Noise filtering inverse transformation

A method for data recovery from a composite signal (DRCS) carrying a composite frame comprising discrete multiple tones (DMT) or multiple sub-bands (MSB), comprising signal processing in frequency domain and time domain wherein amplitudes or phases of a noise or other signals, surrounding a particular data carrying tone or sub-band in a transmission channel, are detected and distortions of said particular tone or sub-band are reversed;

• the DRCS method comprising the steps of:
• processing the composite signal in frequency domain, in order to recover said tones or sub-bands,
• wherein a known phase relation is maintained between the recovered tones or sub-bands and the composite frame;
• processing the tones or sub-bands in time domain, in order to measure amplitudes and phases of singular half-cycles or cycles of the tones or sub-bands;
• detecting said amplitudes or phases of noise or other signals surrounding said particular tone or sub-band;
• using the detected amplitudes or phases for deriving estimates of distortions introduced by the surrounding noise or other signals to the particular tone or sub-band;
• using the distortions estimates for performing a reverse transformation of said measured amplitudes and phases into amplitudes and phases corresponding to amplitudes and phases encoded originally in a transmitted composite signal;
• using the reversely transformed amplitudes and phases for recovering data symbols encoded originally in the transmitted composite signal.

A method for data recovery from a received composite signal carrying composite frame (DRRC) comprising discrete multiple tones (DMT) or multiple sub-bands (MSB), wherein said data recovery comprises signal processing in frequency domain and in time domain, the DRRC method comprising the steps of:

• using a sampling clock, synchronous in phase to the composite frame, for oversampling said received composite signal;
• using clocks, synchronous to the composite frame, for processing the oversampled signal in frequency domain, in order to recover said tones or sub-bands having a known phase relation to the composite frame;
• processing the recovered tones or sub-bands in time domain, in order to measure amplitudes or phases of singular half-cycles or cycles of the recovered tones or sub-bands;
• using a plurality of the measured amplitudes or phases of singular half-cycles or cycles of a particular tone or sub-band, for a recovery of an original data symbol transmitted by the particular tone or sub-band.

A method for synchronous data recovery (SDR) from a composite signal carrying a composite frame comprising discrete multiple tones (DMT) or multiple sub-bands (MSB), wherein said data recovery comprises signal processing in frequency domain and in time domain, the SDR method comprising the steps of:

• processing said composite signal in frequency domain in order to recover said tones or sub-bands,
• wherein the frequency domain processing is driven by clocks or sub-clocks synchronous in phase to the composite frame
• in order to maintain a known phase relation between the recovered tones or sub-bands and the composite frame;
• processing the recovered tones or sub-bands in time domain, in order to measure amplitudes or phases of singular half-cycles or cycles of the recovered tones or sub-bands;
• using a plurality of said measured amplitudes or phases of singular half-cycles or cycles of a particular tone or sub-band, for a recovery of an original data symbol transmitted by the particular tone or sub-band.