Performance of dual‐channel codeless and semicodeless processing

While dual-channel codeless and semicodeless processing are mature techniques used on the Global Positioning System P(Y) signals, the literature lacks assessment of their performance, with derivations from first principles. This paper fills that gap, providing mathematical models of three dualchannel codeless or semicodeless processing approaches. Each exploits a situation where the same signal is transmitted on two carrier frequencies, and the receiver cannot generate a signal replica for conventional processing. The mathematical formulation leads to derivation of analytical models for performance of the three techniques, all having the same parametric form but different parameter values. The models apply to more general cases than previously addressed, allowing any relationship between input signal-to-noise ratios, and including different signal design variants. Computer simulations crosscheck the analytical performance, and comprehensive numerical results are provided. The results provide the foundation for a companion paper assessing how GPS III signal generation affects these types of receivers.