working papers A Search for Spectrum: GNSS Signals in S-Band Part 1
Your GNSS S-band spectrum here?
Frequency allocations suitable for GNSS services are getting crowded. System providers face an ever tougher job as they try to bring on new signals and services while maintaining RF compatibility and, in some cases, spectral separation. This two-part column explores the possibility, advantages, and disadvantages of using allocations in a portion of the S-band spectrum.
Isidre Mateu n recent years, researchers have compatibility with the adjacent radio CNES (French Space Agency) explored possible new allocations astronomy band and GLONASS could Matteo Paonni for Radio Determination Satellite be achieved. Institute of Geodesy and Navigation, IService (RDSS) and Radio Naviga- In any case, any signal occupying University FAF Munich tion Satellite Service (RNSS) spectrum the whole E1/G1 band would have to be Jean-Luc Issler from a regulatory point of view. These backward-compatible and symmetrical CNES studies have mainly discussed S-band in spectrum and correlation character- Bernd Eissfeller and C-band in addition to L-band. istics to avoid creating pseudoranging Institute of Geodesy and Navigation, The International Telecommuni- bias. Furthermore, having a very wide University FAF Munich cations Union (ITU) Radio Regula- band signal in the lower and upper L- tions define RNSS as a subset of RDSS. bands would potentially allow significant Lionel Ries, Cyrille Boulanger Although the allocations are differenti- improvement in terms of pseudoranging CNES (French Space Agency) ated — RDSS usually has a paired uplink performance thanks to the very accurate Paolo Mulassano — both can actually be used for satellite dual-frequency, wideband ionospheric Istituto Superiore Mario BoellA, Torino, Italy navigation. correction and raw pseudoranges that Mario Caporale The eventual need of GNSS systems would be available. In fact, this is the ASI (Italian Space Agency) for additional frequency resources or only way for any new signal to signifi- Sylvain Germaine, Jean-Yves Guyomard signals in S-band and/or C-band is not cantly improve the pseudoranging per- ANFR (French National Agency of driven by the desire to improve the pseu- formance, because C-band today is only Frequencies) doranging or timing performance, but 20 MHz wide (5010–5030 MHz) and S- Frederic Bastide, Jeremie Godet, Dominic Hayes primarily to introduce alternative and band is restricted to 16.5 MHz (2491.75 European Commission complementary capabilities to those MHz ±8.25 MHz. Damien Serant, Paul Thevenon, Olivier Julien services already offered by systems now “Note that an alternate binary offset ENAC (French Civil Aviation University) in operation or under development. carrier with CBOC on each side — that In fact, GNSS pseudoranging or tim- we could define as AltBOC(15, CBOC), Anthony R. Pratt ing performance could be improved with for example — or an equivalent signal Orbstar Ltd. U.K. availability of new code division multi- filtered in the E1/G1 band could by itself Jose-Angel Avila-Rodriguez, Stefan ple access (CDMA) signals in the upper prove superior in terms of accuracy Wallner, Guenter W. Hein L-band alone. These could be defined in compared to the current multiplexed European Space Agency/ESTEC, Noordwijk, the so-called E1+G1 band, for example, BOC (MBOC) planned for Galileo E1 The Netherlands where some room is still available if and GPS L1, while still preserving the www.insidegnss.com september 2010 InsideGNSS 65 working papers
Horizontal trajectories 0.8 technically feasible, tighter hybridizations between mobile 0.7 0.6 from the perspec- communication services and naviga- 0.5 tives of link budget tion services. 0.4 and radio frequency The list of imaginable applications
