Orthogonal superposition coding for direct-sequence communications

• US 20040086027A1
• Filed: 04/16/2003
• Published: 05/06/2004
• Est. Priority Date: 10/31/2002
• Status: Active Grant

• Current Assignee: Arnold Alagar, Department 13, Inc. (Department 13 International Ltd.), Steve Shattil
• Original Assignee: Lot 41 Acquisition Foundation LLC (Intellectual Ventures LLC)
• Inventors: Shattil, Steve J.
• Granted Patent: US 7,317,750 B2
• Time in Patent Office: Days
• US Class Current: 375/146
• CPC Class Codes: H04L 2025/03414 Multicarrier
• CPC Class Codes: H04L 2025/03426 transmission using multiple-input and multiple-output channels
• CPC Class Codes: H04L 25/022 of frequency response
• CPC Class Codes: H04L 25/03159 operating in the frequency domain H04L25/03165, H04L25/03178 take precedence
• CPC Class Codes: H04L 25/03834 using pulse shaping
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/26035 Maintenance of orthogonality, e.g. for signals exchanged between cells or users, or by using covering codes or sequences using different training sequence per antenna H04B7/0684; code allocation H04J13/16
• CPC Class Codes: H04L 27/2621 Reduction thereof using phase offsets between subcarriers
• CPC Class Codes: H04L 27/2631 with polyphase implementation
• CPC Class Codes: H04L 27/26416 Filtering per subcarrier, e.g. filterbank multicarrier [FBMC]
• CPC Class Codes: H04L 27/26524 Fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators in combination with other circuits for demodulation
• CPC Class Codes: H04L 27/2654 Filtering per subcarrier, e.g. filterbank multicarrier [FBMC]
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0026 Division using four or more dimensions
• CPC Class Codes: H04L 5/0039 Frequency-contiguous, i.e. with no allocation of frequencies for one user or terminal between the frequencies allocated to another
• CPC Class Codes: H04L 5/0064 Rate requirement of the data, e.g. scalable bandwidth, data priority

Abstract

An adaptation to Carrier Interferometry synthesis and analysis provides for complex coding and decoding in a sliding window transform. Coding and decoding functionality can be extended to spatial processing in systems employing multiple transceiver elements. Poly-amplitude codes permit successive interference cancellation in spatial and frequency-domain processing. Handoffs in cellular systems are facilitated by selecting spectral/base station combinations that optimize link performance.

Claims

1. A multi-carrier signal comprising:

at least one set of complex sub-carrier weights embodied in a predetermined plurality of subcarriers and adapted to;

map a plurality of data symbols to a plurality of pulse positions for producing a sequence of modulated pulses with spectral components characterized by the predetermined plurality of subcarriers.

2. The multi-carrier signal recited in claim 1 wherein the complex sub-carrier weights are adapted to reduce the peak-to-average power of a signal transmission in a transmitter.

3. The multi-carrier signal recited in claim 1 wherein the plurality of data symbols include at least one of a set of data symbols, including a spread-spectrum code, a multiple-access code, a channel code, a sequence of data symbols, a data-modulated spread-spectrum code, a data-modulated multiple-access code, a data modulated channel code, a data-modulated and channel-coded multiple-access code, a data-modulated and channel-coded spread-spectrum code, and a data-modulated spread-spectrum modulated multiple-access code.

4. The multi-carrier signal recited in claim 1 wherein the complex sub-carrier weights are generated from one or more CI codes.

5. The multi-carrier signal recited in claim 1 wherein the complex sub-carrier weights are generated with a fast transform algorithm.

6. The multi-carrier signal recited in claim 1 wherein the at least one set of complex sub-carrier weights is adapted to provide each pulse in the sequence of modulated pulses with at least one predetermined pulse shape.

7. The multi-carrier signal recited in claim 1 wherein the plurality of data symbols is provided with at least one spectrum-shaping code adapted to perform at least one spectrum-shaping function, including shaping the spectral components and selecting a subset of the spectral components.

8. The multi-carrier signal recited in claim 1 wherein the sequence of modulated pulses is characterized by at least one pulse width and at least one pulse separation, at least one of the at least one pulse width and the at least one pulse separation being adapted to provide at least one of a set of pulse sequences, the set of pulse sequences including an orthogonally positioned sequence of modulated pulses and a pseudo-orthogonally positioned sequence of modulated pulses.

