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 |
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 |
20080279317 | BICM DECODING IN THE PRESENCE OF CO-CHANNEL INTERFERENCE - Systems and methods are provided for computing soft information for digital information based on a received signal, where the received signal suffers from noise and interference. A receiver that decodes the received signal may estimate channel information, such as the channel gain, associated with the interfering source. The receiver may also obtain modulation information through a backbone network or by decoding control information transmitted by the interfering source. Using the modulation information and the channel information, the receiver may estimate the effect that interference has on the received signal, and may compute soft information (e.g., a log-likelihood ratio) for the digital information. | 11-13-2008 |
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 |
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 |
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 |
20100080266 | Physical Layer Data Unit Format - In a wireless communication system wherein communication devices exchange information utilizing data units that conform to a first format, wherein the first format includes a short training field (STF) spread with a first spread code and a first cover code, a method is for generating a physical layer (PHY) data unit that conforms to a second format, wherein the PHY data unit is for transmitting PHY information. A first portion of the PHY data unit is generated to indicate the PHY data unit conforms to the second format, wherein the first portion of the PHY data unit includes an STF spread with at least one of a second spread code different than the first spread code or a second cover code different than the first cover code. A second portion of the PHY data unit is generated according to the second format, wherein the second portion of the PHY data unit includes PHY information elements not specified by the first format. | 04-01-2010 |
20100232475 | Equal Power Output Spatial Spreading Matrix for Use in a Wireless MIMO Communication System - A spatial spreading unit is configured to utilize a spatial spreading matrix to distribute two or more encoded spatial data streams to transmission antennas. The spatial spreading matrix has components (i) associated with each row of a row dimension having a number of rows equal to the number of the transmission antennas to be used to transmit the encoded spatial data streams and (ii) associated with each column of a column dimension having a number of columns equal to the number of the encoded spatial data streams to be transmitted. Additionally, the spatial spreading matrix satisfies one or more of the following two constraints: (1) the ratio of squared norms of the sum of the components of a row, for different rows of the spatial spreading matrix, is equal to a first constant sequence, and (2) the ratio of squared norms of the sum of a symbol Sl to be transmitted, when the symbol Sl is equal to 1 or −1, multiplied by each of the components of a row, for different rows of the spatial spreading matrix, is equal to a second constant sequence. | 09-16-2010 |
20100232483 | Calibration Correction for Implicit Beamforming in a Wireless MIMO Communication System - A first packet is transmitted via a forward channel corresponding to a signal direction from a first transceiver device to a second transceiver device, wherein the first packet includes a request to initiate calibration. A partial dimensional description of a reverse channel is determined based on the reception of a second packet received from the second transceiver device, wherein the second packet includes training information of spatial dimensions used for the transmission of the second packet but does not include training information for all available spatial dimensions of a reverse channel. A correction matrix is developed from the partial dimensional description of the reverse channel and a description of the forward channel, and the correction matrix and a steering matrix is used to process signals to be transmitted via the forward channel. | 09-16-2010 |
20100248635 | Sounding And Steering Protocols For Wireless Communications - The present disclosure includes systems, apparatuses, and techniques relating to wireless local area network devices. Systems, apparatuses, and techniques include communicating with multiple wireless communication devices to determine characteristics of spatial wireless channels, determining steering matrices based on one or more outputs of the communicating, and transmitting signals that concurrently provide data to the wireless communication devices via different spatial wireless channels. The signals can be spatially steered to the wireless communication devices based on the steering matrices. | 09-30-2010 |
20100260159 | PHYSICAL LAYER FRAME FORMAT FOR WLAN - In a method for generating a data unit for transmission via a communication channel, wherein the data unit conforms to a first communication protocol, a preamble of the data unit is generated. The preamble includes a first field having information that indicates a duration of the data unit, the first field being formatted such that the first field is decodable by a receiver device that conforms to a second communication protocol but does not conform to the first communication protocol to determine the duration of the data unit based on the first field. Additionally, the preamble is formatted such that a portion of the preamble is decodable by a receiver device that conforms to a third communication protocol but does not conform to the first communication protocol. Also, the preamble is formatted such that a receiver device that conforms to the first communication protocol can determine that the data unit conforms to the first communication protocol. A data portion of the data unit that conforms to the first communication protocol and does not conform to either (i) the second communication protocol or (ii) the third communication protocol is generated. | 10-14-2010 |
