Mean time to lose lock for a coherent second-order PN-code tracking loop-the singular perturbation approach

The singular perturbation method is used to approximate the mean time to lose lock (MTLL) for a second-order coherent pseudonoise code tracking delay-lock loop (DLL). Approximate expressions for the MTLL are given. The influence of loop offset due to the Doppler rate is studied, and optimal loop parameters (natural frequency and damping factor) which maximize the MTLL are presented. Upper bounds to the maximum allowable Doppler rates for various operating conditions are given.<
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