Yash M Vasavada

US Patent:

20120146849, Jun 14, 2012

Filed:

Dec 14, 2011

Appl. No.:

13/326209

Inventors:

Jun Xu - Clarksburg MD, US
Yash Vasavada - Gaithersburg MD, US
Mike Parr - Del Mar CA, US
Channasandra Ravishankar - Germantown MD, US
Anthony Noerpel - Lovettsville VA, US
Je-Hong Jong - North Potomac MD, US

International Classification:

G01S 19/46
G01S 19/12

US Classification:

34235729, 34235749

Abstract:

An approach provides for conversion of global positioning system (GPS) data. A user terminal receives positioning data from a base station, wherein the positioning data is received in a second format, and wherein the second format was derived from ephemeris data broadcast via a global positioning system (GPS) in a first format. The user terminal converts the positioning data from the second format into a third format that is compatible with a protocol of the GPS system, and determines a first fix using the third format of the positioning data.

US Patent:

20120218141, Aug 30, 2012

Filed:

Feb 23, 2012

Appl. No.:

13/403532

Inventors:

Yash Vasavada - Gaithersburg MD, US
Xiaoling Huang - Boyds MD, US
Ambarish Purohit - Boyds MD, US
Channasandra Ravishankar - Clarksburg MD, US

Assignee:

HUGHES NETWORK SYSTEMS, LLC - Germantown MD

International Classification:

H04B 7/185
H01Q 3/00

US Classification:

342354, 342373, 342377

Abstract:

A method for iterative estimation of a set of unknown channel parameters in a beamforming network including determining a first order estimate of offsets at measurement nodes and an estimate of the confidence in the initial estimate of the measurement nodes' offsets, and iterating, until a desired estimation accuracy is obtained, determining an improved estimate of a parameter set, and the confidence in the estimates, using the prior estimate of the offsets at the measurement nodes and determining an improved estimate of the offsets at the measurement nodes and the associated confidence values using the prior estimate of the parameter set and the corresponding confidence values.

US Patent:

6373858, Apr 16, 2002

Filed:

Jul 2, 1998

Appl. No.:

09/110035

Inventors:

Mohammad Soleimani - Rockville MD
Zheng-Liang Shi - Germantown MD
Yash Vasavada - Germantown MD
Moe Rahnema - Bethesda MD
Yezdi Antia - Gaithersburg MD

Assignee:

Hughes Electronics Corporation - El Segundo CA

International Classification:

H04J 300

US Classification:

370476, 370512

Abstract:

A message format and associated method for estimating the frequency and timing offset of a reference burst of a random access channel in a time-division multiple access communications system. A signal structure in which the continuous wave segment is split into two parts separated by some portion of the content of the random access channel burst is used to provide more precise frequency estimation. Iteration of separate frequency and timing estimation procedures is used to refine both estimates, as the individual estimation processes are more accurate when there is less error in the other parameter. Multiple hypothesis testing is used, in which more than one initial frequency estimate is carried through the iteration process, with thresholding to identify the best frequency offset. Reliable rejection of false ambiguities is achieved because the degradation in timing estimation, due to large frequency offsets, can be detected with thresholding.

US Patent:

20190033464, Jan 31, 2019

Filed:

Feb 22, 2018

Appl. No.:

15/902784

Inventors:

Yash VASAVADA - Gaithersburg MD, US
Channasandra RAVISHANKAR - Clarksburg MD, US
John Corrigan - Chevy Chase MD, US
Gaguk ZAKARIA - College Park MD, US
Xiaoling HUANG - Boyds MD, US

Assignee:

Hughes Network Systems, LLC - Germantown MD

International Classification:

G01S 19/40

Abstract:

A system and method for estimating calibration parameters and locating a Calibration Earth Station (CES) is described. The method may be performed offline. The method includes: providing LxM pilot signal measurements in a matrix R from L CESs and the M feed elements, wherein the matrix R comprises a set of channel coefficients c={c1, c2, . . . , cM}, and k={k1, k2, . . . , kL} perturbations; linking a subset of channel coefficients {c1, c2, . . . , cM} using each of the L CESs; and estimating a relative estimate of the k={k1, k2, . . . , kL} pertubations across the L CESs by using each of the L CESs as a bridging element. In the method, the bridging element provides a strong pilot signal for at least two of the L CESs. A set of criteria for determining locations of CESs have been described. A set of desirable properties for the solution set of L CESs have been disclosed. A combination of inner loop and outer loop methods for determining the final set of optimal locations have been described.

