Research On Integration Of Shipborne Radar And Communication System

In order to improve overall operational effectiveness and survivability, modern combat ships are equipped with various types of radar and communicational equipment generally to meet different needs of detection and communication, and it has led to an "antenna farm" phenomenon. At the same time, it has brought about the problem of poor ability of stealth and poor electromagnetic compatibility. A comprehensive integrated design technology is adopted to make radar and communication system signal sharing and interactive in function based on the similarity between them. It can reduce the number of operational equipment and space occupation greatly, system power and interference between system modules will trend to lower. Therefore, research of integration of radar and communication has gotten more and more attention and rapid development.This paper chooses OFDM-LFM as shared signal in integration of shipborne radar and communication system, and the application of integration of shipborne radar and communication system in a sea environment is studied. Four major parts of contents are stated below in this paper:Firstly, scheme design and system operation mode analysis of integration of shipborne radar and communication system. A scheme design of integration of shipborne radar and communication system has put forward based on simultaneous mechanism. This paper divides system operation mode into one-ship operation mode and ad hoc ship-networks operation mode satisfy needs of different tasks, and explains working mechanism and overall workflow of both operation modes in detail.Secondly, design, analysis and processing of integrated signal of shipborne radar and communication. This paper uses the fractional Fourier transform as modulation and demodulation methods, received signal is processed at this basis. We make a simulation of radar performance about ambiguity function, frequency feature and multi-object performance, radar detection range and radar power are estimated subsequently.Thirdly, communicational performance research of OFDM-LFM signal on sea channel transmission model. This paper chooses sea environment as studying scene, establishing a more precise model to imitate sea environment, and make a further simulation about bit error rate, throughput rate, communication rate and communication range about OFDM-LFM on this model.At last, this paper proposes an algorithm to inhibit peak-to-average power ratio of OFDM-LFM signal based on compressive sensing. With the problem of high value of peak-to-average power ratio, we combine compressive sensing and clipping to propose a modified algorithm, and give an analysis of performance on radar and communication as well as complexity.This research shows that OFDM-LFM signal used for the purpose of radar, it has a better detecting performance, similar spectral characteristics and multi-target resolution performance than OFDM radar signal; OFDM-LFM signal used as communication signal applied in the designed sea channel model, when bit error rate is lower than 22.82 d B, OFDM-LFM signal has a better bit error rate compared with OFDM radar signal, and average throughput rate of link can meet requirement of real-time data transmission in the shipborne environment. Moreover, the proposed algorithm to suppress peak-to-average power ratio focused on OFDM-LFM signal has a low computational complexity, which can improve system bit error rate performance and will not cause too much impact on radar performance.