Systems/methods of sequential modulation of a single carrier frequency by a plurality of elements of a waveform
Systems and/or methods are disclosed for generating a waveform that comprises a plurality of elements by using a Fourier transform and/or an inverse Fourier transform. The waveform that comprises the plurality of elements may be transmitted by transmitting, sequentially in time, the plurality of elements. In some embodiments, the Fourier transform and/or inverse Fourier transform comprises a Fast Fourier Transform and/or Inverse Fast Fourier Transform and the waveform that comprises the plurality of elements may be transmitted by using, sequentially in time, the plurality of elements to modulate a single carrier frequency.
1. A communications method comprising:
forming a desired spectrum shape for a waveform;
generating the waveform responsive to the desired spectrum shape; and
transmitting and/or receiving information by transmitting and/or receiving at a transmitter and/or at a receiver, a plurality of elements of the waveform sequentially one after another via a single carrier frequency;
wherein generating the waveform responsive to the desired spectrum shape comprises generating a discrete time-domain waveform U(nT); wherein n denotes a discrete time index of U(nT); wherein n=1, 2, . . . , N; and NT≦τ; wherein τ denotes a time span of the discrete time-domain waveform U(nT);
wherein transmitting and/or receiving information by transmitting and/or receiving at a transmitter and/or at a receiver, a plurality of elements of the waveform sequentially one after another via a single carrier frequency comprises transmitting and/or receiving the elements of U(nT) sequentially via the single carrier frequency by transmitting and/or receiving U(T) via the single carrier frequency, followed by transmitting and/or receiving U(2T) via the single carrier frequency, . . . , followed by transmitting and/or receiving U(NT) via the single carrier frequency; and
wherein said forming a desired spectrum shape for a waveform further comprises:
using a first plurality of frequencies over a first time interval; and
using a second plurality of frequencies over a second time interval;
wherein the first plurality of frequencies differs from the second plurality of frequencies in at least one frequency.
2. The communications method according to claim 1 , wherein said forming a desired spectrum shape for a waveform is performed at the transmitter.
3. The communications method according to claim 1 , wherein said forming a desired spectrum shape for a waveform is performed at a distance from the transmitter and is then relayed to the transmitter.
4. The communications method according to claim 1 , wherein said forming a desired spectrum shape for a waveform further comprises:
forming the desired spectrum shape to include a first frequency interval comprising a first spectral level that is non-zero and to also include a second frequency interval comprising a second spectral level that is substantially zero.
5. The communications method according to claim 4 , wherein said forming a desired spectrum shape for a waveform further comprises:
forming the desired spectrum shape to also include a third frequency interval comprising a third spectral level that is non-zero;
wherein the second frequency interval that comprises the second spectral level that is substantially zero is situated between the first and third frequency intervals.
6. A communications method comprising:
forming a desired spectrum shape for a waveform to include at least one frequency that provides a frequency content to the waveform and at least one frequency that is excluded from providing a frequency content to the waveform;
generating the waveform responsive to the desired spectrum shape; and
transmitting and/or receiving information by transmitting and/or receiving at a transmitter and/or at a receiver, a plurality of elements of the waveform sequentially one after another via a single carrier frequency;
wherein generating the waveform responsive to the desired spectrum shape comprises generating a discrete time-domain waveform U(nT); wherein n denotes a discrete time index of U(nT); wherein n=1, 2, . . . , N; and NT≦τ; wherein τdenotes a time span of the discrete time-domain waveform U(nT);
wherein transmitting and/or receiving information by transmitting and/or receiving at a transmitter and/or at a receiver, a plurality of elements of the waveform sequentially one after another via a single carrier frequency comprises transmitting and/or receiving the elements of U(nT) sequentially via the single carrier frequency by transmitting and/or receiving U(T) via the single carrier frequency, followed by transmitting and/or receiving U(2T) via the single carrier frequency, . . . , followed by transmitting and/or receiving U(NT) via the single carrier frequency; and
wherein said forming a desired spectrum shape for a waveform further comprises:
using a first plurality of frequencies over a first time interval; and
using a second plurality of frequencies over a second time interval;
wherein the first plurality of frequencies differs from the second plurality of frequencies in at least one frequency.
7. The communications method according to claim 6 , wherein said forming a desired spectrum shape for a waveform is performed at the transmitter.
8. The communications method according to claim 6 , wherein said forming a desired spectrum shape for a waveform is performed at a distance from the transmitter and is then relayed to the transmitter.
