Saeed S Ghassemzadeh

US Patent:

7075968, Jul 11, 2006

Filed:

Jun 6, 2001

Appl. No.:

09/875767

Inventors:

Saeed S. Ghassemzadeh - Andover NJ, US
Matthew J Sherman - Succasunna NJ, US

Assignee:

AT&T Corp. - New York NY

International Classification:

H04B 1/69

US Classification:

375130

Abstract:

Whitening (i. e. , electromagnetic whitening) of a spread spectrum code is achieved, according to principles of the invention, by permuting the code used for spreading of a signal spectrum. Whitening herein means to process the code such that the signal produced while using the code has roughly uniformly distributed power across the entire electromagnetic spectrum of the transmitted signal. In one exemplary embodiment, a base set of codes derived from Walsh matrices is used. The order of chips in each code in the matrix is randomly permuted (using the same permutation for each code) to form a random sequence of chips, which are used to spread information signals. That is the columns of the Walsh matrix are permuted differently each time the codes in the matrix are used for transmission. Because codes derived from Walsh sequences are orthogonal to one another two spread signals using different codes from that Walsh code set but having the same center frequency may transmit without essentially interfering with one another.

US Patent:

7155192, Dec 26, 2006

Filed:

Sep 25, 2001

Appl. No.:

09/962994

Inventors:

Saeed S. Ghassemzadeh - Andover NJ, US
Richard Henry Erving - Piscataway NJ, US
Christopher W. Rice - Parsippany NJ, US

Assignee:

AT&T Corp. - New York NY

International Classification:

H04B 1/06

US Classification:

4552771, 4552772, 455137

Abstract:

The present invention is a system for increasing Signal-to-Noise Ratio (SNR) in a wireless communication system comprising a plurality of antennas each antenna providing a signal, a device for selecting a subset of signals provided by the plurality of antennas, a maximum ratio combiner for summing the selected subset of signals provided by the plurality of antennas, and a decision device for measuring the selected subset of signals against a predefined threshold. The device for selecting the subset of signals is coupled to the plurality of antennas. The maximum ratio combiner is coupled to the selected subset of signals and the decision device for measuring the selected subset of signals against a predefined threshold. The decision device is coupled to the selecting device such that one selected signal of the selected subset of signals is replaced by an unused signal provided by the plurality of antennas.

US Patent:

7187647, Mar 6, 2007

Filed:

Jan 23, 2002

Appl. No.:

10/055336

Inventors:

Saeed S. Ghassemzadeh - Andover NJ, US

Assignee:

AT&T Corp. - New York NY

International Classification:

H04J 11/00

US Classification:

370208, 370335, 370342

Abstract:

An IS-OFDM system for ultra-wideband (UWB) wireless communications that suppresses narrow-band interference, comprising an in-premises base station (IBS) is described. The IBS further comprises an IS-OFDM transceiver for communicating with a plurality of in-premises terminals (ITs) without creating interference outside an in-premises perimeter. Further, a method for operating an IS-OFDM system for ultra-wideband (UWB) wireless communication that suppresses narrow-band interference and provides local area networking services, in-premises distribution of broadcast cable channels and in-premises wireless access and routing to external networks is described, without creating interference outside an in-premises perimeter.

US Patent:

7457602, Nov 25, 2008

Filed:

Sep 14, 2005

Appl. No.:

11/226827

Inventors:

Saeed S. Ghassemzadeh - Andover NJ, US
Richard Henry Erving - Piscataway NJ, US
Christopher W. Rice - Parsippany NJ, US

Assignee:

AT&T Corp. - New York NY

International Classification:

H04B 1/06

US Classification:

4552771, 375101, 375299, 455133

Abstract:

The present invention is a system for increasing Signal-to-Noise Ratio (SNR) in a wireless communication system comprising a plurality of antennas each antenna providing a signal, a device for selecting a subset of signals provided by the plurality of antennas, a maximum ratio combiner for summing the selected subset of signals provided by the plurality of antennas, and a decision device for measuring the selected subset of signals against a predefined threshold. The device for selecting the subset of signals is coupled to the plurality of antennas. The maximum ratio combiner is coupled to the selected subset of signals and the decision device for measuring the selected subset of signals against a predefined threshold. The decision device is coupled to the selecting device such that one selected signal of the selected subset of signals is replaced by an unused signal provided by the plurality of antennas.

