DAVID C BRADY
Broker in Milton, MA
License number
Massachusetts 9517761
Issued Date
Oct 20, 2010
Expiration Date
Feb 10, 2017
Type
Salesperson
Address
Address
Milton, MA 02186
Professional information
Digital Signal Receiver For Measurement While Drilling System Having Noise Cancellation
US Patent:
6741185, May 25, 2004
Filed:
Nov 13, 2001
Appl. No.:
09/979393
Inventors:
Pengyu Shi - Dorchester MA
David Brady - Milton MA
Robert Tennent - Stafford TX
Sandra D. Reyes - Cambridge, GB
David Brady - Milton MA
Robert Tennent - Stafford TX
Sandra D. Reyes - Cambridge, GB
Assignee:
Schlumberger Technology Corporation - Sugar Land TX
International Classification:
G01V 300
US Classification:
3408532, 367 83, 3408546, 175 40, 175 48, 375232, 375346, 375347, 375350
Abstract:
A method is disclosed for reducing noise in a measured telemetry signal. The method includes tracking a characteristic of at least one harmonic of a noise component in the measured telemetry signal band. The at least one harmonic has a frequency outside a telemetry signal band. The characteristic of the noise component is determined for at least one other harmonic thereof. The at least one other harmonic has a frequency inside the telemetry signal band. A noise reference is generated from the characteristic of the in band harmonic, and the noise reference is combined with the measured telemetry signal to generate a noise-canceled telemetry signal.
Imbalance Compensation For Direct Conversion Communication Systems
US Patent:
8526518, Sep 3, 2013
Filed:
Dec 18, 2008
Appl. No.:
12/734762
Inventors:
Jeffrey Ross Feigin - Andover MA, US
David Paul Brady - Milton MA, US
David Paul Brady - Milton MA, US
Assignee:
Skyworks Solutions, Inc. - Woburn MA
International Classification:
H04K 1/10
US Classification:
375260, 376260, 376267, 376299, 376346, 376349, 375350
Abstract:
Most modern integrated circuit transceivers, especially wireless LAN, utilize a direct conversion radio architecture, which is highly advantageous from the perspectives of cost and flexibility, there exist several performance impairments, including gain and phase imbalances between the in-phase (I) and quadrature (Q) of a transmitter or receiver. Disclosed herein is a signal processing methodology and system for compensation of I/Q imbalance for a direct conversion packet-switched OFDM communications system. The imbalance, which accounts for transmitter I/Q imbalance, RX I/Q imbalance, phase/frequency error, and dispersive multipath fading. Both frequency dependent I/Q imbalance and frequency independent cases are considered, covering both wideband and narrowband modulation. The proposed estimation algorithms operate within the fully compliant framework of existing multi-user OFDM radio standards (WLAN, LTE, WimAX). These algorithms accurately estimate and correct transceiver I/Q imbalance on a packet-by-packet basis, all within the receiver's digital baseband.