20120148000 | BICM DECODING IN THE PRESENCE OF CO-CHANNEL INTERFERENCE - Systems and methods are provided for computing soft information for digital information based on a received signal, where the received signal suffers from noise and interference. A receiver that decodes the received signal may estimate channel information, such as the channel gain, associated with the interfering source. The receiver may also obtain modulation information through a backbone network or by decoding control information transmitted by the interfering source. Using the modulation information and the channel information, the receiver may estimate the effect that interference has on the received signal, and may compute soft information (e.g., a log-likelihood ratio) for the digital information. | 06-14-2012 |
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 |
20120201276 | PHYSICAL LAYER DATA UNIT FORMAT - In a wireless communication system in which communication devices exchange information utilizing data units that conform to a first format, wherein the first format includes a short training field (STF) spread with a first spread code, a method for generating a physical layer (PHY) data unit that conforms to a second format includes generating a first portion of the PHY data unit to indicate the PHY data unit conforms to the second format. The first portion of the PHY data unit includes an STF spread with a second spread code different than the first spread code. The method also includes generating a second portion of the PHY data unit according to the second format. The second portion of the PHY data unit includes PHY information elements not specified by the first format. | 08-09-2012 |
20120201315 | Control Mode PHY for WLAN - A first preamble for a first data unit includes a first long training field and a first signal field modulated according to a first technique. The first data unit is generated according to a first data unit format and includes the first preamble. A second preamble, generated for a second data unit, includes a second signal field and a second long training field. Information in the second signal field is repeated and/or the second long training field is generated so that a duration of the second long training field is longer than a duration of the first long training field. A portion of the second signal field is modulated according to a second technique or a portion of the second long training field is modulated according to the second technique to signal to a receiver that the second data unit is formatted according to a second data unit format. | 08-09-2012 |
20120201316 | Control Mode PHY for WLAN - In a method for generating a physical layer (PHY) data unit for transmission via a communication channel, information bits to be included in the PHY data unit are encoded using a forward error correction (FEC) encoder. The information bits are mapped to a constellation symbols. Additionally, either the information bits are encoded according to a block coding scheme, or the constellation symbols are encoded according to the block coding scheme. Orthogonal frequency division multiplexing (OFDM) symbols are generated to include the constellation symbols and the PHY data unit is generated to include the OFDM symbols. | 08-09-2012 |
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 |
20120207192 | PHYSICAL LAYER DATA UNIT FORMAT - In a wireless communication system wherein communication devices exchange information utilizing data units conforming to a first format, a method for generating a physical layer (PHY) data unit conforming to a second format and used to transmit PHY information includes generating a first sequence u of a channel estimation field (CEF) of the PHY data unit. The first sequence u of the CEF includes complementary Golay sequences a and b and is spread with a first cover code. The method also includes generating a second sequence v of the CEF. The second sequence v follows the first sequence u, includes the complementary Golay sequences a and b, and is spread with a second cover code different than the first cover code. The method also includes generating PHY information elements of the PHY data unit. The PHY information elements are not specified by the first format. | 08-16-2012 |
20120219017 | Efficient Physical Layer Preamble Format - A transmitter device includes a controller configured to generate a first field and a second field. The first field is at least one of a packet synchronization information field or a frame boundary indication field, the second field is a channel estimation field starting after the first field ends. The controller is configured to generate the second field at least in part by generating a first channel estimation sequence (CES) symbol and a second CES symbol. At least one of i) a sequence in the first field serves as a cyclic prefix of the first CES symbol, ii) a beginning portion of the second CES symbol serves as a cyclic postfix of the first CES symbol, or iii) an ending portion of the first CES symbol serves as a cyclic prefix of the second CES symbol. | 08-30-2012 |
20120328034 | UPLINK TRAINING FOR MIMO IMPLICIT BEAMFORMING - In a method for beamforming in a multiple input multiple output (MIMO) communication system, a data unit is received from a communication device via a MIMO communication channel, and it is determined whether the data unit satisfies one or more selection criteria. Further, when it is determined that the data unit satisfies the one or more selection criteria, the data unit is selected to be used in developing a steering matrix for transmitting data units to the communication device. | 12-27-2012 |
20130003683 | Sounding and Steering Protocols for Wireless Communications - Systems, apparatuses, and techniques relating to wireless local area network devices are described. A described technique includes transmitting a sounding packet to a wireless communication device(s) to determine characteristics of spatial wireless channels, the sounding packet being based on a spatial mapping matrix; receiving a feedback packet(s) from the device(s), the feedback packet(s) being indicative of one or more feedback matrices, the one or more feedback matrices being derived from wireless channel estimations that are based on received versions of the sounding packet; generating spatially steered data packets based on multiple data streams and one or more steering matrices, which are based on the spatial mapping matrix and the one or more feedback matrices; and transmitting a frame that includes the spatially steered data packets to the device(s). The spatially steered data packets can concurrently provide the streams respectively within the frame to the device(s) via different spatial wireless channels. | 01-03-2013 |
