GPS-Galileo Civil Signal Agreement Reached by U.S. and European Union

Comments from Keith D. McDonald, NavtechGPS’ Technical Director:

" After extensive investigations by the E.U. to assure that the MBOC signal would work with Galileo, the signal structure recommended in March of 2006  by both the United States and Europe has been agreed upon by both parties. This additional L1 civil signal is to be implemented on both future GPS III satellites and on forthcoming operational Galileo satellites. The full text of the announcement that was released on Thursday, July 26th can be found at:

The signal structure, initially recommended by a GPS-GALILEO expert group, is a multiplexed binary offset carrier (MBOC) signal that provides some significant performance features. Technically, it consists of two "split spectrum" BOC PRN (pseudo random noise) coded signals at L1, each with a 1.023 MHz chipping rate. The first of these multiplexed signals has a 1.023 MHz squarewave subcarrier and 10/11 of the coded signal power. The other signal has a 6.138 MHz squarewave subcarrier and carries the balance of the coded power.

Two of the principal advantages of this signal are that it provides superior performance in a multipath environment and has enhanced accuracy.

The "intimate" details of the MBOC signal structure as well as the reasons for its origination and the related signals that were considered are presented in an excellent article entitled MBOC: The New Optimized Spreading Modulation that appeared in the May/June 2006 issue of Inside GNSS."