Multi-Mode Transmitter for Highly-Spectrally-Efficient Communications

1. A system comprising: a transmitter configurable to operate in at least two modes, wherein: which of said modes said transmitter is configured into is controlled based on: feedback or request from a receiver, a measured performance indicator, and/or a command from an application running on a device in which said transmitter is installed; while said transmitter is configured into a first of said modes, said transmitter is configured to use a pulse shaping filter configured as a near zero positive ISI filter; while said transmitter is configured into a second of said modes, said transmitter is configured to generate an inter-symbol correlated (ISC) signal; a symbol constellation used by said transmitter while said transmitter is configured into said first of said modes is the same as a symbol constellation used while said transmitter is configured into said second of said modes; said transmitter comprises an amplifier; while said transmitter is configured into said first of said modes, a first amount of power back-off is used by said amplifier; and while said transmitter is configured into said second of said modes, a second amount of power back-off is used by said amplifier.

2. The system of claim 1 , wherein a maximum throughput achievable while said transmitter is configured into said first of said modes is equal to a maximum throughput achievable while said transmitter is configured into said second of said modes.

3. The system of claim 1 , wherein said symbol constellation is an N-QAM constellation, N being an integer.

4. The system of claim 1 , wherein while said transmitter is configured into the second of said modes, said transmitter is configured to process signals to be transmitted via a partial response pulse shaping filter.

5. The system of claim 1 , wherein a bandwidth used by said transmitter while said transmitter is configured into said first of said modes is greater than a bandwidth used by said transmitter while said transmitter is configured into said second of said modes.

6. A method comprising: performing in a transmitter configurable to operate in at least two modes: controlling into which of said modes said transmitter is configured based on: feedback or request from a receiver, a measured performance indicator, and/or a command from an application running on a device in which said transmitter is installed; while said transmitter is configured into a first of said modes, mapping bits to symbols using a particular symbol constellation and transmitting said symbols onto a channel using a pulse shaping filter configured as a near zero positive ISI filter; while said transmitter is configured into a second of said modes, mapping bits to symbols using said particular symbol constellation and transmitting said symbols onto said channel using a pulse shaping filter configured to generate an inter-symbol correlated (ISC) signal; while said transmitter is configured into said first of said modes, amplifying an output of said pulse shaping filter configured as a near zero positive ISI filter using a first amount of power back-off; and while said transmitter is configured into said second of said modes, amplifying said ISC signal using a second amount of power back-off.

7. The system of claim 6 , wherein a maximum throughput achievable while said transmitter is configured into said first of said modes is equal to a maximum throughput achievable while said transmitter is configured into said second of said modes.

8. The system of claim 6 , wherein said particular symbol constellation is an N-QAM constellation, N being an integer.

9. The system of claim 6 , wherein while said transmitter is configured into the second of said modes, said pulse shaping filter is configured as a partial response pulse shaping filter.

10. The system of claim 6 , wherein a bandwidth used by said transmitter while said transmitter is configured into said first of said modes is greater than a bandwidth used by said transmitter while said transmitter is configured into said second of said modes.

11. A system comprising: a transmitter configurable to operate in at least two modes, wherein: which of said modes said transmitter is configured into is controlled based on: feedback or request from a receiver; a measured performance indicator, and/or an application running on a device in which said transmitter is installed; while said transmitter is configured into a first of said modes, said transmitter is configured to use a pulse shaping filter configured as a near zero positive ISI filter; while said transmitter is configured into a second of said modes, said transmitter is configured to generate an inter-symbol correlated (ISC) signal; a symbol constellation used by said transmitter while said transmitter is configured into said first of said modes is the same as a symbol constellation used while said transmitter is configured into said second of said modes; and a maximum throughput achievable while said transmitter is configured into said first of said modes is equal to a maximum throughput achievable while said transmitter is configured into said second of said modes.

12. The system of claim 11 , wherein said symbol constellation is an N-QAM constellation, N being an integer.

13. The system of claim 11 , wherein while said transmitter is configured into the second of said modes, said transmitter is configured to process signals to be transmitted via a partial response pulse shaping filter.

14. The system of claim 11 , wherein a bandwidth used by said transmitter while said transmitter is configured into said first of said modes is greater than a bandwidth used by said transmitter while said transmitter is configured into said second of said modes.

15. A system comprising: a transmitter configurable to operate in at least two modes, wherein: which of said modes said transmitter is configured into is controlled based on: feedback or request from a receiver; a measured performance indicator, and/or an application running on a device in which said transmitter is installed: while said transmitter is configured into a first of said modes, said transmitter is configured to use a pulse shaping filter configured as a near zero positive ISI filter; while said transmitter is configured into a second of said modes, said transmitter is configured to generate an inter-symbol correlated (ISC) signal; a symbol constellation used by said transmitter while said transmitter is configured into said first of said modes is the same as a symbol constellation used while said transmitter is configured into said second of said modes; and a bandwidth used by said transmitter while said transmitter is configured into said first of said modes is greater than a bandwidth used by said transmitter while said transmitter is configured into said second of said modes.

16. The system of claim 15 , wherein said symbol constellation is an N-QAM constellation, N being an integer.

17. The system of claim 15 , wherein while said transmitter is configured into the second of said modes, said transmitter is configured to process signals to be transmitted via a partial response pulse shaping filter.

18. A method comprising: performing in a transmitter configurable to operate in at least two modes: controlling into which of said modes said transmitter is configured based on: feedback or request from a receiver, a measured performance indicator, and/or a command from an application running on a device in which said transmitter is installed; while said transmitter is configured into a first of said modes, mapping bits to symbols using a particular symbol constellation and transmitting said symbols onto a channel using a pulse shaping filter configured as a near zero positive ISI filter; while said transmitter is configured into a second of said modes, mapping bits to symbols using said particular symbol constellation and transmitting said symbols onto said channel using a pulse shaping filter configured to generate an inter-symbol correlated (ISC) signal; and wherein a maximum throughput achievable while said transmitter is configured into said first of said modes is equal to a maximum throughput achievable while said transmitter is configured into said second of said modes.

19. The system of claim 18 , wherein said particular symbol constellation is an N-QAM constellation, N being an integer.

20. The system of claim 18 , wherein while said transmitter is configured into the second of said modes, said pulse shaping filter is configured as a partial response pulse shaping filter.

21. The system of claim 18 , wherein a bandwidth used by said transmitter while said transmitter is configured into said first of said modes is greater than a bandwidth used by said transmitter while said transmitter is configured into said second of said modes.

22. A method comprising: performing in a transmitter configurable to operate in at least two modes: controlling into which of said modes said transmitter is configured based on: feedback or request from a receiver, a measured performance indicator, and/or a command from an application running on a device in which said transmitter is installed; while said transmitter is configured into a first of said modes, mapping bits to symbols using a particular symbol constellation and transmitting said symbols onto a channel using a pulse shaping filter configured as a near zero positive ISI filter; and while said transmitter is configured into a second of said modes, mapping bits to symbols using said particular symbol constellation and transmitting said symbols onto said channel using a pulse shaping filter configured to generate an inter-symbol correlated (ISC) signal; and wherein a bandwidth used by said transmitter while said transmitter is configured into said first of said modes is greater than a bandwidth used by said transmitter while said transmitter is configured into said second of said modes.

23. The system of claim 22 , wherein said particular symbol constellation is an N-QAM constellation, N being an integer.