Binary offset carrier modulation: Difference between revisions
Started converting <<Further readings>> to references - somebody went thru a lot of work to do it the wrong way |
moved over some more references from Further Reading section |
||
Line 1: | Line 1: | ||
{{Use dmy dates|date=June 2013}} |
{{Use dmy dates|date=June 2013}} |
||
'''Binary offset carrier modulation'''<ref>{{cite journal|last1=Betz|first1=J.|title=The offset carrier modulation for GPS modernization|journal=Proceedings of ION Technical meeting|date=June 1999|pages=639-648|publisher=Cambridge, Massachusetts}}</ref><ref>{{cite web|last1=Betz|first1=J.|title= |
'''Binary offset carrier modulation'''<ref>{{cite journal|last1=Betz|first1=J.|title=The offset carrier modulation for GPS modernization|journal=Proceedings of ION Technical meeting|date=June 1999|pages=639-648|publisher=Cambridge, Massachusetts}}</ref><ref>{{cite web|last1=Betz|first1=J.|title=Overview of the GPS M code signal|url=https://www.mitre.org/publications/technical-papers/overview-of-the-gps-m-code-signal|publisher=MITRE|date=May 2000}}</ref> (BOC modulation) was developed by John Betz, PhD, in order to allow interoperability of satellite navigation systems. It is currently used in the US GPS system, Indian IRNSS system and in [[Galileo (satellite navigation)|Galileo]]<ref>{{cite web|title=Galileo Open Service Signal in Space Interface Control Document (OS SIS ICD v1.3)|url=https://www.gsc-europa.eu/system/files/galileo_documents/Galileo-OS-SIS-ICD.pdf|publisher=Gallileo Space|accessdate=14 December 2017}}</ref> and is a square sub-carrier [[modulation]], where a signal is multiplied by a rectangular [[sub-carrier]] of frequency <math>f_{sc}</math> equal or higher to the [[chip (CDMA)|chip]] rate. Following this [[sub-carrier]] [[multiplication]], the [[spectrum]] of the signal is divided into two parts, therefore BOC modulation is also known as a split-spectrum modulation. |
||
The main idea behind BOC modulation is to reduce the interference with [[BPSK]]-modulated signal, which has a [[sinc function]] shaped spectrum. Therefore, BPSK-modulated signals such as C/A [[Global Positioning System|GPS]] codes have most of their spectral energy concentrated around the [[carrier frequency]], while BOC-modulated signals (used in [[Galileo system]]) have low energy around the carrier frequency and two main spectral lobes further away from the carrier (thus, the name of split-spectrum). |
The main idea behind BOC modulation is to reduce the interference with [[BPSK]]-modulated signal, which has a [[sinc function]] shaped spectrum. Therefore, BPSK-modulated signals such as C/A [[Global Positioning System|GPS]] codes have most of their spectral energy concentrated around the [[carrier frequency]], while BOC-modulated signals (used in [[Galileo system]]) have low energy around the carrier frequency and two main spectral lobes further away from the carrier (thus, the name of split-spectrum). |
||
BOC modulation has several variants: sine BOC (SinBOC),<ref name="ENC-GNSS04">ENC-GNSS04</ref><ref>ION-GPS02</ref> cosine BOC (CosBOC),<ref name="ENC-GNSS04" /><ref>GJU</ref><ref name="Wiley06"> |
BOC modulation has several variants: sine BOC (SinBOC),<ref name="ENC-GNSS04">ENC-GNSS04</ref><ref>ION-GPS02</ref> cosine BOC (CosBOC),<ref name="ENC-GNSS04" /><ref>GJU</ref><ref name="Wiley06">{{cite web|title=BOC modulation techniques in satellite navigation systems|url=http://www3.interscience.wiley.com/cgi-bin/fulltext/112693999/PDFSTART|publisher=Wireless Communications|accessdate=14 December 2017}}</ref> Alternative BOC (AltBOC),<ref>Septentrio</ref><ref>GPSJournal07</ref><ref>Margaria08</ref><ref>IEE06</ref> [[multiplexed BOC]] (MBOC),<ref>{{cite web|title=The MBOC Modulation|url=http://www.insidegnss.com/node/174|publisher=Inside GNSS|accessdate=14 December 2017}}</ref><ref>ION-GNSS07</ref><ref>ION-GNSS07bis</ref><ref>EW07</ref><ref>ESA06</ref> Double BOC (DBOC)<ref name="Wiley06" /> etc. and some of them have been currently selected for Galileo [[GNSS]] signals. |
