Abstract: An apparatus and method for cell acquisition and downlink synchronization acquisition in an OFDMA wireless communication system are provided. In an SS apparatus in a broadband wireless communication system, a preamble subcarrier acquirer extracts subcarrier values having a preamble code from an FFT signal. A multiplier code-demodulates the subcarrier values by multiplying the subcarrier values by a preamble code. A correlator calculates a plurality of differential correlations in the code-demodulated signal. An IFFT processor IFFT-processes the differential correlations by mapping the differential correlations to subcarriers. A maximum value detector detects a maximum value from the IFFT signal and calculates a timing offset using an IFFT output index having the maximum value.

Abstract: In a light emitting diode, a first semiconductor layer supplies electrons, and a second semiconductor layer supplies holes. An active layer is formed between the first and second semiconductor layers. The active layer receives electrons and holes, and emits light in response to coupling between the electrons and the holes. A first reflective layer is formed on a bottom portion of the first semiconductor layer, and a second reflective layer is formed on a top portion of the second semiconductor layer. The light emitted from the active layer exits toward a side of the active layer.

Abstract: An apparatus and method for changing an uplink power control scheme according to mobile status in a TDD mobile communication system are provided. A subscriber station transmits to a base station a power control change request message including information about a requested power control scheme. Upon receipt of the power control change request message, the base station selects a power control scheme for the uplink of the subscriber station and transmits to the subscriber station a power control change command message including information about the selected power control scheme. The subscriber station extracts, upon receipt of the power control change command message from the base station, the power control scheme information from the power control change command message and selects a power control scheme according to the extracted information.

Abstract: An apparatus and method for channel information feedback in a multiple antenna system are provided. The method includes selecting at least one code for at least one Eigen vector based on channel information with a serving node from a codebook including at least one code, constructing a set of codes orthogonal to a first code including the at least one selected code, and indicating the first code using an amount of information that enables expression of the codes of the codebook, indicating codes, other than the first code, in the constructed set using an amount of information that enables expression of the codes included in the set and performing feedback to the serving node.

Abstract: Information for different subscribers of a service with the same modulation and channel encoding method is transmitted by allocating radio resources in a wireless portable Internet system. Also, identifier information on the subscriber of a concurrently allocated radio resource is transmitted through common control information. Therefore, information for a plurality of subscribers coexists in a single radio resource block, and it can be easily transmitted. Since a subscriber station which has received downlink information can know to which radio resource block the information for the corresponding station is allocated through the subscriber identifier information transmitted as common control information, the subscriber station can access desired information by accessing a specific radio resource block to which information for the subscriber is allocated in the received frame.

Abstract: A wireless communication system that divides an entire frequency band into a plurality of subcarrier bands and includes a plurality of subchannels, each of which includes a number of subcarrier bands. The number of subcarrier groups is equal to the number of the base stations included in the system and are generated by classifying the subcarrier bands in a period. For a particular base station, corresponding subcarrier bands are detected from each of the groups according to a sequence. The subcarrier bands detected from each of the groups are assigned as a subchannel for the particular base station. Further, the indexes of the subcarrier groups to which each of subcarriers constituting a subchannel belongs are changed whenever the subchannel is assigned, so as to acquire the desired diversity gain.

Abstract: An apparatus and method for assigning subchannels of a transmitter in a communication system. The method includes dividing an entire frequency band into m subcarrier groups; mapping each of the m subcarrier groups to a subcarrier group index, wherein a subchannel includes n subcarriers selected from each of the m subcarrier groups corresponding to a subcarrier group index sequence; determining that a first data is needed to transmit in a first timing point; and assigning a first subchannel in the first timing point using a first subcarrier group index sequence. The first subcarrier group index sequence is different from a second subcarrier group index sequence used for assigning a second subchannel in a second timing point.

Abstract: A broadband wireless communication system using a fixed allocation scheme is provided. The system includes a controller for configuring change report information to report occurrences of resource release or change when resources are released or changed in a fixed allocation region, a generator for generating a fixed allocation Information Element (IE) including the change report information and history information regarding the resource release or change, and a transmitter for transmitting the fixed allocation IE.

Abstract: Provided is a method of manufacturing a nitride-based semiconductor light-emitting device having an improved structure in which optical extraction efficiency is improved. The method of manufacturing a nitride-based semiconductor light-emitting device including an n-doped semiconductor layer, an active layer, a p-doped semiconductor layer, an n-electrode and a p-electrode includes: forming an azobenzene-functionalized polymer film on a base layer by selecting one layer from the group consisting of the n-doped semiconductor layer, the p-doped semiconductor layer, the n-electrode and the p-electrode as the base layer; forming surface relief gratings of a micro-pattern caused by a photophysical mass transport property of azobenzene-functionalized polymer by irradiating interference laser beams onto the azobenzene-functionalized polymer film; forming a photonic crystal layer using a metal oxide on a recessed gap of the azobenzene-functionalized polymer film, and removing the azobenzene-functionalized polymer film.

