Importance

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Abstract

A pseudorandom noise generator (10) is disclosed which includes a maximum length sequence generator (13) for providing a digital signal having a pseudorandom sequence, modulating circuitry (17,20, 25, 27, 33) responsive to the digital signal for providing a constantly changing modulation signal which changes linearly. In one embodiment, the modulation circuitry provides a sequence of linear ramps which remain within predetermined limits, and a voltage controlled oscillator (29) responsive to the modulation signal for providing a pseudorandom noise output VCOUT. The modulating circuitry causes inversion of the slope of the ramps when they reach the predetermined limits. Also disclosed is a pseudorandom noise generator (110) which includes a maximum length sequency generator (133) for providing a digital signal having a pseudorandom sequence at a selectable rate, a digital counter (111) for providing a digital count signal, circuitry (119, 121, 123, 125, 127, 129, 131, 137, 139) for controlling the count direction of the digital count signal in response to the pseudorandom digital signal and for controlling the digital count signal to remain within predetermined limits, a digital-to-analog converter (115) for converting the digital count to an analog modulation signal, and a voltage controlled oscillator (117) responsive to the analog modulation signal for providing a noise output VCOUT.

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First Claim