||
A BOC waveform is typically denoted via BOC(m,n) or BOC<math>(f_{sc}\;,f_c)</math>, where <math>f_{sc}</math> is the sub-carrier frequency, <math>f_c</math> is the chip frequency, <math>m=f_{sc}/f_{ref}</math>, <math>n=f_{c}/f_{ref}</math>, and <math>f_{ref}=1.023</math> Mcps is the reference chip frequency of C/A [[GPS]] signal. |
A BOC waveform is typically denoted via BOC(m,n) or BOC<math>(f_{sc}\;,f_c)</math>, where <math>f_{sc}</math> is the sub-carrier frequency, <math>f_c</math> is the chip frequency, <math>m=f_{sc}/f_{ref}</math>, <math>n=f_{c}/f_{ref}</math>, and <math>f_{ref}=1.023</math> Mcps is the reference chip frequency of C/A [[GPS]] signal. |
||
Line 16: | Line 16: | ||
<ref name="Wiley06" /><ref>VTC04</ref> |
<ref name="Wiley06" /><ref>VTC04</ref> |
||
BOC-modulated signals, by difference with BPSK signals, create the so-called ambiguities in the correlation function. The BOC-modulated signals in GNSS can be processed either with a Full BOC receiver or via various unambiguous approaches |
BOC-modulated signals, by difference with BPSK signals, create the so-called ambiguities in the correlation function. The BOC-modulated signals in GNSS can be processed either with a Full BOC receiver or via various unambiguous approaches.<ref>{{cite web|title=Efficient Delay Tracking|url=https://jwcn-eurasipjournals.springeropen.com/articles/10.1155/2007/72626|publisher=Springer Open|accessdate=14 December 2017}}</ref><ref>{{cite web|title=Code smoothing for BOC ambiguity mitigation|url=http://ieeexplore.ieee.org/document/6577260/?reload=true|publisher=IEEE|accessdate=14 December 2017}}</ref> |
||
==References== |
==References== |
||
Line 23: | Line 23: | ||
==Further reading== |
==Further reading== |
||
* Ries L, Lestarquit L, Armengou-Miret E, et al. A software simulation tool for GNSS2 BOC signals analysis. In Proceedings of ION GPS, (Portland, OR) September 2002; 2225-2239 (ION-GPS02) |
* Ries L, Lestarquit L, Armengou-Miret E, et al. A software simulation tool for GNSS2 BOC signals analysis. In Proceedings of ION GPS, (Portland, OR) September 2002; 2225-2239 (ION-GPS02) |
||
⚫ | |||
*www.septentrio.com/papers/GallileoAltBOC_paperFinal.pdf |
|||
*E. S. Lohan, A. Lakhzouri, and M. Renfors, “Binary-offset-carrier modulation techniques with applications in satellite navigation systems,” Wiley Wireless Communications and Mobile Computing, vol. 7, no. 6, pp. 767–779, 2006, http://www3.interscience.wiley.com/cgi-bin/fulltext/112693999/PDFSTART (Wiley06) |
*E. S. Lohan, A. Lakhzouri, and M. Renfors, “Binary-offset-carrier modulation techniques with applications in satellite navigation systems,” Wiley Wireless Communications and Mobile Computing, vol. 7, no. 6, pp. 767–779, 2006, http://www3.interscience.wiley.com/cgi-bin/fulltext/112693999/PDFSTART (Wiley06) |
||
* Raghavan SH, Holmes JK. Modeling and simulation of mixed modulation formats for improved CDMA bandwidth efficiency. In Proceedings of Vehicular Technology Conference 2004; 6: 4290-4295 (VTC04). |
* Raghavan SH, Holmes JK. Modeling and simulation of mixed modulation formats for improved CDMA bandwidth efficiency. In Proceedings of Vehicular Technology Conference 2004; 6: 4290-4295 (VTC04). |
||
Line 35: | Line 33: | ||
* E.S. Lohan and M. Renfors, ``On the performance of Multiplexed-BOC (MBOC) modulation for future GNSS signals'', in Proc. of European Wireless Conference, Apr 2007, Paris, France.(EW07) |
* E.S. Lohan and M. Renfors, ``On the performance of Multiplexed-BOC (MBOC) modulation for future GNSS signals'', in Proc. of European Wireless Conference, Apr 2007, Paris, France.(EW07) |
||
