| 摘要 |
A method for constructing and selecting non-recursive orthogonal variable spreading factor (OVSF) codes is provided. The method includes: defining a variable B=SFmax/SFmin, where SFmax is a maximum desired spreading factor and SFmin is a minimum desired spreading factor; forming B unique base matrices Gk of dimension SFminxSFmin, where GiGiT=SFminImin ∀i, where T denotes a matrix transpose and Imin is an SFminxSFmin identity matrix; forming a modulation matrix M of dimension BxB such that MMT=BIB, where IB is a BxB identity matrix; forming an SFmaxxSFmax orthogonal variable spread factor (OVSF) code matrix C' as: C ' = [ M 1 , 1 . G 1 M 1 , 2 . G 2 ... M 1 , B . G B M 2 , 1 . G 1 M 2 , 2 . G 2 ... M 2 , B . G B ⋮ ⋮ ⋰ ⋮ M B , 1 . G 1 M B , 2 . G 2 ... M B , B . G B ] , where Mi,j is a scalar from the i-th row and j-th column of the modulation matrix M, Gl . . . GB is the k-th base matrix Gk and Mi,j.Gk denotes the multiplication of the elements of Gk by the scalar Mi,j; selecting a row of the OVSF code matrix C' to use as a pseudo-noise (PN) code; and one of spreading or despreading a signal using the selected PN code.
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