Aris Technologies, Inc.

Quality Semiconductor Inc.

Jack Wolosewicz

Kanaan Jemili

Curtis J Dicke

A method and apparatus encodes and decodes machine readable signals in audio signals for producing humanly perceived audio transmissions. The encoding device includes circuitry for identifying portions of the audio signal having relatively low energy in a given band and relatively high energy in a band proximally below the given band. The machine readable signals are then inserted into the identified portions of the audio signal. According to another embodiment, the machine readable signals are encoded as a spread-spectrum signal which is added to the original audio signal. The spread-spectrum signal is scaled using a unique technique referred to as Common Mode Scaling.

Apparatus and method for encoding and decoding information in audio

A mixed signal phase locked loop is optimized for fast settling and low noise sensitivity. To this end, this device has a digital wide range delay line and a low gain per stage adjust. When first activated, the loop calibrates the digital delay line to its nominal delay characteristic. This delay line, together with the linear low gain per stage adjust, constitutes the internal oscillator of the phase locked loop. After achieving nominal delay, the oscillator uses the low gain per stage adjust to lock to a desired reference or a submultiple thereof. According to the preferred embodiment, the loop locks its internal 125 MHz oscillator to a 25 MHz reference. After achieving lock, the loop performs synchronous data recovery by locking to an incoming data stream, instead of the internal reference, and performing bit framing. In case of losing lock, the phase locked loop of the present invention is capable of recalibrating itself and regaining lock in under 3 microseconds.

Mixed signal phase locked loop with process and temperature calibration

A method and apparatus for encoding information symbols onto an analog host signal modifies signal peaks of the host signal to fall within predetermined amplitude bands. A set of symbols is defined wherein each symbol corresponds to a defined number of signal peaks or to a particular value of signal peak within a band. An additional information channel may be created by altering polarity changes of signal peaks in accordance with predetermined polarity sequences to represent a second set of defined symbols.

Growing community of inventors

Boston, MA, United States of America

Jack Wolosewicz