9. The communications method according to claim 6 , wherein said forming a desired spectrum shape for a waveform further comprises:
forming the desired spectrum shape to include a first frequency interval comprising a first spectral level that is non-zero and to also include a second frequency interval comprising a second spectral level that is substantially zero.
10. The communications method according to claim 9 , wherein said forming a desired spectrum shape for a waveform further comprises:
forming the desired spectrum shape to also include a third frequency interval comprising a third spectral level that is non-zero;
wherein the second frequency interval that comprises the second spectral level that is substantially zero is situated between the first and third frequency intervals.
11. A communications system comprising:
a processor that is configured to form a desired spectrum shape for a waveform and to generate the waveform responsive to the desired spectrum shape; and
a transmitter and/or receiver that is/are configured to transmit and/or receive information by transmitting and/or receiving a plurality of elements of the waveform sequentially one after another via a single carrier frequency;
wherein the waveform comprises a discrete time-domain waveform U(nT); wherein n denotes a discrete time index of U(nT); wherein n=1, 2, . . . , N; and NT≦τ; wherein τ denotes a time span of the discrete time-domain waveform U(nT);
wherein the transmitter and/or receiver is/are further configured to transmit and/or receive the elements of U(nT) sequentially via the single carrier frequency by transmitting and/or receiving U(T) via the single carrier frequency, followed by transmitting and/or receiving U(2T) via the single carrier frequency, . . . , followed by transmitting and/or receiving U(NT) via the single carrier frequency; and
wherein the processor is configured to form the desired spectrum shape to include:
a first plurality of frequencies over a first time interval; and
a second plurality of frequencies over a second time interval;
wherein the first plurality of frequencies differs from the second plurality of frequencies in at least one frequency.
12. The communications system according to claim 11 , wherein the processor is configured to form the desired spectrum shape to include:
a first frequency interval comprising a first spectral level that is non-zero and a second frequency interval comprising a second spectral level that is substantially zero.
13. The communications system according to claim 12 , wherein the processor is configured to form the desired spectrum shape to further include:
a third frequency interval comprising a third spectral level that is non-zero;
wherein the second frequency interval that comprises the second spectral level that is substantially zero is situated between the first and third frequency intervals.
14. A communications system comprising:
a processor that is configured to form a desired spectrum shape for a waveform and to generate the waveform responsive to the desired spectrum shape; and
a transmitter and/or receiver that is/are configured to transmit and/or receive information by transmitting and/or receiving a plurality of elements of the waveform sequentially one after another via a single carrier frequency;
wherein the processor is configured to generate the waveform responsive to the desired spectrum shape by generating a discrete time-domain waveform U(nT); wherein n denotes a discrete time index of U(nT); wherein n=1, 2, . . . , N; and NT≦τ; wherein τdenotes a time span of the discrete time-domain waveform U(nT);
wherein the transmitter and/or receiver is/are configured to transmit and/or receive information by transmitting and/or receiving a plurality of elements of the waveform sequentially one after another via a single carrier frequency by transmitting and/or receiving the elements of U(nT) sequentially via the single carrier frequency by transmitting and/or receiving U(T) via the single carrier frequency, followed by transmitting and/or receiving U(2T) via the single carrier frequency, . . . , followed by transmitting and/or receiving U(NT) via the single carrier frequency;
wherein the processor is configured to form the desired spectrum shape for the waveform to include:
at least one frequency that provides a frequency content to the waveform; and
at least one frequency that is excluded from providing a frequency content to the waveform; and
wherein the processor is further configured to form the desired spectrum shape to include:
a first plurality of frequencies over a first time interval; and
a second plurality of frequencies over a second time interval;
wherein the first plurality of frequencies differs from the second plurality of frequencies in at least one frequency.
15. The communications system according to claim 14 , wherein the processor is further configured to form the desired spectrum shape to include:
a first frequency interval comprising a first spectral level that is non-zero and to also include a second frequency interval comprising a second spectral level that is substantially zero.
16. The communications system according to claim 15 , wherein the processor is further configured to form the desired spectrum shape to further include:
a third frequency interval comprising a third spectral level that is non-zero;
wherein the second frequency interval that comprises the second spectral level that is substantially zero is situated between the first and third frequency intervals.
