Patent ID: 7359428
Filing Date: 2008-04-15
Classification: H04B,H04L

Abstract:
1. VDSL transmission method, wherein said transmission is organized according to a plurality of parallel branches as a CDMA modulation, said CDMA modulation being effected for each branch on multiple carriers by spreading an original data stream for that branch over different subcarriers thus obtaining a Multi-Carrier CDMA modulation, wherein said Multi-Carrier CDMA modulation is effected using a plurality of different spreading codes in a frequency domain for each subcarrier, wherein transmitting and receiving by said method comprise the steps of: transmitting: inputting a binary source (b) data sequence to transmit; converting or mapping said source data sequence into an alphabet of complex QAM symbols, said conversion being governed by a predetermined bit-loading table that sets a modulation order; parallelizing the QAM symbols according to a plurality (p) of transmission branches (k) each having an own symbol stream (A further parallelizing each symbol stream into a plurality (N spreading according to a plurality of sub-carrier frequencies each symbol sub-stream by means of CDMA codes obtaining transmission contributes (T for each branch carrying out an algebraic sum of said transmission contributes (T associating each sample (T carrying out a multiple carrier transmission based on a reverse Fourier transform (IFFT) of the samples thus associated; and receiving: controlling the samples received with a processor that operates according to a direct Fourier transform (FET); permuting said samples after the FFT according to a law inverse with respect to that used when transmitting; despreading the samples with the same CDMA codes used in transmission to obtain an estimation of the number (N seriating the symbols (Z further seriating the symbols (Z reverse converting or demapping; and estimating the transmitted bits (b).