A method and system are provided for scheduling data transmission in a Multiple-Input Multiple-Output (MIMO) system. The MIMO system may comprise at least one MIMO transmitter and at least one MIMO receiver. Feedback from one or more receivers may be used by a transmitter to improve quality, capacity, and scheduling in MIMO communication systems. The method may include generating or receiving information pertaining to a MIMO channel metric and information pertaining to a Channel Quality Indicator (CQI) in respect of a transmitted signal; and sending a next transmission to a receiver using a MIMO mode selected in accordance with the information pertaining to the MIMO channel metric, and an adaptive coding and modulation selected in accordance with the information pertaining to the CQI.

Methods, systems, and devices for wireless communication are described. Wireless devices may use multiple transmission modes to enable association and authentication procedures for wireless devices with different capabilities. For example, a station may receive, in response to a broadcast probe request, a probe response frame formatted according to a first transmission mode. The station may then transmit a second probe request frame formatted according to the first transmission mode. At some later time, the station may identify that the second probe request frame was not received by the wireless device, and may transmit another probe request frame formatted according to an extended range transmission mode. The station may then establish a connection with the wireless device by completing an association and authentication procedure, and proceed to transmit data or control frames formatted according to the extended range transmission mode.

An adaptable orthogonal frequency-division multiplexing system (OFDM) that uses a multiple input multiple output (MIMO) to having OFDM signals transmitted either in accordance with time diversity to reducing signal fading or in accordance with spatial diversity to increase the data rate. Sub-carriers are classified for spatial diversity transmission or for time diversity transmission based on the result of a comparison between threshold values and at least one of three criteria. The criteria includes a calculation of a smallest eigen value of a frequency channel response matrix and a smallest element of a diagonal of the matrix and a ratio of the largest and smallest eigen values of the matrix.

Methods, devices, and systems for the transmission of information in a wireless communication system are disclosed. In one embodiment, a method for the transmission of information in a wireless communication system comprises receiving a downlink message, wherein the downlink message includes a first control channel element; determining a first index using the location of the first control channel element; determining a second index; determining a first orthogonal resource using the first index; determining a second orthogonal resource using the second index; spreading an uplink message using the first orthogonal resource to form a first spread signal; spreading the uplink message using a second orthogonal resource to form a second spread signal; transmitting the first spread signal using a first antenna; and transmitting the second spread signal using a second antenna.

Methods, devices, and systems for the transmission of information in a wireless communication system are disclosed. In one embodiment, a method for the transmission of information in a wireless communication system comprises receiving a downlink message, wherein the downlink message includes a first control channel element; determining a first index using the location of the first control channel element; determining a second index; determining a first orthogonal resource using the first index; determining a second orthogonal resource using the second index; spreading an uplink message using the first orthogonal resource to form a first spread signal; spreading the uplink message using a second orthogonal resource to form a second spread signal; transmitting the first spread signal using a first antenna; and transmitting the second spread signal using a second antenna.

In generating a data unit for transmission via a communication channel, a preamble of the data unit is generated, including i) generating a set of training fields, and ii) mapping each training field in the set of training fields to a plurality of space-time streams. When the set of training fields consist of four training fields, each training field in the set of training fields is mapped to four space-time streams according to a first space-time stream mapping matrix. When the set of training fields consists of six training fields, each training field in the set of training fields is mapped to six space-time streams according to a second space-time stream mapping matrix, wherein the first space-time stream mapping matrix is not a submatrix of the second space-time stream mapping matrix. A data portion of the data unit is generated so that a receiver device can receive the data portion via a corresponding number of space-time streams using channel information derived from the set of training fields.

A method and system are provided for scheduling data transmission in a Multiple-Input Multiple-Output (MIMO) system. The MIMO system may comprise at least one MIMO transmitter and at least one MIMO receiver. Feedback from one or more receivers may be used by a transmitter to improve quality, capacity, and scheduling in MIMO communication systems. The method may include generating or receiving information pertaining to a MIMO channel metric and information pertaining to a Channel Quality Indicator (CQI) in respect of a transmitted signal; and sending a next transmission to a receiver using a MIMO mode selected in accordance with the information pertaining to the MIMO channel metric, and an adaptive coding and modulation selected in accordance with the information pertaining to the CQI.

A wireless receiver (74) for receiving signals from a transmitter (72). The transmitter comprises a plurality of transmit antennas (TAT.sub.1, TAT.sub.2) for transmitting the signals, which comprise respective independent streams of symbols. Additionally, interference occurs between the respective streams. The receiver comprises a plurality of receive antennas (RAT.sub.1, RAT.sub.2) for receiving the signals as influenced by a channel effect between the receiver and the transmitter. The receiver also comprises circuitry (80) for multiplying the signals times a conjugate transpose of an estimate of the channel effect and times a conjugate transpose of a linear basis transformation matrix. The receiver also comprises circuitry (84) for selecting the linear basis transformation matrix from a finite set of linear basis transformation matrices. Lastly, the receiver comprises circuitry (88) for removing the interference between the respective streams.

A method and system are provided for scheduling data transmission in a Multiple-Input Multiple-Output (MIMO) system. The MIMO system may comprise at least one MIMO transmitter and at least one MIMO receiver. Feedback from one or more receivers may be used by a transmitter to improve quality, capacity, and scheduling in MIMO communication systems. The method may include generating or receiving information pertaining to a MIMO channel metric and information pertaining to a Channel Quality Indicator (CQI) in respect of a transmitted signal; and sending a next transmission to a receiver using a MIMO mode selected in accordance with the information pertaining to the MIMO channel metric, and an adaptive coding and modulation selected in accordance with the information pertaining to the CQI.

According to various embodiments, a reception STA may receive a physical layer protocol data unit (PPDU) including a first field and a second field from a transmission STA. The first field may include information about a configuration of a plurality of resource units (RUs). The second field may include a plurality of user fields for allocating the plurality of RUs to a plurality of users. The reception STA may identify a multiple RU (M-RU) allocated to itself and decode the received PPDU.