Abstract: The present invention relates to a refrigerant composition, including trifluoroiodomethane (CF3I); 1,3,3,3-tetrafluoropropene (HFO-1234ze); difluoromethane (HFC-32), and pentafluoroethane (HFC-125) for use in a heat exchange system, including refrigeration applications and in particular aspects to the use of such compositions as a replacement of the refrigerant R-22 or R-404A for heating and cooling applications and to retrofitting heat exchange systems, including systems designed for use with R-22 or R-404A.

Abstract: A method for controlling communication of information includes selecting a group of stations within range of an access point, transmitting a first signal from the access point to a first station in the group, and receiving at the access point a second signal from a second station in the group. The first signal is transmitted to the first station through a downlink channel. The second signal is received from the second station through an uplink channel. Transmission of the first signal takes place during a first period and reception of the second signal takes place during a second period overlapping the first period, in order to perform full-duplex different-frequency communications based on an 802.11 standard between the access point and the first station and the second station.

Abstract: The present invention includes refrigerant composition, including trifluoroiodomethane (CF3I); 1,1,1,2-tetrafluoropropene (HFO-1234yf); difluoromethane (HFC-32); and pentafluoroethane (HFC-125), for use in a heat exchange system, including refrigeration applications and in particular aspects to the use of such compositions as a replacement of the refrigerant R-404A for heating and cooling applications and to retrofitting heat exchange systems, including systems designed for use with R-404A.

Abstract: A first communication device determines a first spatial direction for beamforming toward a second communication device, and determines a second spatial direction that is orthogonal to the first spatial direction. The first communication device wirelessly transmits the data to the second communication device while performing beamforming in the first spatial direction, and simultaneously wirelessly transmits noise while performing beamforming in the second spatial direction.

Abstract: This disclosure describes a receiver having equalization with noise de-whitening mitigation for wireless communication. An input port receives, via an antenna, a signal communicated over a wireless communication link, the signal comprising a noise component. Control circuitry performs zero forcing equalization of the received signal to generate a zero forcing equalization result signal. The zero forcing equalization causes de-whitening of the noise component by increasing a correlation among elements of the noise component. The control circuitry mitigates the de-whitening of the noise component by: determining a noise variance value based on channel properties of the wireless communication link, and modifying the zero forcing equalization result signal based on the noise variance value. The modified zero forcing equalization result signal is communicated, via an output port, to log-likelihood ratio (LLR) generation circuitry for LLR computation.

Abstract: The present invention provides a refrigerant composition comprising: (a) from about 65% by weight to about 90% by weight of HFO-1234ze(E); (b) from about 10% by weight to about 35% by weight of HFO-1336mzz (E); and optionally (c) from about 0% to about 4.4% by weight of HFC-227ea for use in a variety of refrigeration applications, including air conditioning and/or refrigeration and particularly cooling products such as fruits, vegetables and beverages without exposing those articles to temperatures below the freezing point of water.

Abstract: Disclosed are refrigerants, and heat transfer compositions, heat transfer systems and heat transfer methods containing such refrigerants, wherein the refrigerant comprises at least about 97% by weight of the following three components (a)-(c) and the following fourth component if present: (a) trans-1-chloro-3,3,3-trifluoropropene (HFCO-1233zd(E)), (b) trans-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)), (c) trifluoroiodomethane (CF3I), and. (d) 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea).

Abstract: Methods and systems are disclosed herein for performing channel estimation for multi-stream packets. The method may include receiving a data packet comprising a plurality of training fields, wherein the plurality of training fields comprises a training field, wherein the training field comprises a plurality of tones, and wherein the plurality of tones comprises a first tone and a second tone. The method may include modifying the first tone based on a predetermined signal associated with the first tone. The method may include storing the first tone in a data structure associated with the first tone. The method may include modifying the data structure based on the second tone.

Abstract: A method for providing a compressed beamforming feedback of a communication channel includes receiving, at a first communication device, a plurality of training signals from a second communication device via the communication channel, determining a channel matrix corresponding to the communication channel based on the plurality of training signals, precomputing a sequence of column sorting orders and/or a sequence of scaling factors based on a first intermediate matrix derived from the channel matrix in advance of performing a modified QR decomposition, performing the modified QR decomposition to derive the compressed beamforming feedback based on the first intermediate matrix with the precomputed column sorting orders and/or scaling factors as an input, and transmitting the compressed beamforming feedback from the first communication device to the second communication device to enable the second communication device to steer at least one subsequent transmission to the first communication device based on the

Abstract: Embodiments described herein provide a system for transmitting high efficiency long term training field (HE-LTF) symbols for multiple wireless spatial streams over a wireless channel. An advanced P-matrix design is used to construct HE-LTF symbols that are processed by a receiver such that channel properties such as channel estimates or carrier phase error are determined prior to receiving all HE-LTF symbols. Tone multiplexing of wireless spatial stream is also used to transmit multiple spatial streams based on an assignment of sets of spatial streams to sets of tones available for transmission, increasing the throughput of the transmission system. The advanced P-matrix design and tone multiplexing are used in combination to achieve calculate channel properties before receiving all HE-LTF symbols while minimizing power fluctuation among the high efficiency short training field symbol and the HE-LTF symbols.

Abstract: A WLAN AP includes an array of antennas, a transceiver and a processor. The transceiver is configured to transmit via the array of antennas downlink packets to WLAN STAs, and to receive uplink packets from the STAs. The processor is coupled to the transceiver and is configured to send a request to a plurality of the STAs to transmit a respective plurality of channel-sounding packets corresponding to the plurality of STAs, to receive the plurality of channel-sounding packets from the plurality of STAs in response to the request, to compute, based on the received plurality of channel-sounding packets, a beamforming matrix that defines subsequent transmission beams aimed toward at least a subset of the plurality of STAs, and to transmit one or more downlink data packets to one or more of the STAs via the array of antennas, in accordance with the beamforming matrix.

