Patent application number | Description | Published |
20080219373 | CODEBOOK SELECTION FOR TRANSMIT BEAMFORMING - A method select a codebook for transmit beamforming. The method constructs an estimated channel matrix based on a codebook, selects a channel submatrix from the estimated channel matrix, calculates a selection matrix from the channel submatrix; and assigns a steering matrix based on the selection matrix. There may be multiple codebooks and the method may construct an estimated channel matrix, select a channel submatrix, and calculate a selection matrix for each of the codebooks, then select an optimal codebook. The steering matrix is assigned based on the optimal codebook. The steering matrix may be used in steering a transmitted packet. The method may also calculate a post-MIMO equalizer signal-to-noise ratio for a data stream, based on the estimated channel matrix and the selected codebook. A related system is also disclosed. Other embodiments are provided, and each of the embodiments described herein can be used alone or in combination with one another. | 09-11-2008 |
20080247370 | Training Signals for Selecting Antennas and Beams in Mimo Wireless Lans - A computer implemented method selects antennas in a multiple-input, multiple-output wireless local area network that includes multiple stations, and each station includes a set of antennas. Multiple consecutively transmitted sounding packets are received in a station. Each sounding packet corresponds to a different subset of the set of antennas. A channel matrix is estimated from the multiple consecutively transmitted sounding packets, and a subset of antennas is selected according to the channel matrix. | 10-09-2008 |
20080260002 | ANTENNA SELECTION AND TRAINING USING A SPATIAL SPREADING MATRIX FOR USE IN A WIRELESS MIMO COMMUNICATION SYSTEM - A wireless communication system and method uses a spatial spreading matrix to distribute the encoded spatial data streams to a number of transmit chains and further uses the spatial spreading matrix for antenna selection computation in a transmitter. The spatial spreading matrix is designed such that a receiver is able to know and utilize the spatial spreading matrix for computing transmission antenna selection, receiver antenna selection and joint transmission/receiving antenna selection. The use of this spatial spreading matrix for antenna selection computation provides increased accuracy in antenna selection for transmission of spatial data streams, where the number of spatial data streams is less than the number of transmit or receive chains between the transmitter and receiver, and the number of transmit or receive chains is less than the corresponding transmission or receiving antennas. | 10-23-2008 |
20080266176 | POWER AMPLIFIER ADJUSTMENT FOR TRANSMIT BEAMFORMING IN MULTI-ANTENNA WIRELESS SYSTEMS - One or more beamsteering matrices are applied to a plurality of signals to be transmitted via multiple antennas. The plurality of signals are provided to a plurality of power amplifiers coupled to the multiple antennas after applying the one or more beamsteering matrices to the plurality of signals. Signal energies are determined for the plurality of signals provided to the plurality of power amplifiers, and output power levels of the plurality of power amplifiers are adjusted based on the determined signal energies. | 10-30-2008 |
20090022093 | WIRELESS NETWORK WITH SIMULTANEOUS UPLINK TRANSMISSION OF INDEPENDENT DATA FROM MULTIPLE CLIENT STATIONS - A wireless network comprises R client stations that respectively generate simultaneous uplink transmission (SUT) data, where R is an integer greater than one. An access point (AP) receives SUT data from each of the R client stations during an SUT period. | 01-22-2009 |
20090022128 | ACCESS POINT WITH SIMULTANEOUS DOWNLINK TRANSMISSION OF INDEPENDENT DATA FOR MULTIPLE CLIENT STATIONS - A wireless network device comprises R modulation modules that receive R independent data streams, that modulate the R independent data streams, and that apply a multiplexing matrix to generate M modulated and multiplexed data streams, respectively, where R and M are integers greater than one. M summing modules sum portions of each of the M modulated and multiplexed data streams to generate M transmit data streams. M transmitters simultaneously transmit the M transmit data streams during a simultaneous downlink transmission (SDT) period. | 01-22-2009 |
20090086690 | Method for Selecting Antennas and Beams in MIMO Wireless LANs - A computer implemented method selects antennas in a multiple-input, multiple-output wireless local area network that includes multiple stations, and each station includes a set of antennas. Multiple consecutively transmitted sounding packets are received in a station. Each sounding packet corresponds to a different subset of the set of antennas. A channel matrix is estimated from the multiple consecutively transmitted sounding packets. A frame including a high throughput (HT) control field is sent to initiate a selecting of antennas, and a subset of antennas is selected according to the channel matrix. | 04-02-2009 |
20090097395 | Beamforming Using Predefined Spatial Mapping Matrices - Systems and methods for transmitting packets to a receiver. In an implementation, the method includes storing, in a memory, a plurality of predefined spatial mapping matrices for use in a transmission of one or more packets to a receiver; sequentially transmitting one or more packets to the receiver, in which each of the sequential transmissions of one or more packets comprises using a different one of the plurality of predefined spatial mapping matrices stored in the memory; and selecting one of the plurality of predefined spatial mapping matrices stored in the memory for use in a subsequent transmission of one or more packets to the receiver, in which the selection of the one of the plurality of predefined spatial mapping matrices for use in the subsequent transmission is based on a quality of reception of the one or more data packets transmitted in each of the sequential transmissions | 04-16-2009 |
