Abstract: Method for generating a built-symbol including plurality of sub-symbols for transmission including data of an original symbol of an orthogonal multi-carrier modulation-signal reducing the peak-to-average power-ratio (PAPR) and increase its robustness against Doppler-effects of the orthogonal multi-carrier modulation-signal, the original symbol lasting a duration, Ts and carried by N-tones; also including: applying intrinsic temporal diversity properties of complex N-points Inverse-Fast-Fourier-Transform to the original symbol, where plurality of sub-symbols number is M, each M sub-symbols lasts Ts/M and is carried by N/M disjoint-tones, the M sub-symbols are time-multiplexed, so the time-multiplexed built-symbol contains all-data at the same rate of the original symbol. The built-symbol is demodulated, utilizing an orthogonal multi-carrier receiver.

Abstract: Method for generating a built-symbol including plurality of sub-symbols for transmission including data of an original symbol of an orthogonal multi-carrier modulation-signal reducing the peak-to-average power-ratio (PAPR) and increase its robustness against Doppler-effects of the orthogonal multi-carrier modulation-signal, the original symbol lasting a duration, Ts and carried by N-tones; also including: applying intrinsic temporal diversity properties of complex N-points Inverse-Fast-Fourier-Transform to the original symbol, where plurality of sub-symbols number is M, each M sub-symbols lasts Ts/M and is carried by N/M disjoint-tones, the M sub-symbols are time-multiplexed, so the time-multiplexed built-symbol contains all-data at the same rate of the original symbol. The built-symbol is demodulated, utilizing an orthogonal multi-carrier receiver.

Abstract: In a telecommunications transmission system using a DTM system as a multicarrier system and having at least two VDSL systems, each including a pair of modems, the at least two VDSL systems belonging to a single binder group common to both VDSL systems, a method in the DMT system for keeping DMT frames aligned to the same frame timing includes estimating the time mis-alignment and power of cross-talk DMT signals added to a received DMT signal when the estimate is used by the modem to synchronize its own frame timing to a main cross-talkers frame timing, using auto-correlation on the received signal and a delayed copy of the received signal, and detecting correlation maxima that determine the frame boundaries of different DMT components of the received signal.

Abstract: The demodulation of data modulated on a set of carriers with equidistant frequencies by a plurality of transmitters (T1 . . . Tn) is executed in the present transmission system (TS) by a discrete multitone receiver (DMT-R). The transmitters (T1 . . . Tn) in the transmission system (TS) modulate their data on subsets of carriers which form part of the set of carriers with equidistant frequencies. These transmitters (T1 . . . Tn) are possibly additionally equipped with a cyclic prefix adder (CPA); synchronization between them is guaranteed if a predefined condition is fulfilled.

Abstract: The present invention discloses a so called Discrete Multi Tone or DMT signal processor which is coupled to a transmitting end of a communication line and which reduces the need for the clipping of the amplitude of the output signal OS'. The signal processor includes the cascade connection of a vector transformation circuit VTC, a modulator MOD and a peak detection circuit PDC. The VTC circuit is provided with a plurality of input vectors IN whereon a vector transformation is performed according to a signal at a control terminal (CT) of the peak detection circuit PDC which is indicative of the fact that the amplitude of the output signal OS provided by the modulator MOD exceeds a predetermined threshold value.