Abstract: A multicarrier transmitter performs bit-interleaving suitable for transmitting more than one spatial stream over a multicarrier communication channel. The multicarrier transmitter may include a bit-grouping shifter to shift QAM symbol-bit groupings of a spatial stream among subcarriers of the multicarrier communication signal, and a bit-position permuter to rotate bits among bit positions within subgroupings of the QAM symbol-bit groupings of the second spatial stream.

Abstract: A mixed data unit for use in a wireless network may include a first portion having information that is coded over a single frequency channel and a second portion having information that is coded across multiple frequency channels. In at least one embodiment, the first portion includes duration related information that may be used by legacy client devices within the network to determine a duration for which the legacy device is to remain quiet to avoid packet collisions in the network.

Abstract: High data rate, high diversity transmission is provided in a dual transmit antenna system over multiple sample times though the use of coding.

Abstract: An encoded input bit stream is interleaved across a number of symbols having different bit sizes in a manner that ensures that the bits assigned to each symbol from the bit stream are separated by a minimum separation. In this manner, bits that are adjacent within the bit stream do not get assigned to the same symbol.

Abstract: In a wireless device having multiple receive antennas, wireless medium sensing operations are performed using a reduced number of receive antennas. Receive chains associated with unused receive antennas are deactivated to reduce power consumption within the device.

Abstract: A multicarrier transmitter may transmit cyclically delayed linear combinations of two or more data streams with three or more antennas. In some embodiments, the multicarrier transmitter may transmit cyclically delayed linear combinations of three data streams with four antennas.

Abstract: Complex antennas weights for use in beamforming in a multiple-antenna system are determined based upon clear channel assessment (CCA) information in a wireless networking environment.

Abstract: Subcarrier phase rotation is implemented in an OFDM transmitting apparatus to overcome problems such as, for example, non-frequency selective multipath fading. In at least one embodiment, subcarrier phase rotation is practiced in an OFDM system implementing multiple input multiple output (MIMO) techniques.

Abstract: Methods and apparatus to control transmission of a multicarrier wireless communication channel through multiple antennas is generally described

Abstract: An apparatus and associated methods for performing space-frequency interleaving in a multicarrier wireless communication system is generally described.

Abstract: A multicarrier receiver includes spatial channel decouplers to separate signal components that are separately transmitted with more than one transmit antenna or over more than one spatial channel.

Abstract: A method and apparatus for selecting an optimal set of antennas from a plurality of antennas for use by a transmitter and/or receiver having a plurality of RF chains to transmit and/or receive a wireless signal on a wireless link. According to the invention information concerning transmission of wireless signals on the wireless link is determined and an optimal set of antennas from the plurality of antennas is selected based on the information. Thereafter, the RF chains are connected to the optimal set of antennas to permit transmission and/or reception of the wireless signal from the RF chains on the wireless link via the optimal set of antennas. The RF chains correspond in number to the number of antennas in the optimal set of antennas, and the number of antennas included in the plurality of antennas is greater than the number of RF chains.

Abstract: In an orthogonal frequency division multiplexed (OFDM) system, a transmitter and/or receiver communicate separate data streams on non-orthogonal spatial channels. Each spatial channel may use the same set of OFDM subcarriers and may take advantage of the multipath characteristics of the spatial channel allowing the communication of additional data without an increase in frequency bandwidth. Space-frequency subcarrier modulation assignments may be dynamically assigned on a per subcarrier basis as well as a per spatial channel basis to help maximize the data-carrying capacity of the channel. In some embodiments, each of the spatial channels may be associated with one of a plurality of spatially diverse antennas. In other embodiments, beamforming may be performed to allow the transmission and/or reception of signals within the spatial channels.

Abstract: In a wireless local area network (WLAN) that includes high-throughput communication devices with multiple antennas and legacy communication devices with single antennas, training tones are transmitted over a plurality of spatial channels during a first portion of an orthogonal frequency division multiplexed (OFDM) packet-training preamble. The training tones are interspersed among subcarrier frequencies of the spatial channels. The training tones are retransmitted during a second portion of the packet-training preamble. The training tones are shifted among the subcarrier frequencies of the spatial channels during the retransmission allowing a high-throughput receiving station to perform a channel estimation on different subcarrier frequencies of the spatial channels. The legacy communication devices may receive and process the training tones and may set their network allocation vector to refrain from communicating during a subsequent interval.

Abstract: A mixed data unit for use in a wireless network may include a first portion having information that is coded over a single frequency channel and a second portion having information that is coded across multiple frequency channels. In at least one embodiment, the first portion includes duration related information that may be used by legacy client devices within the network to determine a duration for which the legacy device is to remain quiet to avoid packet collisions in the network.

Abstract: A multicarrier transmitter includes a space-frequency interleaver and a space-frequency coder to encode multicarrier signals for transmission over a plurality of spatial channels.

Abstract: Briefly, in accordance with one embodiment of the invention, a wireless communication system may adaptively switch between a multiple input, multiple output mode and a spatial division, multiple access mode based at least in part on channel conditions and traffic conditions.

Abstract: Various embodiments are described for a trained data transmission for communication systems.

Abstract: Briefly, in accordance with one embodiment of the invention, a transmitter may adaptively select between a post-data channel feedback system and a pre-data channel feedback system based at least in part on packet length and channel conditions.

Abstract: An apparatus and associated methods to improve diversity gain while preserving channel throughput in a multicarrier communication channel are generally presented.