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Heidari, US

Alireza R. Heidari, Encinitas, CA US

Patent application numberDescriptionPublished
20110294501CODEC DEPLOYMENT USING IN-BAND SIGNALS - After a call is established between two stations using a codec that has been negotiated during call setup, in-band signaling may be used between the two stations to change the codec that is to be used. The in-band signals are indicative that the station that is transmitting the in-band signals can operate with a second codec and are used to probe whether the receiving station can also operate with that second codec. If the receiving station detects and reacts to the in-band signals, then both stations change to communicate with the second codec. The second codec has compatible packet sizes of the deployed (originally negotiated) codec without any need of infrastructure upgrade and/or quality compromise to legacy phone users (i.e., stations that cannot operate with the second codec).12-01-2011

Amir Homayoun Heidari, Houston, TX US

Patent application numberDescriptionPublished
20090279958PONTOONLESS TENSION LEG PLATFORM - A pontoonless tension leg platform (TLP) has a plurality of buoyant columns connected by an above-water deck support structure. The design eliminates the need for subsea pontoons extending between the surface-piercing columns. In certain embodiments, the buoyancy of the columns is increased by the addition of subsea sections of increased diameter (and/or cross-sectional area) to provide the buoyancy furnished by the pontoons of the TLPs of the prior art. A pontoonless TLP has a smaller subsea projected area in both the horizontal and vertical planes than a conventional multi-column TLP of equivalent load-bearing capacity having pontoons between the columns. This reduction in surface area produces a corresponding reduction in the platform's response to ocean currents and wave action and consequently allows the use of smaller and/or less costly mooring systems. Moreover, the smaller vertical projected area results in a shorter natural period which enables a pontoonless TLP according to the invention to be used in water depths where conventional TLPs cannot be used due to their longer natural periods. The absence of pontoons in a multi-column TLP also has the added benefit of providing an unobstructed path for risers to connect with the deck of the platform.11-12-2009
20110114005BATTERED COLUMN SEMI-SUBMERSIBLE OFFSHORE PLATFORM - A semisubmersible platform includes a deck supported on the upper ends of support columns extending upwardly from a horizontally disposed pontoon-ring. The columns are battered inwardly and upwardly from the pontoon-ring to the deck. Mooring lines passing through fair leads on the outer faces of the base nodes anchor the platform to the seabed. The footprint of the battered columns is greater than the footprint of the deck supported on the upper ends of the columns.05-19-2011

Mohammad Heidari, Worcester, MA US

Patent application numberDescriptionPublished
20110074626IMPROVEMENT OF THE ACCURACY AND PERFORMANCE OF A HYBRID POSITIONING SYSTEM - The present disclosure relates to a method for determining the position of a WLAN positioning system (WPS) and satellite positioning system (SPS) enabled device. The method can include determining an initial WPS position of the device using WPS, calculating an error region around the initial WPS position of the device, dividing the error region into a plurality of points, obtaining satellite measurements from at least two satellites in view of the device, determining a variation in a receiver clock bias for each point within the error region based on the satellite measurements from at least two satellites, selecting the point with the lowest variation in the receiver clock bias, and determining whether or not to use the point with the lowest variation in receiver clock bias to refine the initial WPS position of the device.03-31-2011
20110080317METHOD OF DETERMINING POSITION IN A HYBRID POSITIONING SYSTEM USING A DILUTION OF PRECISION METRIC - The disclosed subject matter relates to a method for determining the position of a device in a hybrid positioning system. The method includes determining an initial position estimate of a device using a non-satellite positioning system, obtaining satellite measurements from less than four satellites, wherein the measurements include each satellite's position with respect to the initial position estimate, determining a dilution of precision (DOP) based on the satellite measurements, if the DOP is small, refining the initial position estimate using the satellite measurements, and if the DOP is large, providing the initial estimate as a final position estimate for the device. In some embodiments, the non-satellite positioning system is a WLAN positioning system. In some embodiments, the method includes obtaining satellite measurements from two satellites or three satellites.04-07-2011
20110080318Determining A Dilution of Precision Metric Using Two or Three GPS Satellites - The disclosed subject matter relates to a method for determining a Dilution of Precision Metric (DOP) with less than four satellites in a hybrid positioning system. In some embodiments, the method includes determining an initial position estimate of a device using a non-satellite positioning system, obtaining satellite measurements from less than four satellites, wherein the measurements include each satellite's position with respect to the initial position estimate, constructing a geometry matrix corresponding to the measurements from the less than four satellites using each satellite's position and the initial position estimate, multiplying the geometry matrix by its transpose to construct an H matrix, determining an inverse of the H matrix, and determining the DOP based on a sum of the diagonal elements of the inverse H matrix. In some embodiments, the non-satellite positioning system is a WLAN positioning system.04-07-2011

