Apurva N Mody, Age 51181 Littleton Rd UNIT 309, Chelmsford, MA 01824

7310304, Dec 18, 2007

Apr 24, 2002

10/128756

Apurva N. Mody - Atlanta GA, US
Gordon L. Stuber - Atlanta GA, US

BAE Systems Information and Electronic Systems Integration Inc. - Nashua NH

H04J 11/00

370208, 370206, 370281

In a communication system, and in particular a wireless Orthogonal Frequency Division Multiplexing (OFDM) communication system, the present invention provides systems for estimating parameters of a channel across which a signal is transmitted. The present invention may be used in a Multi-Input, Multi-Output (MIMO) system in which the data is transmitted from any number of transmitting antennas and received by any number of receiving antennas. The number of transmitting and receiving antennas does not necessarily have to be the same. Circuitry is provided for calculating parameters indicative of the characteristics of the communication channel. Estimates of channel parameters may include channel estimates and noise variance estimates.

7706458, Apr 27, 2010

Jun 7, 2006

11/448395

Apurva N. Mody - Atlanta GA, US
Gordon L. Stuber - Atlanta GA, US

H04K 1/10

375260, 375299

In a communication system, and in particular a wireless Orthogonal Frequency Division Multiplexing (OFDM) communication system, the present invention provides systems for synchronizing data transmitted across a channel. The present invention may be used in a Multi-Input, Multi-Output (MIMO) system in which the data is transmitted from any number of transmitting antennas and received by any number of receiving antennas. The number of transmitting and receiving antennas does not necessarily have to be the same. Circuitry is provided for synchronizing the data in both the time domain and frequency domain. Time synchronization involves coarse time synchronization and fine time synchronization. Frequency synchronization involves coarse frequency offset estimation, fine frequency offset estimation, and frequency offset correction.

7889819, Feb 15, 2011

Oct 6, 2003

10/680629

Apurva Mody - Atlanta GA, US
Gordon Stuber - Atlanta GA, US

H04L 27/06
H04L 27/28
H04K 1/10

375344, 375260

Methods and systems that are capable of detecting and correcting the sampling frequency offset as part of signal synchronization in MIMO OFDM systems. An exemplary MIMO OFDM system includes a transmitter with a number of OFDM modulators that provide data to antennas for transmission across a channel to a receiver. The OFDM modulators include a training symbol inserter that may insert a matrix of pilot tones into the data. The data including the matrix of pilot tones is received by a receiver having a number of OFDM demodulators including a synchronization circuit. The synchronization circuit uses the matrix of pilot tones to detect and correct the sampling frequency offset as part of the signal synchronization. The synchronization circuit may apply an open loop process including sampling frequency offset estimation, phase rotation, and channel estimation. Alternatively, the synchronization circuit may apply a closed loop process including error generation, loop filtering and accumulation as well as sampling frequency offset estimation, phase rotation, and channel estimation.

RE43294, Apr 3, 2012

Sep 8, 2009

12/555332

Gordon L. Stuber - Atlanta GA, US
Apurva N. Mody - Lowell MA, US

Taffco Three Fund, L.L.C. - Wilmington DE

H04L 27/28
H04L 27/36
H04B 7/02
H04J 11/00

375260, 375267, 375299, 370208

Apparatus and methods for providing efficient space-time structures for preambles, pilots and data for multi-input, multi-output (MIMO) communications systems are provided. One such embodiment includes providing a computer program that includes logic configured to provide an initial structure. The computer program further includes logic configured to verify that the rows of the initial structure are linearly independent and logic configured to apply an orthonormalization procedure to the initial structure to obtain a space-time structure. Methods are also provided for providing efficient space-time structures for preambles, pilots and data for MIMO communications systems.

8154666, Apr 10, 2012

Dec 23, 2008

12/342485

Apurva N Mody - Lowell MA, US

BAE Systems Information and Electronic Systems Integration Inc. - Nashua NH

H04N 5/50
H04L 12/28
H04L 12/413
H04J 3/26
H04B 1/00

348732, 370390, 370432, 370445, 375130, 375132, 375144

A method and system are disclosed to detect a broad class of signals including Advanced Television Systems Committee (ATSC) digital television (DTV) and wireless microphone signals. This signal detection method performs in Gaussian noise, employing Higher Order Statistics (HOS). Signals are processed in time and frequency domains as well as by real and imaginary components. The spectrum sensing employed also supports Denial of Service (DoS) signal classification. The method can include parameters that may be tailored to adjust the probability of detection and false alarm.

8161089, Apr 17, 2012

Jun 18, 2007

11/820063

Apurva N. Mody - Lowell MA, US

BAE Systems Information and Electronic Systems Integration Inc. - Nashua NH

G06F 17/14
G06F 15/00

708404, 708200

An algorithm to detect a broad class of signals in Gaussian noise using higher-order statistics. The algorithm detects a number of different signal types. The signals may be in the base-band or the pass-band, single-carrier or multi-carrier, frequency hopping or non-hopping, broad-pulse or narrow-pulse etc. In a typical setting this algorithm provides an error rate of 3/100 at a signal to noise ratio of 0 dB. This algorithm gives the time frequency detection ratio that may be used to determine if the detected signal falls in Class Single-Carrier of Class Multi-Carrier. Additionally this algorithm may be used for a number of different applications such as multiple signal identification, finding the basis functions of the received signal and the like.

8170152, May 1, 2012

Jul 11, 2008

12/439168

Apurva N Mody - Lowell MA, US
Paul D Fiore - Chelmsford MA, US

BAE Systems Information and Electronic Systems Integration Inc. - Nashua NH

H04L 27/06

375340, 375136, 375147, 375260, 375316, 375350, 370210, 370480

A method is disclosed to detect a broad class of signals in Gaussian noise using higher order statistics. The method detects a number of different signal types. The signals may be in the base-band or the pass-band, single-carrier or multi-carrier, frequency hopping or non-hopping, broad-pulse or narrow-pulse etc. In a typical setting this method provides an error rate of 3% at a signal to noise ratio of 0 dB. This method gives the time frequency detection ratio which may be used to determine if the detected signal falls in Class Single-Carrier of Class Multi-Carrier. Additionally, this method may be used for a number of different applications such as multiple signal identification, finding the basis functions of the received signal.

8326309, Dec 4, 2012

Mar 6, 2009

12/399730

Apurva N. Mody - Lowell MA, US
Ranga Reddy - Bridgewater NJ, US

BAE Systems Information and Electronic Systems Integration Inc. - Nashua NH

H04W 72/00

4554521, 455450, 4555521, 370310

Techniques are disclosed that allow for resource allocation during situations requiring co-existence in cognitive radios. Even under situations of bandwidth scarcity, the techniques allow various users to be guaranteed quality of service (QoS) by proper distribution and allocation of resources. The techniques allow wireless communication systems to operate in a normal mode and a co-existence mode. In the co-existence mode of operation, sub-frame creation, sharing and zone formation schemes are implemented that enable the existing underlying frame structure to remain intact and inter-operable with the legacy systems and at the same time, provide a guaranteed QoS. The zones effectively create partitions in space, time and frequency, which result in interference avoidance and allow various users in neighboring cells to communicate on the same frequencies.