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 |
20130154881 | 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. | 06-20-2013 |
20130177051 | CALIBRATION CORRECTION FOR IMPLICIT BEAMFORMING IN A WIRELESS MIMO COMMUNICATION SYSTEM - A transmitter beamforming technique for use in a MIMO wireless communication system determines a partial description of a reverse channel without determining a full dimensional description of the reverse channel. A correction matrix is developed from the partial description of the reverse channel and a description of the forward channel. The correction matrix is used to process signals to be transmitted via the forward channel, and a steering matrix is used to perform beamforming in the forward channel. | 07-11-2013 |
20130230126 | 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. | 09-05-2013 |
20130235908 | APPARATUS FOR GENERATING SPREADING SEQUENCES AND DETERMINING CORRELATION - A circuit for use in a complementary Golay sequence generator or in a complementary Golay sequence correlator includes an input configured to receive an input signal, a set of delay elements, including delay elements corresponding to respective delays of 1, 2, 4, 8, 16, 32, and 64, and a set of multipliers interconnected with the input and the set of delay elements. The set of multipliers is configured to apply weight factors, and the weight factors define the sequence 1,1,−1,1,−1,1,−1. The circuit also includes a pair of outputs configured to output, in response to the input signal, one of (i) a pair of complementary Golay sequences or (ii) a pair of correlation output signals, using (a) the set of delay elements and (b) the set of weight multipliers. | 09-12-2013 |
20130242968 | PHYSICAL LAYER DATA UNIT FORMAT - A beamforming training (BFT) data unit for transmission via a communication channel in a wireless personal area network is generated, and in particular, is for transmitting beamforming training information. A physical layer header and first BFT data are encoded using block encoding to generate a first block. Second BFT data are encoded using block encoding to generate a second block. The BFT data unit is generated with a fixed-length payload, such that the BFT data unit includes only i) a preamble, ii) the first block, and iii) the second block. | 09-19-2013 |
20130259017 | Physical Layer Frame Format for WLAN - In a method for generating a data unit conforming to a first communication protocol, a first field and a second field to be included in a preamble of the data unit are generated. The first field includes a first set of one or more information bits that indicate a duration of the data unit and is formatted such that the first field allows a receiver device that conforms to a second communication protocol to determine the duration of the data unit. The second field includes a second set of one or more information bits that indicate to a receiver device that conforms to the first communication protocol that the data unit conforms to the first communication protocol. The first field and the second field are modulated using a modulation scheme specified for a field corresponding to the first field and the second field, respectively, by the second communication protocol. | 10-03-2013 |
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 |
20130315050 | CHANNEL SOUNDING AND ESTIMATION STRATEGIES FOR ANTENNA SELECTION IN MIMO SYSTEMS - A method of antenna selection, in a MIMO system in which a transmitter having a first plurality of RF chains communicates with a receiver having a second plurality of RF chains, includes transmitting consecutive sounding packets produced by the first plurality of RF chains. The consecutive sounding packets each include a training symbol, and collectively sound a full-size channel for the MIMO system. The method also includes receiving channel state information for each of a plurality of scaled sub-channel estimates determined at the receiver. The channel state information includes at least one of respective gain factors that were applied to the consecutive sounding packets received at the receiver and respective scaling factors that were applied to sub-channel estimates determined at the receiver. The method also includes adjusting power levels applied to the first plurality of RF chains in response to receiving the channel state information. | 11-28-2013 |
20140003384 | Sounding and Steering Protocols for Wireless Communications | 01-02-2014 |
20140029681 | CONTROL MODE PHY FOR WLAN - In a method for generating a physical layer (PHY) data unit for transmission via a communication channel, information bits to be included in the PHY data unit are encoded using a forward error correction (FEC) encoder. Also, the information bits are encoded according to a block coding scheme, where m copies of each bit are included in the information bits, and one or more bits in the m copies of each bit are flipped. The information bits are mapped to a plurality of constellation symbols, and a plurality of orthogonal frequency division multiplexing (OFDM) symbols are generated to include the plurality of constellation symbols. The PHY data unit is generated to include the plurality of OFDM symbols. | 01-30-2014 |
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 |
20140072080 | 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. | 03-13-2014 |
20140105337 | BICM DECODING IN THE PRESENCE OF CO-CHANNEL INTERFERENCE - Systems and methods are provided for computing soft information for digital information based on a received signal, where the received signal suffers from noise and interference. A receiver that decodes the received signal may estimate channel information, such as the channel gain, associated with the interfering source. The receiver may also obtain modulation information through a backbone network or by decoding control information transmitted by the interfering source. Using the modulation information and the channel information, the receiver may estimate the effect that interference has on the received signal, and may compute soft information (e.g., a log-likelihood ratio) for the digital information. | 04-17-2014 |
