Abstract: Techniques for sending control information in a wireless communication system are described. In an aspect, a UE spreads control information across frequency with a DFT and across time with an orthogonal sequence to obtain output data for the control information. In one design, the UE receives codewords for N HARQ processes in N downlink subframes, determines an ACK value for each HARQ process, codes N ACK values for the N HARQ processes to obtain ACK information, generates output data for the ACK information, and sends the output data in one of M uplink subframes. In another aspect, first control information is processed based on a first coding and multiplexing scheme utilizing code division multiplexing in time and frequency domains. Second control information is processed based on a second coding and multiplexing scheme utilizing code division multiplexing in time domain and spreading in frequency domain.

Abstract: Systems and methodologies are described that facilitate applying cyclic delay diversity (CDD) and precoding to wireless transmissions. In particular, data vectors to be transmitted to a number of receive antennas of a receiver can be transformed to a virtual antenna domain. CDD can be applied to this domain followed by precoding to allow the benefits of precoding to remain though CDD is applied. In this regard, the resulting signals can be transmitted without pouring transmission energy into null spaces unreachable by receiving devices.

Abstract: A method of transmitting data in a multi-cell cooperative wireless communication system is provided. The method includes splitting data to be transmitted into first data and second data, determining a first beamforming vector for the first data and a second beamforming vector for the second data, and transmitting the first data by using the first beamforming vector and the second data by using the second beamforming vector. The present invention provides a data transmission method which does not cause deterioration of overall system performance while minimizing inter-cell interference.

Abstract: One embodiment includes a method of receiving a transmitted signal. The method comprises receiving a signal transmitted over a channel. The signal comprises a known signal and an information signal. The method further includes determining at least one indicator of channel characteristics based at least in part on the portion of the known signal. The method further includes generating a first value indicative of the information signal based at least in part on the at least one indicator of the channel characteristics. The first value comprises an error signal. The method further comprises removing the error signal from the first estimate of the signal based at least in part on the portion of the known signal. Other embodiments include systems for performing the method and methods of making such systems.

Abstract: Techniques for supporting MIMO transmission with layer permutation are described. In one aspect, multiple codewords may be generated for transmission from multiple antennas (e.g., virtual antennas), with the number of codewords being less than the number of antennas. Each codeword may be mapped across the multiple antennas. Two codewords may be generated. For rank 3, the first codeword may be mapped to one layer (or one antenna on each subcarrier), and the second codeword may be mapped to two layers (or two antennas on each subcarrier). For rank 4, each codeword may be mapped to two layers. In another aspect, a base CQI indicative of an average signal quality may be determined. A delta CQI indicative of improvement over the average signal quality may also be determined. In yet another aspect, selection may be performed with different penalty factors for different ranks or number of codewords.

Abstract: The present invention discloses a method in which a base station transmits a downlink signal in a wireless communication system. In detail, the method comprises the following steps: allocating a transmitting resource to data symbols for transmitting downlink signals, in the direction of increasing a frequency index; and transmitting the downlink signal to a terminal, using the allocated resource. The frequency band of preset orthogonal frequency division multiplexing (OFDM) symbols, from among the transmitting resource, contains a control domain and a segment band. The step of allocating the transmitting resource comprises the step of puncturing the data symbol using a control channel, to which the control domain contained in the preset OFDM symbols is allocated.

Abstract: A method of transmitting a signal of a base station in a wireless communication system is provided. The method includes transmitting a first signal to the relay station through the transmission period in a subframe including a transmission period and a guard time for transmission/reception switching of a relay station, and transmitting a second signal to a macro user equipment through the guard time. Accordingly, a signal can be effectively transmitted in the wireless communication system employing the relay station.

Abstract: A method for a transmitting and receiving a signal from a relay station in a radio communication system is provided. The method comprises the steps of: receiving offset time information from a base station; configuring a time difference between an access downlink transmission subframe that transmits an access downlink signal to a relay station terminal according to the offset time information and a backhaul downlink reception subframe that receives a backhaul downlink signal from the base station; transmitting a control signal from the access downlink transmission subframe to the relay station terminal; and receiving the backhaul downlink signal from the base station in the backhaul downlink reception subframe.

Abstract: A method and apparatus for transmitting a downlink reference signal in a wireless communication system supporting multiple antennas is disclosed. A method for transmitting Channel State Information-Reference Signals (CSI-RSs) for eight or less antenna ports includes selecting one of a plurality of CSI-RS Resource Element (RE) groups defined on a data region of a downlink subframe and mapping CSI-RSs for the eight or less antenna ports to the selected CSI-RS RE group, and transmitting the downlink subframe in which the CSI-RSs for the eight or less antenna ports are mapped. The plurality of CSI-RS RE groups is defined such that a transmission diversity RE pair for data transmitted on the downlink subframe is not broken.

Abstract: A scheduling method in a wireless communication system using a relay station is provided. The method includes receiving scheduling information from the relay station, and performing scheduling by using the scheduling information, wherein a scheduling metric is determined for each mobile station or each connection when the scheduling is performed. Accordingly, scheduling can be effectively performed since a base station can recognize a state of a relay station.

Abstract: To support cell search, multiple (e.g., two) synchronization transmissions are sent in a frame with non-uniform spacing. Information is conveyed via the non-equal distances between consecutive synchronization transmissions. Multiple levels of non-uniform spacing may be used to convey different types of information. In one design, the multiple synchronization transmissions are sent in different subframes of a frame, and each synchronization transmission is sent in one of multiple symbol periods in a respective subframe. The synchronization transmissions may be sent in non-evenly spaced subframes to convey frame boundary. One synchronization transmission may be sent in one of multiple possible symbol periods depending on the information, e.g., a particular group of cell IDs, being conveyed. The distances between synchronization transmissions may also be used to convey cyclic prefix length.

