Carrier interferometry transmitter
A transmitter in a wireless communication network comprises a Carrier Interferometry (CI) coder and a multicarrier modulator communicatively coupled to the CI coder. The CI coder encodes a plurality of data symbols with a plurality of CI codes to produce a plurality of CI symbol values, wherein each of the plurality of CI symbol values equals a sum of information-modulated CI code chips. Each information-modulated CI code chip equals a CI code chip multiplied by one of the plurality of data symbols. The modulator modulates each CI symbol value onto a different subcarrier frequency to produce a multicarrier signal.
1. A method of communication for use in a wireless communication network, with the wireless communication network employing a first set of complex-valued codes to encode data symbols to be transmitted and a second set of complex-valued codes to recover transmitted data symbols from a received signal, the method comprising:
enabling a device for use in the wireless communication network, wherein enabling the device comprises using a processor configured for:
selecting a plurality of subcarriers to be transmitted;
encoding the data symbols with the first set of complex-valued codes to produce encoded data symbols;
applying the encoded data symbols to the plurality of subcarriers to produce a spread-Orthogonal Frequency Division Multiplexing (OFDM) signal; and
communicating the spread-OFDM signal to a transmitter located in the device that transmits the spread-OFDM signal in the wireless communication network;
wherein the first set of complex-valued codes are complex conjugates of the second set of complex-valued codes.
2. The method of claim 1 , wherein encoding the data symbols comprises configuring the processor to employ an invertible transform.
3. The method of claim 1 , wherein the first set of complex-valued codes comprise complex values of a discrete Fourier transform matrix.
4. The method of claim 1 , wherein the processor is configured to append a cyclic prefix or a guard interval to the spread-OFDM signal.
5. The method of claim 1 , wherein selecting the plurality of subcarriers comprises selecting one of a plurality of selectable subcarrier-frequency spacings.
6. The method of claim 1 , wherein the plurality of subcarriers have contiguous subcarrier frequencies or non-contiguous subcarrier frequencies.
7. The method of claim 1 , wherein the plurality of subcarriers comprises a number N of subcarriers with a frequency spacing fs, and applying the encoded data symbols to the plurality of subcarriers produces a sufficient number of samples in the spread-OFDM signal to produce a main lobe duration of 2/N·fs and side lobe duration of 1/N·fs.
8. The method of claim 1 , wherein the transmitter is configured to aggregate multiple frequency bands to transmit the spread-OFDM signal.
9. A wireless terminal for communication in a wireless communication network, with the wireless communication network employing a first set of complex-valued codes to encode data symbols to be transmitted and a second set of complex-valued codes to recover transmitted data symbols from a received signal, the wireless terminal comprising:
a baseband processor coupled to the transmitter, and configured to:
select a plurality of subcarriers to be transmitted;
encode the data symbols with the first set of complex-valued codes to produce encoded data symbols;
apply the encoded data symbols to the plurality of subcarriers to produce a spread-Orthogonal Frequency Division Multiplexing (OFDM) signal; and
a transmitter coupled to the baseband processor, the transmitter configured to transmit the spread-OFDM signal in the wireless communication network;
wherein the first set of complex-valued codes are complex conjugates of the second set of complex-valued codes.
10. The apparatus of claim 9 , wherein the baseband processor employs an invertible transform to encode the data symbols.
11. The apparatus of claim 9 , wherein the first set of complex-valued codes comprise complex values of a discrete Fourier transform matrix.
12. The apparatus of claim 9 , wherein the baseband processor is configured to append a cyclic prefix or a guard interval to the spread-OFDM signal.
13. The apparatus of claim 9 , wherein the baseband processor is configured to select one of a plurality of selectable subcarrier-frequency spacings.
14. The apparatus of claim 9 , wherein the plurality of subcarriers is selected to have contiguous subcarrier frequencies or non-contiguous subcarrier frequencies.
15. The apparatus of claim 9 , wherein the plurality of subcarriers comprises a number N of subcarriers with a frequency spacing fs, and the baseband processor is configured to produce a sufficient number of samples in the spread-OFDM signal to produce a main lobe duration of 2/N·fs and side lobe duration of 1/N·fs.
16. The apparatus of claim 9 , wherein the transmitter is configured to aggregate multiple frequency bands to transmit the spread-OFDM signal.
17. A method of provisioning a baseband processor for communication in a wireless communication network, with the wireless communication network employing a first set of complex-valued codes to encode data symbols to be transmitted and a second set of complexvalued codes to recover transmitted data symbols from a received signal, the method comprising:
configuring the baseband processor to select a plurality of subcarriers to be transmitted;
configuring the baseband processor to encode the data symbols with the first set of complex-valued codes to produce encoded data symbols;
configuring the baseband processor to apply the encoded data symbols to the plurality of subcarriers to produce a spread-Orthogonal Frequency Division Multiplexing (OFDM) signal; and
configuring the baseband processor to communicate the spread-OFDM signal to a transmitter that transmits the spread-OFDM signal in the wireless communication network;
wherein the first set of complex-valued codes are complex conjugates of the second set of complex-valued codes.
18. The method of claim 17 , wherein configuring the baseband processor to encode the data symbols comprises configuring the baseband processor to employ an invertible transform.
19. The method of claim 17 , wherein the first set of complex-valued codes comprise complex values of a discrete Fourier transform matrix.
20. The method of claim 17 , further comprising configuring the baseband processor to append a cyclic prefix or a guard interval to the spread-OFDM signal.
21. The method of claim 17 , wherein configuring the baseband processor to select the plurality of subcarriers comprises selecting one of a plurality of selectable subcarrier-frequency spacings.
22. The method of claim 17 , wherein the plurality of subcarriers have contiguous subcarrier frequencies or non-contiguous subcarrier frequencies.
23. The method of claim 17 , wherein the plurality of subcarriers comprises a number N of subcarriers with a frequency spacing fs, and configuring the baseband processor to apply the encoded data symbols to the plurality of subcarriers produces a sufficient number of samples in the spread-OFDM signal to produce a main lobe duration of 2/N·fs and side lobe duration of 1/N·fs.
24. The method of claim 17 , wherein the transmitter is configured to aggregate multiple frequency bands to transmit the spread-OFDM signal.