Performance of new BOC-AW-modulated signals for GNSS system

Mustapha Flissi,Djamel Chikouche,Abdehalim Mayouf,Salim Atia,Khaled Rouabah

doi:10.1186/1687-1499-2013-124

Abstract

Abstract In this paper, we propose efficient signal waveforms (WFs) with optimized spectrum for multipath (MP) mitigation and jamming reduction in global navigation satellite system. These WFs are based on the use of sine-phased binary offset carrier (BOC) with adjustable width (BOC-AW). They are generated by adjusting the width of the three-level WF {-1, 0, 1}. By exploiting the three-level BOC-AW subcarriers in sine-phasing signal model, we developed several forms of BOC-AW by means of superposition and width adjustment. The resulting power spectral densities and autocorrelation functions of the proposed WFs were calculated and introduced. Also calculated were the spectral separation coefficients (SSCs) and the Cramér-Rao lower bounds (CRLBs). The SSCs and CRLBs prove the efficiency of the proposed WFs in terms of interference separation. In addition, the simulation results show that the proposed WFs present better performances in MP mitigation compared to the WFs adopted by the Galileo and global positioning system modernization.

Highlights

The binary offset carrier (BOC) modulation represents a serious candidate for global navigation satellite system (GNSS), especially for future global positioning system (GPS)
Other forms of modulation derived from the BOC concept are used for new GPS and Galileo systems, such as quaternary phase shift keying modulation in L5 GPS signals [4], alternative BOC modulation in E5 Galileo signals [4], multiplexed BOC (MBOC) modulation with composite BOC (CBOC) implementation for Galileo, and timemultiplexed BOC (TMBOC) implementation for future GPS L1C [5]
The effort to search for new signal waveforms (WFs) for navigation continues in order to propose a WF that has lower levels of interference with existing signals with an insurance of better performances in terms of MP mitigation and jamming reduction

Summary

Introduction

The binary offset carrier (BOC) modulation represents a serious candidate for global navigation satellite system (GNSS), especially for future global positioning system (GPS). The expression of BOC(p,q) subcarrier used in Galileo and modernized GPS can be obtained from Equation 3 (corresponding to our proposed WFs) with M = 2 and α(2) = [α1 = 0, α2 = 1] (see Figure 1a).

Results

Conclusion