Method for generating high-precision frame synchronous pulse signal of spread spectrum receiver

Abstract

The invention provides a method for generating a high-precision frame synchronous pulse signal of a spread spectrum receiver, aiming at providing a method which can reduce the ambiguity error and the random noise jittering error of a system clock. The method comprises the following steps of: firstly, reading a residual value during phase overflow by using a high-speed clock which is higher than an accumulator work clock of an NCO (numerically controlled oscillator) from a phase holding register inside a code loop circuit, and processing the residual value and a threshold value to obtain a phase overflow moment with higher precision; and secondly, reading a residual value of a code tracking loop module during phase overflowing through a code loop circuit formed by division of the code tracking loop module in the receiver by using the high-speed clock which is higher than the accumulator work clock of the NCO, judging an overflow residual error of the code tracking loop module through an overflow judgment module and an overflow residual error judgment module to generate a high-precision code clock, and feeding the high-precision code clock back to a coarse frame pulse signal with 1 / s system clock ambiguity error, output by a frame synchronization module to carry out synchronous triggering to generate the high-precision frame synchronous pulse signal.

Description

technical field [0001] The invention relates to a method for generating high-precision frame synchronization pulses of digital receivers in the fields of spread spectrum telemetry and spread spectrum navigation, in particular to a method for generating high-precision frame synchronization pulse signals of spread spectrum receivers. Background technique [0002] The spread spectrum receiver is the key equipment in the autonomous external measurement system. It usually consists of two parts: fast capture and tracking. Its main function is to receive, capture, track, demodulate and forward the spread spectrum signal from the target. The fast capture is used for The spread spectrum signal returned by forwarding is quickly captured, and the tracking channel performs tracking demodulation after the signal is captured. The fast capture and tracking modules of spread spectrum signals are implemented by FPGA, which integrates the functions of various special-purpose chips on a large-...

AI Technical Summary

Problems solved by technology

[0008] In summary, the existing design methods and various existing products cannot guarantee the accuracy of the second pulse signal and frame synchronization pulse signal to reach 2 nanoseconds, and cannot meet the requirements of high-precision timing systems

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