Multi-mode transmitter for highly-spectrally-efficient communications
A transmitter may comprise a symbol mapping circuit that is configurable to operate in at least two configurations, wherein a first of the configurations of the symbol mapping circuit uses a first symbol constellation and a second of the configurations of the symbol mapping circuit uses a second symbol constellation. The transmitter may also comprise a pulse shaping circuit that is configurable to operate in at least two configurations, wherein a first of the configurations of the pulse shaping circuit uses a first set of filter taps and a second of the configurations of the pulse shaping circuit uses a second set of filter taps. The first set of filter taps may correspond to a root raised cosine (RRC) filter and the second set of filter taps corresponds to a partial response filter.
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.