Abstract: An apparatus and method for transmitting data restoration information in a communication system are provided, in which a BS transmits first data in a first zone of a frame, transmits second data in a second zone of the frame, transmits first data restoration information for restoring the first data in the first zone, and transmits second data restoration information for restoring the second data in the second zone. The first data comprises the same data as data transmitted simultaneously by at least one repeater and the second data comprises data that is different from data transmitted by the at least one repeater.

Abstract: An apparatus and method for transmitting and receiving data in a communication system are provided. In the method, a BS selects a repeater group from among a plurality of repeater groups, for use in transmitting first data to an MS and transmits the first data to the MS according to the number of repeaters of the selected repeater group. The first data is different from data transmitted by the repeaters of the selected repeater group.

Abstract: A system and method for transmitting/receiving a signal in a communication system are provided, in which a transmitter determines to change a transmission time of a superframe header, when a structure of a superframe is changed, determines the transmission time of the superframe header according to a result of the determination to change the transmission time of the superframe header, transmits information about the determined transmission time to a receiver, and transmits the superframe header at the determined transmission time.

Abstract: Provided is a red phosphor which is excellent in emission efficiency by a long wavelength UV excitation source and has a fine and uniform particle size. The red phosphor includes a compound represented by (Li.sub.(2?z)?xM.sub.x)(AO.sub.4).sub.y:Eu.sub.z,Sm.sub.q and a flux wherein M is K, Mg, Na, Ca, Sr, or Ba, A is Mo or W, 0.ltoreq.x.ltoreq.2, 0.5.ltoreq.y.ltoreq.5, 0.01.ltoreq.z.ltoreq.1.5, and 0.001.ltoreq.q.ltoreq.1.0. Provided is also a method of preparing the red phosphor.

Abstract: An apparatus and method for preventing errors in an HARQ operation and improving HARQ performance are provided. In the apparatus and method, upon receipt of HARQ feedback information, an information interpreter interprets the HARQ feedback information and determines whether the HARQ feedback information includes an error. If the HARQ feedback information includes an error, a scheduler controls a data pattern with the receiver to be generated.

Abstract: An apparatus and a method for allocating feedback channels in a wireless communication system are provided. The method includes determining a number of common feedback channels to be allocated commonly to one or more terminals using a capacity loss according to the feedback channel allocation; and generating feedback channel change information to change the number of the common feedback channels per terminal.

Abstract: A method and apparatus for controlling a transmission (Tx) power in a mobile communication system based on fractional frequency reuse are provided. In a method of operating a base station (BS) for controlling the Tx power in the mobile communication system, the method includes receiving from neighboring BSs received signal strength indication (RSSI) information for one or more restricted band allocated, calculating backoff values of the Tx power for the restricted bands by using the RSSI information, and determining the Tx power for each restricted band by using a difference between the backoff value of the Tx power for the restricted band and a maximum Tx power. Accordingly, resources can be further effectively used.

Abstract: An apparatus and method for estimating a carrier to interference and noise ratio (CINR) in a mobile communication system based on a fractional frequency reuse are provided. The method includes receiving a report on CINR information on a common zone from a mobile station (MS) allocated a restricted zone, calculating a received signal power value using a CINR value and an interference level value for the common zone of the MS, and estimating a CINR value for a restricted zone using the received signal power value of the MS and an interference level for the restricted zone.

Abstract: A two-dimensional subchannel assigning method and apparatus in a time-frequency domain where a plurality of subcarriers are arranged along a time domain with a plurality of symbols and along a frequency domain with a plurality of subbands in an OFDM communication system. In the subchannel assigning method, the plurality of subcarriers are divided into a plurality of frequency bands and the frequency bands are grouped into the subbands. A plurality of groups are generated by dividing each of the subbands in the frequency domain by the number of the symbols in the time domain. Subcarriers selected from the respective groups in each of the subbands are assigned as an AMC subchannel to which an AMC scheme is applied.

Abstract: Provided are a highly transmissive optical thin film having an improved structure, in which, optical reflection (due to a difference in the refractive index between a semiconductor material and the air, when light is extracted from a semiconductor light emitting device into the air) may be suppressed, an optical output loss may be reduced and light transmittance efficiency may be maximized or increased, a semiconductor light emitting device having the same, and methods of fabricating the same.

Abstract: An apparatus and method for circuit mode resource allocation in a Broadband Wireless Access (BWA) system is disclosed. The method includes generating a first resource allocation message which comprises currently used slot bitmap information with respect to a circuit mode region in a frame; allocating resources to one or more terminals with respect to currently unused slots in the circuit mode region according to the currently used slot bitmap information; and generating a second resource allocation message which comprises information relating to the resource allocation. Thus, the effective circuit mode resource allocation can be achieved without holes in the circuit mode, while maintaining backward compatibility with the existing standards.