The lifting coefficients of SWE13/7 are all simple fractions,so wavelets transform only with integer shift and adder operations can be obtained in computing process,the computing complexity is efficiently lower than D9/7,and the result is equivalent to those using floating number in computing process.
This paper also present a recursive formula and a polynomial-time algorithm for the computing of differential probabilities for addition modulo 2~n with multiple inputs, which cut down the computing complexity of the computing XOR differential probabilities for addition modulo 2~n with m inputs from O(2~(mn)) to O(m~5n).
Because HECC's encrypted strength is very high, and computation complexity is very great, therefore, to realize the HECC will have great theory significances and application values for enhancing the information systems security and researching the more powerful cryptography.
The optimization of EC is taken as a combination optimization problem, in this thesis, which is investigated from model analysis, algorithm design, and its application on the basement of computation complexity theory.
By the Fast Fourier Transform(FFT),this paper present a fast algorithm for multiplication of level-k(r1,r2,...,rk)-circulant matrices of type(n1,n2,...,nk) of order n,their computation time complexity are O(nlog2n),where n=ni.
The steepest decent method features fast convergence at the initial iteration and small computation complexity.
The proposed algorithm can greatly reduce the state number, thus leads to the computation complexity reduction.
This method can reduce the computation complexity and pick up the vector coding process.
In comparison with schemes based on channel estimation, our algorithm need not explicitly estimate the space-frequency channel for each active user, so it has lower computation complexity.
Compared with the conventional M-ary MC-CDMA receiver, the proposed scheme increases bandwidth efficiency, meanwhile, it achieves M-ary despread spectrum and multi-carrier demodulation, which reduces computation complexity remarkably.