... Theory, Vol. IT-20, May 1974, pp. 397–399.56 CDMA: ACCESS AND SWITCHING[7] X.D. Lin and K.H. Chang ‘Optimal PN Sequence Design for Quasisyn-chronous CDMA Communication System’ IEEE Trans. on Commun.,Vol. ... z1· z2···zkThe orthogonal matrices Hzcan be constructed by any method described above.40 CDMA: ACCESS AND SWITCHINGFigure 2.4 Fourier, Hadamard and Karhunen–Loeve orthogonal codes of size-16.SPREADING ... W∗denotes the Hermitian conjugate (transpose, complex conjugate) and I is the unitmatrix.42 CDMA: ACCESS AND SWITCHING−−−−−−−−−−−−=43454345474347447454745434434474434543454744344745474543411111111111111118ππππππππππππππππππππππππππππππjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjeejeejeejeejeejeejeejeejeejeejeejeejeeeejeejeHFigure...