180 Park Ave - Building 103
Florham Park, NJ
http://www2.research.att.com/~saeedg
Subject matter expert in Communication system design, analysis, simulation and integration/testing, wireless channel measurement and field testing, wireless channel characterization and modeling.
Saeed Ghassemzadeh received his Ph.D. degree in electrical engineering from the City University of New York in 1994.
From 1989-1992, he was with SCS Mobilecom, a wireless technology development company, where he conducted research in the areas of propagation and CDMA systems. In 1992, SCS Mobilecom merged with IMM (International Mobile Machines) to form InterDigital Communications corp.. From 1992-1995, While pursuing his Ph.D., he worked as a principal research engineer at InterDigital, where he conducted research in the areas of fixed/mobile wireless channels and was involved in system design/development, integration, and testing of Broadband CDMA systems. During the same time, he was also an adjunct lecturer at City University of New York.
In 1995, he joined AT&T Wireless communication center of excellence at AT&T Bell-Labs as a member of technical staff involved in design and development of the fixed wireless base station development team. He also conducted research in areas of CDMA access technologies, propagation channel measurement and modeling, satellite communications, wireless local area networks and coding in wireless systems. Currently, he is a principal member of technical staff in Communication Technology Research department at AT&T Labs-Research, Florham Park, NJ. His current research interest includes wireless channel measurement and modeling, wireless LANs, remote tele-health monitoring and THz communication.
Saeed is an editor for IEEE Transactions on Wireless Communications and Journal of Communications and Networks. He is an IEEE Fellow and a member of IEEE communication society and IEEE Vehicular technology society.
IEEE Fellow, 2013.
For contributions to measurement and modeling of broadband wireless channels and their applications to system design.
Optimum Cognitive Radio Transmission Scheme for Reducing Average Interference Power
Canadian Workshop on Information Theory - 2011,
May 2011.
[BIB]
Group Randomness Properties of Pseudo-Noise and Gold Sequences
Canadian Workshop on Information Theory - 2011,
May 2011.
[BIB]
TAS Protocols of a PASD system with limited feedback information
IEEE Global Communication Conference 2009,
Dec. 2009.
[BIB]
Wireless Neighborhood Area Network Path Loss Characterization at 5.7 GHz
IEEE Vehicular Technology Conference - Fall 2010,
Sep. 2010.
[BIB]
Service Coverage for Cognitive Radio Networks with Cooperative Relays in Shadowed Hotspot Areas
IEEE Wireless Communications & Networking Conference- 2011,
Mar. 2011.
[BIB]
Beam Selection Gain Versus Antenna Selection Gain
IEEE Transactions on Information Theory,
Accepted for Publication.
[BIB]
On Effects of Antenna Pointing Accuracy For on-the-move Satellite Networks
IEEE Transactions on Vehicular Technology 2011,
Accepted for Publications.
[BIB]
Rate of Channel Hardening of Antenna Selection Diversity Schemes and Its Implication on Scheduling
IEEE Transactions on Information Theory,
v55,
#10,
pp 4353-4365 ,
Oct. 2009.
[BIB]
An Empirical Model for Dual-Diversity Reception over Fixed Wireless Channels in Suburban Macrocell Environments
IEEE Transactions on Wireless Communications,
v8,
#8,
pp 4220 - 4229,
Aug. 2009.
[BIB]
Ricean K-Factors in Narrowband Fixed Wireless Channels: Theory, Experiments and Statistical Models
IEEE Transactions on Vehicular Technology,
v58,
#8,
pp 4000-4012,
Oct. 2009.
[BIB]
Narrowband Interference Rejection For Ultra-Wideband Systems,
Tue Mar 26 17:25:31 EDT 2013
A technique for reducing interference between a direct-sequence ultra-wideband communications system and a narrowband communications system uses interference-rejecting spreading codes to reduce signal power in a frequency band associated with the narrowband communications system. A method of operating an ultra-wideband communications system includes applying an interference-rejecting spreading code to a signal for transmission. The interference-rejecting spreading code is configured to reduce power in a particular frequency band of a transmit or receive power spectral density associated with the ultra-wideband signal without substantially reducing power outside that particular frequency band of the transmit or receive power spectral density associated with the ultra-wideband signal.
Ultra-Wide Bandwidth System And Method For In-Premises Wireless Networking,
Tue Mar 13 16:09:33 EDT 2012
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.
Method And Apparatus For GPS Coordinates Extrapolation When GPS Signals Are Not Available,
Tue Dec 21 15:05:22 EST 2010
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.
Arrangement For Synchronizing Access Points In WLAN Using Direct-Sequence Spread Spectrum Signaling,
Tue Feb 02 15:03:21 EST 2010
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.
System And Method For Generating Orthogonal Codes,
Tue Mar 24 16:07:00 EDT 2009
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.
Multi-antenna/multi-receiver array diversity system,
Tue Nov 25 18:13:17 EST 2008
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.
Ultra-wide bandwidth system and method for in-premises wireless networking,
Tue Mar 06 18:11:56 EST 2007
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.
Multi-antenna/multi-receiver array diversity system,
Tue Dec 26 18:11:46 EST 2006
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.
Method for whitening spread spectrum codes,
Tue Jul 11 18:11:24 EDT 2006
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.
System and method for generating orthogonal codes,
Tue Mar 02 18:09:06 EST 2004
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.
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