Robert A Lorenz

US Patent:

6552591, Apr 22, 2003

Filed:

Nov 1, 2001

Appl. No.:

10/002902

Inventors:

Kamran Khorram Abadi - Menlo Park CA
James T. Walker - Palo Alto CA
Robert Gustav Lorenz - Menlo Park CA

Assignee:

PiRadian, Inc. - Menlo Park CA

International Classification:

H04B 116

US Classification:

327306, 327331, 327350, 327553, 330278, 333 14

Abstract:

Method and apparatus are provided for processing a wide dynamic range analog signal which comprises a compressive nonlinear transfer function responsive to the average amplitude of the signal without feedback along the signal path. The invention employs frequency selective filtering and expansion of the compressed signal. The invention is applicable to any analog signal system having a plurality of channels carrying related signal information.

US Patent:

6920188, Jul 19, 2005

Filed:

Nov 16, 2000

Appl. No.:

09/715395

Inventors:

James Terrell Walker - Palo Alto CA, US
Kamran Khorram Abadi - Memlo Park CA, US
Robert Gustav Lorenz - Menlo Park CA, US

Assignee:

Piradian, Inc. - Menlo Park CA

International Classification:

H03D003/00

US Classification:

375322, 381106, 704224, 370202

Abstract:

An apparatus is provided for processing a wide dynamic range analog signal which comprises multiple components such as a signal with an in-phase component and a quadrature-phase component in for example separate I and Q data channels, wherein each channel has a dynamic range compressor stage and an operator stage which processes the compressed signals. Optionally the apparatus has a dynamic range expander stage following the operator stage. A method according to the invention involves processing I and Q information after first independently compressing the dynamic range of the signal according to a logarithmic transfer characteristic over a frequency range of interest. A mathematical operation through a F(i,q) function (corresponding to the operator stage) is performed on the compressed components, thereby producing normalized components. The operating transfer function F(i,q) cross links the data channels to effect normalization based on amplitude of information in each of the channels. Dynamic range expansion provides expanded components in an expanded domain.

US Patent:

7545876, Jun 9, 2009

Filed:

Feb 14, 2006

Appl. No.:

11/355293

Inventors:

Vara J. Prasad - Santa Clara CA, US
Ozgur Oyman - Palo Alto CA, US
Erik Lindskog - Santa Clara CA, US
Robert Lorenz - Santa Clara CA, US
Kamlesh Rath - Santa Clara CA, US

International Classification:

H04B 7/02

US Classification:

375267, 455102

Abstract:

Systems and methods for optimizing transmission of a plurality of data streams on a multiple-input multiple-output channel are described. The systems and methods for optimizing reduce the multiple-input multiple-output channel for each transmission scheme to an equivalent single-input single-output channel for the transmission scheme and transmit the plurality of data streams based on the single-input single-output channel for the transmission scheme. Systems and methods for optimizing the transfer of data for any number of transmit and receive antennas are described.

US Patent:

7602334, Oct 13, 2009

Filed:

Apr 3, 2008

Appl. No.:

12/080639

Inventors:

Robert G. Lorenz - Santa Clara CA, US

Assignee:

BECEEM Communications Inc. - Santa Clara CA

International Classification:

G01S 1/02
G01S 3/02

US Classification:

34235706, 342457

Abstract:

A method and apparatus of a mobile subscriber (MS) estimating position are disclosed. One method includes the MS receiving at least one satellite transmitted signal with a first receiver, and estimating a time of arrival of the at least one satellite transmitted signal. The MS additionally receives at least one terrestrial base station signal with a second receiver, and estimates a time of arrival of the at least one terrestrial base station signal. The MS estimates its position based on the estimated time of arrival of the at least one satellite transmitted signal and the estimated time of arrival of the at least one terrestrial base station signal.