US Patent:

7508749, Mar 24, 2009

Filed:

Feb 26, 2004

Appl. No.:

10/787613

Inventors:

Saeed S. Ghassemzadeh - Andover NJ, US

Assignee:

AT&T Corp. - New York NY

International Classification:

H04J 11/00
H04B 7/216

US Classification:

370208, 370335, 370342

Abstract:

The invention provides an apparatus and method for generating overspread orthogonal codes. Overspread orthogonal codes are generated code-multiplying orthogonal codes generated by any method and the overspread orthogonal code length is the product of the code lengths of the orthogonal codes that were code-multiplied. In a telecommunication application, for example, a communication signal is first spread by a first orthogonal code and then overspread by a second orthogonal code. The output of the overspreading process may be further overspread by a third orthogonal code and so on until a desired code length is obtained. Thus, orthogonal code lengths unobtainable by any of the known orthogonal code generators may be generated by overspreading using codes generated by any orthogonal code generator(s) to obtain a desired code length.

US Patent:

7656855, Feb 2, 2010

Filed:

Aug 16, 2006

Appl. No.:

11/505553

Inventors:

Saeed S. Ghassemzadeh - Andover NJ, US
John F. Murray - Denville NJ, US

Assignee:

AT&T Intellectual Property II, LP - Reno NV

International Classification:

H04J 3/06

US Classification:

370350, 370323, 370333

Abstract:

An arrangement for providing synchronization between a number of overlapping area access points within a wireless LAN utilizes a Power over Ethernet (PoE) cable connection to transmit synchronization signals from a centralized hub/switch to each of the access points connected to the cable. The synchronization signal takes the form of a direct sequence spread spectrum (DS-SS) signal that is coupled onto the twisted pair used to provide the low voltage PoE signal to various powered devices. At each access point, a filter is used to remove the synchronization signal from the PoE transport, allowing for the group of access points to share a common beacon signal and allow for frequency re-use among the access points. The DS-SS signal is preferable created by a combination of a baseband signal and a set of separate pseudo noise (PN) sequences defining a precision phase (“pilot tone”) signal, a time mark (superframe/beacon) signal, and a time-of-day (real-time clock) signal.

US Patent:

7855683, Dec 21, 2010

Filed:

Nov 4, 2008

Appl. No.:

12/264564

Inventors:

Leonid Razoumov - Riverdale NY, US
Saeed Ghassemzadeh - Andover NJ, US
Robert Miller - Convent Station NJ, US

Assignee:

AT&T Intellectual Property I, L.P. - Reno NV

International Classification:

G01S 19/42

US Classification:

342458, 34235725

Abstract:

Systems and methods for extrapolating GPS coordinates beyond line of sight are disclosed. A coordinate extrapolation system (CES) can include a memory, a processor, and a GPS receiver. The CES can receive GPS signals and determine GPS coordinates corresponding to a location. If GPS signals are unavailable, the CES models the surface of the earth and extrapolates the GPS coordinates corresponding to the location at which GPS signals are unavailable. Methods for extrapolating the GPS coordinates and calibrating the CES are also disclosed.

US Patent:

8134913, Mar 13, 2012

Filed:

Dec 13, 2006

Appl. No.:

11/637750

Inventors:

Saeed S. Ghassemzadeh - Andover NJ, US

Assignee:

AT&T Intellectual Property II, L.P. - Atlanta GA

International Classification:

H04J 11/00

US Classification:

370208, 370210, 370330, 370344, 370366, 370478, 370480, 375260, 725 81, 725123, 725148

Abstract:

An IS-OFDM system for ultra-wideband (UWB) wireless communications that suppresses narrow-band interference, comprising an in-premises base station (IBS) is described. The IBS further comprises an IS-OFDM transceiver for communicating with a plurality of in-premises terminals (ITs) without creating interference outside an in-premises perimeter. Further, a method for operating an IS-OFDM system for ultra-wideband (UWB) wireless communications that suppresses narrow-band interference and provides local area networking services, in-premises distribution of broadcast cable channels and in-premises wireless access and routing to external networks is described, without creating interference outside an in-premises perimeter.