1. A method of generating a correlation function, the method comprising: receiving a CBOC(6,1,1/11) signal; interpreting a subcarrier pulse period of the CBOC(6,1,1/11) signal as a subcarrier pulse period of BOC sin (6,1); combining partial correlation functions constituting an autocorrelation function of CBOC(6,1,1/11) to generate a correlation function; and weighted-combining the correlation function to generate an unambiguous correlation function.