Harris Corporation

Mark Chamberlain

Paul Edward Voglewede

Joseph B Shaver

Edwin McCall Leiby, Iii

John Wesley Nieto

Fred C Kellerman

David A Clark

Daniel Ernest Stephens

Patrick Lang

Edwin Leiby

John Alvermann

Gary Anton Schwenck

Anthony Richard Alan Keane

Leonard Picone

Igor A Spivak

Timothy Vogl

Eric Peach

A method is provided for transmitting voice data in a secure communication system. The method includes: transmitting voice data using a plurality of data packets; embedding a cryptographic message indicator into each of the plurality of data packets; and correcting for bit errors in the cryptographic message indicator at a packet receiver using code-combining across two or more of the data packets.

Robust delivery of packet based secure voice

A method is provided for decoding data streams in a voice communication system. The method includes: receiving two or more data streams having voice data encoded therein; decoding each data stream into a set of speech coding parameters; forming a set of combined speech coding parameters by combining the sets of decoded speech coding parameters, where speech coding parameters of a given type are combined with speech coding parameters of the same type; and inputting the set of combined speech coding parameters into a speech synthesizer.

Multiple stream decoder

A vocoder and method transcodes Mixed Excitation Linear Prediction (MELP) encoded data for use at different speech frame rates. Input data is converted into MELP parameters such as used by a first MELP vocoder. These parameters are buffered and a time interpolation is performed on the parameters with quantization to predict spaced points. An encoding function is performed on the interpolated data as a block to produce a reduction in bit-rate as used by a second MELP vocoder at a different speech frame rate than the first MELP vocoder.

Vocoder and associated method that transcodes between mixed excitation linear prediction (MELP) vocoders with different speech frame rates

A mobile ad-hoc network includes a plurality of N mobile nodes and wireless communication links connecting the mobile nodes, which each include a communications device for transmitting and routing data packets wirelessly to other mobile nodes via the wireless communication links in accordance with a time division multiple access (TDMA) data transmission protocol using a TDMA epoch that is divided into a beacon interval, digital voice interval and digital data interval. The mobile nodes monitor channel conditions using the beacon, digital voice and digital data intervals and provide a network conductivity performance as valid receptions occur within mobile nodes. A data rate is calculated and set for other N&#x2212;1 mobile nodes using monitored channel conditions for the beacon, digital voice and digital data intervals.

System and method for setting a data rate in TDMA communications

A communications device includes a modulator and a filter downstream therefrom and operable to generate an output wideband complex signal with a frequency notch therein. The filter includes a finite impulse response (FIR) filter with L taps to generate N output values, with L&#x3e;N. A Fast Fourier Transform (FFT) block is downstream from the FIR filter and has a length N so that filter transition regions occur between frequency bins of the FFT block. A notching block is downstream from the FFT block to generate the frequency notch. An Inverse Fast Fourier Transform (IFFT) block is downstream from the notching block and has the length N.

Communications device including a filter for notching wideband transmit signals and associated methods

An improved method is provided for decoding data in a frequency hopping communications system. The method includes: monitoring transition points between data bits in a demodulated data stream, where the data bits are transmitted to a receiver over different transmission frequencies; determining a frequency over which data bits are transmitted to the receiver; determining a reliability metric for each frequency over which data bits were received, where the reliability metric is based on transition points of data bits transmitted over a given frequency; and performing a decoding operation using the reliability metric for each frequency over which data bits were received.

Method for decoding digital data in a frequency hopping communication system

Systems () and methods () for noise error amplitude reduction. The methods involve configuring a first microphone system () and a second microphone system () so that far field sound originating in a far field environment relative to the first and second microphone systems produces a difference in sound signal amplitude at the first and second microphone systems. The difference has a known range of values. The methods involve () dynamically identifying the far field sound based on the difference. The methods also involve () automatically reducing substantially to zero a gain applied to the far field sound responsive to the identifying step.

Noise error amplitude reduction

To avoid signal jamming, a method is provided for selecting a dwell channel on a receiver in a frequency hopping communication system. The method includes: measuring a noise level on channels over which a data signal is received at the receiver; selecting a dwell channel based on the estimated noise levels, where the dwell channel having the lowest noise level amongst a group of permissible channels over which to acquire a signal from a transmitter; and tuning the receiver to the selected dwell channel during a search state in which the receiver attempts to synchronize with a transmitter.

Signal jamming avoidance method for a frequency hopping communication system

A communications device includes pre-processing circuitry for processing a received wideband complex signal including an undesired narrowband interference component therein, and for determining a frequency of the undesired narrowband interference component. A filter is downstream from the pre-processing circuitry and operable to generate a received wideband complex signal with at least one frequency notch therein to suppress the undesired narrowband interference component. The filter includes a finite impulse response (FIR) filter with L taps to generate N output values, with L&#x3e;N. A Fast Fourier Transform (FFT) block is downstream from the FIR filter and has a length N so that filter transition regions occur between frequency bins of the FFT block. A notching block is downstream from the FFT block to generate the frequency notch. An Inverse Fast Fourier Transform (IFFT) block is downstream from the notching block and has the length N.

Communications device including a filter for notching wideband receive signals and associated methods

A method is provided for protecting flash memory residing on a computing device. The method includes: receiving a data file having a digital signature at a main processor; forwarding the data file from the main processor to a secondary processor for signature validation; validating the digital signature associated with the data file at the secondary processor; enabling a write capability of a flash memory upon successful validation of the digital signature; and writing the data file to the flash memory.

Method and apparatus for protecting flash memory

A circuit () is provided that is connectable between input lines () and output lines (). The circuit is comprised of a primary battery () and a hold-up battery (). The hold-up battery is connected in parallel with the primary battery. The circuit is further comprised of an RC circuit () connected in parallel with the primary battery and is isolated from the hold-up battery by unidirectional current valves (). A comparator is provided with a first input () coupled to the RC circuit and a second input () coupled to a voltage reference. A switching device () is provided that is controlled by an output of the comparator. The switching device connects the hold-up battery to output lines in a first state and disconnects the hold-up battery from output lines in a second state. The unidirectional current valves prevent reverse leakage current from the hold-up battery from charging a capacitor during a discharge period of the RC circuit.

Time limit circuit for a hold-up battery

A system and method for noise cancellation with noise ramp tracking in the presence of severe or ramping acoustic noise. The system conducts an estimation of the noise level in the input signal and modifies the signal based upon this noise estimate. A windowed Fourier transform is performed upon the input speech signal and an estimation of a histogram of the frequency magnitudes of the noise level and other related parameters is generated and used to compute a spectral gain function that is applied to components of the Fourier transform of the input speech signal. The enhanced components of the Fourier transform are processed by an inverse Fourier transform in order to reconstruct a noise reduced speech signal.

Growing community of inventors

Honeoye Falls, NY, United States of America

Mark Chamberlain