North 0.3 compatibility. We based on the combined use of S- and L- 0.2 must also under- band or S-band alone is a lengthy one, 0.1 0.0 line the fact that the including the following: -0.1 results presented in • An accurate self-positioning of 0.0 0.5 this column neither future Globalstar mobile phones East pretend to cover using Galileo, without the need to all solutions agree to 1cm RMS the whole palette of add any L-band hardware in the Glo- GNSS signals and balstar (or other mobile com) termi- FIGURE 1 Example of accuracy close to one centimeter provided by the in- teger ambiguity resolution on undifferenced phase (IARUP) technique frequency resources nal to save costs in this equipment. using GPS L1 and L2 signals that could be dis- Single-frequency S-band ionospheric cussed, nor pretend correction could be provided using necessary backward compatibility with to be an official baseline for an evolved techniques such as those described a composite BOC (CBOC) in E1. Galileo system. in other research on this topic listed In principle, another very important Future developments could be in dif- in the Additional References. field for improving accuracy worldwide ferent or complementary directions to • Assistance of GNSS acquisition without the need of extra frequency those that we will discuss here. Having indoor using Globalstar signals, or bands (that is, in addition to L-band) is a said this, we recall that the main objec- using other mobile communication technique called integer ambiguity reso- tive of the authors is to open a construc- signals also transmitted in S-band lution on undifferenced phase (IARUP) tive discussion on where GNSS could • To perform the orbit and time deter- or possible equivalent techniques, which evolve to. The first part of this column mination of both Galileo (or another will allow very precise positioning accu- will take up the issues of S-band’s poten- GNSS system) and Globalstar sat- racies close to a few centimeters in real tial for GNSS operations, presenting ellites, thanks to a single ground time (See Figure 1). IARUP is described results of several comparative technical network of updated Galileo Sensor further in the paper by D. Laurichesse analyses. Station (receivers), using double dif- and F. Mercier listed in the Additional Part 2, which will follow in the Octo- ference measurements in S-band, Resources section at the end of this ber issue of Inside GNSS, will focus on single frequency ionospheric deter- article. (We should point out that such the subject of compatibility and interop- mination in S-band, and intersystem techniques are also known by the acro- erability with other systems operating assistance/cross-validations thanks nym PPP-Wizard, standing for “Precise at S-band as well as signal modulations to L-band measurements. A GNSS Point Positioning With Integer Zero-dif- that might work well for GNSS services system could then offer the time and ference Ambiguity Resolution Demon- there. orbit determination of Globalstar stration.”) and/or other mobile satellite service Having this in mind and recalling Potential Benefits of S-band (MSS) systems, if the necessary relat- that our objective is to focus on S-band, for Navigation ed security measures were taken. alternative solutions that employ C-band New functions and services that could • To assist the acquisition of MSS sig- and/or G1/G2. L-band will not be dis- be imagined for potential S-band signals nals like the Globalstar ones, provid- cussed further in this article, except for do not necessarily include the improve- ing an accurate time, without requir- the relevant L/S-band link budget com- ment of the ionospheric correction. ing any L-band–specific hardware in parisons. Regarding C-band, several In fact, a new signal in the G1 L-band the mobile com terminal. studies have been undertaken in recent would also significantly improve the • To use the communication channel years to investigate the suitability of this ionospheric correction efficiency as dis- to provide assisted-GNSS to a GNSS- frequency band for GNSS purposes and cussed above. embedded receiver. This would allow possible alternatives for a signal baseline, Moreover, Globalstar, a low Earth communication to support GNSS. mainly in the framework of the Europe- orbit (LEO) mobile telecommunication A possible approach could be, for an Space Agency’s GNSS Evolution Pro- constellation, also applies S-band Dop- instance, to use the Open Mobile gram. (The interested reader can refer to pler compensation based on radio links Alliance–Secure User Plane Loca- the papers by J. A. Avila-Rodriguez et between the ground and the LEO satel- tion (OMA-SUPL) approach. alia (2008b) and A. Schmitz-Peiffer et lites in addition to its GPS on-board real- • To allow RDSS multi-constellation alia listed in Additional Resources.) time orbit determination and synchro- positioning in S-band by means This two-part column will show that nization. Further, the new functions and of Beidou/Compass future S-band potential new services in S-band are services provided by S-band are rather signals or from the Indian IRNSS/