Abstract: The present invention relates to a method and to an apparatus for transmitting/receiving data in a relay communication system. The method comprises the steps of: setting, as a guard band, the first predetermined number of symbol transmission slots of a data transmission period in a subframe resource element of a downlink channel constituted by a control signal transmission period to which a control signal is allocated and the data transmission period to which downlink data is allocated; allocating reference signals to symbols of the data transmission period; puncturing the symbols corresponding to the guard band from among the symbols to which said reference signals are allocated; and transmitting signals to which said reference signals are allocated.

Abstract: The present invention relates to a method and to an apparatus for transmitting/receiving data in a relay communication system. The method comprises the steps of: setting, as a guard band, the first predetermined number of symbol transmission slots of a data transmission period in a subframe resource element of a downlink channel constituted by a control signal transmission period to which a control signal is allocated and the data transmission period to which downlink data is allocated; allocating reference signals to symbols of the data transmission period; puncturing the symbols corresponding to the guard band from among the symbols to which said reference signals are allocated; and transmitting signals to which said reference signals are allocated.

Abstract: The present application discloses a method for transmitting a downlink signal in a multi-antenna wireless communication system. In detail, the method comprises: a step of mapping a signal of a codeword domain to a signal of a layer domain; a step of mapping the signal of the layer domain to a signal of a virtual antenna port domain using a precoding matrix; and a step of transmitting the signal of the virtual antenna port domain to a physical antenna port, wherein the precoding matrix is changed in a channel measurement unit, and the signal of the layer domain is layer-permutated in the channel measurement unit. Preferably, the channel measurement unit is constituted by one or more resource blocks (RBs).

Abstract: Techniques for facilitating cell search by user equipments (UEs) in a wireless communication system are described. In an aspect, a primary synchronization code (PSC) sequence may be generated based on a Frank sequence and a constant amplitude sequence that is repeated multiple times. In another aspect, a set of PSC sequences may be generated based on complementary sequences having good aperiodic correlation properties and efficient implementations. In one design, PSC sequences A+B and B+A may be formed based on Golay complementary sequences A and B, there “+” denotes concatenation. In yet another aspect, a set of secondary synchronization code (SSC) sequences may be generated based on a set of base sequences and different modulation symbols of a modulation scheme. Each base sequence may be modulated by each of M possible modulation symbols for the modulation scheme to obtain M different SSC sequences.

Abstract: A method for performing a hybrid automatic repeat request (HARQ) by a relay station (RS) in a wireless communication system is provided. The method comprises performing HARQ with a mobile station (MS) by a fixed HARQ period; and performing HARQ with a base station (BS) by a HARQ period series, wherein the HARQ period series comprises a plurality of HARQ period series element (Xk,yk), where (Xk,yk) indicates that when data is transmitted in n-th subframe, an ACK/NACK signal is received in (n+xk)-th subframe and the data is retransmitted in (n+xk+yk)-th subframe when the ACK/NACK signal is a NACK signal, wherein at least one of xk and yk for one HARQ period in the HARQ period series is different from at least one of xk and yk for the other HARQ period in the HARQ period series.

Abstract: According to one embodiment of the present invention, a method for searching for an access point in a terminal supporting a multiple wireless access scheme is provided. The method may comprise the steps of; receiving, from a base station using a first wireless access scheme, information relating to an access point using a second wireless access scheme; determining whether one or more access points exist using the second wireless access scheme in the cell coverage of the base station on the basis of the information: searching for an access point accessible for a period that is shorter than a normal period when determining that the access point using the second wireless access scheme exists; and accessing the found access point using the second wireless access scheme.

Abstract: Provided is a method and a device for precoding in a wireless communication system. The method for precoding comprises the following steps: generating a first precoding matrix, W1, for deciding the transmission power of one transmission antenna from a plurality of transmission antennas as the maximum power per antenna; generating a zero forcing (ZF) precoding matrix, Ti, which does not influence the transmission antenna having the power which is decided as the maximum power per antenna, based on the (i?1)th precoding matrix Wi?1 (i=2,3, . . .

Abstract: To support cell search, multiple (e.g., two) synchronization transmissions are sent in a frame with non-uniform spacing. Information is conveyed via the non-equal distances between consecutive synchronization transmissions. Multiple levels of non-uniform spacing may be used to convey different types of information. In one design, the multiple synchronization transmissions are sent in different subframes of a frame, and each synchronization transmission is sent in one of multiple symbol periods in a respective subframe. The synchronization transmissions may be sent in non-evenly spaced subframes to convey frame boundary. One synchronization transmission may be sent in one of multiple possible symbol periods depending on the information, e.g., a particular group of cell IDs, being conveyed. The distances between synchronization transmissions may also be used to convey cyclic prefix length.

Abstract: Techniques for transmitting data using a combination of explicit cyclic delay and implicit cyclic delay are described. A transmitter may perform first processing for cyclic delay diversity (or explicit cyclic delay processing) based on a first set of cyclic delay values known to a receiver. The transmitter may perform precoding based on a precoding matrix either before or after the explicit cyclic delay processing. The transmitter may perform second processing for cyclic delay diversity (or implicit cyclic delay processing) based on a second set of cyclic delay values unknown to the receiver. The transmitter may perform both explicit and implicit cyclic delay processing for data and may perform only implicit cyclic delay processing for pilot. One entity may select the first set of cyclic delay values and inform the other entity. The transmitter may autonomously select the second set of cyclic delay values without informing the receiver.