*Avila-Rodriguez J.A., Wallner S., Hein G.W.: MBOC: The New Optimized Spreading Modulation Recommended for Galileo E1 OS and GPS L1C, ESA Navitec 2006, Noordwijk, The Netherlands, 11-13 Dec. 2006 (ESA06) |
*Avila-Rodriguez J.A., Wallner S., Hein G.W.: MBOC: The New Optimized Spreading Modulation Recommended for Galileo E1 OS and GPS L1C, ESA Navitec 2006, Noordwijk, The Netherlands, 11-13 Dec. 2006 (ESA06) |
||
*A. Burian, E.S. Lohan, and M. Renfors, Efficient Delay Tracking Methods with Sidelobes Cancellation for BOC-Modulated Signals, EURASIP Journal on Wireless Communications and Networking, Volume 2007 (2007), Article ID 72626, 20 pages (Burian07) |
|||
⚫ | |||
*M. Navarro Gallardo, G. Seco-Granados, G. López-Risueño, M. Crisci, "Code Smoothing for BOC Ambiguity Mitigation", Proc. International Conference on Localization and GNSS (ICL-GNSS), 2013 (Navarro2013) |
|||
{{Refend}} |
|||
<!-- can't find links for these: |
|||
==External links== |
|||
⚫ | |||
* Binary Offset Carrier (BOC) signal generator in Matlab, https://web.archive.org/web/20100614000658/http://www.mathworks.com/matlabcentral/fileexchange/12829 |
|||
⚫ | |||
--> |
|||
{{DEFAULTSORT:Binary Offset Carrier}} |
{{DEFAULTSORT:Binary Offset Carrier}} |
Revision as of 22:58, 14 December 2017
Binary offset carrier modulation[1][2] (BOC modulation) was developed by John Betz, PhD, in order to allow interoperability of satellite navigation systems. It is currently used in the US GPS system, Indian IRNSS system and in Galileo[3] and is a square sub-carrier modulation, where a signal is multiplied by a rectangular sub-carrier of frequency equal or higher to the chip rate. Following this sub-carrier multiplication, the spectrum of the signal is divided into two parts, therefore BOC modulation is also known as a split-spectrum modulation.
The main idea behind BOC modulation is to reduce the interference with BPSK-modulated signal, which has a sinc function shaped spectrum. Therefore, BPSK-modulated signals such as C/A GPS codes have most of their spectral energy concentrated around the carrier frequency, while BOC-modulated signals (used in Galileo system) have low energy around the carrier frequency and two main spectral lobes further away from the carrier (thus, the name of split-spectrum).
BOC modulation has several variants: sine BOC (SinBOC),[4][5] cosine BOC (CosBOC),[4][6][7] Alternative BOC (AltBOC),[8][9][10][11] multiplexed BOC (MBOC),[12][13][14][15][16] Double BOC (DBOC)[7] etc. and some of them have been currently selected for Galileo GNSS signals.
A BOC waveform is typically denoted via BOC(m,n) or BOC, where is the sub-carrier frequency, is the chip frequency, , , and Mcps is the reference chip frequency of C/A GPS signal.
A sine BOC(1,1) modulation is similar to Manchester code, that is, in digital domain, a '+1' is encoded as a '+1 −1' sequence, and a '0' is encoded as a '−1 +1' sequence. For an arbitrary modulation order, in sine BOC(m,n) case, a '+1' is encoded as an alternating sequence of '+1 −1 +1 −1 +1 ...', having elements, and a '0' (or '−1') is encoded as an alternating '−1 +1 ...' sequence, also having elements.
BOC modulation is typically applied on CDMA signals, where each chip of the pseudorandom code is split into BOC sub-intervals, as explained above (i.e., there are BOC intervals per chip).
The power spectral density of a BOC-modulated signal depends on the BOC modulation order and its derivation can be found, for example, in. [7][17]
BOC-modulated signals, by difference with BPSK signals, create the so-called ambiguities in the correlation function. The BOC-modulated signals in GNSS can be processed either with a Full BOC receiver or via various unambiguous approaches.[18][19]
References
- ^ Betz, J. (June 1999). "The offset carrier modulation for GPS modernization". Proceedings of ION Technical meeting. Cambridge, Massachusetts: 639–648.
- ^ Betz, J. (May 2000). "Overview of the GPS M code signal". MITRE.
