A system and method for transmitting LDPC parameters is provided. In the method, an initial number of OFDM symbols (Nsym_init) is determined for a packet that is based on the number of information bits to be delivered in the packet. An STBC value is also determined. A number of extra symbols (Nsym_ext) value is generated based on the Nsym_init value, wherein a Nsym value is based on said Nsym_init value and said Nsym_ext value. An Nldpc_ext value is determined based on the STBC value and the Nsym_ext value for purposes of determining LDPC parameters associated with the packet.

The present invention relates to a transmission and receiving method and apparatus using a dynamically determined Inter-Frame Space (IFS) in a Wireless Local Area Network (WLAN). According to one aspect of the present invention, a method for processing a received frame by a Station (STA) in a WLAN may include receiving a first frame including downlink data for a plurality of STAs, if the received first frame has no error, transmitting a second frame including an ACKnowledgement (ACK) of the STA simultaneously with ACKs of one or more other STAs, and if the received first frame has an error, performing carrier sensing using a variably determined IFS.

Systems, methods, and instrumentalities are provided to implement a method of communicating a feedback in a wireless local area network (WLAN). A WLAN device may receive a data frame with a hybrid automatic repeat request (HARQ) data indicator in a frame header. The WLAN device may send an acknowledgement frame when the data frame is correctly received and decoded. The WLAN device may send a negative acknowledgement frame when the data frame is not correctly received and decoded.

Provided is a wireless communication terminal that wirelessly communicates with a base wireless communication terminal. The wireless communication terminal includes a transceiver, and a processor. The processor is configured to set an integer selected from a range of 0 to a value equal to or smaller than an OFDMA Contention Window (OCW) as a counter for random access, receive a trigger frame for triggering random access using one or more resource units (RUs) allocated for the random access from the base wireless communication terminal using the transceiver, decrement a value of the counter based on the one or more RUs allocated for the random access, randomly select one RU based on the one or more RUs allocated for the random access when the value of the counter is 0 or reaches 0, and attempt transmission to the base wireless communication terminal using the selected RU.

Methods and apparatus for efficient demapping of constellations are described. In an embodiment, these methods may be implemented within a digital communications receiver, such as a Digital Terrestrial Television receiver. The method reduces the number of distance metric calculations which are required to calculate soft information in the demapper by locating the closest constellation point to the received symbol. This closest constellation point is identified based on a comparison of distance metrics which are calculated parallel to either the I- or Q-axis. The number of distance metric calculations may be reduced still further by identifying a local minimum constellation point for each bit in the received symbol and these constellation points are identified using a similar method to the closest constellation point. Where the system uses rotated constellations, the received symbol may be unrotated before any constellation points are identified.

The present invention provides an FBMC transmit diversity transmission method and apparatus. The method includes: obtaining a to-be-transmitted data sequence, where the to-be-transmitted data sequence includes 2*M*N pieces of data; performing transmit diversity processing on the to-be-transmitted data sequence to obtain FBMC signals of a first antenna and a second antenna, where a precoding matrix is (I) or (II), a matrix that includes the FBMC signals of the first antenna and the second antenna is (III), a matrix that includes the to-be-transmitted data sequence is (IV), 0≦i≦M−1, 0≦j≦N−1, Y=WX, the 2*M*N pieces of data of the to-be-transmitted data sequence are denoted by x.sup.(0)(k,l) and x.sup.(1)(k,l), 0≦k≦M−1, 0≦l≦N−1, FBMC signals of the first antenna and the second antenna on an r.sup.th subcarrier and an s.sup.th symbol are denoted by y.sup.(0)(r,s) and y.sup.(1)(r,s), 0≦r≦2M−1, and 0≦s≦N−1; and transmitting the FBMC signals of the first antenna and the second antenna.

A radio base station, user equipment (UE), and method of control signaling in wireless communication systems. Control information is transferred from a base station to at least one UE, via a plurality of common pilot channels. A set of unique pilot sequences is predefined, and the base station assigns specific pilot sequences from the set of pilot sequences to specific common pilot channels, forming a pilot sequence assignment pattern representing specific control information. The UE, having knowledge of the relations between pilot sequence assignment patterns and control information, interprets the received pilot sequence assignment pattern as specific control information. The method is particularly well suited for broadcast type control information.

Methods, devices, and systems for the transmission of information in a wireless communication system are disclosed. In one embodiment, a method of transmission in a wireless communication system comprises determining by a wireless device (201) a configuration of a plurality of power amplifiers (207) to achieve a single antenna transmission mode; amplifying a signal by said wireless device (201) using the configuration of the plurality of power amplifiers (207) to form a plurality of amplified signals; simultaneously transmitting at or about the same time by the wireless device (201) to a base station (202) the plurality of amplified signals from a plurality of physical antennas (212), wherein the plurality of physical antennas (212) are coupled to the configuration of the plurality of power amplifiers (207); and wherein the measured transmit power from the totality of the plurality of physical antennas (212) is about the same as the required transmit power using the single antenna transmission mode.

The present invention relates to a method and a device for reselecting a synchronization signal in a wireless communication system supporting device-to-device direct communication and the method includes: receiving a first synchronization signal from a second UE and receiving a second synchronization signal from a third UE; comparing a first reception power level indicating reception power of the first synchronization signal and a second reception power level indicating the reception power of a second synchronization signal with a first threshold value indicating minimum reception power; and selecting the first synchronization signal or the second synchronization signal according to the comparison result, and the synchronization signal is a synchronization signal selected in the previously synchronization procedure.

A method is described for generating and transmitting a frame by a station. The method includes determining a bandwidth of a frame to be transmitted by the station; generating a long training field for the frame, wherein the long training field includes a set of pilot tones located at a set of subcarrier positions, wherein when the bandwidth of the frame is 10 MHz, the set of subcarrier positions include four subcarrier positions and the four subcarrier positions are set as {−21-α1,−7-α2,7+α3,21+α4} where α1, α2, α3, and α4 are odd values, and wherein when the bandwidth of the frame is 20 MHz, the set of subcarrier positions include six sub carrier positions, including {−53-β1,−25-β2,−11-β3, 11+β4,25+β5,53+β6} where β1, β2, β3, β4, β5, and β6 are odd values.