Mohammad A. Heidari, Worcester, MA US

Patent application numberDescriptionPublished
20120112958METHOD OF AND SYSTEM FOR INCREASING THE RELIABILITY AND ACCURACY OF LOCATION ESTIMATION IN A HYBRID POSITIONING SYSTEM - Methods and systems of hybrid positioning are provided for increasing the reliability and accuracy of location estimation. According to embodiments of the invention, the quality of reported locations from specific sources of location is assessed. Satellite and non-satellite positioning systems provide initial positioning estimates. For each positioning system relevant information is collected and based on the collected information each system is assigned appropriate weight.05-10-2012

Mohammad Ali Heidari, Bellevue, WA US

Patent application numberDescriptionPublished
20100129137LOAD ABSORPTION SYSTEM - An apparatus comprises a tubular body with a channel and a number of stiffeners that allow the tubular body to absorb additional mechanical energy through axial compression. The number of stiffeners is located on a number of locations for the tubular body.05-27-2010

Mohammad E. Heidari, Vista, CA US

Patent application numberDescriptionPublished
20100045404PHASE ERROR CANCELLATION FOR DIFFERENTIAL SIGNALS - In one embodiment, the present invention includes an electronic circuit comprising a first stage having a first differential inductive element and a second differential inductive element, and a second stage coupled to an output of the first stage, the second stage having a first differential inductive element and a second differential inductive element, wherein the first and second differential inductive elements of the first stage couple magnetically to generate a first phase error, wherein the first and second differential inductive elements of the second stage couple magnetically to generate a second phase error, and wherein the second phase error cancels the first phase error.02-25-2010
20100233979Wide Bandwidth Fast Hopping Frequency Synthesizer Circuits and Methods - Embodiments of the present invention include methods for wide bandwidth synthesizer circuits and methods. In one embodiment, the present invention includes a frequency synthesizer comprising a multiplexer and a band group selector. The multiplexer is coupled to receive a plurality of sinusoidal signals. Each sinusoidal signal has a unique frequency. The band group selector selects between a plurality of band groups. The band group selector is coupled to receive a first signal from the multiplexer. The multiplexer multiplexes between the plurality of sinusoidal signals and provides the first signal. The band group selector includes a band mixer. The band mixer mixes the first signal with a band signal having a band frequency. The band signal corresponds to a band group selected from the plurality of band groups. The band group selector provides a transmitter mixer signal and a receiver mixer signal.09-16-2010

