Abstract: Non-coherent modulation is used to communicate coding information via pilot signals using a first subset of resources, and coherent modulation is used to generate data signals. This allows for a stronger global code while keeping individual signaling complexity low. First and second communications devices communicate information using a set of communications resources. By performing non-coherent demodulation on pilot signals received on a first subset of the set of communications resources coding information is recovered. First and second channel estimates are generated from the pilot signals received on the first subset of the communications resources. Coherent demodulation is performed on data signals received on a second subset of the set of communications resources using the first and second channel estimates and the coding information to recover information communicated by the first communications device and to recover separate information communicated by the second communications device.

Abstract: Methods and apparatus for detecting, controlling and/or mitigating interference are described. Various embodiments are well suited to wireless communications systems in which shared communications resources are used, e.g., in a peer to peer communications systems lacking centralized control. In some embodiments, a communications device receives signals on shared communications resource, evaluates its capability to decode a received signal, and conditionally transmits an interference signal, e.g., on the shared communications resource. The interference signal is intended to cause a device transmitting on the shared communications resource to switch to a different communications resource, e.g., in response to the interference signal, so that its transmitted signal can be successfully decoded. In at least one embodiment, the shared communications resource is a peer discovery air link resource associated with a peer discovery resource identifier.

Abstract: Sets of communications resources, e.g., sets of peer discovery resources, in a peer to peer communications system are used concurrently by multiple transmitting devices. The communications system supports a plurality of different pilot sequences. Multiple transmitting devices may transmit their signals on the same set of communications resources, but with different pilot sequences. This approach allows receiving devices to distinguish between multiple signal sources, e.g., wireless terminals, using a shared communications resource. A wireless communications device monitors a plurality of different sets of communications resources and selects, e.g., based on received energy levels, a set of communications resources from said plurality of different sets of communications resources to use for communication.

Abstract: Methods and a gateway apparatus for facilitating communication between communications devices which support different communications protocols are described. The gateway device may receive an identifier of interest from a first device which supports a first communications protocol but not a second communications protocol. The gateway monitors signals corresponding to the second communications protocol to detect signals corresponding to the identifier of interest. An externally perceivable alert is generated by the gateway device when a signal corresponding to the identifier of interest is detected. Communications is established between the first communications device and a second communications device with the gateway device performing protocol conversion to the extent required. The first device may power down its interface after sending the identifier of interest to the gateway and then power up the interface in response to sensing of the alert or input from a user responding to the alert.

Abstract: Methods and apparatus for communicating information using different transmission power levels during different time periods are described. Various described methods and apparatus are well suited for use in a peer to peer wireless communication system. A device uses a high transmission power level for transmitting during a first predetermined period, so that information can be transmitted to at least some devices which are not reachable using lower transmission power levels. The high transmission power level used during the first predetermined period of time exceeds a maximum average permitted power level permitted for a second predetermined period of time. In some embodiments a device refrains from transmitting for a period of time after transmitting at the high transmission power level. In some embodiments the device transmits at a lower transmission power level during a third period of time following the first period of time.

Abstract: Aspects relate to interference management in a multiple-input-multiple-output peer-to-peer network utilizing connection scheduling. When channel side information is available at both transmitter and receiver, both devices determine transmit/receiver beamforming vectors. Transmitter sends a first transmission request signal with first transmit beamforming vector and a second transmission request signal with second transmit beamforming vector in a transmission request block. Receiver estimates SINRs of the MIMO channels associated with the receive beamforming vectors and determines whether to return request response signals. Based on received request response signals, transmitter decides to transmit streams of data using the corresponding transmit beamforming vectors in the data burst. When channel side information is available only at receiver, transmitter sends one transmission request signal.

Abstract: Methods and apparatus of using a licensed spectrum to transmit a signal when an unlicensed spectrum is congested are disclosed. One method includes receiving, at a first mobile device, a request signal from a second mobile device, receiving, at the first mobile device, a remote signal from one or more mobile devices using the unlicensed spectrum, and transmitting a control signal from the first mobile device to the second mobile device using the licensed spectrum, the control signal being based on the remote signal. The control signal carries control information that is based on at least one of a time at which the second mobile device sends a signal to the first mobile device or the received powers of the remote signal and the request signal.

