424 results about "Signal field" patented technology

A method and apparatus for session layer framing for interoperability between packet-switched systems is described. The method includes the steps of: generating (1210) a communication frame at the session layer including a plurality of fields; providing (1220) for a payload field in the plurality of fields for carrying a payload; and providing (1230) for a signal field in the plurality of fields for carrying a control signal.

Provided is a tracking system, including a motor coupled to a medical instrument and configured to generate at least one magnetic field, and at least one receiver coil configured to sense the magnetic field. Also provided is a method of tracking, including rotating a rotor of a motor, wherein the rotor comprises a permanent magnet that generates a rotating magnetic field when the rotor is rotated, sensing the rotating magnetic field with at least one receiver, transmitting to a processor a signal indicative of the rotating magnetic field, and processing the signal to determine a position of the motor. Further provided is a method of tracking, comprising energizing a stator coil of a motor to generate at least one magnetic field, sensing the at least one magnetic field with at least one receiver, transmitting to a processor a signal indicative of the at least one magnetic field, and processing the signal to determine a position of the motor.

The technology in this application provides a method and apparatus for efficiently using common uplink radio resources, e.g. a common uplink enhanced-dedicated physical channel (E-DCH) resource. A UE releases a common E-DCH resource very quickly after a completed transmission. In addition or alternatively, a base station may release a common E-DCH resource configuration from the network side to free up common E-DCH resources for use by other UEs. A low overhead signaling scheme for quickly and effectively releasing of common E-DCH resources between a UE and a base station is also described. For example, existing signaling fields on protocol layer 2 (L2) or layer 1 (L1) may be used. In one preferred example embodiment, signaling fields already in use in a CELL_DCH service state are given a different meaning for UEs in a CELL_FACH service state so that common E-DCH resources are quickly and effectively released.

A wireless network includes a transmitting device and a plurality of receiving devices. The transmitting device is configured to receive a plurality of data packets, including a first data packet and a second data packet, prepare a preamble, prepare a signal field for each of the plurality of data packets, including a first signal field based on the first data packet and a second signal field based on the second data packet, and broadcast the preamble, the first signal field, the first data packet, the second signal field, and the second data packet as a concatenated packet.

A method and apparatus are disclosed for transmitting symbols in a multiple antenna wireless communication system, such that the symbols can be interpreted by a lower order receiver (i.e., a receiver having a fewer number of antennas than the transmitter). For example, subcarriers from one or more symbols can be transmitted such that each of the subcarriers are active on only one of the antennas at a given time. In one implementation, the subcarriers are diagonally loaded across logically adjacent antennas. The symbols can include one or more long training symbols and optionally a SIGNAL field that indicates a duration that a receiver should defer until a subsequent transmission. In this manner, a transmitter in accordance with the present invention may be backwards compatible with a lower order receiver and a lower order receiver can interpret the transmitted symbols or defer for an appropriate duration.

A system and method are provided for traffic signaling in wireless or sensor networks. The system and method use information or bits in a Signal Field (SIG) of Physical Layer (PHY) preamble in a packet to provide traffic control information. An embodiment method implemented by a network component comprises indicating a traffic direction and a traffic type for traffic control in a SIG in a frame and transmitting the frame including the SIG. Another method comprises receiving in a frame a SIG for traffic control that indicates a transmission type and decoding the SIG field to determine whether to process remaining information in the frame if the frame comprises data payload or a Media Access Control (MAC) header.

A method for automatically detecting a packet mode in a wireless communication system supporting a multiple transmission mode includes: acquiring at least one of data rate information, packet length information and channel bandwidth information from a transmitted frame; and determining the packet mode on the basis of the phase rotation check result of a symbol transmitted after a signal field signal and at least one of the data rate information, the packet length information and the channel bandwidth information acquired from the transmitted frame.