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PMDr: Leeheim Vorgang: B2 001/00374/09 BEIDOU-1B GINS, which is also planned to tance in S- and Empfangsantenne: MBA Polarisation: Zirkular transmit at 2491 MHz. An example L-band, thanks Richtung: 102.8° Elevation: 04.2° -63 of the signal that could be employed to the previous- ] bm -66
Figure 2 [d
is shown in , which depicts ly mentioned the Chinese geostationary orbit Asian, U.S., and
ator -69
satellite (GSO) RDSS signal at 2491 European sys- ys al -72
MHz. The paper by T. Grelier et alia tems. An
(2006) cited in Additional Resourc- All these appli- -75 sung
es has measured and analyzed cations might be le -78 the Beidou GNSS S-band pseudo- satisfied by a single Ab 75 75 75 75 75 75 75 75 75 75 noise (PN) code spectrum lines. signal, hosting sev- 75 7. 7. 1. 5. 3. 5. 9. As we can see, this is the same eral services simul- 9. 49 491. 501. 49 49 49 2. 2. 2. 2.48 2.48 2. 2. 2. 2.48 2.483. central frequency employed by Glo- taneously. Up till 2.48 balstar. We also noticed that the now, no need for Frequency [MHz] Datum Uhrzeit: 15.07.2009 12:15 Japanese high accuracy clock (HAC) two different Gali- Mittenfrequenz: 2491.7500 [MHz] Span: 20.0000 [MHz} GNSS signal experiment already uses leo waveforms and Analysator: R&S FSIQ Betriebsart: a 1023 chips — 1.023 Mcps code at spectrum in S-band Messfilter: 1 MHz Videofilter: 10 MHZ Uberlaufzeit: 5.00 [msec] 2491 MHz transmitted from the ETS has been identified. FIGURE 2 Spectrum of Beidou 1-B in S-band (measurement made July 15, VIII geostationary satellite of JAXA. However, this does 2009, at the earth monitoring station, Leeheim, Germany) Current modernized GPS satellites not mean that an are also provided with an experimen- eventual Galileo S-band signal should E1 minimum received power level [dBW] -157.25 tal search and rescue (SAR) payload necessarily have only one main lobe. Free-space loss in S-Band [dB] 189.54 transmitting in S-band. It is worth noting that L/S-band fre- • We should also note that with equiv- quency was selected for low-cost radio Tropospheric losses [dB] 0.41 alent signal bandwidths, L+S iono- development (commercial wireless Polarization losses [dB] 0.5 spheric dual-frequency corrections technology) in a GPS IIF SAR low-cost Ionospheric losses [dB] 0.5 are more accurate than L+L ones. design study involving a 2.4 GHz down- Total losses in S-band at 5° elevation [dB] 190.95 This advantage remains for dual- link. S-band is also used for satellite Required EIRP in S-band [dBW] 33.70 frequency classical ionospheric cor- formation flying RF GNSS technology, rections without the need to require using GPS-like C/A codes. The potential TABLE 1. Calculation of the transmitted effective isotropic radiated power in S-band to obtain the wider bandwidths. However, this services to be provided by Galileo in a same power level at the ground as for E1-OS benefit does not appear for single- hypothetical future S-band system are frequency ionospheric corrections still under study. resents an increase of four decibels from where the higher the carrier frequen- what is required in E1. This is needed in cy, the smaller the ionospheric delay Link Budget order to compensate for the higher free- is, but also the smaller the code-car- We have calculated a link budget to space losses in S-band. rier divergence that results. On the quantify the effect of an S-band signal In order to assess pseudorange accu- other hand, because this code-carrier upon a satellite’s power supply. For the racy, the signal modulation has to be slipping also allows single-frequency sake of the comparison between signals taken into account. We considered five retrieval of the ionospheric