF local signal, wherein the IF local unit comprises: a first frequency synthesizer for generating the IF local signal; and a first distributor for distributing the IF local signal into an IF local signal for transmission and an IF local signal for reception, and wherein the RF local unit comprises: a second frequency synthesizer for generating the RF local signal; and a switch for distinguishing the RF signal into an RF local signal for transmission and an RF local signal for reception, and switching the RF local signal for transmission to a transmission path and the RF local signal for reception to a receive path.

Abstract: The present invention relates to an apparatus and method for transmitting uplink signals in a wireless telecommunication system. According to the present invention, it is characterized that at least one uplink signal is allocated to other symbol duration for time dispersion in case a plurality of uplink signals are scheduled to be allocated to the same symbol duration of the uplink frame that the terminal transmits to the base station. Accordingly, the terminal can enhance the power spectral density of the uplink signal and the error rate can be reduced.

Abstract: The present invention relates to an apparatus and method for estimating a channel in a MIMO wireless telecommunication system supporting the 0FDM/0FDMA. The present invention, in estimating a channel by using two or more pilots included in at least one received signal among received signals of a first channel and a second channel received through a first receiving antenna and received signals of a third channel and a fourth channel received through a second receiving antenna, determines a subchannel mapping rule respectively for the received signals of the first channel to the fourth channel, and estimates a channel with a different method according to the determined subchannel mapping rule.

Abstract: An automatic gain control circuit and method for stably maintaining received power in a mobile Internet system is disclosed. An efficient automatic gain control circuit structure is provided which uses no separate analog circuit elements in a process of detecting the level of a received signal. Therefore, it is possible to reduce a complexity of hardware, the size of the automatic gain control circuit and a manufacturing cost. Further, an automatic gain control (AGC) unit, which is made in a Fluctuating Gunn-Peterson Approximation (FGPA) type, performs an automatic gain control simply by referring to a lookup table based on the level of a received signal. Therefore, the present automatic gain control circuit can not only be more simply designed or modified than a conventional automatic gain control circuit, but also stabilize the level of the received signal simply without periodically checking the level of the received signal for the automatic gain control.

Abstract: A channel estimation apparatus of the present invention includes a preamble channel operation unit for carrying out an operation on pilot channel estimation values of pilots, which are transmitted from a transmitting antenna that transmits a preamble, as an improved pilot channel estimation value by employing a preamble channel estimation value based on a preamble included in received signals respectively received by a plurality of receiving antennas, a first channel estimation unit for estimating a channel for each of the receiving antennas through interpolation of a symbol axis and a frequency axis employing the improved pilot channel estimation value, and a second channel estimation unit for estimating a channel for each of the receiving antennas through interpolation of a symbol axis and a frequency axis employing pilot channel estimation values of pilots transmitted from the same transmitting antenna, of pilots transmitted from a transmitting antenna that does not transmit the preamble, of a plurality of

Abstract: The present invention relates to a method and apparatus for performing a handover in a wireless telecommunication system. The present invention measures a signal strength of a serving base station and a neighbor base station, and triggers an anchor base station update when the signal strength of the neighbor base station is higher than the signal strength of the serving base station by a predetermined triggering value, thereby preventing the signal strength of the serving base station from being rapidly decreased and capable of efficiently performing a handover.

Abstract: A frequency reusing method in a wireless communication system including a coverage region, which has first, second and third regions, and a radio access station (RAS) transmitting a traffic to a portable subscriber station (PSS) in the coverage region, comprises (a) transmitting the traffics by assigning an identical frequency band to the first, second and third regions during a first interval; (b) transmitting the traffics by assigning the identical frequency band to the first region during a second interval; (c) transmitting the traffics by assigning the identical frequency band to the second region during a third interval; and (d) transmitting the traffics by assigning the identical frequency band to the third region during a fourth interval.