Abstract: Methods and apparatus of using a licensed spectrum to transmit data when an unlicensed spectrum is congested are disclosed. The method includes transmitting a first signal from a first mobile device to a second mobile device using an unlicensed spectrum, determining, at the first mobile device, whether a first response signal has been received by the first mobile device using the unlicensed spectrum, and transmitting a second signal from the first mobile device to the second mobile device using a licensed spectrum when the first response signal has not been received by the first mobile device using the unlicensed spectrum.

Abstract: Aspects describe different multiple antenna techniques that can be utilized in a peer-to-peer network based on a network congestion level. A MIMO scheme where a transmitter sends to a receiver multiple spatial streams at substantially the same time in the same traffic segment can be utilized when network congestion level is low. A receiver beam forming scheme where transmitter sends a single stream in a traffic segment and receiver uses multiple receive antennas to maximize signal to noise ratio can be utilized when network congestion level is high. The connection pair (transmitter and receiver) occupy more control resources in the MIMO scheme than the receiver beam forming scheme. The decision related to which technique to utilize can be made at about the same time as a communication is initiated. Further, if network conditions change during a communication, the antenna technique that is utilized can be switched to a different technique during the communication exchange.

Abstract: Aspects relate to mitigating interference in a communication network that does not employ a centralized scheduler. A transmission sent on a subset of resources is evaluated to determine a number of communication pairs that have selected that subset of resources on which to transmit. If there are a large number of communication pairs transmitting on that subset, the transmission is ignored by a receiving device. The number of degrees of freedom that contain energy on the subset is evaluated to determine if an expected number of degrees of freedom that should have energy is met or exceeded. If the expected threshold number is met or exceed, the transmission is decoded by the receiving device, else the transmission is not decoded.

Abstract: Methods and apparatus for communicating information, e.g., peer discovery information, to peer communications devices using multiple antenna patterns at different times are described. One exemplary method includes transmitting first peer discovery information during a first period of time using a first antenna pattern, and transmitting second peer discovery information during a second period of time using a second antenna pattern which is different from the first antenna pattern. In at least some embodiments the first antenna pattern is a beam antenna pattern and the second antenna pattern is an omni-directional antenna pattern. In some embodiments, an omni-directional antenna pattern is used at least 50% of the time. This allows devices near the transmitting device to quickly obtain peer discovery information while devices further away make take longer to obtain the peer discovery information since they may need for a beam pattern facing their direction to be used.

Abstract: A disposable insert for use with an adult diaper, said insert having a webbed “T” configuration and a plurality of absorbent pads or batts, one of which is positioned at the lower end of the “T” configuration such that when the insert is placed on the patient wide portion across the patient's abdomen and narrow portion positioned through the patient's crotch, fluid tending to puddle is absorbed without leakage. The insert may be applied to the patient with very little, if any, lifting of the patient required.

Abstract: A method is provided for 3-D MR imaging of structure such as a cardiac region of a subject, which is disposed to cyclical motion. The method comprises detecting commencement of each of a succession of motion cycles, and acquiring a set of MR views of the region during each motion cycle. Each view is at a known radial distance from the center of a two-dimensional k-space, and each set includes a view of lowest spatial frequency, which is located proximate to the k-space center. The order in which the views of respective sets are acquired is selected so that the lowest frequency views of respective sets are each acquired at the same specified time, following commencement of their respectively corresponding motion cycles. The views of each set collectively define a segment in the k-space, respective segments being placed in an interleaved spiral or elliptical arrangement with respect to one another.