delay, the in L-band and the potential signal in S- different possible alternatives: efficiency of ionospheric correction band, we assumed that the new signal • Bi-phase shift key, BPSK(1) — “Glo- using combined classical dual-fre- will guarantee at least the same received balstar like” or “IRNSS like” signal, quency and single-frequency cor- power on the ground and offer the same occupying only the central portion recting techniques is approximately performance in terms of pseudorange of the available spectrum the same no matter what the the cen- accuracy, as the Galileo Open Service • BPSK(4) — analog of the signal trans- tral carrier frequencies are. (See the in E1/L1. mitted by the Beidou-1 geostationary discussion in the papers by J.-L. Issler The Galileo OS Signal-in-Space satellites et alia and O. Julien et alia in Addi- Interface Control Document (ICD) sets • BPSK(8) — the idea behind this sig- tional Resources.) The only notice- a minimum received power of -157.25 nal would be to effectively occupy the able advantage of S-band (or C-band) dBW for its open service on E1 at an whole S-band RDSS spectrum; related to ionospheric corrections is elevation angle of five degrees. Table 1 • BOC(1,1) — having the same spec- smaller scintillations compared to L- shows that an effective isotropic radiated trum as the core of the GPS/Galileo band. power (EIRP) of 33.7 dBW would need CBOC at E1 central frequency, this • To allow RNSS multi-constellation to be transmitted in S-band to obtain the signal could ensure high commu- positioning and inter-system assis- same power on the ground, which rep- nality;
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• CBOC(6,1,1/11) — to use the same this value, the pseudorange error has Minimum user received power [dBW] -157.25 modulation already fixed to be the been also calculated using the previously Implementation loss [dB] 2 Galileo OS signal in the E1/L1 band introduced expression. Considering a Receiver antenna gain at low elevation -3 would guarantee maximum com- coherent integration time of four milli- (circularly polarized antenna) [dB] munality within the S-Band signal seconds, a loop bandwidth of one hertz, Noise level [dBW/Hz] (T=600K) -201.5 and the Galileo OS and GPS civil a 12.27 megahertz front-end bandwidth signals. and a 0.1-chip spacing, this calculation C/N0 [dBHz] 39.25 In the second part of this column to produces a code noise of 0.25 meter. TABLE 2. L-band link budget be found in the October Issue of Inside GNSS, we explore the use of orthogonal CBOC(6,1,1/11) BOC(1,1) BPSK(1) BPSK(4) BPSK(8) frequency division multiplex (OFDM) Required C/N0 [dBHz] 39.25 42.1 46.8 40.5 37.5 modulation. Noise level [dBW/Hz] (T=600K) -201.5 For each of the modulations consid- Receiver antenna gain at 5° [dB] -3 ered here, we have calculated the power that is required to be transmitted to Implementation Loss [dB] 2 obtain the same raw thermal noise pseu- Total losses in S-band at 5° elevation [dB] 190.95 dorange error as that of E1 OS. Transmitted EIRP in S-band [dBW] 33.7 36.55 41.25 34.95 31.95 In order to calculate the minimum Required EIRP to guarantee -157.25 dBW of 33.7 required carrier-to-noise density ratio received power at ground level [dBW]
(C/N0) for a given thermal noise value, EIRP to guarantee both the required we followed the same approach as that C/N0 and the minimum received power at 33.7 36.55 41.25 34.95 33.7 described in the paper by M. Paonni et ground level [dBW] alia cited in Additional Resources, where TABLE 3. Calculation of the transmitted power in S-band to obtain the same the pseudorange errors as for E1-OS the code tracking error is calculated with the theory presented in the referenced CBOC(6,1,1/11) BOC(1,1) BPSK(1) BPSK(4) BPSK(8) article by J. Betz. The steady state code EIRP [dBW] 33.7 36.55 41.25 34.95 33.70 tracking error expressed in terms of the PFD [dBW/MHz/m²] -132.48 -129.18 -122.78 -132.38 -136.38 standard deviation of the thermal noise max TABLE jitter σDLLt [chips] adopts the following 4. Transmitted power and maximum power flux density level for each modulation form for the particular case of a non- coherent early-late discriminator: been used to produce the results.