A wireless communication device (‘device’) is configured to generate an OFDM / A packet that includes at least one OFDM / A symbol that includes at least one SIG having SIG information modulated on only even (or odd) sub-carriers and does not include any information modulated on odd (or even) sub-carriers of a set of OFDM / A sub-carriers. The set of OFDM / A sub-carriers may be all or less than all of available sub-carriers. The device may generate the packet to include a preamble and a payload such that the payload, which may be composed of at least one additional OFDM / A symbol, includes data modulated on some or all of the sub-carriers of the set of OFDM / A sub-carriers. The device can modulate and transmit SIG information and data differently within the preamble and the payload (e.g., with higher ordered modulation or MCS for the data and less power per sub-carrier than for the preamble).

A method for configuring a multiple input multiple output (MIMO) wireless communication begins by generating a first preamble for a first antenna of the MIMO communication, wherein the first preamble includes a carrier detect field, a first channel select field, a first signal field, and a second signal field. The method continues by generating a second preamble for at least one other antenna of the MIMO communication, wherein the second preamble includes the carrier detect field, a plurality of channel select fields, and the second signal field. The method continues by simultaneously transmitting the carrier detect field via the first antenna and the least one other antenna. The method continues by transmitting the first channel select field and the first signal field via the first antenna. The method continues by, subsequent to the transmitting the first channel select field and the first signal field via the first antenna, transmitting the plurality of channel select fields via the at least one other antenna. The method continues by simultaneously transmitting the second signal field via the first antenna and the at least one other antenna.

A “Sensor Array Post-Filter” provides an adaptive post-filter that accurately models and suppresses both diffuse and directional noise sources as well as interfering speech sources. The post-filter is applied to an output signal produced by a beamformer used to process signals produced by a sensor array. As a result, the Sensor Array Post-Filter operates to improve the signal-to-noise ratio (SNR) of beamformer output signals by providing adaptive post-filtering of the output signals. The post-filter is generated based on a generative statistical model for modeling signal and noise sources at distinct regions in a signal field that considers prior distributions trained to model an instantaneous direction of arrival for signals captured by sensors in the array.

A method for configuring a multiple input multiple output (MIMO) wireless communication begins by generating a first preamble for a first antenna of the MIMO communication, wherein the first preamble includes a carrier detect field, a first channel select field, a first signal field, and a second signal field. The method continues by generating a second preamble for at least one other antenna of the MIMO communication, wherein the second preamble includes the carrier detect field, a plurality of channel select fields, and the second signal field. The method continues by simultaneously transmitting the carrier detect field via the first antenna and the least one other antenna. The method continues by transmitting the first channel select field and the first signal field via the first antenna. The method continues by, subsequent to the transmitting the first channel select field and the first signal field via the first antenna, transmitting the plurality of channel select fields via the at least one other antenna. The method continues by simultaneously transmitting the second signal field via the first antenna and the at least one other antenna.

A system is disclosed for detecting a signal field from a sample volume. The system includes a source system and an optical fiber system. The source system provides a first electromagnetic field at a first frequency and a second electromagnetic field at a second frequency that is different from the first frequency. The optical fiber system includes at least one optical fiber for guiding the first and second electromagnetic fields to the sample volume to generate coherent radiation characteristic of molecular vibrations by non-linear interaction of the first and second fields with the sample volume. The optical fiber system also receives the signal field resulting from the coherent radiation, and guides the signal field to a detector.

The present invention relates to a method and apparatus for beamformed transmission in a wireless local area network. According to one aspect of the present invention, a method for transmitting a Physical layer Protocol Data Unit (PPDU) frame to a plurality of stations (STAs) by an Access Point (AP) in a wireless local area network may be provided. The method may include transmitting a SIGNAL field of the PPDU frame, the SIGNAL field including beamforming information indicating whether beamforming is applied to respective data units of the PPDU frame, and transmitting the data units of the PPDU frame, the data units being individually beamformed or not beamformed according to the beamforming information.

