Performance of GPS/Galileo Receivers Using m-PSK BOC Signals

Anthony R. Pratt, and John I.R. Owen

Abstract:	There has been considerable interest in Galileo signal structures with low signal interaction with GPS signals, both now and those envisioned for future use. Signal interactions are most usually established using Spectral Separation Coefficients (SSC) or Partial SSC’s (ref 1). SSC’s are useful in establishing the mutual levels of interference which one system has on another due to a specific signal emission. As part of the quest for low levels of mutual interference between the Galileo and GPS on L1, analysis has been reported on the use of a variety of signal waveforms including an 8-PSK BOC(2,2) modulation for Galileo. This has a low SSC’s with GPS BOC(10,5) emissions when those receivers are fitted with filters selectively attenuating the main lobe of the Galileo signals. SSC’s as low as – 92dB/Hz have been established. In the context of the Galileo signal development, it is necessary to establish the likely receiver performance which m-PSK Offset Carrier receivers can sustain. This paper provides the first analysis such receivers in respect of the following functions: (a) Correlation losses due to simplified receiver techniques including binary, tertiary and quad level processing for various receiver bandwidths. These are compared with similar figures for BOC(x,y) receivers (that is using binary modulation rather than m-PSK). (b) Sensitivity to multi-path interference. A first estimate has been published using the signal rms bandwidth (ref 1). Reports have been made covering multi-path error envelopes for various signal delays. (c) Tracking error considerations due to thermal (wideband) noise for both carrier and code tracking loops. The paper provides initial analysis to support these new signal types for navigation purposes. It is clear from the results that for some receiver bandwidths, m-PSK BOC signals can provide performance exceeding that of the equivalent (BOC) signals whilst simultaneously guaranteeing low mutual interference with existing navigation signals. The m-PSK BOC signals may be potential candidates for 3rd Generation Satellite Navigation Systems.
Published in:	Proceedings of the 2004 National Technical Meeting of The Institute of Navigation January 26 - 28, 2004 The Catamaran Resort Hotel San Diego, CA
Pages:	362 - 370
Cite this article:	Pratt, Anthony R., Owen, John I.R., "Performance of GPS/Galileo Receivers Using m-PSK BOC Signals," Proceedings of the 2004 National Technical Meeting of The Institute of Navigation, San Diego, CA, January 2004, pp. 362-370.
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