Patent ID: 7944997

Claim:
A system for determining a code phase error of a multimodal spread spectrum signal spread by a multimodal code being a spread spectrum chipping code having a multimodal autocorrelation function having modal peaks, the system being a coherent system for further coherently receiving an arbitrary code spread spectrum signal with the multimodal spread spectrum signal, the arbitrary code spread spectrum signal having an arbitrary autocorrelation function the system comprising, a demodulator for carrier demodulating the multimodal spread spectrum signal into multimodal quadrature signals and for carrier demodulating the arbitrary code spread spectrum signal into arbitrary quadrature signals, a generator for generating multimodal code replicas of the multimodal code, the multimodal code replicas being offset in time to the multimodal code by the code phase error, an arbitrary code generator for generating arbitrary code replicas of the arbitrary code, the arbitrary code replicas being offset in time to the multimodal code by the code phase error; a correlator for receiving multimodal quadrature signals and correlating the multimodal quadrature signals into multimodal quadrature correlations using the multimodal code replicas, the correlator further for receiving the arbitrary quadrature signals and correlating the arbitrary code quadrature signals into arbitrary code quadrature correlations using the arbitrary code replicas, and a tracking system for receiving the multimodal quadrature correlations and the arbitrary code quadrature correlations and for detecting an arbitrary envelope of the arbitrary autocorrelation function coherently encompassing the modal peaks for the multimodal code and for identifying a mode of the modal peaks for generating the code phase error.