Method and Apparatus for Cross-Talk Cancellation in Frequency Division Multiplexed Transmission Systems

Abstract

A method and apparatus are disclosed for canceling cross-talk in a frequency-division multiplexed communication system. The disclosed frequency-division multiplexed communication system employs multiple carriers having overlapping channels and provides an improved cross-talk cancellation mechanism to address the resulting interference. Bandwidth compression is achieved using n level amplitude modulation in each frequency band. An FDM receiver is also disclosed that decomposes the received broadband signal into each of its respective frequency bands and returns the signal to baseband in the analog domain. Analog requirements are relaxed by removing cross-talk from adjacent RF channels, from image bands, and minimizing the performance degradation caused by In-phase and Quadrature-phase (I/Q) phase and gain mismatches in modulators and demodulators. The disclosed transmitter or receiver (or both) can be fabricated on a single integrated circuit.

1 . A method for receiving a frequency division multiplexed signal, said method comprising the steps of:
 decomposing said frequency division multiplexed signal into a plurality of frequency bands;   returning said decomposed frequency bands to baseband signals; and   removing far-end cross-talk from one or more of said baseband signals, wherein said far-end crosstalk is caused by one or more of said frequency bands.   
     
     
         2 . The method of  claim 1 , wherein said plurality of frequency bands are overlapping. 
     
     
         3 . The method of  claim 1 , wherein said removing step further comprises the step of removing said far-end cross-talk from a given baseband signal using said given baseband signal and at least one additional baseband signal. 
     
     
         4 . A method for receiving a frequency division multiplexed signal, said method comprising the steps of:
 decomposing said frequency division multiplexed signal into a plurality of frequency bands;   returning said decomposed frequency bands to baseband signals;   removing far-end cross-talk from one or more of said baseband signals, wherein said far-end crosstalk is caused by one or more of said frequency bands; and   removing image bands from said baseband signal.   
     
     
         5 . An integrated circuit, comprising:
 RF carrier demodulators to decompose a frequency division multiplexed signal into a plurality of frequency bands and return said decomposed frequency bands to baseband signals; and   a cross-talk canceller for removing far-end cross-talk in one or more of said baseband signals, wherein said far-end crosstalk is caused by one or more of said frequency bands.   
     
     
         6 . The integrated circuit of  claim 5 , wherein said cross-talk canceller is a digital signal processor. 
     
     
         7 . A system for receiving a frequency division multiplexed signal, said system comprising:
 a demodulator for decomposing said frequency division multiplexed signal into a plurality of frequency bands and returning said decomposed frequency bands to baseband signals; and   a cross-talk canceller for removing far-end cross-talk from one or more of said baseband signals, wherein said far-end crosstalk is caused by one or more of said frequency bands.   
     
     
         8 . The system of  claim 7 , wherein said plurality of frequency bands are overlapping. 
     
     
         9 . The system of  claim 7 , wherein said cross-talk canceller removes said far-end cross-talk from a given baseband signal using said given baseband signal and at least one additional baseband signal. 
     
     
         10 . The system of  claim 7 , further comprising an image band canceller for removing image bands from said baseband signal. 
     
     
         11 . The system of  claim 10 , wherein said image band canceller is at a receiver. 
     
     
         12 . The system of  claim 10 , wherein said image band canceller is at a transmitter.