Abstract: A method of and an apparatus therefor searching a cell in a mobile station of a communication system in which a plurality of cells are grouped into a plurality of cell groups, and each cell group includes at least two cells. The method includes detecting a primary synchronization signal and a secondary synchronization signal from a received signal, and identifying a cell based on a combination of the primary synchronization signal and the secondary synchronization signal. The secondary synchronization signal is related to the cell group to which the mobile station belongs and the primary synchronization signal is related to the cell to which the mobile station belongs within the cell group.

Abstract: A method and apparatus for discontinuously transmitting or receiving packets for low-power consumption of a terminal in a cellular system for packet transmission, for example, a method for performing discontinuous reception operation of a terminal in a wireless communication system, including: receiving parameters for performing the discontinuous reception operation from the base station; and performing, in a state being capable of transmitting or receiving data to or from the base station, the discontinuous reception operation based on the received parameters.

Abstract: Provided is a method of forming a signal in a wireless communication system in which a plurality of terminals commonly use time and frequency resources for efficient code hopping. The method includes allocating the same frequency-axis sequence and different time-axis sequences to a plurality of terminals by using a resource index according to a first slot in the first slot; and allocating different frequency-axis sequences and different time-axis sequences to the plurality of terminals by using a resource index according to a second slot in the second slot.

Abstract: A transmission method performed by a mobile station for random access channel (RACH) burst transmission diversity gain is provided. According to the method, a variety of combinations of a time switching transmit diversity (TSTD) technique, a frequency hopping technique, and a power ramping technique that are robust against fading channel environments are applied to transmission of an RACH burst, thereby increasing the probability of detecting an RACH signature of a base station. Also, by using the transmission parameters (subband frequencies, transmission antennas, power, etc.) which are used for successful transmission of an RACH burst, for transmission of a successive user packet data, reliable transmission of the successive user packet data can be performed.

Abstract: The present invention relates to a method of generating a downlink frame. The method of generating the downlink frame includes generating a first sequence and a second sequence for identifying cell groups; generating a first scrambling sequence and a second scrambling sequence that are one-to-two mapped to the sequence number of the primary synchronization signal; scrambling the first sequence with the first scrambling sequence and scrambling the second sequence with the second scrambling sequence; and generating a secondary synchronization signal including the scrambled first sequence and second sequence and mapping the secondary synchronization signal to a frequency domain.

Abstract: Provided are a cell search method, a forward link frame transmission method, an apparatus using the methods, and a forward link frame structure in an Orthogonal Frequency Division Multiplexing cellular system, wherein the time it takes to perform a cell search and the complexity of the cell search can be reduced. The cell search apparatus includes a sync acquirer which receives a signal according to a forward link frame comprising a plurality of sync channel symbols each having different intervals between the adjacent sync channel symbols and achieves synchronization of the sync channel symbols using a sync channel of the received signal, and a boundary detector which detects a frame boundary using an interval pattern between the sync channel symbols, based on the achieved synchronization.

Abstract: Provided are a channel estimation method and apparatus in mobile communication system having dispersed pilot. The channel estimation apparatus includes an entire band channel estimation unit and an edge channel estimation unit. The entire band channel estimation unit performs channel estimation on an entire frequency band. The edge channel estimation unit performs channel estimation on an edge region. By separately performing the gating operation of the entire band channel estimation unit and the gating operation of the edge channel estimation unit, a channel frequency response is more accurately calculated even in an edge region.

Abstract: Provided are an apparatus for receiving signals in an OFDM communication system using multiple transmission/reception antennas and a method thereof. The method includes modulating a predetermined part of a data stream based on a multi-dimensional reception procedure to generate a first modulated data stream; regenerating a symbol corresponding to the modulated data stream; eliminating the regenerated symbol from a remained data stream; modulating the eliminated data stream to generate a second modulated data stream; and outputting an output signal obtained by serializing the first modulated data stream and the second modulated data stream.

Abstract: An apparatus and method for determining the position of a target object in a wireless local area network (WLAN) environment are provided. According to the apparatus and method, it is possible for a user to easily identify each neighboring target object and to precisely select any desired neighboring target object. Therefore, it is possible to improve user convenience.

Abstract: A base station applies frequency switching transmission diversity and a precoding vector to a synchronization channel and applies a space-frequency block coding and a precoding vector to a broadcast channel. The base station controls the synchronization channel and the broadcast channel to be positioned adjacent each other and then generates and transmits a downlink frame. The base station includes partial information on the number of antennas in the synchronization channel, and other information thereon in the broadcast channel.

Abstract: Provided are a method and apparatus for transmitting control information and packet data. The method includes generating control channels which transmit the control information; generating control indication channel which indicates whether the control channels are transmitted or not; generating data channels in order to transmit the packet data based on the control information; multiplexing the control channels, the control indication channels, and the data channels; and transmitting the control channels, the control indication channels, and the data channels. According to the present invention, when control information and packet data are transmitted in downlink, by transmitting additional information indicating whether control channels are transmitted or not, resources not actually allocated to control channels can be allocated to data channel and the mobile station can receive data channel using the control indication information.