Once the C/N 0 is determined, the required transmitted power is cal- culated making a reverse link budget calculation. Table 3 summarizes the where Tc is the chip period, BDLL is the The idea that has been used in order obtained results. delay-locked loop (DLL) bandwidth, B to introduce new signals for the S-Band Note that Table 3 shows a minimum is the double-sided RF front-end band- is to fix the minimum transmitted power EIRP for the BPSK(8) signal that is high- width, T is the coherent integration time, for each signal so that the ranging per- er than the values calculated to guaran-
C/N0 is the carrier-to-noise density ratio, formance is always at least equal to that tee the minimum required C/N0. This is and Gs(f) is the power spectral density of the Galileo E1 OS. Therefore, the C/ because a minimum received power on of the signal. N0 required for each of the considered the ground of -157.25 dBW also has to We begin by calculating the thermal modulations in S-band can be deduced be guaranteed, and this leads to a mini- noise for the Galileo E1 OS signal. To by the value just calculated. In the case of mum EIRP of 33.7 dBW. do this, a value of signal-to-noise ratio CBOC it will be the same as for E1 (as the Therefore, for BPSK(8) modulations is needed, which we obtained using the pseudorange error does not vary with the the limiting factor for the transmit- link budget presented in Table 2. In this carrier frequency), namely 39.25 dBHz. ted power is the received power on the link budget a receiver antenna gain of -3 For the other modulations the C/N0 ground, while for BOC(1,1), BPSK(1), decibels and implementation losses of 2 has been obtained simply by inverting and BPSK(4) it is the pseudorange accu- decibels have been considered. the thermal noise jitter expression. A racy, which is consistent with the fact
As can be read in the table, a C/N0 chip spacing of 0.1 chips and a front- that the pseudorange error decreases as of 39.25 dBHz has been obtained. Using end bandwidth of 16.5 megahertz have the signal bandwidth increases.
68 InsideGNSS september 2010 www.insidegnss.com working papers
Multipath Envelopes Front-End BW =16.5 MHz - E-L Correlator - Chip spacing=0.1 Table 4 summarizes the obtained values for the transmit- CBOC(6,1,1/11) ted power, as well as the corresponding maximum power flux 6 BOC(1,1) density (PFD) level on the ground within the band, which has BPSK(1) been calculated through integration of one megahertz of the 4 BPSK(4) signal’s power spectral density (PSD) around the maximum ] BPSK(8)
[m 2 of its main lobe. r
ro In order to complete the performance comparison between 0 the different modulations under study, we also undertook an ing Er analysis of the multipath resistance performance. Multipath -2
Rang error envelopes and their running averages have been assessed -4 for the various signals with the results shown in Figure 3 and Figure 4. -6 As can be seen in these plots, for short multipath the CBOC modulation outperforms all the other solutions studied here, 0 100 200 300 400 Multipath Delay [m] while BPSK(8) performs best when considering multipath with a longer delay. This result comes as no surprise, because FIGURE 3 Multipath error envelopes CBOC performs better than the BPSK(4) and even better than the BPSK(8) for short multipath due to its front-end bandwidth Running Averages of 16.5 megahertz. Front-End BW =16.5 MHz - E-L Correlator - Chip spacing=0.1 The advantage of the higher chip rate of the BPSK(4) and CBOC(6,1,1/11) BPSK(8) is more than offset by the quite narrow receiver band- 8 BOC(1,1) width that has been assumed. We can also observe this by BPSK(1) plotting the Cramer-Rao Lower Bound for the five signals, as
] BPSK(4) represented in Figure 5.