20140146909 | Beamforming Using Predefined Spatial Mapping Matrices - In one or more aspects data packets are iteratively transmitted to a receiver using predefined spatial mapping matrices, channel estimates are received from the receiver responsive to iteratively transmitted data packets, and one of the predefined spatial mapping matrices is selected for transmitting additional data packets to the receiver based on the received channel estimates. | 05-29-2014 |
20140205029 | METHODS AND APPARATUS FOR WLAN TRANSMISSION - In a method for generating a PHY data unit for transmission via a communication channel, a modulation scheme is selected from a plurality of modulation schemes, information bits are encoded to generate encoded data using one or more encoders, and an interleaving parameter N | 07-24-2014 |
20140220914 | 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. | 08-07-2014 |
20140294111 | CHANNEL SOUNDING AND ESTIMATION STRATEGIES IN MIMO SYSTEMS - In a system having a first communication device with a first plurality of radio-frequency (RF) chains coupled to a first plurality of antennas and a second communication device with a second plurality of RF chains coupled to a second plurality of antennas, the second communication device receives consecutive training packets that were transmitted by the first communication device, the consecutive training packets having been produced at the first communication device by a power level rule to the first plurality of RF chains. The second communication device determines respective channel measurements corresponding to the consecutive training packets based on the power level rule, and selects a transmit parameter based on the respective channel measurements, the transmit parameter to be used by the first communication device when transmitting to the second communication device. The second communication device transmits and indication of the selected transmit parameter to the first communication device. | 10-02-2014 |
20140307568 | METHOD AND APPARATUS FOR TESTING THE BEAMFORMING PERFORMANCE OF A WIRELESS COMMUNICATION DEVICE - Systems and techniques relating to beamforming testing for wireless communication are described. A described technique includes controlling a first wireless device to deactivate or activate a beamforming mode, the first device being configured to selectively use the beamforming mode to transmit data over multiple antennas; causing the first device to send a first portion of data traffic to a second wireless device via a wireless channel while the beamforming mode is deactivated; measuring first throughput values of the first portion of data traffic while the beamforming mode is deactivated; causing the first device to send a second portion of data traffic to the second device via the wireless channel while the beamforming mode is activated; measuring second throughput values of the second portion of the data traffic while the beamforming mode is activated; and producing a test result based on a comparison of the first and second throughput values, and predetermined criteria. | 10-16-2014 |
20140307821 | Method and Apparatus for Mitigating Interference in a Wireless Network Through Use of Transmit Beamforming - In a method for reducing interference in wireless communications, a beamforming matrix is determined at a first communication device based on an estimate of a multiple input, multiple output (MIMO) communication channel between the first communication device and a second communication device. Both the first communication device and the second communication device belong to a first wireless network. Alternatively, the beamforming matrix may be generated based on the estimate of the MIMO communication channel and received at the first communication device. The beamforming matrix is used at the first communication device for the purpose of reducing interference to a second wireless network. where the interference is caused by the first communication device transmitting to the second communication device via the MIMO communication channel. | 10-16-2014 |
20140321479 | PHYSICAL LAYER DATA UNIT FORMAT - In a wireless communication system wherein communication devices exchange information utilizing data units that conform to a first format, wherein the first format includes a short training field (STF) spread with a first spread code, a physical layer (PHY) data unit that conforms to a second format and is for transmitting PHY control information is generated. Generating the PHY data unit includes generating a first portion of the PHY data unit to indicate the PHY data unit conforms to the second format, wherein the first portion of the PHY data unit includes an STF spread with a second spread code different than the first spread code. A second portion of the PHY data unit is generated according to the second format, wherein the second portion of the PHY data unit omits header fields specified by the first format. | 10-30-2014 |
20140334473 | METHOD AND APPARATUS FOR MITIGATING INTERFERENCE IN A WIRELESS NETWORK THROUGH USE OF TRANSMIT BEAMFORMING - In a method for reducing interference in a first wireless communication network and a second wireless communication network, a first access point (AP) device of the first wireless communication network coordinates with a second AP device of the second wireless communication network with respect to utilizing transmit beamforming at the first AP device and transmit beamforming at the second AP device for the purpose of reducing interference in the first wireless communication network and the second wireless communication network. Based on coordinating with the second AP device, the first AP device uses a beamforming matrix to transmit, via a multiple input, multiple output (MIMO) communication channel, to one or more first stations in the first wireless communication network for mitigating interference between the first wireless communication network and the second wireless communication network. | 11-13-2014 |
20150071366 | UPLINK TRAINING FOR MIMO IMPLICIT BEAMFORMING - In a method for beamforming in a multiple input multiple output (MIMO) communication system, a data unit is received from a communication device via a MIMO communication channel, and it is determined whether the data unit satisfies one or more selection criteria. Further, when it is determined that the data unit satisfies the one or more selection criteria, the data unit is selected to be used in developing a steering matrix for transmitting data units to the communication device. | 03-12-2015 |