The Modified Codeword Design Of Space-Time Block Coded Spatial Modulation

Spatial Modulation(SM)on which numerous researchers concentrate is a potential multiple-input-multiple-output(MIMO)technique.The space-tme block coded SM(STBC-SM)combines STBC matrix with SM,and obtains more diversity gains compared with SM.The codewords effect the performance of STBC-SM obviously,so our paper is concentrated on the modified codeword design of STBC-SM.The paper is organized as follows:First of all,we take Alamouti and V-BLAST as examples to introduce two main MIMO strategies:space-time block coding and spatial multiplexing.We also introduce the principle and model about SM and general SM.The analysis is given about above schemes by the simulation.Secondary,we discuss the STBC-SM and several modified STBC-SM deeply.The principle and normal design method about STBC-SM are introduced.Our paper analysis the reason why the codewords can effect the performance of STBC-SM.And two modified STBC-SM schemes are introduced in our paper.The first modified STBC-SM introduces a new conception called flexible coefficients,which optimize the STBC-SM codewords by angle and amplitude jointly.The optimal flexible coefficients and rotation angles are given for different PSK modulation by theoretical analysis.The simulation verifies the advantage of flexible coefficients.The super-orthogonal space-time trellis codes are the set of various space-time block codes.The second modified STBC-SM replace the space-time block codes with the super-orthogonal space-time trellis codes.This modified STBC-SM can enhance the coding gain using the original method to design codewords.The simulation verifies the advantage of the modified scheme.