[m 6 BPSK(8) e One would have expected that, given the higher chip rate of ag the BPSK(4) and BPSK(8) signals , the ranging performance of 4 the CBOC(6,1,1/11) modulation should be much worse. This is not happening because the performances are not analyzed in
Running Aver terms of infinite bandwidth but instead for signals filtered over 2 the available bandwidth. Consequently, the filtering losses that the two BPSK signals are experiencing worsen their ranging performance. 0 0 100 200 300 400 Multipath Delay [m] Conclusion and Further Work This article has considered S-band signal design criteria related FIGURE 4 Running average of the multipath error envelopes to raw pseudorange thermal noise in comparison with L-band
and in terms of the C/N0 needed for signal acquisition. Several Cramer Rao Lower Bound other signal design criteria would have to be considered in the Front-End BW =16.5 MHz 10 future, in addition to these. For instance, for a given power flux, CBOC(6,1,1/11) wideband signals such as BPSK(8), BPSK(4), and CBOC are BOC(1,1) more interesting than the other signals considered for indoor 8 BPSK(1) BPSK(4) applications. BPSK(8)
] For such a given power flux, the wider the band occupied
[m 6 by the main lobe(s), e.g, for BPSK(8), the higher the received e
is power — and, therefore, the higher the indoor penetration No 4 — would be. As a result, wideband modulations that gener-
Code ate small multipath errors for reflections coming from various sides of a building are more interesting to consider for indoor 2 applications. Another possible signal design criteria is interoperability with 0 open or commercial signals of other systems, such as the planned 15 20 25 30 35 40 45 50 Indian Regional Navigation Satellite System (IRNSS) and/or Glo- C/N0 [dB-Hz] balstar. These two examples of signal design criteria — efficacy
FIGURE 5 Cramer-Rao Lower Bound in indoor environments, interoperability with other system(s) — might be met by employing multiple main-lobe signals.
www.insidegnss.com september 2010 InsideGNSS 69 working papers
Satisfying all the required signal C-Band,” ION-GNSS 2008, Savannah, USA, Sep- design criteria would be much complicat- tember 2008 ed if two different GNSS waveform and [4] Berthias, J-P., and P. Broca, A. Comps, S. spectrum, associated to separated ser- Gratton, D. Laurichesse, and F. Mercier, “Lessons vices, would have to be fitted in S-band. Learned from the Use of a GPS Receiver in Less This difficulty would be compounded by Than Optimal Conditions,” CNES seminar, Toulouse, France, January 2002 the need to preserve a certain spectral separation with non-interoperable ser- [5] Betz, J. W., “Generalized Theory of Code Track- ing with an Early Late Discriminator, Part 1: Lower vices provided by other GNSS systems in Bound and Coherent Processing,” IEEE Transac- S-band, such a spectral separation being tions on Aerospace and Electronic Systems, vol. another signal design criterion. Taking 45, no. 4, pp. 1538-1550, 2009 into account all these signal design cri- [6] Cheung, R. P., and S, Lee, and T. A. Vo, “Feasi- teria, and not only the two ones consid- bility Study of a Low-Cost Search & Rescue Pay- ered in Table 4, a reasonable PFD limit load Onboard the GPS Satellites,” ION GPS 2000, for a GNSS signal in S-band seems to be Salt Lake City, Utah, USA, September 2008 close to – 126 dBW/MHz/m². [7] Cohen, C., and B. Pervan, and B. Parkinson, In Part 2 of this column on S-band Estimation of Absolute Ionospheric Delay Exclu- and GNSS, we will return to the subject of sively through Single-Frequency GPS measure- inter-system interference and interoper- ments, ION GPS 1992, Albuquerque, New Mexico, ability, with particular attention on Glo- USA, September 1992 balstar. We will also consider the OFDM [8] Fleury, R., and M. Clemente, P. Lassudrie- modulation further as a candidate GNSS Duchesne, and F. Carvalho, “Modelling of High- signal design element in S-band. Order Errors for New Generation GNSS,” Anales des Telecommunications, vol. 64 no. 9-10, pp. 615- Disclaimer 623, 2009 The authors would like to make it clear [9] Grelier, T. (2006), and L. Ries, J.