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New systolic architectures for computing the discrete cosine transform (DCT) of length of power 2 and its inverse, are presented in this thesis. With an efficient reordering for the input, the N-point DCT can be formulated as the real part of the N-point fast Fourier transform (FFT) following by a post modulation. In contract, with the same reordering for the output, the N-point inverse discrete cosine transform (IDCT) can be formulated as the real part of a pre-modulation following by the N-point FFT. Both formulations respectively lend themselves to the two different particular matrix factorizations which suggest direct implementations by linearly-connected systolic arrays. In the proposed implementation for the DCT/IDCT, the number of processors and multipliers required are only proportional to log2N, which has lower hardware overheads than other recent implementations. In addition, the quantization error that exhibits the effect of finite precision arithmetic used for hardware realization is analyzed. With the finite-word- length analysis, it is shown that if the length of data sequence is quadrupled, then to maintain the same noise-to-signal ratio, one additional bit must be added to the register length.
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