Techniques Of MIMO Array Synthesis For Distributed Shipborne High Frequency Surface Wave Radar

Compared to shore-based high-frequency ground wave radars,the shipboard array platform brings higher flexibility and security to high-frequency ground-wave radars,and is of great significance in ocean exploration and deep-sea operations.The distributed shipboard platform studied in this paper can successfully achieve the purpose of aperture expansion through shipboard formation and bring about better mainlobe performance.However,different ship-borne formation models and the minimum safety distance between ships will cause serious deterioration of the peak sidelobe performance of the array,which greatly reduces the anti-jamming capability of the radar.In addition,with the increase in the number of ships,the number of array elements has increased exponentially,which brings a huge pressure on the array system cost and signal processing complexity of the radar system,thus hindering its application in practical projects.In order to solve the above problems,this topic takes the array synthesis technology as an entry point,and how to reduce the high side-lobe caused by the safety distance limitation in the process of combining the distributed shipboard high-frequency ground wave radar and MIMO array technology.Problems are researched and analyzed.First,for three simplified ship formation models,a linear distributed MIMO array,a staggered distributed MIMO array,and a fan-shaped distributed MIMO array model were established.The corresponding patterns of different array modes under three array models were simulated and analyzed.Performance verified the problem of peak side lobe elevation caused by large-interval subarrays.Afterwards,for the linear distributed MIMO array model,the problem of weight optimization,array scrambling,and array element position and weight value joint optimization for a half-wavelength uniform full array of sub-arrays is solved.Simulations verify the effectiveness of array optimization algorithms based on chicken swarm optimization and salv swarm algorithm proposed in recent years,and compare and analyze the optimization performance of the two algorithms.In the joint optimization problem of array thinning,array element location and weights,combined with the needs of actual ship layout,the constraints of the sub-array distribution are proposed.Through simulation experiments,the influence of this constraint on the peak sidelobe performance optimization results is analyzed.Finally,for the staggered distributed and fan-shaped distributed MIMO array model,the problem of array scrim design is studied.The optimal peak side-lobe performance corresponding to different subarrays is given when the scatter rate of array element is 30%.Corresponding optimal array position distribution.For two different array models,PSO and GA were used to design thin arrays.The simulation verifies the effectiveness of the algorithm and gives the position distribution of array elements after thinning optimization.