Quick convergence self-adaptive pseudo code delay lock loop

Abstract

The invention discloses a quick convergence self-adaptive pseudo code delay lock loop used for solving a problem of signal quick traction and positioning of a GNSS satellite navigation receiver. The technical scheme includes that through noise bandwidth of a pseudo code delay loop is adjusted in a self-adaptive manner by utilizing a loop parameter controller through smooth filtering wave output and traction time timing of a code ring phase discriminator. In a loop traction initial phase, a comparatively wide bandwidth is selected for realizing quick oscillation and convergence of the loop. After the initial traction is completed, self-adaptive adjustment on the bandwidth of a loop filter is performed through the magnitude of phase discrimination errors, so that stable and accurate tracking of the loop is realized. The invention overcomes the conflict of high tracking precision and quick convergence of a prior fixed bandwidth pseudo code tracking loop, and the loop convergence speed is accelerated under the premise of not reducing loop steady state tracking precision.

Description

technical field [0001] The invention belongs to the technical field of satellite navigation, in particular to a rapidly convergent adaptive pseudo-code delay-locked loop. Background technique [0002] With the construction of the global satellite navigation system GNSS and the wide application of GNSS receivers, users have put forward higher and higher requirements for the continuous positioning capability of GNSS receivers. However, in applications in complex environments such as cities, jungles, and valleys, satellite signals are often blocked for a short time, so the fast relocation technology after loss of lock has become one of the research hotspots of GNSS receivers. For short-term signal occlusion, the GNSS receiver can use the code phase prediction method to complete the fast acquisition of the signal, but from the completion of the acquisition, the pseudo-code error is usually 0.5 chips to the pseudo-code tracking loop is stable, and the pseudo-code error is usually...

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Problems solved by technology

The literature "Bandwidth Optimization of Carrier / Code Tracking Loops in GPS Receiver [ResearchGate, Available from: wei-lung Mao, Retrieved on: 21November 2016]" believes that the optimal code loop bandwidth for normal positioning and dynamic needs should be 4.556Hz to 2.4283Hz, however, the code loop convergence time under this bandwidth is usually 1 second or longer, which makes the GNSS receiver unable to meet the needs of fast relocation after loss of lock

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