- ^ "Galileo Open Service Signal in Space Interface Control Document (OS SIS ICD v1.3)" (PDF). Gallileo Space. Retrieved 14 December 2017.
- ^ a b ENC-GNSS04
- ^ ION-GPS02
- ^ GJU
- ^ a b c "BOC modulation techniques in satellite navigation systems". Wireless Communications. Retrieved 14 December 2017.
- ^ Septentrio
- ^ GPSJournal07
- ^ Margaria08
- ^ IEE06
- ^ "The MBOC Modulation". Inside GNSS. Retrieved 14 December 2017.
- ^ ION-GNSS07
- ^ ION-GNSS07bis
- ^ EW07
- ^ ESA06
- ^ VTC04
- ^ "Efficient Delay Tracking". Springer Open. Retrieved 14 December 2017.
- ^ "Code smoothing for BOC ambiguity mitigation". IEEE. Retrieved 14 December 2017.
Further reading
- Ries L, Lestarquit L, Armengou-Miret E, et al. A software simulation tool for GNSS2 BOC signals analysis. In Proceedings of ION GPS, (Portland, OR) September 2002; 2225-2239 (ION-GPS02)
- E. S. Lohan, A. Lakhzouri, and M. Renfors, “Binary-offset-carrier modulation techniques with applications in satellite navigation systems,” Wiley Wireless Communications and Mobile Computing, vol. 7, no. 6, pp. 767–779, 2006, http://www3.interscience.wiley.com/cgi-bin/fulltext/112693999/PDFSTART (Wiley06)
- Raghavan SH, Holmes JK. Modeling and simulation of mixed modulation formats for improved CDMA bandwidth efficiency. In Proceedings of Vehicular Technology Conference 2004; 6: 4290-4295 (VTC04).
- D. Margaria, F. Dovis, P. Mulassano, An Innovative Data Demodulation Technique for Galileo AltBOC Receivers, Journal of Global Positioning Systems, Journal of Global Positioning Systems, Vol.6, No.1, pp. 89–96, ISSN 1446-3156, 2007, http://www.gmat.unsw.edu.au/wang/jgps/v6n1/v6n1p10.pdf (GPSJournal07)
- D. Margaria, F. Dovis, P. Mulassano, Galileo AltBOC Signal Multiresolution Acquisition Strategy, IEEE Aerospace and Electronic Systems Magazine, Vol.23, No.11, pp. 4–10, ISSN 0885-8985, November 2008. (Margaria08)
- E. S. Lohan, A. Lakhzouri, M. Renfors, ``Complex Double-Binary-Offset-Carrier modulation for a unitary characterization of Galileo and GPS signals, IEE Proceedings on Radar, Sonar, and Navigation, vol. 153(5), pp. 403-408, Oct 2006.[IEE06]
- Avila-Rodriguez, J.A., Hein, G.W., Wallner, S., Issler, J.L., Ries, L., Lestarquit, L., De Latour, A., Godet, J., Bastide, F., Pratt, T., Owen, J. The MBOC Modulation- A Final Touch for the Galileo Frequency and Signal Plan, http://www.insidegnss.com/node/174 Inside GNSS (InsideGNSS07)
- Avila-Rodriguez, J.A., Wallner, S., Hein, G.W., Eissfeller, B., Irsigler, M., Issler, J.L.: A vision on new frequencies, signals and concepts for future GNSS systems, Proceedings of ION GNSS 2007, Fort Worth, Texas, USA, 25–28 September 2007 (ION-GNSS07)
- Avila-Rodriguez, J.A., Hein, G.W., Wallner, S., Issler, J.L., Ries, L., Lestarquit, L., De Latour, A., Godet, J., Bastide, F., Pratt, T., Owen, J.: The MBOC Modulation: The Final Touch to the Galileo Frequency and Signal Plan, Proceedings of ION GNSS 2007, Fort Worth, Texas, USA, 25–28 September 2007 (ION-GNSS07bis)
- E.S. Lohan and M. Renfors, ``On the performance of Multiplexed-BOC (MBOC) modulation for future GNSS signals, in Proc. of European Wireless Conference, Apr 2007, Paris, France.(EW07)
- Avila-Rodriguez J.A., Wallner S., Hein G.W.: MBOC: The New Optimized Spreading Modulation Recommended for Galileo E1 OS and GPS L1C, ESA Navitec 2006, Noordwijk, The Netherlands, 11-13 Dec. 2006 (ESA06)