Achievement of Preassigned Spectra in the Synthesis of Band-Pass Constant-Envelope Signals by Rapidly Hopping through Discrete Frequencies

TL;DR

This paper presents an optimization-based method for synthesizing constant-envelope band-pass signals with preassigned spectra using rapid frequency hopping, relevant for spread-spectrum applications in communications and testing.

Contribution

It introduces a novel optimization approach for selecting modulation parameters to achieve desired spectral properties with limited frequency hopping.

Findings

Multiple local optima exist in the design space.

Local optima can be efficiently explored by adjusting initial parameters.

The method effectively synthesizes signals with specified spectral characteristics.

Abstract

Spread-spectrum signals are increasingly adopted in fields including communications, testing of electronic systems, Electro-Magnetic Compatibility (EMC) enhancement, ultrasonic non-destructive testing. This paper considers the synthesis of constant-envelope band-pass wave-forms with preassigned spectra via an FM technique using only a limited number of frequencies. In particular, an optimization-based approach for the selection of appropriate modulation parameters and statistical features of the modulating waveform is proposed. By example, it is shown that the design problem generally admits multiple local optima, but can still be managed with relative ease since the local optima can typically be scanned by changing the initial setting of a single parameter.