Abstract: Various embodiments are described for adaptive puncturing techniques.

Abstract: Various embodiments are described for adaptive puncturing techniques involving an adaptive bit loading block to select a modulation scheme and a puncturing pattern for each of a plurality of subcarriers or subcarrier bands based on subcarrier channel state information.

Abstract: A transmitter may include a set of stream groups, each including two or more streams producing a set of orthogonal frequency division multiplexed (OFDM) stream-symbols and a coding unit interleaving the stream-symbols into an interleaved signal. An input bit multiplexer may route an input data signal to be divided among each of the streams. An inverse fast Fourier transform unit may operate on a combined signal formed from interleaving the interleaved signals from each stream group. Each stream may include for example a baseband signal processor producing the OFDM stream-symbols.

Abstract: A multicarrier signal is generated by pre-compensating frequency-domain subcarrier symbols for substantially linear distortion subsequently introduced by a time-domain baseband filter.

Abstract: Briefly, an adaptive transmitted power control scheme, which may be used in stations of a communication system, for example, a wireless communication system. The scheme may allocate transmission power to a communication station based on multiplying each of at least one transmitted subcarrier complex number by a corresponding subcarrier weight. Additionally, a detection scheme may detect whether a transmitted power control scheme according to an embodiment of the invention is used by stations of the communication system. The allocation of transmission power may be also used to transmit additional service information through channels.

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 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: Briefly, in accordance with one embodiment of the invention, a channel estimator may be adapted to provide a channel estimate based at least in part on an estimated delay spread. The channel estimator may be adapted to provide a more accurate channel estimation in the event of a lower estimated delay spread. In one embodiment, the channel estimator provides a frequency domain channel estimate, and in another embodiment the channel estimator provides a time domain channel estimate.

Abstract: A frame format provides for wideband wireless local area network communications and informs narrower-band communication units when the channels are occupied by wider-band communication units. In some embodiments, the frame format includes a channelization field identifying channels that are used for communicating subsequent wideband fields of a packet, and a wideband-header field communicated on the identified channels. The wideband-header field may identify sub-fields that may be present in the wideband-header field, and may identify the presence of a wideband-data field. A long-compatibility field may be present that provides protection at the MAC level. The long-compatibility field may transport MAC frames that may include medium-reservation information compatible with narrower-band communication units.

Abstract: A frame format provides for wideband wireless local area network communications and informs narrower-band communication units when the channels are occupied by wider-band communication units. In some embodiments, the frame format includes a channelization field identifying channels that are used for communicating subsequent wideband fields of a packet, and a wideband-header field communicated on the identified channels. The wideband-header field may identify sub-fields that may be present in the wideband-header field, and may identify the presence of a wideband-data field. A long-compatibility field may be present that provides protection at the MAC level. The long-compatibility field may transport MAC frames that may include medium-reservation information compatible with narrower-band communication units.

Abstract: Adaptive channelization is achieved in a high throughput multicarrier system by first subdividing a high throughput channel into a number of frequency sub-channels. A channelization decision may then be made within a device as to which of the sub-channels to use for a corresponding high throughput wireless link based on channel state information.

Abstract: To mitigate the effects of non-linear amplification in a digital transmission system employing a multi-carrier multiplexing communications technique, such as orthogonal frequency division multiplexing or discrete multi-tone, predistortion of an input signal to a power amplifier with a non-linear transfer characteristic is performed in the frequency domain by modifying frequency-domain symbols used to modulate individual sub-carriers. The frequency-domain symbols are modified in a manner that compensates for the amplifier's non-linear transfer characteristic.

Abstract: A data rate is selected for subcarriers of each frequency and spatial channel of a slowly varying frequency selective multicarrier channel to provide uniform bit loading (UBL) for faster link adaptation. Signal to noise ratios (SNRs) for subcarriers of the multicarrier communication channel may be calculated from channel state information and a transmit power level. A throughput may be estimated for the data rates from the SNRs and one of the data rates may be selected based on the estimated throughputs.

Abstract: A frame structure for communicating over a high-throughput communication channel includes a channelization field as part of a current data unit to indicate a frequency and space configuration of subsequent portions of the current data unit.

Abstract: Embodiments of wireless device and method for communicating in a wireless network are generally described herein. Other embodiments may be described and claimed. In some embodiments, a wireless device establishes a link using a directional antenna in an initially selected direction with another wireless device. If the link in the initially selected direction deteriorates, the link may be reestablished in a previously identified alternate direction. In some embodiments, the initially selected direction and the alternate direction are jointly selected by both the first and second wireless devices.

Abstract: An adaptive multicarrier wireless communication system, apparatus and associated methods are generally disclosed herein. In at least one embodiment, channel state information is used to perform bit loading and power allocation within a multicarrier system. In an example technique, after active subcarriers have been identified for a multicarrier channel and an initial power distribution has been made, a subset of active subcarriers may be found that exceed a channel quality performance threshold. Excess power may then be identified by determining how much power could be reduced in the identified subcarriers so that they still meet, but do not exceed the channel quality performance threshold. In one possible approach, the excess power may be re-allocated to other subcarrier subsets.

Abstract: The channelization of a WB OFDM channel may be determined by detecting a plurality of subchannels and generate a channelization vector indicating which of the subchannels are active and which of the subchannels are inactive. In response to the channelization vector, data-symbol processing may be performed on the active subchannels and may be refrained from being performed on the inactive subchannels. In some embodiments, a decoded bit stream may be generated from the combined contributions of the active channels. In some embodiments, the subchannels may be detected with a parallel set of matched filters. The matched filters may have a coefficient spectrum matched to a corresponding one of the subchannels.

Abstract: A method and apparatus to reduce crosstalk in a communication system are described.

Abstract: An apparatus and associated methods to perform intelligent transmit power control with subcarrier puncturing in a multicarrier wireless communication channel is generally disclosed.

Abstract: Briefly, an adaptive transmitted power control scheme, which may be used in stations of a communication system, for example, a wireless communication system. The scheme may allocate transmission power to a communication station based on multiplying each of at least one transmitted subcarrier complex number by a corresponding subcarrier weight. Additionally, a detection scheme may detect whether a transmitted power control scheme according to an embodiment of the invention is used by stations of the communication system. The allocation of transmission power may be also used to transmit additional service information through channels.