20090196372 | Channel Sounding and Estimation Strategies for Antenna Selection in MIMO Systems - Techniques and devices for antenna selection in a multiple-input-multiple-output (MIMO) system, in which communication is between a transmitter having a first plurality of radio-frequency (RF) chains coupled to a first plurality of antennas and a receiver having a second plurality of RF chains coupled to a second plurality of antennas, are provided. Techniques include receiving consecutive sounding packets each have a training symbol and that collectively sound a full-size channel for the MIMO system. A sub-channel estimate for each sounding packet can then be determined based on various factors, such as a known power level rule and gain factor. Scaling factors may be applied to each of these sub-channel estimates to produce a scaled sub-channel estimates. | 08-06-2009 |
20090252104 | Physical Layer Frame Format Design for Wideband Wireless Communications Systems - Systems and methods are provided for processing a payload portion of a received signal in a single carrier mode or a multiple carrier mode using a wireless channel receiver based on a portion of the received signal, where a signaling portion of the received signal is a single carrier signal. A single carrier signaling portion is received, and whether the payload portion of the signal is a single carrier signal or a multiple carrier signal is detected from the received single carrier signaling portion. The payload portion of the received signal is demodulated in a single carrier mode if the detecting determines that the payload portion of the received signal is a single carrier signal, and the payload portion of the received signal is demodulated in a multiple carrier mode if the detecting determines that the payload portion of the received signal is a multiple carrier signal. Data from the demodulated payload portion of the received signal is stored in a computer-readable memory. | 10-08-2009 |
20090285240 | Efficient Physical Layer Preamble Format - A method of generating a data unit preamble includes generating a first field associated with at least one of packet synchronization information or frame boundary indication, and generating a second field associated with channel estimation, including generating a first channel estimation sequence (CES) symbol and generating a second CES symbol, so that at least one of 1) a sequence in the first field serves as a cyclic prefix of the first CES symbol, 2) a beginning portion of the second CES symbol serves as a cyclic postfix of the first CES symbol, or 3) an ending portion of the first CES symbol serves as a cyclic prefix of the second CES symbol. | 11-19-2009 |
20090285241 | Efficient Physical Layer Preamble Format - A method for generating a preamble of a data unit includes generating a short training field (STF) of the preamble to include one of a repeating series of a sequences or a repeating series of b sequences, such that a and b are complementary sequences, a sum of out-of-phase aperiodic autocorrelation coefficients of a and b is zero, and where the STF is associated with at least synchronization information, and generating a long training field (LTF) of the preamble after the STF to include a′ sequences and b′ sequences, such that a′ is the sequence a cyclically shifted by zero or more positions, b′ is the sequence b cyclically shifted by zero or more positions, and where the LTF is associated with channel estimation information. | 11-19-2009 |
20090285269 | PHY Preamble Format for Wireless Communication System - A system and method of extracting data from data packets transmitted over a wireless network includes receiving a data packet having a preamble portion and a payload portion. The preamble portion is cross correlated with a first known spreading sequence to generate a first timing signal and the preamble portion is cross correlated with a second known spreading signal to generate a frame timing signal. An impulse is detected in the first timing signal and a first timing parameter is set based upon the detected impulse in the first timing signal. An impulse is detected in the frame timing signal and a frame timing parameter is set based upon the detected impulse in the frame timing signal. Data is extracted from the received payload portion according to the first timing parameter and the frame timing parameter. | 11-19-2009 |
20090285319 | Efficient Physical Layer Preamble Format - A method for generating a preamble of a data unit for transmission via a communication channel includes generating a first field of the preamble using one of a first sequence or a second sequence, such that the first sequence and the second sequence are complementary sequences such that a sum of out-of-phase aperiodic autocorrelation coefficients of the first sequence and the second sequence is zero; generating, using the other one of the first sequence or the second sequence, an indicator of a start of a second field of the preamble, the second field associated with channel estimation information, such that the indicator of the start of the second field immediately follows the first field; and generating the second field of the preamble. | 11-19-2009 |
