Joseph R Cavallaro

US Patent:

6529495, Mar 4, 2003

Filed:

May 24, 1999

Appl. No.:

09/317333

Inventors:

Joseph R. Cavallaro - Pearland TX
Gang Xu - Houston TX

Assignee:

Nokia Telecommunications, Oy

International Classification:

H04B 7216

US Classification:

370342, 375148, 375150

Abstract:

A multistage detector is disclosed that maximizes computation power while minimizing system delay. The differencing multistage detector receives signals from a plurality of users in a cell of a communications system and reduces the effect of multiple access interference to a signal from a desired user caused by interference from other users in the cell. The differencing multistage detector includes a plurality of stages, each stage including an interference canceller for removing intra-cell interference caused by the other users in the cell and producing an estimation output vector, wherein except for a first stage, the estimation output vector of a current stage is based on both a decision of the interference canceller of the current stage and the output from an interference canceller of a previous stage. The estimation output vector of a current stage is produced by combining the output from an interference canceller of a previous stage and the decision of the interference canceller of the current stage. Except for the first stage each interference canceller calculates an estimate of multi-user interference by computing a product of a cross-correlation of the received signals and a difference signal thereby reducing the number of multiplication operations required.

US Patent:

7483480, Jan 27, 2009

Filed:

Nov 24, 2004

Appl. No.:

10/997442

Inventors:

Yuanbin Guo - Richardson TX, US
Dennis McCain - Lewisville TX, US
Joseph R Cavallaro - Pearland TX, US

Assignee:

Nokia Corporation - Espoo

International Classification:

H03K 5/159
H04B 1/10

US Classification:

375232, 375350

Abstract:

A receiver, such as a CDMA MIMO receiver, includes a LMMSE-based chip-level equalizer constructed so as to implement a FFT accelerated iterative algorithm having a complexity of order O(N log(N)), where N is the dimension of a covariance matrix. The equalizer uses one of an overlap-save or an over-lap add FFT architecture.

US Patent:

7492815, Feb 17, 2009

Filed:

Nov 24, 2004

Appl. No.:

10/997397

Inventors:

Yuanbin Guo - Richardson TX, US
Jianzhong Zhang - Irving TX, US
Dennis McCain - Lewisville TX, US
Joseph R. Cavallaro - Pearland TX, US

Assignee:

Nokia Corporation - Espoo

International Classification:

H04B 1/707
H03H 7/30

US Classification:

375229, 375147, 375232

Abstract:

Disclosed is a LMMSE receiver that restores orthogonality of spreading codes in the downlink channel for a spread spectrum signal received over N receive antennas. The FFT-based chip equalizer tap solver reduces the direct matrix inverse of the prior art to the inverse of some submatrices of size N×N with the dimension of the receive antennas, and most efficiently reduces matrix inverses to no larger than 2×2. Complexity is further reduced over a conventional Fast Fourier Transform approach by Hermitian optimization to the inverse of submatrices and tree pruning. For a receiver with N=4 or N=2 with double oversampling, the resulting 4×4 matrices are partitioned into 2×2 block sub-matrices, inverted, and rebuilt into a 4×4 matrix. Common computations are found and repeated computations are eliminated to improve efficiency. Generic design architecture is derived from the special design blocks to eliminate redundancies in complex operations.

US Patent:

7706430, Apr 27, 2010

Filed:

Feb 25, 2005

Appl. No.:

11/067498

Inventors:

Yuanbin Guo - Irving TX, US
Dennis McCain - Lewisville TX, US
Joseph R. Cavallaro - Pearland TX, US

Assignee:

Nokia Corporation - Espoo

International Classification:

H04L 27/06

US Classification:

375148, 375343, 375346, 375147, 370319, 370320, 370312

Abstract:

A system, apparatus and method for a multi-stage Parallel Residue Compensation (PRC) receiver for enhanced suppression of the Multiple Access Interference (MAI) in Code Division Multiple Access (CDMA) systems. The accuracy of the interference estimation is improved with a set of weights computed from an adaptive Normalized Least Mean Square (NLMS) algorithm. In order to reduce complexity, the commonality of the multi-code processing is extracted and used to derive a structure of PRC to avoid direct interference cancellation. The derived PRC structure reduces the interference cancellation architecture from a complexity that is proportional to the square of the number of users to a complexity that is linear with respect to the number of users. The complexity is further reduced by replacing dedicated multiplier circuits with simple combinational logic.

