Motorola Corporation

Freescale Semiconductor,inc.

Nxp Usa, Inc.

James A Stephens

Douglas Allan Hardy

Barry N Altschuler

Joseph Kish, Iii

William Chunhung Yip

David L Barron

Peter J Armbruster

Dominique Delbecq

James Brian Piket

Richard Soja

Vijay K Kapoor

Donald J Sabourin

Kenneth W Hines

Sean S You

Ernest Pei-Ching Chen

David Stephen Saewert

Bradley T Sanders

Stuart L Card

John N Fielden

Daniel M Perrine

Lam Tak Wing

A technique that reduces the startup time of a processing system authenticates a proxy for an image stored in tracked memory instead of authenticating the image stored in the tracked memory. A controller generates an alteration log authentication code based on an alteration log that is updated prior to programming the image stored in tracked memory. The controller records an alteration log authentication code in secure memory. The alteration log is indirectly related to a most recent image stored in the tracked memory. Authentication of the image of the alteration log is used as a proxy for authentication of the image stored in tracked memory, which is performed only when the tracked memory is modified. Use of the contents of the alteration log as a proxy for the contents of tracked memory accelerates the startup time of the system.

Fast secure boot from embedded flash memory

Methods and receiver circuits are provided for correlating an incoming signal with PN codes. An embodiment of the method includes receiving I/Q baseband samples in the I/Q domain; converting the I/Q baseband samples to phase baseband samples; generating a pseudonoise (PN) code; converting the PN code to PN phase data; performing a correlation on the phase baseband samples using the PN phase data to generate correlated I/Q values; performing an adding operation on the correlated I/Q values to generate demodulated I/Q values; converting the demodulated I/Q values into demodulated phase values; performing a frequency correction operation on the demodulated phase values to generate frequency correction data; converting the demodulated I/Q values into demodulated magnitude values; and performing signal decoding and synchronization on the magnitude values to generate output data. The operation of performing correlation on the phase baseband samples using the PN phase data is accomplished using scalar subtraction.

System and method for demodulating an incoming signal

A comfort noise generator () suitable for use in a communication system includes a finite impulse response (FIR) filter (), a random number generator (), and a coefficient updater (). The coefficient updater () determines an updated set of filter coefficients () based on the signal frame of the input signal (). The updated set of filter coefficients () is output to the FIR filter (). The FIR filter () shapes a white noise signal () supplied by the random number generator () to provide a simulated background noise signal, or comfort noise signal (). The comfort noise signal () is selectively output from an echo suppression system or corresponding method to overwrite or suppress reflected residual echoes.

Low-complexity comfort noise generator

A signal detector for detecting a signal having a first nominal frequency, Fand a second nominal frequency F, the signal intermixed with an interfering signal to form a composite signal, the signal detector including a first and a second band pass filter centered at Fand Ffor filtering the composite signal to provide an Fand Fsignal; a parameter estimator for determining an Fand Fperiod for the Fand Fsignal for a sequence of frames and an average period shift (APS) for a current frame and a plurality of earlier frames; a metric calculator for calculating a metric that corresponds to the Fand Fperiod and the APS; and a decision processor for deciding whether the signal has been detected based in part on a comparison of the metric and a threshold.

Method and apparatus for signal detection

The step sizes for tap positions of an adaptive filter ( ) in an echo canceller ( ) for canceling an echo signal are individually selected based upon a profile of the echo environment. A training signal ( ) is injected into the echo canceller and to the echo path during a training interval, or period. The adaptive filter profiles the echo path during the training interval. Respective step sizes &agr;&lsqb;k&rsqb; for the tap positions are generated as a function of the echo profile so generated.

Method and apparatus for setting a step size for an adaptive filter coefficient of an echo canceller

A call is connected between secure terminals (16) through a network (12). If a network address for the call is included on an approved list (46), a secure call setup procedure (54) is performed automatically. One terminal (16) automatically sends an auto-secure signal. If the other terminal detects the auto-secure signal, secure call setup procedure (54) is performed automatically. The secure call setup procedure (54) determines a current user-identity for the opposing party. If the current user-identity corresponds to a user-identity included on an approved list (76), an abbreviated secure call setup process (80) is performed. If the current user identity is not approved, a full secure call setup process (78) is performed. The abbreviated process (80) differs from the full process (78) in that it uses a traffic key obtained from a prior secure communication session and may be performed more quickly.

Secure communication setup method

A space-based communications network (10) includes satellites (12) placed in low-earth orbits (14). Satellites (12) engage in bulk communications with central switching offices (CSOs 22) and round control stations (GCSs 24). CSOs (22) and GCSs (24) include a network gateway (30) and any number-of remotely located earth terminals (32). Network gateway may provide telemetry, tracking and control functions for the constellation of satellites. Data are conveyed between the gateway (30) and earth terminals (32) over fiber optic cables (42) which convey a variety of different signals. Opposing unidirectional primary and secondary data communication channels each include signal sets having a gapped clock signal (76) and a data signal (86). The gapped clock signal (76) oscillates in synchronism with the data signal (86) and conveys both data timing and frame timing cable bundles (42) additionally convey LAN signals.

Apparatus and method for conveying frame timing, data timing, and data

A method (50) reconstructs messages from segments (30) which are received in an unknown order and at different times. Each segment (30) comprises a header (31) and payload information (38). The method (50) reconstructs messages from the received segments (30) by reassembling the order as specified in the header (31) of the segment (30). Once the message is reconstructed, the message is delivered. This method (50) is especially important in satellite-based communications where no guarantee exists that the messages will be received in a sequential order or at a specified time.

Method of reconstructing and delivering segmented messages

A method and apparatus for data collision detection and resolution in a multi-processor communication system. The system includes a plurality of processors coupled via a common bus. When it is required that one processor communicate with another processor, the first processor determines whether a data collision flag is set. The processor then checks a number of indicators to determine whether the identity of the transmitting processor is what it is expected to be. If a data collision is found, the processor waits a selective time before transmitting a message. The processor then repeats the data collision checking and transmitting the message to the other processor when no data collision is found. The time to wait is dependent upon the identity of the processor and is table driven.

Method and apparatus for data collision detection in a multi-processor

An apparatus comprises a first and a second input and a processor coupled to the inputs. The processor estimates peak and minimum levels of each of the first and second input signals. A first signal regulator is coupled to the first input and to a first output for delivering a first output signal from the first signals. A second signal regulator is coupled to the second input and to a second output for delivering a second output signal from the second audio signals. A gain adjustment device is coupled to the processor and the first and second signal regulators. The gain adjustment device provides control signals to the first and second signal regulators to adjust an output signal level of the first output signal in response to minimum and peak levels of the first and second input signals. The output signal level is continuously variable over a range.

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Chandler, AZ, United States of America

James A Stephens