Sam Heidari, Los Altos Hills, CA US

Patent application numberDescriptionPublished
20090049347Method and apparatus for bit error determination in multi-tone transceivers - A transceiver with a plurality of components coupled to one another to form a transmit path and a receive path for multi-tone modulation of user data across a communication medium. The transceiver includes a framer and a deframer. The framer is configured to momentarily suspend framing of user data before processing bits associated with tones targeted for reference data transport and injects the pre-agreed reference pattern therein, after which framing of user data resumes. The deframer is configured to momentarily suspend deframing of received user data bits before processing bits associated with tones targeted for transport of pre-agreed reference data and extracts the received reference bits thereof for comparison with the corresponding pre-agreed reference bits to determine errors therein, after which deframing of user data resumes.02-19-2009
20100002755Method and apparatus for a multi-tone modem - A multi-tone modem with shared and discrete components forming a transmit path and a receive path configured to couple to a wired communication medium to communicate at least one multi-tone modulated communication channel thereon. The modem includes a multi-tone modulator component and a configurable frequency up converter component. The multi-tone modulator component is configured for multi-tone modulation and demodulation of a transmitted and received communication channel at a base band frequency range. The configurable frequency up converter component is coupled to the multi-tone modulator to selectably up convert the frequency range of the transmitted base band signal from the multi-tone modulator to that of a selected communication band and down convert received signals from the selected communication band to the base band for demodulation by the multi-tone modulator.01-07-2010
20100046738Method and apparatus for DMT crosstalk cancellation - An apparatus for precoding multi-tone modulated transmissions of a plurality of communication channels over bundled subscriber lines. The apparatus includes a pseudo symbol controller and a precoder. The pseudo symbol controller detects a victim communication channel and an interferer communication channel having non-matching symbol rates, and transforms the interferor channel into a pseudo-symbol having both a substantially similar length as a corresponding symbol of the victim channel together with defined tonal characteristics expressed in terms of the interferor channel. The precoder assigns crosstalk coefficients to selected sub-channels or tones of the pseudo symbol and precodes the victim channel with the pseudo symbol using the crosstalk coefficients; thereby generating a precoded victim symbol which exhibits reduced crosstalk between the selected victim and interferor.02-25-2010
20110058535Primary user detection - A low complexity primary user detection system is disclosed. Signals are filtered to reduce the number of signals that must be processed. Width and PRI of the signals are used to match a constellation associated with a primary user. If the constellation is matched, communication parameters are adjusted to make way for the primary user.03-10-2011
20110096739CHANNEL SCANNING AND CHANNEL SELECTION IN A WIRELESS COMMUNICATION NETWORK - A method and apparatus to select the best channel of a wireless network for data communication at any given time, during normal operation of the network, is described. The network may be an IEEE standard 802.11 compliant network. Channel scanning may be performed in any station on the wireless network, such as an access point (AP) or a mobile station, or both. Channel scanning may be performed during data communication idle time, or simultaneously with data communication on the network. The technique can be implemented in a multiple-input multiple-output (MIMO) communication system, where the antenna or antennas used for channel scanning can be selected dynamically during operation, to optimize one or more performance characteristics.04-28-2011
20110110345MESSAGE ROUTING IN WIRELESS MESH NETWORKS - Disclosed are methods and apparatuses related to the routing of communications in a wireless mesh network so as to provide improved range, reliability and/or throughput. At least some aspects of the techniques and apparatuses can be implemented in an intermediary node (relay node) on a wireless mesh network. The relay node and other devices on the wireless network may implement a form of multiple-input multiple-output (MIMO) communication, such as multi-user MIMO (MU-MIMO). The devices on the network can communicate in accordance with IEEE standard 802.11.05-12-2011
20110268060ACCESS POINT RANGE EXTENSION - A technique for expanding the range of coverage for a wireless local area network (WLAN) involves locating a wireless access point (WAP) away from an interworking unit (IWU) at the edges of the WLAN and a (typically) wired network. The WAP, when located away from the IWU, can be referred to as an untethered access point (UAP) because it communicates with the IWU on a wireless channel. Stations on the WLAN will be capable of communicating with the WAP, whether or not it is a UAP, via a known or convenient wireless protocol, such as Wi-Fi, and may or may not be capable of communicating with one another via a direct station-to-station protocol.11-03-2011
20110293027ADJUSTABLE OPERATIONAL STATE WIRELESS MIMO - Wireless devices capable of one or more of extended multiple input multiple output (MIMO), dual bonded, and dual concurrent operation are disclosed. Methods for switching between the operational states for wireless devices capable of multiple operational states are also disclosed.12-01-2011

Patent applications by Sam Heidari, Los Altos Hills, CA US