Abstract: The present invention relates to an apparatus for estimating and compensating a carrier frequency offset, and a data receiving method in a receiver of a wireless communication system. The apparatus correlates a received signal with a signal delayed by a predetermined period of the received signal in a correlation window, wherein the correlation window is set based on a Cycle Prefix (CP) and a preamble repetition length from a predetermined position, converts the correlated value into a phase value, compensates a phase of the converted result according to preamble segment numbers, and estimates an initial carrier frequency offset value.

Abstract: The present invention relates to an apparatus and method for estimating and compensating for a time offset and a carrier frequency offset in a Multiple Input Multiple Output (MIMO) communication system that supports Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiplexing Access (OFDMA). According to the present invention, a phase difference of pilot signals of the same transmitting antenna, which are received through receiving antennas, is calculated. An arc tangent operation is then carried out on the phase difference of the pilot signals to calculate a time offset linear phase and/or a carrier frequency offset linear phase. Further, a time offset compensation value and/or a carrier frequency offset compensation value are found by employing the time offset linear phase and/or the carrier frequency offset linear phase.

Abstract: A method of detecting a frame boundary of a received signal in a digital communication system, the method including: generating a delayed signal by delaying the received signal by a predetermined period; calculating a correlation value by correlating the received signal with the delayed signal for a predetermined correlation length in a time domain; and determining a timing index corresponding to a maximum value, as a frame boundary index, from a plurality of correlation values which are obtained by repeating the calculation. According to an embodiment of the present invention, a correlation calculation in a time domain is performed without oversampling, in a limited length including a cyclic prefix. Accordingly, accuracy of frame boundary detection may be improved and complexity of hardware and software may also be reduced.

Abstract: There is provided a method of switching a zone through which services are provided to subscriber stations (SS) in an environment using an FRF-1 zone and an FRF-3 zone based on traffic load of each zone in order to reduce the inter-cell interference in 802.16/WiBro systems. The service zone switching method based on load considering inter-cell interference in 802.

Abstract: An apparatus for searching for a cell in a mobile communication system, including: a preamble sequence storage unit storing preamble sequences each of which corresponds to one preamble index, and a cell searching unit correlating a received signal and the stored preamble sequences in a time domain and identifying the preamble index corresponding to the received signal. The cell searching apparatus correlates a received signal and stored preamble sequences in a time domain. The apparatus employs binary quantization of preamble sequences to reduce calculation and memory size. Also, the stored preamble sequences are phase pre-rotated according to a segment number, to prevent from a burden of frequency offset correction caused by three different hypotheses. Accordingly, a complexity of the cell searching apparatus is reduced and cell searching performance becomes more accurate.

Abstract: The present invention relates to a router (for example, ACR) which provides a mobility function and a delivery function with a portable Internet core network while controlling RAS, which is a base station, as a basis network element of an access network in a portable Internet (for example, WiBro) service, and particularly, provides a new paging algorithm in order to overcome the limit of a paging in a conventional routing scheme, and to effectively process the buffering function for seamless connection maintenance and the paging function for a destination terminal with respect to the terminated call of a terminal in a non-active mode. A router of the present invention includes a control plane that buffers a data packet for a non-active mode, and performs a paging for a corresponding non-active mode terminal.

Abstract: A likelihood metric calculation method including: estimating a channel of a received signal and generating a channel estimate; compensating a channel of the received signal according to the channel estimate; calculating a region variable according to the channel estimate; and comparing the region variable and a magnitude of the compensated received signal and calculating a likelihood metric of the received signal according to a result of the comparison.

Abstract: Disclosed is an interface for interfacing an element management server in a wireless telecommunication system and a method for the same. The element management server for managing an ACR and an RAS, which are elements of the wireless telecommunication system, are adapted to interwork with the ACR and the RAS, respectively, so that the server can directly manage the ACR and the RAS and, particularly, the RAS can be operated more efficiently and maintained/repaired more quickly. The element management server manages the version of a package regarding all processors of lower elements and software to be loaded, and respective processors of the lower elements store nothing but their setup information (e.g. software, version) so that, if necessary, the element management server can transmit specific software only to the lower elements. This guarantees fast software download and provides users with stable services.