20090285339 | Apparatus for Generating Spreading Sequences and Determining Correlation - An apparatus includes a signal generator to output one of a first sequence or a second sequence and to augment sequences with cover codes, such that a sum of out-of-phase aperiodic autocorrelation coefficients of the first sequence and the second sequence of is zero, a physical layer preamble controller to control the signal generator to generate a preamble of a data unit, including a short training field (STF) formatter to cause the signal generator to generate an STF for use in at least frame synchronization, and a long training field (LTF) formatter to cause the signal generator to generate an LTF for use in at least channel estimation, such that the STF formatter controls the signal generator to include the first sequence in a last portion of the STF, and the LTF formatter controls the signal generator to include the second sequence in a beginning portion of the LTF. | 11-19-2009 |
20090290563 | Antenna/Beam Selection Training in MIMO Wireless LANs with Different Sounding Frames - A method selects antennas in a multiple-input, multiple-output (MIMO) wireless local area network (WLAN) that includes a plurality of stations, and each station includes a set of antennas. Plural consecutive packets, received at a station, include plural consecutive sounding packets. Each sounding packet corresponds to a different subset of the set of antennas, and at least one of the plural consecutive packets includes a high throughput (HT) control field including a signal to initiate antenna selection and a number N indicative of a number of sounding packets which follow the at least one packet including the HT control field and which are to be used for antenna selection. A channel matrix is estimated based on a characteristic of the channel as indicated by the received N sounding packets, and a subset of antennas is selected according to the channel matrix. Station and computer program product embodiments include similar features. | 11-26-2009 |
20100008436 | Physical Layer Frame Format Design for Wideband Wireless Communications Systems - Systems and methods are provided for processing a payload portion of a received signal in a single carrier mode or a multiple carrier mode based on a portion of the received signal. A single carrier signaling portion is received at a first rate, and whether the payload portion of the signal is a single carrier signal or a multiple carrier signal is detected from the received single carrier signaling portion. The payload portion of the received signal is received at the first rate and demodulated in a single carrier mode if the detecting determines that the payload portion of the received signal is a single carrier signal, and the payload portion of the received signal is demodulated in a multiple carrier mode if the detecting determines that the payload portion of the received signal is a multiple carrier signal. | 01-14-2010 |
20100054223 | Physical Layer Data Unit Format - In a wireless communication system wherein communication devices exchange information utilizing data units that conform to a first format, a beamforming training (BFT) data unit that conforms to a second format is transmitted, wherein a length of the BFT data unit is shorter than lengths supported by the first format, wherein the BFT data unit is for transmitting PHY beamforming training information. Information to indicate the BFT data unit conforms to the second format is transmitted to a receiving device. The BFT data unit is generated according to the second format, wherein the BFT data unit includes BFT information elements. The BFT data unit is then transmitted to the receiving device. | 03-04-2010 |
20100056062 | Beamforming by Sector Sweeping - A method for beamforming in a communication system includes receiving a first plurality of training data units via a plurality of antennas, applying a different steering vector as each training data unit is received, generating a first plurality of quality indicators based on the first plurality of received training data units, such that each of the first plurality of quality indicators corresponds to a respective one of the first plurality of received training data units, and selecting a steering vector based on the different steering vectors and the first plurality of quality indicators. | 03-04-2010 |
20100226415 | Mapping for MIMO Communication Apparatus - A method, MIMO communication device and electronic storage medium for mapping symbols during a duration of each plural consecutive frames of each of a plurality of first data streams ( | 09-09-2010 |
20120177015 | Wireless Network With Simultaneous Uplink Transmission of Independent Data From Multiple Client Stations - A wireless network comprises R client stations that respectively generate simultaneous uplink transmission (SUT) data, where R is an integer greater than one. An access point (AP) receives SUT data from each of the R client stations during an SUT period. | 07-12-2012 |
20120182982 | ACCESS POINT WITH SIMULTANEOUS DOWNLINK TRANSMISSION OF INDEPENDENT DATA FOR MULTIPLE CLIENT STATIONS - A wireless network device includes modulation modules, each configured to receive a data stream and modulate the data stream to generate a modulated data stream. A matrix module generates a multiplexing matrix based on channel conditions between the wireless network device and each of a plurality of client stations, and applies the multiplexing matrix to each of the modulated data streams to generate multiplexed data streams. The wireless network device also includes summing modules, each configured to sum at least two of the multiplexed data streams to generate a transmit data stream. A first transmitter transmits a first one of the transmit data streams during a downlink transmission period to a first one of the client stations. A second transmitter transmits a second one of the transmit data streams to a second one of the client stations while the first transmitter transmits the first one of the transmit data streams. | 07-19-2012 |
