Abstract:
The present invention relates to a cooperative communication method, in which a plurality of cells performs multiple antenna transmission and receiving cooperatively with each other in a cellular wireless system, and a terminal transmits channel state information (CSI) wirelessly to a serving cell and to at least one cooperative cell such that the serving cell and the cooperative cell use the CSI to perform multipoint communication. Although the serving cell and the cooperative cell may be of different base stations from each other, the transmission delay and traffic increase in a backhaul network can be prevented by minimizing information exchange between these cells.
Abstract:
Provided is method of forming a signal in a wireless communication system in which a plurality of terminals commonly use a resource in the time domain and the frequency domain. The method includes multiplying a signal to be transmitted by a frequency domain orthogonal code symbol corresponding to a first cyclic shift index in a first slot to be transmitted to a base station, wherein the multiplying is performed by a first terminal and a second terminal; and multiplying information to be transmitted by a frequency domain orthogonal code symbol corresponding to a second cyclic index that is different from the first cyclic index of the first slot to be transmitted to the base station, in a second slot, wherein the multiplying is performed by the first terminal and the second terminal.
Abstract:
Provided is a method of efficiently transmitting an acknowledgement/negative acknowledgement (ACK/NACK) bit supporting hybrid automatic repeat request (HARQ) in a wireless communication system supporting multi-user multi-input and multi-output (MIMO). The method transmits the same downlink code and in-phase/quadrature (I/Q) multiplexed ACK/NACK bit to two mobile stations using the same uplink resource block. Accordingly, the method can efficiently transmit the ACK/NACK bit for multi-user MIMO and efficiently use downlink radio resources.
Abstract:
In a cellular system in which OFDM is used, a forward link synchronization channel, a common pilot channel structure, an initial cell searching method of a mobile station, and an adjacent cell searching method for handover are required. A method of transmitting a forward synchronization signal in a wireless communication system according to the present invention includes generating a frame comprised of a plurality of sync blocks; and transmitting the frame through a forward link, wherein the frame comprises primary synchronization channel sequences which provide timing information of the sync blocks and a plurality of secondary synchronization channel sequences which provide timing information of the frame, wherein a cell identifier is specified by a combination of the primary synchronization channel sequence and a hopping code word specified by the plurality of the secondary synchronization channel sequences Therefore, the cell searching time can be efficiently reduced in an OFDM system.
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:
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:
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.