-L. Issler, New that no extra frequency plan has been Spectral Measurements of GNSS Signals,” 2006 ION National Technical Meeting, Monterey, California, decided yet in Europe for the second USA, January 2006 generation of Galileo in addition to the [10] Grelier, T. (2008), and A. Garcia, E. Péragin, frequency plan backward compatible L. Lestarquit, J. Harr, D. Seguela, J.-L. Gerner, J.-L. with the current navigation signals of Issler, J.-B. Thevenet, N. Perriault, C. Mehlen, C. Galileo. Neither has it been decided yet Ensenat, N. Wilhelm, A.-M. Badiola Martinez, P. whether in the future the second genera- Colmenarejo, “GNSS in Space, Part 1: Formation tion of Galileo will transmit navigation Flying Radio Frequency Missions, Techniques, and signals in S-band in addition to L-band. Technology,” Inside GNSS, vol. 3, no. 8, November/ Accordingly, this column should be con- December 2008 sidered as a scientific exercise that only [11] Grelier, T. (2009), and A. Garcia, E. Péragin, emphasizes the great interest in consid- L. Lestarquit, J. Harr, D. Seguela, J.-L. Gerner, J.-L. ering use of this band for GNSS. Issler, J.-B. Thevenet, N. Perriault, C. Mehlen, C. Ensenat, N. Wilhelm, A.-M. Badiola Martinez, P. Additional Resources Colmenarejo, “GNSS in Space, Part 2: Formation, [1] Antreich, F., and J. A. Nossek, and J-L. Issler, Flying Radio Frequency Missions, Techniques, and “GNSS Signal Design Considering Receiver Perfor- Technology,” Inside GNSS, vol. 4, no. 1, January/ mance,” Navitec ‘08, Noordwijk, December 2008 February 2009 [2] Avila-Rodriguez, J-A., (2008a) and G. W. Hein, [12] Hein, G. W., and J.-A. Avila-Rodriguez, S. Wall- S. Wallner, J-L. Issler, L. Ries, L. Lestarquit, A. de ner, B. Eissfeller, M. Irsigler, J-L. Issler, “A Vision on Latour, J. Godet, F. Bastide, T. Pratt, J. Owen, M. Fal- New Frequencies, Signals and Concepts for Future cone, T. Burger, “The MBOC Modulation: The Final GNSS Systems,” Proceedings of ION-GNSS 2007, Touch to the Galileo Frequency and Signal Plan,” pp. 517-534, Fort Worth, Texas, USA, 2007 Proceedings of ION-GNSS 2008, pp. 2189–2198, [13] Inoue, T., and S. Nakamura, R. Nakamura, Fort Worth, Texas USA, September 2008 and S. Katagiri, “ETS-VIII High Accuracy Clock [3] Avila-Rodriguez, J. A., (2008b) and S. Wall- Synchronisation Experiments,” 2F15 ETS-VIII, ner, J.H. Won and B. Eissfeller, A. Schmitz-Peiffer 2008 Japan Science and Technology Agency con- and J.J. Floch, E. Colzi and J.L. Gerner, “Study on ference, 2008 a Potential Galileo Signal and Service Plan for [14] Issler, J.-L., and L. Ries, J-M. Bourgeade, L. Lestarquit, and C. Macabiau, “Probabilistic
70 InsideGNSS september 2010 www.insidegnss.com approach of frequency diversity as interference Authors mitigation Means,” ION GPS 2004, Long Beach, Isidre Mateu graduated in telecommunications California, USA, September 2004 engineering from the Universitat Politècnica de [15] Julien, O., and C. Macabiau, J.