A motion vector between a current block and a reference block of a reference frame is determined by calculating the exact linear cross-correlation between the current block and the potential reference blocks of the reference picture. The current block is orthogonally transformed using DCT/DST transforms of a first type without prior zero padding of the current block to generate a current quadruple of transform coefficient blocks. The current quadruple is processed together with a reference quadruple of transform coefficient blocks generated from four of the search region blocks to generate a quadruple of processed transform coefficient blocks. The quadruple of processed transform coefficient blocks is inversely transformed using inverse DCT/DST transforms of a second type to generate a block of exact cross-correlations between the current block and the search region. The motion vector is determined from the block of exact cross-correlations.
Apparatus, and an associated method, for facilitating communications in an OFDM communication system. A sending station of the OFDM communication system performs inverse discrete trigonometric transforms upon modulation symbols representative of data that is to be communicated. And, a transformed vector is formed by the inverse discrete trigonometric transformer. A symmetric extension adder adds an extension to the transformed vector to attain desired symmetry or anti symmetry properties. The apparatus formed at a receiving station of the OFDM system includes a discrete trigonometric transformer for performing transform operations upon data received thereat.
