A method and device for reducing cognitive radio out-of-band interference

Abstract

The invention provides a method and device for reducing out-of-band interference of cognitive radio. The method comprises the steps that NMSK coded modulation is conducted on an OFDM baseband signal and a modulated OFDM-NMSK single side band signal is obtained; according to the modulated OFDM-NMSK single side band signal and the requirement for interference elimination of each cognitive frequency band, subcarrier bandwidths needing to be closed and corresponding to each windowing coefficient are determined in advance; an interference elimination closing data list at least comprising the interference elimination requirement of each cognitive band, each windowing coefficient and the corresponding subcarrier bandwidths needing to be closed is established ; when a user need to exit out of the occupied cognitive frequency band, the interference elimination closing data list is inquired according to the interference elimination requirement of the cognitive frequency band and the corresponding windowing coefficient is selected; according to the selected windowing coefficient, a corresponding number of subcarriers are closed. According to the method and device for reducing the out-of-band interference of the cognitive radio, the out-of-band interference of the cognitive radio is effectively reduced and meanwhile the system performance is improved.

Description

technical field [0001] The present application relates to the technical field of mobile communication, and in particular to a method and device for reducing cognitive radio out-of-band interference. Background technique [0002] In the traditional wireless communication technology field, the spectrum allocation system is fixed spectrum allocation. In order to avoid interference between different systems, the radio management department conducts unified management of radio spectrum resources, and allocates specific frequency bands for each system by issuing radio spectrum licenses to different systems, thereby dividing the spectrum into authorized frequency bands and unlicensed There are two parts of the frequency band. The licensed frequency band is generally only used by the corresponding authorized users (LU, License User), and will not be used by other unauthorized users. [0003] However, with the rapid development of wireless communication services in recent years, spe...

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Problems solved by technology

[0009] However, in the above-mentioned first method, although the out-of-band interference can be suppressed through the window filter, adding the window filter will also broaden the signal, so in order to meet the interference cancellation requirements of the licensed frequency band, the closed subcarrier bandwidth remains bigger

In addition, due to the broadening of the signal, in order to ensure the original transmission efficiency remains unchanged, the length of the guard interval must be reduced, which may lead to the destruction of the orthogonality of the subcarriers, resulting in inter-carrier interference (ICI) and symbol Interference Interference (ISI), resulting in cognitive system performance degradation

[0010] In the above-mentioned second method, although the out-of-band interference can be effectively suppressed, in order to obtain the weights inserted into the AIC subcarriers on both sides, a large number of matrix operations are required, which will bring great impact to the cognitive system. burden, reducing system performance

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