US Patent:

20180316414, Nov 1, 2018

Filed:

Jun 17, 2016

Appl. No.:

15/186417

Inventors:

- Germantown MD, US
John CORRIGAN - Chevy Chase MD, US
Rajeev GOPAL - North Potomac MD, US
Yash VASAVADA - Gaithersburg MD, US
James JONG - North Potomac MD, US
Nassir BENAMMAR - Rockville MD, US
Gaguk ZAKARIA - College Park MD, US
Anthony NOERPEL - Lovettsville VA, US
Harish RAMCHANDRAN - Germantown MD, US
Xiaoling HUANG - Boyds MD, US

International Classification:

H04B 7/185
H04W 84/06

Abstract:

A satellite system comprises LEO satellites and MEO satellites, and a control plane protocol architecture. The PHY, MAC, MAC/RLC and RRC layers are optimized for satellite environment. When the satellites are not processing satellites, eNB functions are implemented in a satellite gateway, and, when the satellites are processing satellites, protocol architecture in the control plane differ from LTE, as follows: PHY layer is moved to the communicating LEO/MEO satellite on the user link, MAC/RLC, RRC and PDCP are be located in satellite or gateway depending on satellite complexity, and the need to have mesh connectivity between UTs. When the RRC is implemented in the satellite, the RRC is divided into RRC-Lower and RRC-Upper layers. The RRC-L is satellite-based, and handles UT handover. The RRC-U is eNB-based, and handles resource management functions. The RRC-U communicates with the PDCP layer in the eNB to configure security, header and data compression.

US Patent:

20180074208, Mar 15, 2018

Filed:

Sep 9, 2017

Appl. No.:

15/700098

Inventors:

- Germantown MD, US
John CORRIGAN - Chevy Chase MD, US
Deepak ARUR - McLean VA, US
Yash VASAVADA - Gaithersburg MD, US

International Classification:

G01S 19/25
G01S 19/05

Abstract:

Approaches for efficient broadcast of satellite ephemeris information or data in NGSO satellite systems, based on Keplerian parametric models of the satellite orbits, are provided. Keplerian orbit parameters are utilized (e.g., parametric orbit models) for improved efficiency in broadcast of ephemeris data over use of point-wise vectors. The linear change and harmonic variations in Keplerian orbit parameters are accounted for, for example, based on the specification of the linear and harmonic terms, increasing accuracy and extending duration of validity of the orbit parameters. Data compression is employed by (i) differential encoding of orbital parameters, and (ii) exploiting the correlation between the harmonic (Fourier) coefficients model of the orbit parameters. An efficient transport mechanism entails classification of information in Classes with different repetition/update rates based on information types, significantly reducing required broadcast/update data rates while allowing for a wide variation in the orbit orientation.

US Patent:

20160192303, Jun 30, 2016

Filed:

Dec 29, 2014

Appl. No.:

14/584652

Inventors:

- Germantown MD, US
Yash VASAVADA - Germantown MD, US
Deepak ARUR - Germantown MD, US
Tariq MUHAMMAD - Germantown MD, US

International Classification:

H04W 56/00
H04B 7/185

Abstract:

An apparatus and method for synchronizing communication between systems having different clock rates, is described. The apparatus includes a communication unit, a synchronization unit, and an interface unit. The communication unit receives upstream information and generates a first sample stream representative of the upstream information based on a first clock rate. The synchronization unit converts the first sample stream to a second sample stream based on a second clock rate and in accordance with a predetermined burst plan. The interface unit receives the second sample stream at the second clock rate and outputs it based on the predetermined burst plan.

US Patent:

20150318916, Nov 5, 2015

Filed:

Jul 17, 2014

Appl. No.:

14/334658

Inventors:

- Germantown MD, US
Stanley KAY - Rockville MD, US
James Lykins - Darnestown MD, US
Channasandra RAVISHANKAR - Germantown MD, US
Yash VASAVADA - Gaithersburg MD, US

International Classification:

H04B 7/185
H04L 29/06

Abstract:

A system is provided for reducing latency data collection from space-based sensor satellites. A mobile vehicle platform, configured to travel around the Earth, includes a sensor module and a relay satellite terminal. The sensor module monitors certain conditions, circumstances, environments and/or situations occurring on or around, or associated with, the Earth, and generates sensor data resulting from the monitoring. The relay satellite terminal executes data communications with a first of a plurality of satellites while the mobile vehicle platform is in a first area within a communications range of the first satellite, and, upon moving to a second area within a communications range of a second of the plurality of satellites, the relay satellite terminal switches the data communications to the second satellite. The data communications relay the sensor data, via the satellites, to a central processing facility for aggregation, processing, analysis and/or dissemination of the data.