-L. Issler, Catalunya. He currently works as a navigation “Ionospheric Delay Estimation Strategies Using engineer in the French Space Agency (CNES) Galileo E5 Signals Only,” ION GNSS 2009, Savan- Signal and Radionavigation Department, and col- nah, Georgia, USA, September 2009 laborates with the ESA-CNES integrated team for [16] Laurichesse, D., and F. Mercier, “Integer EGNOS evolutions. Ambiguity Resolution on Undifferenced GPS Matteo Paonni is research Phase Measurements and Its Application to PPP,” associate at the Institute Proceedings of ION-GNSS 2007, pp. 839–848, Fort of Geodesy and Naviga- Worth, Texas, 2007 tion at the University of [17] Lestarquit, L., and N. Suard, and J.-L. Issler, the Federal Armed Forces “IONO-GPS Software: Determination of the Munich, Germany. He Ionospheric Error Using Only L1 Frequency GPS received his B.S. and Receiver,” 1997 ION National Technical Meeting, M.S. in electrical engineering from the University Santa Monica, California, USA, January 1997 of Perugia, Italy. He is involved in several Euro- [18] Moreno, R., and N. Suard, and L. Lestarquit, pean projects that focus on GNSS. His main topics “Ionospheric Delay Using Only L1: Validation and of interest are GNSS signal structure, GNSS Application to GPS Receiver Calibration and to interoperability and compatibility, and GNSS per- Inter-frequency Biases AEstimation,” 1999 ION formance assessment. National Technical Meeting, San Diego, California, Jean-Luc Issler is head of USA, January 1999 the Instrumentation [19] Nakagawa, F., and Y. Takahashi, R. Tabuchi, Telemetry/telecommand J. Amagai, S. Tsuchiya, S. Hama, and H. Noda, and Propagation (ITP) “Results of Time Comparison Equipment on ETS- department of the CNES VIII. Time transfer experiments,” 2F16 ETS-VIII, Radiofrequency sub- Japan Science and Technology Agency confer- directorate since August ence, 2008 2009. He is one of the inventors of CBOC and pro- [20] Nisner, P., and M. Trethewey, “GPS Iono- posed the Galileo E5 signal using the AltBOC 8- sphere Determination Using L1 Only,” 1996 ION PSK invention made by Laurent Lestarquit. Issler National Technical Meeting, Santa Monica, Cali- graduated from the Ecole Supérieure fornia, USA, January 1996 d’Electronique de l’Ouest (ESEO). He received the Astronautic Prize French Aeronautical and Astro- [21] Paonni, M., and M. Anghileri, J.-A. Ávila- nautic Association in 2004, as well as the EADS Rodríguez, S. Wallner, and B. Eissfeller, “Meth- Science and Engineering prize awarded in 2008 by odologies for the Determination of the Minimum the French Academy of Sciences for his work on Required Carrier to Noise Ratio to Receive GNSS GNSS frequencies and modulations, and space- Signals,” 4th European Workshop on GNSS Signals borne RF equipment. and Signal Processing, Germany, December 2009 Guenter W. Hein is head [22] Schmitz-Peiffer, A., and L. Stopfkuchen, of the Galileo Operations F. Soualle, J.-J. Floch, R. King, A, Fernandez, R. and Evolution Depart- Jorgensen, B. Eissfeller, J.-A. Avila-Rodriguez, S. ment of the European Wallner, J.H. Won, T. Pany, M. Anghileri, B. Lankl, Space Agency. Previ- T. Schüler, and E. Colzi, “Assessment on the Use of ously, he was a full pro- C-Band for GNSS within the European GNSS Evolu- fessor and director of the tion Program,” ION-GNSS 2008, Savannah, Georgia Institute of Geodesy and Navigation at the Univer- USA, September 2008 sity FAF Munich. In 2002 he received the presti- [23] Thevenon, P., and M. Bousquet, Th. Grelier, L. gious Johannes Kepler Award from the U.S. Insti- Ries, D. Roviras, “Regulatory Analysis of Potential tute of Navigation (ION) for “sustained and Candidate Bands for the Modernisation of GNSS significant contributions to satellite navigation.” Systems in 2015-2020,” Satellite and Space He is one of the CBOC inventors. Communications, pp. 172-175, IEEE International [Editor’s note: biographies of additional authors Workshop, 2008 will be made available on-line at
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