17. A communications method comprising:
selecting a frequency interval over which a waveform U(nT) is to exist; wherein n denotes a discrete time index and wherein n=1, 2, . . . , N;
allowing at least one frequency that is included in the selected frequency interval to provide a frequency content to the waveform U(nT);
excluding at least one frequency that is included in the selected frequency interval from providing a frequency content to the waveform U(nT);
forming the waveform U(nT) comprising a plurality of elements U(T), U(2T), . . . , U(NT), corresponding to respective integer values 1, 2, . . . , N of the discrete time index n; and
transmitting and/or receiving information by transmitting and/or receiving at a transmitter and/or at a receiver, the plurality of elements U(T), U(2T), . . . , U(NT) of the waveform U(nT) sequentially one after another via a single carrier frequency by first transmitting and/or receiving U(T) via the single carrier frequency, followed by transmitting and/or receiving U(2T) via the single carrier frequency, . . . , followed by transmitting and/or receiving U(NT) via the single carrier frequency;
wherein said forming the waveform U(nT) further comprises:
generating a first waveform using a first plurality of frequencies over a first time interval; and
generating a second waveform using a second plurality of frequencies over a second time interval;
wherein the second plurality of frequencies differs from the first plurality of frequencies in at least one frequency.
18. The communications method according to claim 17 , wherein said forming the waveform U(nT) comprises:
generating a waveform comprising a first spectral shape that is non-zero over a first plurality of frequencies that is included in said selected frequency interval and a second spectral shape that is substantially zero over a second plurality of frequencies that is also included in said selected frequency interval.
19. The communications method according to claim 17 , wherein said selecting a frequency interval over which a waveform U(nT) is to exist comprises:
identifying frequencies to be used to communicate; and
reducing a measure of interference by preferentially using the identified frequencies while refraining from using other frequencies.
20. The communications method according to claim 17 , wherein said selecting a frequency interval over which a waveform U(nT) is to exist comprises:
selecting a frequency interval that is between 1525 MHz and 1660.5 MHz and excluding a GPS frequency interval that is included therein.
21. The communications method according to claim 17 , wherein said forming the waveform U(nT) comprises:
using a Fourier transform and an inverse Fourier transform.
22. A communications system comprising:
a processor that is configured to select a frequency interval over which a waveform U(nT) is to exist, wherein n denotes a discrete time index and wherein n=1, 2, . . . , N; to allow at least one frequency that is included in the selected frequency interval to provide a frequency content to the waveform U(nT); to exclude at least one frequency that is included in the selected frequency interval from providing a frequency content to the waveform U(nT) and to form the waveform U(nT) comprising a plurality of elements U(T), U(2T), . . . , U(NT), corresponding to respective integer values 1, 2, . . . , N of the discrete time index n; and
a transmitter and/or receiver that is/are configured to transmit and/or receive information by transmitting and/or receiving the plurality of elements U(T), U(2T), . . . , U(NT) of the waveform U(nT) sequentially one after another via a single carrier frequency by first transmitting and/or receiving U(T) via the single carrier frequency, followed by transmitting and/or receiving U(2T) via the single carrier frequency, . . . , followed by transmitting and/or receiving U(NT) via the single carrier frequency;
wherein the processor is further configured to:
generate a first waveform using a first plurality of frequencies over a first time interval; and
generate a second waveform using a second plurality of frequencies over a second time interval;
wherein the second plurality of frequencies differs from the first plurality of frequencies in at least one frequency.
23. The communications system according to claim 22 , wherein the processor is further configured to:
generate a waveform comprising a first spectral shape that is non-zero over a first plurality of frequencies that is included in said selected frequency interval and a second spectral shape that is substantially zero over a second plurality of frequencies that is also included in said selected frequency interval.
24. The communications system according to claim 22 , wherein the processor is further configured to:
identify frequencies to be used to communicate such as to reduce a measure of interference and to preferentially use the identified frequencies and refrain from using other frequencies.
25. The communications system according to claim 22 , wherein the processor is further configured to:
select a frequency interval that is between 1525 MHz and 1660.5 MHz and exclude a GPS frequency interval that is included therein.
26. The communications system according to claim 22 , wherein the transmitter comprises a wireless transmitter.
27. The communications system according to claim 22 , wherein the processor is further configured to form the waveform U(nT) comprising the plurality of elements U(T), U(2T), . . . , U(NT) by using a Fourier transform and an inverse Fourier transform.
28. The communications system according to claim 27 , wherein the Fourier transform provides a spectrum shape that is altered in at least one frequency thereof responsive to an interference concern; and wherein the inverse Fourier transform provides a time-domain waveform responsive to the altered spectrum shape that is used by the processor to form the waveform.