The invention relates to a control channel signal for use in a mobile communication system providing at least two different scheduling modes. Further the invention relates to a scheduling unit for generating the control channel signal and a base station comprising the scheduling unit. The invention also relates to the operation of a mobile station and a base station for implementing a scheduling mode using the control channel signal proposed by the invention. In order to facilitate the use of different scheduling schemes for user data transmission while avoiding an additional flag for indicating the scheduling mode in the control signaling, the invention proposes the use of code points in existing control channel signal fields. Further, the invention proposes a specific scheduling mode for use in combination with the proposed new control channel signal according to the invention. According to this scheduling mode control channel information is only provided for retransmissions, while initial transmissions are decoded using blind detection.

A method and apparatus are disclosed for transmitting symbols in a multiple antenna communication system according to a frame structure, such that the symbols can be interpreted by a lower order receiver (i.e., a receiver having a fewer number of antennas than the transmitter). The disclosed frame structure comprises a legacy preamble having at least one long training symbol and N-I additional long training symbols that are transmitted on each of N transmit antennas. The legacy preamble may be, for example, an 802.11 a / g preamble that includes at least one short training symbol, at least one long training symbol and at least one SIGNAL field. A sequence of each of the long training symbols on each of the N transmit antennas are time orthogonal. The long training symbols can be time orthogonal by introducing a phase shift to each of long training symbols relative to one another.

The invention discloses a receiving method and device of an MIMO (multiple-input multiple-output) communication system compatible to multiple frame formats and belongs to the technical field of wireless communication. In a millimeter-wave wireless communication system, stations working in the same basic service set are likely to receive three different types of PPDUs (physical layer protocol data units), namely a single-carrier MIMO PPDU, an OFDM (orthogonal frequency division multiplexing) MIMO PPDU and an OFDM MU-MIMO (multi-user multiple-input multiple-output) PPDU. Preambles of the three frame formats are identical to signaling fields A in format and sent in a single-carrier mode. The receiving method includes that a receiver demodulates the signaling fields A with the single-carrier mode, a receiving process is configured on the basis of the signaling fields A and signaling fields B, and the various PPDUs are demodulated. Compared with the prior art, the receiving method and device have the advantage that reliability and compatibility of the system are improved effectively.

A method and apparatus are disclosed for transmitting symbols in a multiple antenna communication system according to a frame structure, such that the symbols can be interpreted by a lower order receiver (i.e., a receiver having a fewer number of (antennas than the transmitter). The disclosed frame structure comprises a legacy preamble having at least one long training symbol and N-1 additional long training symbols that are transmitted on each of N transmit antennas. The legacy preamble may be, for Q example, an 802.11 a / g preamble that includes at least one short training symbol, at least one long training symbol and at least one SIGNAL field. A sequence of each of the long training symbols on each of the N transmit antennas are time orthogonal. The long training symbols can be time orthogonal by introducing a phase shift to each of long training symbols relative to one another.

In a method for implementation of a magnetic resonance examination, and a magnetic resonance apparatus, and an array for acquisition of magnetic resonance signals, and a magnetic resonance signal at a magnetic resonance frequency are acquired from an examination region with an array of frequency conversion units after an RF excitation and are radiated as frequency-converted signals. The resulting signal field is acquired by a number of reception antennas of a second antenna array, which are arranged at different spatial positions and thus allow a spatial resolution of the frequency-converted signals. The acquired acquisition signals are used for image reconstruction.

Methods and systems for communicating in a wireless network may distinguish different types of packet structures by modifying the phase of a modulation constellation, such as a binary phase shift keying (BPSK) constellation, in a signal field. Receiving devices may identify the type of packet structure associated with a transmission or whether the signal field is present by the phase of the modulation constellation used for mapping for the signal field. In one embodiment, the phase of the modulation constellation may be determined by examining the energy of the I and Q components after Fast Fourier Transform. Various specific embodiments and variations are also disclosed.