Abstract: A method for converting source data to a channel-modulated signal having a plurality of pairs of in-phase (I) and quadrature-phase (Q) data in a mobile station, wherein the mobile station uses at least one channel, includes the steps of: a) encoding the source data to generate at least one data part and a control part; b) generating at least one spreading code to be allocated to the channel, wherein each spreading code is selected on the basis of a data rate of the data part and the control part and spreading codes are selected so that two consecutive pairs of the I and Q data are correspondent to two points located on same point or symmetrical with respect to a zero point on a phase domain; and c) spreading the control part and the data part by using the spreading code, to thereby generate the channel-modulated signal.

Abstract: A transmission method performed by a mobile station for random access channel (RACH) burst transmission diversity gain is provided. According to the method, by combining and using switching diversity by beam forming, frequency hopping, and power ramping, the probability that when the speed of a mobile station is low, the mobile station falls into a deep fading environment is lowered, thereby increasing the probability of detecting an RACH signature of the base station. Also, by using the transmission parameters (subbands, precoding matrixes, power, etc.) which are used for successful transmission of an RACH burst, for transmission of a successive user packet data, reliable transmission of the successive user packet data can be performed.

Abstract: The embodiments relate to a wireless communication system that counts UEs using an MBMS. The wireless communication system is connected with a UE through a radio link, and includes a Node B and a controlling radio network controller (CRNC). The Node B receives sequence setting information on a sequence included in a preamble transmitted from the UE network manager. The CRNC controls the Node B, detects a sequence according to whether to use an MBMS based on the sequence setting information, and performs a counting process for counting UEs based on whether the UE uses the MBMS. According to the embodiments, counting of UEs using an MBMS can be performed by using a predetermined sequence. Particularly, the counting process can be simplified by reducing complexity in access probability management of a network manager, thereby increasing efficiency in data transmission by reducing signaling for random access probability and omitting a random access probability calculation process.

Abstract: Provided are a random access method of a mobile station and a mobile communication device performing the same. The mobile station can obtain a diversity gain without a Random Access Channel (RACH) burst collision by hopping according to a cell group in a frequency domain and transmitting a random access when random access resources are used between neighboring cells and detect an RACH even with low transmission power by applying switching diversity together with the frequency hopping.

Abstract: The invention provides a method of generating a downlink signal and searching a cell on the basis of the downlink signal in an OFDM-based cellular system. The downlink signal includes a plurality of synchronization blocks each having a plurality of sub-frames, and a synchronization pattern composed of a combination of a cell group identification code for identifying a cell group and a frame synchronization identification code for indicating a frame start point is generated in each of the synchronization blocks. Different frame synchronization identification codes are allocated to the synchronization blocks.

Abstract: The present invention provides an OFDM symbol generating apparatus. The OFDM symbol generating apparatus generates a plurality of weight-applied symbol groups by applying a plurality of weights to a digital modulation symbol group, and generates a plurality of IFFT symbol groups by performing an IFFT operation on the plurality of weight-applied symbol groups. Subsequently, an IFFT symbol group having the minimum PAPR is selected from among the plurality of IFFT symbol groups such that a characteristic of a PAPR can be improved without reducing data transmission speed.

Abstract: Provided is a method and apparatus for discontinuously transmitting/receiving packets for low-power consumption of a terminal in a cellular system for packet transmission. The present research provides a method and apparatus that can perform a low-power consuming operation when a terminal is in active state in a cellular system. The method for discontinuously transmitting/receiving packet data to reduce power consumption of a terminal in a cellular system, including a) establishing discontinuous reception/transmission (DRX/DTX) parameters including discontinuous DRX/DTX cycle information for terminals operating in a transmission suspension mode, which is a sub-state of an active state; and b) performing DRX/DTX based on the DRX/DTX parameters in the terminals operating in the transmission suspension mode.

Abstract: The present invention relates to a transmit diversity method of a mobile communication system and a base station transmitting apparatus using the same. A first code and a second code that is diversity-encoded from the first code are generated, and transmit symbols are spread with the first code and the second code. A first transmit symbol spread with the first code and a second transmit symbol spread with the second code are mapped to symbols in frequency and time domains in a frame and transmitted through antennas. Therefore, various diversity techniques can be provided to the mobile communication system, and the diversity technique is not restricted to symbols transmitted to the same mobile station and can also be applied to a 1-bit channel.

Abstract: The present invention relates to an orthogonal frequency division multiplexing (OFDM) signal transmitting and receiving device, in which a peak to average power ratio characteristic is improved without reducing a data transmission speed. The OFDM signal transmitting device separates a digital modulated symbol as a real part and an imaginary part, and performs discrete cosine transform (DCT) and discrete sine transform (DST) operations respectively for real and imaginary part symbols, performs an inverse fast Fourier transform operation, and generates an OFDM symbol. The OFDM signal receiving device performs a fast Fourier transform operation for the OFDM symbol, and performs an inverse DCT operation and an inverse DST operation, performs a digital demodulating operation, and generates a final binary data symbol.