Multi-band DMT receiver
There is disclosed a receiver for receiving a multi-band DMT signal. The receiver includes a plurality of demodulators, each demodulator having a discrete Fourier transform and being provided to demodulate a respective one of a plurality of bands in the multi-band signal, the multi-band signal being modulated in an inverse discrete Fourier transform. A method of demodulating a multi-band signal is also provided.
1. A receiver for use in a multi-carrier transmission system, the receiver configured to receive a multi-tone signal modulated using an inverse discrete Fourier transform, comprising:
a first demodulator configured to receive a first stream of data from the received modulated multi-tone signal, wherein the first stream of data has a plurality of tones spaced in frequency within a first frequency band and wherein the first demodulator includes:
a first discrete Fourier transform module configured to utilize a first sampling rate, wherein the first sampling rate is optimized for the first frequency band; and
a second demodulator configured to receive a second stream of data from the received modulated multi-tone signal, wherein the second stream of data has a plurality of tones spaced in frequency within a second frequency band and wherein the second demodulator includes:
a second discrete Fourier transform module configured to utilize a second sampling rate, wherein the second sampling rate is optimized for the second frequency band,
wherein the first sampling rate is different than the second sampling rate.
2. The receiver of claim 1 , wherein the first demodulator further comprises:
a first time equalizer coupled to an input of the first discrete Fourier transform module.
3. The receiver of claim 2 , wherein the second demodulator further comprises:
a second time equalizer coupled to an input of the second discrete Fourier transform module.
4. The receiver of claim 1 , wherein the first demodulator further comprises:
a first frequency equalizer coupled to an output of the first discrete Fourier transform module.
5. The receiver of claim 4 , wherein the second demodulator further comprises:
a second frequency equalizer coupled to an output of the second discrete Fourier transform module.
6. The receiver of claim 1 , wherein the first demodulator is configured to receive a downsampled stream of data.
7. The receiver of claim 1 , further comprising:
a splitter for dividing the received modulated multi-tone signal into the first stream of data and the second stream of data.
8. The receiver of claim 1 , wherein the first demodulator includes an echo canceller coupled to an input of the first discrete Fourier transform module.
9. The receiver of claim 6 , wherein the echo canceller comprises an adaptive filter.
10. A receiver for use in a multicarrier transmission system, wherein the receiver is configured to receive a multi-tone signal modulated using an inverse discrete Fourier transform and having a plurality of tones spaced in frequency in a frequency band, comprising:
a module for separating the received multi-tone signal into a first stream of data having a first set of tones in the plurality of tones and a second stream of data having a second set of tones in the plurality of tones, wherein the first set of tones is spaced in frequency within a first frequency sub-band of the frequency band and the second set of tones is spaced in frequency within a second frequency sub-band of the frequency band;
a first discrete Fourier transform module configured to receive the first set of tones and to utilize a first sampling rate to demodulate data in the first set of tones, wherein the first sampling rate is optimized for the first frequency sub-band; and
a second discrete Fourier transform module configured to receive the second set of tones and to utilize a second sampling rate to demodulate data in the second set of tones, wherein the second sampling rate is optimized for the second frequency band,
wherein the first sampling rate is different than the second sampling rate.
11. The receiver of claim 10 , further comprising:
a first time equalizer coupled to an input of the first discrete Fourier transform module.
12. The receiver of claim 11 , further comprising:
a second time equalizer coupled to an input of the second discrete Fourier transform module.
13. The receiver of claim 10 , further comprising:
a first frequency equalizer coupled to an output of the first discrete Fourier transform module.
14. The receiver of claim 13 , further comprising:
a second frequency equalizer coupled to an output of the second discrete Fourier transform module.
15. The receiver of claim 12 , wherein the first discrete Fourier transform module is configured to receive a downsampled stream of data.
16. The receiver of claim 11 , wherein further comprising:
an echo canceller coupled to an input of the first discrete Fourier transform module.
17. The receiver of claim 16 , wherein the echo canceller comprises an adaptive filter.
18. A transceiver for use in a multi-carrier transmission system, comprising:
a transmitter configured to transmit a data signal; and
a receiver configured to receive a multi-tone signal modulated using an inverse discrete Fourier transform, wherein the receiver includes:
a first demodulator configured to receive a first stream of data from the received modulated multi-tone signal, wherein the first stream of data has a plurality of tones spaced in frequency within a first frequency band and wherein the first demodulator includes:
a first discrete Fourier transform module configured to utilize a first sampling rate, wherein the first sampling rate is optimized for the first frequency band, and
an echo canceller configured to remove an echo associated with the data signal in the transmitter from the received multi-tone signal, and
a second demodulator configured to receive a second stream of data from the received modulated multi-tone signal, wherein the second stream of data has a plurality of tones spaced in frequency within a second frequency band and wherein the second demodulator includes:
a second discrete Fourier transform module configured to utilize a second sampling rate, wherein the second sampling rate is optimized for the second frequency band,
wherein the first sampling rate is different than the second sampling rate.