Abstract: In an MR imaging system, a method is provided for operating an MR gradient coil to provide a pulse sequence which comprises first and second sub-sequences. During the first sub-sequence, the coil is operated to produce a pair of diffusion-weighted imaging pulses, each having a gradient amplitude and a slew-rate. During the second sub-sequence the coil is operated to produce a train of echo-planar imaging pulses, each having a gradient amplitude which is selectively less than the amplitude of the diffusion-weighted pulses, and a slew-rate which is selectively greater than the slew-rate of the diffusion-weighted pulses. Thus, the invention is directed to a gradient system which can provide optimal performance for both diffusion-weighted imaging and echo-planar imaging, while using only a single coil for a given gradient axis.

Abstract: A phase-sensitive method of inversion recovery MR imaging is provided, which is directed to a specified object. The method comprises the steps of applying an inversion-recovery MR sequence to the object to acquire a set of MR data for an initial image, wherein the initial image comprises a pixel matrix of specified size, each of the initial image pixels having an associated MR signal and a phase vector. The method further comprises generating a phase vector image from information provided by respective initial image pixels, the phase vector image having a matrix size which is substantially less than the matrix size of the initial image. A region-growing procedure is applied to the phase vector image to remove phase errors therefrom. Thereupon, the phase vector image is zoomed or expanded to a matrix of the same size as the initial image matrix. For multi-slice imaging where TI time is comparatively long, the method may employ a distributed interleave mode of data acquisition to reduce total imaging time.

Abstract: To acquire tomographs, two detectors (1, 2) are secured together in a support structure (3) in such a manner that their detection fields are inclined relative to each other. The angle of inclination between them is preferably 90°. This pair of detectors is then placed in such a manner that the plane (9) bisecting the two detection fields includes the axis of rotation (4) around which the pair of detectors is to rotate to perform tomography on a subject. For fat subjects, the pair is moved away (13) from the axis, and for thin subjects it is moved towards it. It is shown that to avoid detector displacement interfering with tomography computation, it suffices merely to change computation parameters in the reconstruction algorithm.

Abstract: A method is provided for correcting for effects of translational motion or movement of an object in MR imaging. In accordance with the method, an MR point source is joined to the object for translational movement in unison therewith, the point source being maintained in selectively spaced-apart relationship with the object. The method further comprises acquiring a set of k-space data representing images of the object and point source collectively, and deriving a function representing the square of the magnitude of the k-space data set. An inverse Fourier transform operation is applied to the derived function to generate a correlation function with a number of correlation components, a specified one of the correlation components comprising the cross-correlation of the object and the point source.

Abstract: In a method for providing an MR image of a section taken through an object, wherein the section is acquired in the presence of in-plane translational motion of the object, an MR system is operated to acquire a set of imaging data points from the section, the set of imaging data points being contaminated by phase errors resulting from the motion. The MR system is further operated to acquire a plurality of correction data point sets, each correction data point in one of said sets being acquired along an alignment line or other trajectory and at a location coinciding with the location of one of the imaging data points. The imaging data points respectively coinciding with the correction data points comprise, collectively, a subset of the imaging data points. The phase difference between each correction data point set and its corresponding subset of imaging data points is determined, and then used to remove the phase errors from the set of imaging data points.

Abstract: A method is provided for acquiring MR image data, which comprises the steps of applying a succession of RF excitation pulses to a selected region of an imaging subject to produce a corresponding succession of MR data signals, generating a readout gradient in association with each of the MR data signals, and acquiring sets of data points from the MR data signals to provide views respectively corresponding thereto. The data points of a view are respectively identified by positions in k-space along a first k-space axis, each of the positions along the first k-space axis having a time offset with respect to a reference.

Abstract: A method and apparatus is provided for generating an MR image of a structural portion of a subject, the portion lying within a hypothetical imaging volume. A specified level of hyperpolarized magnetization is provided within the imaging volume, and a series of MR pulse sequences are applied to the imaging volume to generate respective corresponding MR data signals, each pulse sequence comprising a number of magnetic field gradient pulses and an excitation pulse, and having an associated flip angle determined by the excitation pulse. The associated flip angles of successive pulse sequences are progressively increased to maintain the signal strength of the corresponding MR data signals at a substantially constant level. Acquired MR data signals are cumulatively processed to provide an image of the structural portion.