Título:
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A fast OFDM-CDMA user demultiplexing architecture
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Autor/a:
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Marti Puig, Pere; Sala Álvarez, José
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Otros autores:
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Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions; Universitat Politècnica de Catalunya. SPCOM - Grup de Recerca de Processament del Senyal i Comunicacions |
Abstract:
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A fast algorithm based on a butterfly structure is presented that demultiplexes the symbols of a particular type of MC-MA (multi-carrier multiple-access) modulation previously proposed for indoor radio communications. A special transform is used to packetize the different symbols on the down-link such that the code sequences associated with the different symbols are transmitted synchronously at the base station. The input to the FFT bins is defined as a symbol-dependent combination of Walsh-Hadamard codes. We derive a fast architecture that can combine the common redundancy found in the Walsh-Hadamard and the inverse Fourier transform. In the direct implementation, the receiver would compute the IFFT (as in OFDM) before the Walsh-Hadamard transform. The proposed algorithm evaluates both transforms in a single step. A general expression for the butterfly weights is derived and the savings in computational complexity in terms of the frame length is evaluated. |
Abstract:
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Peer Reviewed |
Materia(s):
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-Àrees temàtiques de la UPC::Enginyeria de la telecomunicació -Modulation (Electronics) -Hadamard codes -OFDM modulation -Code division multiple access -Computational complexity -Modulació (Electrònica) |
Derechos:
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Tipo de documento:
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Artículo - Versión publicada Objeto de conferencia |
Editor:
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Institute of Electrical and Electronics Engineers (IEEE)
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