Abstract: A device whose location is to be determined (target device) generates a plurality of frames (messages) and time of departure (TOD) timestamp information indicating when the target device transmits the plurality of frames in a sequence or burst. The target device transmits the plurality of frames and the TOD information, wherein the plurality of frames are transmitted such that at least two of the frames are on different radio frequency (RF) channels. Within a sequence or burst (or across multiple sequences or bursts), multiple widely spaced transmissions on the same channel are included to allow for estimation of the crystal frequency offset of the transmitting device. The TOD information included in the transmitted packets allows devices that receive the packets not to change their channels of operation solely for the purpose of receiving packets from the device to be located.

Abstract: Techniques are provided herein for training a digital predistortion module in a wireless communication device. At a controller apparatus that is capable of communicating with a plurality of wireless devices, a particular wireless device that requires adjustment of predistortion parameters is identified. The controller also identifies one or more participating wireless devices to participate in a training session during which the particular wireless device makes test transmissions and the one or more participating wireless devices make measurements based on reception of the test transmissions sent by the particular wireless device. The controller apparatus sends commands to the particular wireless device and to the one or more participating wireless devices to initiate the training session. The controller receives measurement data from the one or more participating wireless devices based on reception of the test transmissions from the particular wireless device during the training session.

Abstract: Techniques are provided to derive the spatial expansion matrix used when one wireless communication device sends a transmission with a number of spatial streams less than the number of its transmit antennas to another wireless communication device. These techniques involve, at the receiving wireless communication device, generating channel estimate information for received transmissions sent with different numbers of spatial streams and to determine when sufficient information is available to estimate a spatial expansion matrix for different spatial expansion scenarios.

Abstract: Interference in an unlicensed frequency band is spatially filtered out from received signals at a wireless device operating in the unlicensed frequency band. Energy received at a plurality of antennas of the wireless is device is analyzed to detect interference in the unlicensed frequency band. The detected interference is classified by type. Parameters for a nulling filter are generated or selected based on the type of interference detected in the received energy. During a time interval when it is expected to receive desired signals, the nulling filter is applied using the parameters to signals obtained from energy received at the plurality of antennas during the time interval.

Abstract: Techniques are provided to de-correlate sub-bands of a packet to be transmitted. At a communication device, a signal (packet or frame) is generated for transmission. The packet or frame comprises a plurality of subcarriers in each of a plurality of sub-bands. Different cyclic delays are applied to the plurality of sub-bands of the signal. The signal is amplified after applying the different cyclic delays for transmission from the communication device.

Abstract: An apparatus, a method, and logic encoded in computer readable media that when executed operable to carry out the method. The method includes wirelessly receiving at a receiving station a signal transmitted from a transmitting station in a wireless network. The signal includes a network identifier, e.g., MAC address of the transmitting station. The method includes determining one or more RF waveform characteristics of at least a transient part of the received signal, decoding the received signal to determine the network identifier, e.g., MAC address, determining one or more behavior characteristics from the received signal; and using the decoded network identifier, e.g., MAC address and a combination of the one or more waveform characteristics and the one or more behavior characteristics to ascertain whether or not the network identifier, e.g., MAC address is a spoofed identifier, the ascertaining using historical samples of combinations for different network identifiers.

Abstract: Techniques are provided herein for training a digital predistortion module in a wireless communication device. At a controller apparatus that is capable of communicating with a plurality of wireless devices, a particular wireless device that requires adjustment of predistortion parameters is identified. The controller also identifies one or more participating wireless devices to participate in a training session during which the particular wireless device makes test transmissions and the one or more participating wireless devices make measurements based on reception of the test transmissions sent by the particular wireless device. The controller apparatus sends commands to the particular wireless device and to the one or more participating wireless devices to initiate the training session. The controller receives measurement data from the one or more participating wireless devices based on reception of the test transmissions from the particular wireless device during the training session.

Abstract: Multiple-input multiple-output (MIMO) wireless communication techniques are provided that involve mapping multiple spatial streams to corresponding modes of a wireless channel between a plurality of antennas of a first wireless communication device and a plurality of antennas of a second wireless communication device so as to allocate or distribute power unequally to the plurality of modes. In addition, techniques are provided herein to cyclically shift a mapping of spatial streams to modes of the channel.

Abstract: Techniques are provided to derive the spatial expansion matrix used when one wireless communication device sends a transmission with a number of spatial streams less than the number of its transmit antennas to another wireless communication device. These techniques involve, at the receiving wireless communication device, generating channel estimate information for received transmissions sent with different numbers of spatial streams and to determine when sufficient information is available to estimate a spatial expansion matrix for different spatial expansion scenarios.

Abstract: Techniques are provided to measure how fast a wireless channel is changing between a first wireless communication device (e.g., a wireless base station or access point) and a second wireless device (e.g., a wireless client device) based on signals that the first communication wireless device receives at a plurality of antennas from a second wireless communication device. Techniques are also provided to measure a degree of mobility of the second wireless communication device based on signals received at the first communication wireless device from the second communication wireless device.

Abstract: A method and an apparatus for detecting the start-of-packet in a wireless receiver operating in a packetized wireless network. One method embodiment includes calculating a plurality of start of packet (SOP) indicators, each for one or more of a plurality of receive chains in the receiver; determining one or more linear combinations of respective pluralities of the calculated SOP indicators to form one or more combined SOP indicators; comparing each of a plurality of SOP indicators or combined SOP indicators, including at least one of the combined SOP indicators to a respective threshold to form one or more respective SOP events; and, in the case there is more than one SOP event, determining a logic function of the SOP events to form a SOP decision event.

Abstract: Techniques are provided herein to estimate parameters of a wireless communication channel. At each of a first plurality of antennas of a first wireless communication device, a transmission is received that is associated with each of one or more spatial streams transmitted via a second plurality of antennas of a second wireless communication device. The transmission comprises at least first and second training fields which are configured for channel estimation. Multidimensional channel information between the first plurality of antennas and the second plurality of antennas is computed from receive values in the first and second training fields for one more dimension above a number of the spatial streams transmitted by the second wireless communication device and up to a lesser of a number of the first plurality of antennas and a number of the second plurality of antennas.

Abstract: A device whose location is to be determined (target device) generates a plurality of frames (messages) and time of departure (TOD) timestamp information indicating when the target device transmits the plurality of frames in a sequence or burst. The target device transmits the plurality of frames and the TOD information, wherein the plurality of frames are transmitted such that at least two of the frames are on different radio frequency (RF) channels. Within a sequence or burst (or across multiple sequences or bursts), multiple widely spaced transmissions on the same channel are included to allow for estimation of the crystal frequency offset of the transmitting device. The TOD information included in the transmitted packets allows devices that receive the packets not to change their channels of operation solely for the purpose of receiving packets from the device to be located.

Abstract: An apparatus, a method, and logic encoded in computer readable media that when executed operable to carry out the method. The method includes wirelessly receiving at a receiving station a signal transmitted from a transmitting station in a wireless network. The signal includes a network identifier, e.g., MAC address of the transmitting station. The method includes determining one or more RF waveform characteristics of at least a transient part of the received signal, decoding the received signal to determine the network identifier, e.g., MAC address, determining one or more behavior characteristics from the received signal; and using the decoded network identifier, e.g., MAC address and a combination of the one or more waveform characteristics and the one or more behavior characteristics to ascertain whether or not the network identifier, e.g., MAC address is a spoofed identifier, the ascertaining using historical samples of combinations for different network identifiers.