Inter-antenna and subblock shifting and inversion for peak-to-average power ratio reduction in MIMO-OFDM systems

In this article, an inter-antenna inter-subblock shifting and inversion （IASSI） scheme is proposed to reduce the peak-to-average power ratio （PAPR） in multi-input multioutput orthogonal frequency division multiplexing （MIMO- OFDM） systems. It exploits multiple antennas and subblocks to provide additional degrees of freedom to benefit the system. To reduce the implementation complexity of the proposed scheme, two simple suboptimal schemes are further presented based on the minimum current maximum criterion; one adopts sequential search and the other employs random binary grouping. The simulation results exhibit the effectiveness of these proposed schemes.

Global algorithms for maximal eigenpair

This paper is a continuation of our previous work [Front. Math. China, 2016, 11（6）： 1379-1418] where an efficient algorithm for computing the maximal eigenpalr was introduced first for tridiagonal matrices and then extended to the irreducible matrices with nonnegative off-diagonal elements. This paper introduces mainly two global algorithms for computing the maximal eigenpair in a rather general setup, including even a class of real （with some negative off-diagonal elements） or complex matrices.

Improved global algorithms for maximal eigenpair

This paper is a continuation of our previous paper[Front.Math.China,2017,12(5):10231043]where global algorithms for computing the maximal cigcnpair were introduced in a rather general setup.The efficiency of the global algorithms is improved in this paper in terms of a good use of power iteration and two quasi-symmetric techniques.Finally,the new algorithms are applied to Hua’s economic optimization model.

Efficient algorithm for principal eigenpair of discrete p-Laplacian

This paper is a continuation of the author＇s previous papers [Front. Math. China, 2016, 11（6）： 1379-1418; 2017, 12（5）： 1023-1043], where the linear case was studied. A shifted inverse iteration algorithm is introduced, as an acceleration of the inverse iteration which is often used in the non-linear context （the p-Laplacian operators for instance）. Even though the algorithm is formally similar to the Rayleigh quotient iteration which is well-known in the linear situation, but they are essentially different. The point is that the standard Rayleigh quotient cannot be used as a shift in the non-linear setup. We have to employ a different quantity which has been obtained only recently. As a surprised gift, the explicit formulas for the algorithm restricted to the linear case （p = 2） is obtained, which improves the author＇s approximating procedure for the leading eigenvalues in different context, appeared in a group of publications. The paper begins with p-Laplacian, and is closed by the non-linear operators corresponding to the well-known Hardy-type inequalities.

Reaction ergodography for the 1,2-H shift and inversion processes of amino-carbene

The ab initio calculations have been performed on the reaction paths of 1,2-H shift and inversion processes of amino-carbene molecule by the Intrinsic Reaction Coordinate(IRC)method. We have determined the equilibrium geometries and energies of the reactant,transition state and product,and obtained the activation energies,reaction heats,frequency factors and the activation entropies of these two reaction processes.The vibrational correlation from reactant to transition state indicated that the IRCs of 1,2-H shift and inversion processes were associated with the deformation modes of 1540 and 1208 cm^(-1),respectively.The vibrational coupling between normal coordinates in the inversion process would be helpful for selecting the inversion reaction channel.