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Dopla frequency shift compensation method in the MPSK mobile communication system

A mobile communication system, Doppler frequency shift technology, applied in the transmission system, frequency modulation carrier system, phase modulation carrier system, etc., can solve complex carrier recovery circuit and other problems, achieve simplified communication system, stable operation, save carrier The effect of the recovery circuit

Inactive Publication Date: 2009-12-30
HARBIN INST OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] The purpose of the present invention is to provide a kind of compensation method of Doppler frequency shift in the MPSK mobile communication system for MPSK mobile communication system, to overcome the shortcoming that prior art needs complex carrier recovery circuit

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  • Dopla frequency shift compensation method in the MPSK mobile communication system
  • Dopla frequency shift compensation method in the MPSK mobile communication system
  • Dopla frequency shift compensation method in the MPSK mobile communication system

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Embodiment Construction

[0013] Attached below figure 1 The application of the present invention is further described. At the sending end of mobile communication, the transmission symbol is modulated by QPSK and up-converted f c , transmitted to the receiving end through the channel, the intermediate frequency unit of the receiving end receives the signal, and then undergoes coherent demodulation and clock recovery, and then applies the method of the present invention to compensate for the Doppler frequency shift. The steps before the clock recovery do not belong to the present invention content.

[0014] The present invention mainly includes two main parts: phase estimation and LMS adaptive algorithm; wherein, the LMS adaptive algorithm is the core part of the present invention. Due to the high data transmission rate, it can be considered that the Doppler frequency shift per data packet is constant; the phase is the integral of the frequency, and for a constant frequency shift, the phase deviation ...

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Abstract

The disclosed Doppler shift compensation method in MPSK mobile communication system comprises: fixing the receiver local carrier frequency, coherent demodulating and recovering clock to receive the features of both sides by data package head; unbiased estimating the code phase difference, then using simple LMS algorithm to compensate other offset and initial phase. This invention combines phase estimation and LMS algorithm, and uses less reference bit, and compensates fast.

Description

technical field [0001] The invention belongs to the field of mobile communication, and in particular relates to a compensation method for Doppler frequency shift in an MPSK mobile communication system. Background technique [0002] In a mobile communication system, due to the relative motion of the two parties in communication, the frequency shift of the receiver is called Doppler frequency shift, and the Doppler frequency shift is proportional to the relative motion speed of the two parties. It can be seen that for mobile communication, especially for the very fast LEO satellite communication system, the Doppler frequency shift is usually relatively large, and for the MPSK (multiphase phase shift keying) mobile communication system using coherent demodulation That is to say, if the Doppler frequency shift is not compensated, the local carrier cannot achieve synchronization with the signal carrier, resulting in frequency deviation, which in turn leads to a deviation in the d...

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04B7/01H04L27/18H04L27/16
Inventor 井庆丰郭庆李陆石磊严晓菊
Owner HARBIN INST OF TECH