Performance Comparison of Code Discriminators in the Presence of CW Interference

This paper considers the effect of continuous wave interference (CWI) on code tracking loops for global navigation satellite system signal. Based on the integrate-dump model analysis, the overall correlation results in the presence of CWI are theoretically analyzed incorporating the sum frequency interference terms which were regarded as negligible quantities in previous studies. Using the obtained correlation results, the closed-form expressions of the code tracking errors caused by CWI for three types of code discriminators (coherent, noncoherent, and barycenter) are derived and formulated as the solutions of quadratic equations using reasonable assumptions of trigonometric functions. Simulations are performed to demonstrate the accuracy of the theoretical correlation results. Also, the simulated code tracking errors are also presented to corroborate the effectiveness of the closed-form code tracking errors in terms of interference parameters (frequency and phase). It is indicated that the barycenter discriminator has the superior performance and could be preferred for mitigating CWI in tracking stage. These results can be applied for performance comparison, signal design, receiver design, and interference mitigation techniques in the presence of CWI.