Hybrid Precoding Algorithm Based on Millimeter Wave Massive MIMO in Satellite-Terrestrial Links
To improve the spectral efficiency of the satellite-terrestrial links in satellite communication system,an Improved-OMP hybrid precoding algorithm based on the Orthogonal Matching Pursuit(OMP)algorithm is proposed for millimeter Wave(mmWave)Massive Multiple Input Multiple Output(Massive MIMO)systems.Firstly,an extended Saleh-Valenzuela(S-V)channel model is introduced for the specific scenario of communication between satellite and terrestrial links.Secondly,in order to avoid excessive iterations when solving the analog precoding matrix in OMP,on the basis of the multi-step length,analog precoding matrix is obtained by extracting from the array response set's optimal columns equaling to the number of RF chains.In addition,in order to reduce the high complexity of the inversion operations in the OMP algorithm,matrix decomposition and Holder inequality are combined to simplify the acquisition of digital precoding.Under the ideal channel state conditions,the simulation results demonstrate that the Improved-OMP algorithm can achieve better performance when the gap between the number of RF chains and the number of data streams is small.Furthermore,the Improved-OMP scheme effectively reduces the computational complexity.