US Patent:

8027404, Sep 27, 2011

Filed:

Feb 5, 2008

Appl. No.:

12/025971

Inventors:

Kiarash Amiri - Houston TX, US
Raghavendar Mysore Rao - Austin TX, US
Christopher H. Dick - San Jose CA, US
Joseph R. Cavallaro - Pearland TX, US

Assignee:

Xilinx, Inc. - San Jose CA

International Classification:

H04B 7/02

US Classification:

375267, 375299, 375347

Abstract:

A circuit detects symbols communicated between multiple transmitting antennas and multiple receiving antennas (MIMO). Distance blocks are coupled in a sequence according to an ordering of the transmitting antennas. The respective distance block associated with each transmitting antenna determines a distance value for each pairing of one or more candidates and a symbol in a constellation. A respective selector block is coupled between each successive pair of distance blocks in the sequence. The respective selector block selects the one or more candidates for the successive distance block as a limited number of the pairings having smaller ones of the distance values. A limit block coupled to the selector blocks provides the limited number to each selector block. An identifier block selects the pairing having a smaller one of the distance values from the last distance block in the sequence.

US Patent:

8040981, Oct 18, 2011

Filed:

Jul 10, 2008

Appl. No.:

12/170468

Inventors:

Kiarash Amiri - Houston TX, US
Christopher H. Dick - San Jose CA, US
Raghavendar Mysore Rao - Austin TX, US
Joseph R. Cavallaro - Pearland TX, US

Assignee:

XILINX, Inc. - San Jose CA

International Classification:

H04L 27/06

US Classification:

375340, 375267, 375347

Abstract:

Circuits are provided for detecting symbols transmitted from multiple transmitting antennas to multiple receiving antennas. A circuit includes distance blocks, selectors, and an identifier block. Each distance-block includes at least one sub-block, and each sub-block inputs a candidate for a corresponding transmitting antenna. The sub-block determines partial distances for pairings of the candidate and each symbol in a constellation from a partial distance of the candidate and signals received at the receiving antennas. At least one selector assigns each pairing for each candidate for a corresponding transmitting antenna to a bin having a range that includes the partial distance of the pairing. The selector selects candidates for a successive transmitting antenna from the bins having the smaller ranges. The identifier block selects a final candidate that is one of the pairings for a last transmitting antenna having a smaller partial distance.

US Patent:

8059761, Nov 15, 2011

Filed:

Jul 10, 2008

Appl. No.:

12/170474

Inventors:

Kiarash Amiri - Houston TX, US
Christopher H. Dick - San Jose CA, US
Raghavendar Mysore Rao - Austin TX, US
Joseph R. Cavallaro - Pearland TX, US

Assignee:

Xilinx, Inc. - San Jose CA

International Classification:

H04L 27/06

US Classification:

375340

Abstract:

Circuits detect communications from multiple transmitting antennas to multiple receiving antennas. A respective first block for each non-initial transmitting antenna determines partial distances for pairings of a first candidate and a quadrature-phase amplitude. A respective second block for the initial transmitting antenna determines partial distances for combinations of phase amplitudes. A respective second block for each non-initial transmitting antenna determines partial distances for pairings of a second candidate and an in-phase amplitude. A respective first selector for each non-initial transmitting antenna selects the first candidates from the pairings for the respective second block having smaller partial distances. A respective second selector for each non-initial transmitting antenna selects the second candidates from the pairings for the respective first block having smaller partial distances. An identifier circuit selects a final candidate with a smaller partial distance from the pairings of the respective second block for the last transmitting antenna.

US Patent:

8139512, Mar 20, 2012

Filed:

May 30, 2008

Appl. No.:

12/156211

Inventors:

Gilles Charbit - Hampshire, GB
Jorma O. Lilleberg - Oulu, FI
Joseph R. Cavallaro - Pearland TX, US
Marjan Karkooti - Bryan TX, US

Assignee:

Nokia Corporation - Espoo

International Classification:

H04B 7/14

US Classification:

370279, 455 7, 455 15, 455 16

Abstract:

A source sends an encoded data block during a first time interval to a destination and to a relay. The source sends additional parity bits for the encoded data block during a second time interval. The relay partially decodes that encoded data block to a process-defined end point (typically only a partial decoding), such as a fixed number of decoding iterations. After partial decoding the relay forms a modified data block having corrected information bits and the parity bits of the block it received, and sends the modified data block to the destination, during the second time interval. The destination decodes to a results-defined end point the modified data block it received from the relay using the additional parity bits it received from the source. If that end-point cannot be reached, the destination may begin anew decoding the original encoded data block it received from the source.