Author(s)

Li Peng, Qiuping Peng, Lingling Yang

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We generalized an constructing method of noncoherent unitary space time codes (N-USTC) over Rayleigh flat fading channels. A family of N-USTCs with T symbol peroids, M transmit and N receive antennas was constructed by the exponential mapping method based on the tangent subspace of the Grassmann manifold. This exponential mapping method can transform the coherent space time codes (C-STC) into the N-USTC on the Grassmann manifold. We infered an universal framework of constructing a C-STC that is designed by using the algebraic number theory and has full rate and full diversity (FRFD) for t symbol periods and same antennas, where M, N, T, t are general positive integer. We discussed the constraint condition that the exponential mapping has only one solution, from which we presented a approach of searching the optimum adjustive factor α_opt that can generate an optimum noncoherent codeword. For different code parameters M, N, T, t and the optimum adjustive factor α_opt, we gave the simulation results of the several N-USTCs.

Noncoherent Uintary Space-Time Codes (N-USTC), Coherent Space-Time Codes (C-STC), Grassmann Manifold, Degree of Freedom, Exponenatial Map, Full Rate and Full Diversity (FRFD)

L. Peng, Q. Peng and L. Yang, "A Design Method of Noncoherent Unitary Space-Time Codes," International Journal of Communications, Network and System Sciences, Vol. 4 No. 7, 2011, pp. 430-435. doi: 10.4236/ijcns.2011.47051.