Time-frequency modulation and demodulation method based on instantaneous frequency estimation

A time-frequency modulation and instantaneous frequency technology, applied in the direction of frequency modulation carrier system, etc., can solve the problem of complex algorithm structure, and achieve the effect of good anti-interference performance, easy implementation and fast calculation time.

Active Publication Date: 2019-03-19
UNIV OF ELECTRONIC SCI & TECH OF CHINA
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Problems solved by technology

The structure of the energy-based algorithm is complex and the technology involves the design of the matched filter, and the design of the matched filter is relatively complex; the selection of the time delay and the continuity of the signal based on the sideband correlation algorithm have a greater impact on the quality of the demodulation influences

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  • Time-frequency modulation and demodulation method based on instantaneous frequency estimation
  • Time-frequency modulation and demodulation method based on instantaneous frequency estimation
  • Time-frequency modulation and demodulation method based on instantaneous frequency estimation

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Embodiment Construction

[0029] Embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

[0030] A time-frequency modulation and demodulation method based on instantaneous frequency estimation, is characterized in that, comprises the following steps:

[0031] S1, modulate and send the four-time four-frequency time-frequency modulation signal, wherein, the modulation process of the four-time four-frequency time-frequency modulation signal is: two binary symbols are compiled into a group to form a symbol combination, and the length of the two binary symbols is Divide them equally to obtain four time slots. After selecting different frequency modulations in each time slot, a four-time four-frequency time-frequency modulation signal is obtained. Each symbol combination corresponds to a frequency sequence combination including four frequency sequences, and the frequency sequence is obtained. The relative magnitude relationship of the four frequenc...

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Abstract

The invention provides a time-frequency modulation and demodulation method based on instantaneous frequency estimation, and belongs to the technical field of time-frequency modulation of short-wave communication. The time-frequency modulation and demodulation method based on instantaneous frequency estimation utilizes an instantaneous frequency algorithm to estimate a relative value of the frequency between different time slots, performs former address sorting on the estimation result, finds the correspondence between the frequency value and the frequency order according to the sorting result,and obtains, according to the relationship between the frequency order and the symbol combination order, the symbol order sent by the current transmitting terminal to realize demodulation of a time-frequency modulated signal. Since the frequency value of a current signal does not need to be accurately estimated during the estimation process, the method can demodulate the signal at a lower signalto noise ratio. The method is simple, the bit error rate performance is better, and the operation time is short.

Description

technical field [0001] The invention belongs to the technical field of short-wave communication time-frequency modulation, in particular to a time-frequency modulation and demodulation method based on instantaneous frequency estimation. Background technique [0002] Time-frequency modulation technology is a kind of short-wave communication. Short-wave communication is radio communication through the ionosphere by using electromagnetic waves with a wavelength of 10m-100m and a frequency of 3MHz-30MHz. Short-wave communication has the characteristics of low cost, strong invulnerability, and flexible networking, and short-wave is the only long-distance communication method that is not restricted by the network hub and active relay system, but there are certain limitations in short-wave communication that limit the quality of communication , the most obvious of which is the severe fading in the short wave and the intersymbol interference caused by the multipath effect. In order ...

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Application Information

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IPC IPC(8): H04L27/12H04L27/14
CPCH04L27/12H04L27/14
Inventor 吕明张翔周映伶
Owner UNIV OF ELECTRONIC SCI & TECH OF CHINA
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