Linear frequency modulation signal jam avoidance transmitting method based on fractional number Fourier transforming field

Abstract

Disclosed is a transmission method for avoiding interference to linear frequency modulation signals based on fractional Fourier transform domain, relating to wireless communication transmission technology. The invention aims at solving the problem that fractional-domain communication system only changes the frequency modulation rate of CSEP signals and does not change the center frequency of the CSEP signals, which makes the CSEP signals overlap in frequency domain, leading to limitation on the capacity and the performance of the system. In the transmitting process, a data source outputs binary numerical signal which is transmitted together with the CSEP signals to a wave generator for modulation, then the CSEP signals and carrier wave signals are multiplied and the resulting high-frequency signals are transmitted through an antenna at a transmitting terminal. In the receiving process, the received signals pass through a filter, a fractional Fourier transformer and a peak value position detector so as to get the information of the users. The transmission method clearly shows through simulation validation that frequency bands of the information of different users can be separated as much as possible within the allowable range, thus avoiding superposition of the CSEP signals of multiple users in the frequency domain and reducing interference among the users.

Description

technical field [0001] The invention relates to a transmission technology in wireless communication, in particular to a transmission method for avoiding interference of chirp signals based on fractional Fourier transform domain. Background technique [0002] The fractional Fourier transform is a generalized Fourier transform, and the representation of the signal in the fractional Fourier domain contains both time domain and frequency domain information. The integral form of the fractional Fourier transform is defined as: [0003] F p f ( u ) = ∫ - ∞ + ∞ f ( t ) K p ( u , t ) dt [0004] ...

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Problems solved by technology

[0010] Although the fractional domain communication system has the characteristics of simple structure and anti-multipath interference, but because only the modulation frequency k of the Chip signal is changed, that is, only the bandwidth B of the Chip signal is changed, and the center frequency of the Chip signal is not changed. f 0 , so that each chip signal overlaps in the frequency domain. When there are many users supported, it is greatly affected by multiple access interference. In addition to relying on the anti-multiple access capability of the fractional domain communication system itself, there is no more anti-multiple access interference. method, so that the system capacity and performance are limited

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