Improving time-delay estimation and multipath resistance is one of the most important drivers for designing new satellite signals, together with noise and multiple access interference reduction. This chapter proposes a theoretical analysis for designing new spreading waveforms that can achieve this multiform problem. Following a systematic approach for designing new signal-in-space waveforms has lead to an implementable mathematical optimization problem to improve time delay estimation for the additive white Gaussian noise channel with two-ray multipath (MP) propagation. In this scenario, minimizing the Gabor bandwidth with a constraint on the sidelobe levels is shown to represent an effective optimization criterion for designing spreading signals with higher robustness against MP. Starting from the generic waveform formulation of the signal as a cardinal interpolation of the cardinal sine function, the proposed band-limited non-binary signal represents an effective way to optimize the performance following the Gabor bandwidth analysis.

Inspec keywords: AWGN channels; signal processing; interpolation; interference suppression; delay estimation; Global Positioning System; radiofrequency interference; spread spectrum communication

Other keywords: signal-in-space waveforms; bandlimited nonbinary signal; satellite signals; MP propagation; additive white Gaussian noise channel; multiple access interference reduction; Gabor bandwidth minimization analysis; delay-tracking features; two-ray multipath propagation; cardinal interpolation; nonbinary spread spectrum signals; time-delay estimation; noise reduction; generic waveform formulation; systematic approach; cardinal sine function; sidelobe levels; satellite positioning; multipath resistance

Subjects: Satellite communication systems; Other topics in statistics; Radionavigation and direction finding; Interpolation and function approximation (numerical analysis); Electromagnetic compatibility and interference; Signal processing and detection