20120202439 | POWER AMPLIFIER ADJUSTMENT FOR TRANSMIT BEAMFORMING IN MULTI-ANTENNA WIRELESS SYSTEMS - One or more beamsteering matrices are applied to one or more signals to be transmitted via multiple antennas. After the one or more beamsteering matrices are applied to the one or more signals, the plurality of signals is provided to a plurality of power amplifiers coupled to the multiple antennas. Signal energies are determined for the plurality of signals provided to the plurality of power amplifiers, and relative signal energies are determined based on the determined signal energies. Output power levels of the plurality of power amplifiers are adjusted based on the determined relative signal energies. | 08-09-2012 |
20120207181 | EFFICIENT PHYSICAL LAYER PREAMBLE FORMAT - A method for processing a preamble of a data packet, received via a communication channel, using a pair of complementary sequences, wherein a sum of out-of-phase aperiodic autocorrelation coefficients of the pair of complementary sequences is zero, and wherein the preamble includes a first field that provides synchronization information and a second field that provides channel estimation information, includes at least one of (i) correlating a received signal corresponding to the preamble with at least one sequence of the pair of complementary sequences to generate a plurality of respective correlation signals, or (ii) autocorrelating the received signal to generate an autocorrelation signal. The method also includes determining a cover code in the preamble using at least one of (i) the plurality of respective correlation signals, or (ii) the autocorrelation signal. The method also includes using the cover code to decode the preamble. | 08-16-2012 |
20130107833 | WLAN TRANSMIT MODES AND COEXISTENCE | 05-02-2013 |
20130114764 | Physical Layer Frame Format Design for Wideband Wireless Communications Systems - Systems and methods are provided for processing a payload portion of a received signal in a single carrier mode or a multiple carrier mode using a wireless channel receiver based on a portion of the received signal, where a signaling portion of the received signal is a single carrier signal. A single carrier signaling portion is received, and whether the payload portion of the signal is a single carrier signal or a multiple carrier signal is detected from the received single carrier signaling portion. The payload portion of the received signal is demodulated in a single carrier mode if the detecting determines that the payload portion of the received signal is a single carrier signal, and the payload portion of the received signal is demodulated in a multiple carrier mode if the detecting determines that the payload portion of the received signal is a multiple carrier signal. Data from the demodulated payload portion of the received signal is stored in a computer-readable memory. | 05-09-2013 |
20130136063 | PHY Preamble Format For Wireless Communication System - A system and method of extracting data from data packets transmitted over a wireless network includes receiving a data packet having a preamble portion and a payload portion. The preamble portion is cross correlated with a first known spreading sequence to generate a first timing signal and the preamble portion is cross correlated with a second known spreading signal to generate a frame timing signal. An impulse is detected in the first timing signal and a first timing parameter is set based upon the detected impulse in the first timing signal. An impulse is detected in the frame timing signal and a frame timing parameter is set based upon the detected impulse in the frame timing signal. Data is extracted from the received payload portion according to the first timing parameter and the frame timing parameter. | 05-30-2013 |
20130272439 | CODEBOOK SELECTION FOR TRANSMIT BEAMFORMING - A method selects a codebook for transmit beamforming. The method constructs an estimated channel matrix based on a codebook, selects a channel submatrix from the estimated channel matrix, calculates a selection matrix from the channel submatrix; and assigns a steering matrix based on the selection matrix. The method may construct an estimated channel matrix, select a channel submatrix, and calculate a selection matrix for each of multiple codebooks, then select an optimal codebook. The steering matrix is assigned based on the optimal codebook. The steering matrix may be used in steering a transmitted packet. The method may also calculate a post-MIMO equalizer signal-to-noise ratio for a data stream, based on the estimated channel matrix and the selected codebook. A related system is also disclosed. Other embodiments are provided, and each of the embodiments described herein can be used alone or in combination with one another. | 10-17-2013 |
20140071973 | METHOD AND APPARATUS FOR TRANSMITTING FIRST DATA STREAMS VIA RESPECTIVE TRANSMITTERS TO MULTIPLE CLIENTS STATIONS DURING A SAME PERIOD AND SUCCESSIVELY TRANSMITTING SECOND DATA STREAMS - An access point including a first transmitter and a second transmitter. The first transmitter is configured to (i) during a first window, transmit a first data stream to a first client station, and (ii) during a second window, transmit a second data stream to a second client station. The second transmitter is configured to: during the first window and while the first transmitter transmits the first data stream to the first client station, transmit a third data stream to a third client station; during a first portion of the second window and while the first transmitter is transmitting the second data stream to the second client station, refrain from transmitting a fourth data stream to a fourth client station; and subsequent to the first transmitter completing the transmission of the second data stream and during a second portion of the second window, transmit the fourth data stream to the fourth client station. | 03-13-2014 |