US Patent:

7835432, Nov 16, 2010

Filed:

Apr 19, 2007

Appl. No.:

11/788265

Inventors:

Djordje Tujkovic - Santa Clara CA, US
Ying Xia - Santa Clara CA, US
Robert Lorenz - Santa Clara CA, US
Sriram Mudulodu - Santa Clara CA, US

Assignee:

BECEEM Communications Inc - Santa Clara CA

International Classification:

H04B 3/46
H04B 17/00
H04Q 1/20

US Classification:

375224, 370341

Abstract:

Embodiments are directed to a wireless receiver system that utilizes a special structure of pilot symbols used for synchronization and channel estimation in transmission packets to measure noise power at the receiver. The periodicity of the pilot signal sequences is used to extract the noise power from the received signal. Such extraction is achieved by subtracting the received signals from two pilot slots which are separated by the known periodicity of the training sequence. This method relies on the fact that desired signal and system interference signals will cancel out after the subtraction process. Measuring the power of the residual signal after subtraction represents the estimate of the noise power. Several consecutive such residual signals can be first summed up before measuring the power to improve the estimate of the noise power at the receiver. To further improve the performance, estimates of the desired signal produced by a channel estimation block can be first subtracted from each of the received signals on two pilot slots which are then to be subtracted and are separated by the known periodicity of the pilot sequence.

US Patent:

7929595, Apr 19, 2011

Filed:

Nov 29, 2007

Appl. No.:

11/998240

Inventors:

Sriram Mudulodu - Santa Clara CA, US
Harold Artes - Santa Clara CA, US
Bertrand Hochwald - Santa Clara CA, US
Guojie Dong - Santa Clara CA, US
Robert G. Lorenz - Santa Clara CA, US
Javvadi Varaprasad - Santa Clara CA, US

Assignee:

Broadcom Corporation - Irvine CA

International Classification:

H04L 27/18

US Classification:

375222, 375220

Abstract:

A method and system of estimating frequency offset at a subscriber station is disclosed. One method includes the subscriber station receiving a composite signal, wherein the composite signal includes multi-carrier signals transmitted from a plurality of base stations. The subscriber station selects a first pair of multi-carrier symbols of the composite signal, wherein each multi-carrier symbol of the first pair of multi-carrier symbols includes a pilot sub-carrier having a common sub-carrier index. The subscriber station selects a second pair of multi-carrier symbols of the composite signal, the second pair having different symbol indices than the first pair, but having a same symbol index separation, wherein each of the multi-carrier symbols of the second pair of multi-carrier symbols includes a pilot sub-carrier having a second common sub-carrier index. The subscriber station estimates a phase based on a first sum of complex conjugate products between received symbols on the pilot sub-carriers of the first pair of multi-carrier symbols, and/or based on a second sum of complex conjugate products between received symbols on the pilot sub-carriers of the second pair of multi-carrier symbols. The subscriber station provides the phase to a filter of a frequency tracking loop of the subscriber station.

US Patent:

7957328, Jun 7, 2011

Filed:

Jan 31, 2007

Appl. No.:

11/701009

Inventors:

David Garrett - Santa Clara CA, US
Robert Lorenz - Santa Clara CA, US
Trevor Pearman - Santa Clara CA, US

Assignee:

Broadcom Corporation - Irvine CA

International Classification:

H04B 7/005

US Classification:

370278

Abstract:

A method and system for managing change-over in radio functionality at a radio front-end in a Time Division Duplexing (TDD) system is provided. The method comprises storing one or more control commands. The one or more control commands may correspond to the change-over. The change-over may be a transmitter-to-receiver change-over or a receiver-to-transceiver change-over. The method further comprises receiving a trigger time corresponding to the one or more control commands. The trigger time comprises a timing requirement for the change-over. Thereafter, one or more control commands are released based on a predetermined condition.

US Patent:

8194774, Jun 5, 2012

Filed:

Oct 10, 2008

Appl. No.:

12/287619

Inventors:

Bertrand Hochwald - Santa Clara CA, US
Robert G. Lorenz - Santa Clara CA, US
Harold Artes - Santa Clara CA, US

Assignee:

Broadcom Corporation - Irvine CA

International Classification:

H04B 7/02
H04L 1/02

US Classification:

375267, 375299, 375347, 375260, 375346, 370252, 370382, 455500, 455101

Abstract:

A method and apparatus of a receiver estimating a plurality of channels is disclosed. The method includes the receiver receiving a composite signal. The composite signal includes a signal from each of a plurality of transmission antennas, wherein the signal of each transmission antenna includes a delay relative to other signals of other antennas. The receiver estimates channels between the receiver and the plurality of transmission antennas based on amplitude and a phase of a received composite signal, at a plurality of frequencies.