Abstract: The present disclosure describes methods and apparatuses for phase-based cyclic redundancy check (CRC) verification for wireless communication. In some aspects, a soft phase value and a sliced phase value are received for a symbol of a data packet, the data packet received via a wireless interface. An error measurement is determined for the symbol based on the soft phase value and the sliced phase value. The error measurement for the symbol is then compared to an error measurement threshold for detecting symbol-level errors in the data packet. Based on the error measurement exceeding an error measurement threshold, a bit error can be detected in the data packet, which may have passed CRC. By detecting the bit error despite a CRC pass, the bit error can be indicated to higher-level entity of the wireless interface. This can be effective to prevent the bit error from impairing operation of the higher-level entity.

Abstract: A first communication device calculates an initial matrix from an estimate of a communication channel, and performs a matrix decomposition of the initial matrix to decompose the initial matrix into a plurality of decomposition matrices. Performing the matrix decomposition comprises determining angles for rotation operations performed on the initial matrix as part of decomposing the initial matrix. The first communication device determines compressed feedback using the angles that were determined as part of decomposing the initial matrix into the plurality of decomposition matrices. The compressed feedback is a compressed representation of a beamforming steering matrix corresponding to the estimate of the communication channel. The first communication device transmits the compressed feedback to a second communication device to enable the second communication device to beamform at least one subsequent transmission to the first communication device.

Abstract: Disclosed are cascade refrigerant systems for providing cooling of air located in an enclosure that is occupied by or which will be exposed to humans or other animals during normal use, wherein systems includes; (1) a first, relatively low temperature heat transfer circuit having a first evaporator located within the enclosure and a first heat transfer fluid in the low temperature heat transfer circuit; (2) a second heat transfer circuit located substantially outside the enclosure comprising a second heat transfer fluid; (3) a heat exchanger which serves as the condenser in the low temperature circuit thermally coupled with the high temperature circuit by virtue of rejecting heat into the second heat transfer fluid; and (4) in the high temperature loop of a heat exchanger which transfers heat from the second heat transfer fluid exiting from a high temperature condenser to the portion of the second heat transfer fluid which is traveling to the suction side of the compressor.

Abstract: Disclosed are heat transfer compositions and methods and systems containing refrigerants consisting essentially of difluoromethane (HFC-32), and trifluoroiodomethane (CF3I), and heat transfer compositions and methods and systems containing refrigerants consisting essentially of difluoromethane (HFC-32), and trifluoroiodomethane (CF3I) and CO2.

Abstract: This disclosure describes a receiver having equalization with noise de-whitening mitigation for wireless communication. An input port receives, via an antenna, a signal communicated over a wireless communication link, the signal comprising a noise component. Control circuitry performs zero forcing equalization of the received signal to generate a zero forcing equalization result signal. The zero forcing equalization causes de-whitening of the noise component by increasing a correlation among elements of the noise component. The control circuitry mitigates the de-whitening of the noise component by: determining a noise variance value based on channel properties of the wireless communication link, and modifying the zero forcing equalization result signal based on the noise variance value. The modified zero forcing equalization result signal is communicated, via an output port, to log-likelihood ratio (LLR) generation circuitry for LLR computation.

Abstract: A first communication device receives a plurality of training signals from a second communication device via a communication channel. The first communication device determines, based on the plurality of training signals, a channel matrix corresponding to the communication channel, and determines, based the channel matrix and without decomposing a steering matrix, compressed feedback to be provided to the second communication device. The first communication device transmits the compressed feedback to the second communication device to enable the second communication device to steer at least one subsequent transmission to the first communication device.

Abstract: A receiver device generates a bit stream corresponding to a received signal at least by demodulating the received signal. The received signal includes an address that was encoded at a transmitter device using a forward error correction code. The receiver device correlates the bit stream with an encoded known address to generate a correlation output that indicates a degree of similarity between a segment of the bit stream and the encoded known address. The encoded known address corresponds to a known device address that was encoded using the error correction code. The receiver device determines when the correlation output is greater than a threshold that corresponds to a particular degree of similarity with the encoded known address. The receiver device determines that the bit stream includes the known device address when the receiver device determines that the correlation output is greater than the threshold.

Abstract: Disclosed are distributed refrigeration systems, comprising: a plurality of first refrigeration circuits, with each first refrigeration circuit being provided in a respective refrigeration unit; a second refrigeration circuit, the second refrigeration circuit comprising a second circuit heat exchanger; and a third refrigeration circuit, wherein each first circuit heat exchanger is arranged to transfer heat energy between its respective first refrigeration circuit and the second refrigeration circuit; and a third circuit heat exchanger arranged to transfer heat energy between the second refrigeration circuit and the third refrigeration circuit.

Abstract: Disclosed are refrigeration systems of the type having a heat source to be cooled and a heat sink into which heat can be rejected, said system preferably having a capacity of from about 2 to about 30 tons and comprising: (a) a heat transfer composition comprising a refrigerant comprising at least about 80% by weight of trans1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(E)) or at least about 80% by weight of trans1,3,3,3-tetrafluoropropene (HFO-1234ze(E)); (b) a centrifugal compressor having: (i) a refrigerant suction for receiving a relatively low-pressure refrigerant vapor at a pressure of from about 40 to about 350 kPa and (ii) a discharge for discharging a relatively high pressure refrigerant vapor at a pressure wherein the discharge:suction pressure ratio is at least about 2:1; (c) a condenser operating at temperature in the range of from about 10° C. to about 60° C.