Multi-band data transmission

1. A system for transmitting and receiving data, the system comprising:

a physical adaptation block configured to separate data into a plurality of frequency bands, wherein each frequency band has an associated symbol time, and each associated symbol time is a whole multiple of one half of a smallest symbol time of all of the frequency bands;

an analog front end configured to provide the data in the plurality of frequency bands; and

a signal combiner block configured to combine the data in the plurality of frequency bands into a single signal for simultaneous transmission on a transmission medium.

2. The system of claim 1 , further comprising a transmitter including i) the physical adaptation block and ii) the analog front end, wherein the transmitter is configured to simultaneously transmit the data in the plurality of frequency bands.

3. The system of claim 1 , further comprising a receiver configured to simultaneously receive the data in the plurality of frequency bands.

4. The system of claim 1 , wherein the transmission medium comprises an electrical grid, a coaxial cable, or a twisted-pair wire.

5. The system of claim 1 , wherein each frequency band has a width of at least 20 MHz.

6. The system of claim 1 , wherein the system uses direct discrete Fourier transforms (DFTs) and inverse DFTs (IDFTs) to convert the data between a time domain and a frequency domain, and wherein the DFTs and the IDFTs have a same number of points in each of the plurality of frequency bands.

7. The system of claim 1 , wherein automatic gain control is applied independently to each of the plurality of frequency bands.

8. The system of claim 1 , wherein the system performs synchronization using only one of the plurality of frequency bands, and wherein a frequency of the one of the plurality of frequency bands is less than frequencies of remaining ones of the plurality of frequency bands.

9. The system of claim 1 , wherein the data in the plurality of frequency bands is simultaneously transmitted and received during a first period, and is not simultaneously transmitted and received during a second period.

10. A method for transmitting and receiving data, the method comprising:

separating data into a plurality of frequency bands, wherein each frequency band has an associated symbol time, and each associated symbol time is a whole multiple of one half of a smallest symbol time of all of the frequency bands; and

combining the data in the plurality of frequency bands into a single signal; and

providing the data in the plurality of frequency bands in the single signal for simultaneous transmission on a transmission medium.

11. The method of claim 10 , further comprising:

simultaneously transmitting the data in the plurality of frequency bands.

12. The method of claim 10 , further comprising:

simultaneously receiving the data in the plurality of frequency bands.

13. The method of claim 10 , wherein the transmission medium comprises an electrical grid, a coaxial cable, or a twisted-pair wire.

14. The method of claim 10 , wherein each of the plurality of frequency bands has a width of at least 20 MHz.

15. The method of claim 10 , further comprising:

using direct discrete Fourier transforms (DFTs) and inverse DFTs (IDFTs) to convert the data between a time domain and a frequency domain, wherein the DFTs and the IDFTs have a same number of points in each of the plurality of frequency bands.

16. The method of claim 10 , further comprising:

applying automatic gain control to each of the plurality of frequency bands independently.

17. The method of claim 10 , further comprising:

performing synchronization using only one of the plurality of frequency bands, wherein a frequency of the one of the plurality of frequency bands is less than frequencies of remaining ones of the plurality of frequency bands.

18. The method of claim 10 , further comprising:

simultaneously transmitting and receiving the data in the plurality of frequency bands during a first period; and

not simultaneously transmitting and receiving the data in the plurality of frequency bands during a second period.