Research On Adaptive Selection Of Wireless Signals For Shipborne Vehicle On-shore Task Formation

When carrier-based aircraft formation carries out counter-shore combat tasks,the adaptive selection of wireless signal modulation mode according to field coverage can improve the adaptability to battlefield environment and maximize information transmission.In this essay,the problem of wireless signal selection is concretely transformed into the problem of fast prediction of spatial field strength range.Because of the real-time changes of flight trajectory and residence time,it is impossible to predict the specific position of the receiver and calculate the received field strength of each position point by point in real time.Therefore,how to quickly predict the field strength range of space under complex terrain conditions and select the modulation technology adaptively based on the current spatial field strength range are of great significance.In order to solve the above problems,this essay will study from the following aspects.Firstly,considering the characteristics of fast flight in three-dimensional space of aircraft,the relationship between bit error rate and bit signal-to-noise ratio of BPSK,QPSK,16 QAM and 64 QAM digital modulation modes under Gauss white noise channel and coherent demodulation is simulated according to the recommendation of IEEE 802.16 protocol standard.Combining with the background of the project,the relationship between signal field strength calculation and digital modulation mode selection is clarified.At the same time,the combination of spatial field strength range prediction and adaptive selection of modulation mode is realized.Secondly,considering that it takes too long to calculate the spatial field strength point by point in actual combat,a fast method of predicting the spatial field strength range by using part of the calculated field strength under the condition of obstacle terrain is proposed.According to the characteristi cs that compressed sensing algorithm can reconstruct the whole with high probability by collecting a small number of points,K-SVD dictionary training algorithm and compressed sensing algorithm are combined to solve the problem of poor sparsity of terrain signal occluded by obstacles.At the same time,the validity of reconstructing spatial field strength range by using observed partial field strength of empirical obstacle terrain is verified.For non-empirical obstacle terrain,the three-dimensional interpolation method can rapidly predict the distribution of spatial field strength range even at the expense of some accuracy.Finally,this essay continues to excavate the law of the distribution between similar terrain to further improve the speed of field strength range prediction of similar terrain.Through data simulation,the law of the coefficients relationship between the field strength range of similar terrain within the allowable range of certain errors is verified,and a similar terrain matching method based on density estimation is proposed.If the matching result of similar terrain satisfies the requirement,the field strength range of unknown terrain can be predicted directly by coefficient conversion.Combining with the background of the subject,two kinds of modulation strategies are proposed,and the adaptive selection of modulation modes is carried out by using the spatial field strength range predicted by similar terrain.