A wireless communication system includes a first communication station configured to operate according to a first communication protocol, and a second communication station capable of operating according to both the first communication protocol and a second communication protocol. When the second communication station transmits a packet according to the second communication protocol, at least a first signal field compliant with the first communication protocol and a second signal field compliant with the second communication protocol are attached to a header of the packet, and the first signal field includes a parity bit. When the second communication station receives a packet from another communication station, the second communication station performs a parity check on the first signal field of the packet, and when no parity error is detected, the second communication station further checks whether content of the first signal field is compliant with the first communication protocol.

A digital version of both amplitude and phase of at least one generic polarization component of a received optical signal is developed using dual-polarization direct differential detection with digital signal processing. The received signal is split into orthogonal polarization components, each of which is split into three copies. For each orthogonal polarization component a) an intensity profile is conventionally obtained using a copy and b) phase information is obtained by supplying each remaining copy to a respective one of a pair of optical delay interferometers having orthogonal phase offsets, followed by respective balanced intensity detectors. The outputs the balanced intensity detectors and the intensity profiles are converted into digital representations and used to develop, via signal processing, the optical field information of at least one generic polarization component of the received optical signal. Compensation of impairments, such as PMD, is realized through further processing.

A method of arranging a packet in a wireless communication system includes a preamble sequence and a data sequence. The preamble sequence includes a legacy training field (L-TF), a legacy signal field (L-SIG), a very high throughput signal field (VHT-SIG), a very high throughput short training field (VHT-STF) and at least one very high throughput long training field (VHT-LTF). The method includes generating a first VHT-SIG field and a second VHT-SIG field according to the VHT-SIG field; and arranging the L-TF field, the L-SIG field, the first VHT-SIG field, the VHT-STF field, one of the at least one VHT-LTF fields, the second VHT-SIG field and the rest of the at least one VHT-LTF fields in a predetermined sequence.

A wireless device, method, and signal for use in communication of a wireless packet between transmitting device and a wireless receiving device via a plurality of antennas, wherein a signal generator generates wireless packet including a short-preamble sequence used for a first automatic gain control (AGC), a first long-preamble sequence, a signal field used for conveying a length of the wireless packet, an AGC preamble sequence used for a second AGC to be performed after the first AGC, a second long-preamble sequence, and a data field conveying data. The AGC preamble sequence is transmitted in parallel by the plurality of antennas.

Methods and apparatus for estimating and correcting carrier frequency offsets in a bust multi-tone receiver are described. Course and fine carrier frequency estimates are generated from the signal's preamble. Decision directed carrier frequency offset estimates are then generated from the signal field and data fields of the multi-tone signal. Frequency error estimates are generated for each tone of the signal and combined using a weighted average to generate the frequency error estimate used to perform the correction operation. Error estimates corresponding to noisy data tones are weighted less then estimates corresponding to less noisy data tones. In cases of low SNR frequency error estimates corresponding to pilots are weighted by an extra amount as compared to error estimates corresponding to tones used to transmit data symbols. During times of high SNR error estimates corresponding to pilot tones are weighted in the same manner as error estimates corresponding to data tones.

The present invention relates to methods for transmitting a frame by grouping a plurality of wireless terminals in a multiuser based wireless communication system. The present invention includes a method for transmitting a frame by including information about multiple receiver terminals in a MAC frame, another method for transmitting a frame by allocating group addresses and then using a corresponding group address for frame transmission, and yet another method for transmitting a frame by using a unique group sequence number that is allocated to each group and group control information that contains bitmap information. The group control information is included in a destination address field of a MAC layer, or in a signal field of a physical layer, or in both the MAC layer and the physical layer.

A method and system for constant-power loading for asymmetric antenna configurations. The sounding packet, the sounding bit in HT-SIG field, and the HT-LTF field in the PLCP protocol data unit (PPDU) are used to determine the number of transmit antennas and the number of data streams, wherein if the number of transmission streams is the same as the number of data streams, then a first set of power loading level (fixed uneven power loading) is applied, otherwise a second set of power loading level is applied. Alternatively, one additional bit in the HT-SIG filed of PLCP protocol data unit (PPDU) signaling field is used to signal the set of power loading level used.