9. The multi-carrier signal recited in claim 1 wherein the predetermined set of subcarriers are selected relative to at least one of a set of conditions, including availability of spectrum, multipath fading, interference, quality of service, link priority, throughput requirements of at least one user, network load, and geographical location of at least one user.

10. The multi-carrier signal recited in claim 1 wherein the predetermined set of subcarriers are provided with at least one of a set of sub-carrier selections, including contiguous frequencies, non-contiguous equally spaced frequencies, unequally spaced frequencies, hopped frequencies, and chirped frequencies.

11. The multi-carrier signal recited in claim 1 wherein the plurality of data symbols includes data symbols allocated to a plurality of users, the multi-carrier, signal adapted to provide for multiple access with respect to at least one multiple-access technique, including time division multiple access, frequency division multiple access, code division multiple access, and space division multiple access.

12. The multi-carrier signal recited in claim 1 further including at least one of a set of guard intervals, the set including a cyclic prefix, a cyclic postfix, and a sequence of zeros.

13. A multi-carrier transmitter for communications including:

a sub-carrier allocator adapted to allocate at least one set of subcarriers for communication,

a pulse generator coupled to the sub-carrier allocator, the pulse generator adapted to generate a plurality of pulses having spectral components corresponding to the at least one set of subcarriers,

a modulator coupled to at least one of the sub-carrier allocator and the pulse generator, the modulator adapted to impress at least one data symbol onto the plurality of pulses, and

a sequential pulse positioner coupled to at least one of the sub-carrier allocator, the pulse generator, and the modulator, the sequential pulse positioner adapted to sequentially position the plurality of pulses.

14. The multi-carrier transmitter recited in claim 13 further including a coder coupled to the modulator, the coder adapted to encode the at least one data symbol with at least one code from a set of codes, including a spread-spectrum code, a multiple-access code, a spectrum-shaping code, a channel code, and an encryption code.

15. The multi-carrier transmitter recited in claim 13 further including a cyclic-prefix prepender coupled to at least one of the pulse generator ad the sequential pulse positioner, the cyclic-prefix prepender adapted to provide the plurality of pulses with at least one of a set of guard intervals, the set including a cyclic prefix, a cyclic postfix, and a sequence of zeros.

16. The multi-carrier transmitter recited in claim 13 wherein the pulse generator is adapted to combine the at least one set of subcarriers to generate the plurality of pulses.

17. The multi-carrier transmitter recited in claim 13 wherein the pulse generator includes a subcarrier weighting module and a sub-carrier combiner, the subcarrier weighting module adapted to impress at least one set of complex weights onto the at least one set of subcarriers to generate a plurality of weighted subcarriers, the at least one set of complex weights being generated from at least one CI code, and the sub-carrier combiner adapted to combine the weighted subcarriers to produce the plurality of pulses.

18. The multi-carrier transmitter recited in claim 13 wherein at least one of the sub-carrier allocator, the pulse generator, the modulator, and the sequential pulse positioner are adapted to provide for multiple access with respect to at least one multiple-access technique, including time division multiple access, frequency division multiple access, code division multiple access, and space division multiple access.

19. The multi-carrier transmitter recited in claim 13 wherein the sub-carrier allocator is configured to allocate the at least one set of subcarriers with respect to at least one of a set of conditions, including availability of spectrum, multipath fading, interference, quality of service, link priority, throughput requirements of at least one user, network load, and geographical location of at least one user.

20. The multi-carrier transmitter recited in claim 13 wherein the sequential pulse positioner is configured position the plurality of pulses to provide at least one of a set of pulse sequences, the set of pulse sequences including an orthogonally positioned sequence of modulated pulses and a pseudo-orthogonally positioned sequence of modulated pulses.

21. The multi-carrier transmitter recited in claim 13 wherein the pulse generator is adapted to shape the plurality of pulses.

22. The multi-carrier transmitter recited in claim 13 wherein the pulse generator is adapted to perform at least one spectrum-shaping function, including weighting the at least one set of subcarriers and selecting a subset of the at least one set of subcarriers.

23. A receiver for communications including:

a sliding-window transform adapted to perform a time-domain to frequency-domain transform of at least one received signal to generate a plurality of sets of frequency-domain components, each set corresponding to a sliding transform window with a unique time offset, and

a Carrier Interferometry (CI) decoder coupled to the sliding-window transform, the CI decoder adapted to coherently combine the sets of frequency-domain components to generate a sequence of estimated symbols values.

24. The receiver recited in claim 23 further including a frequency-domain equalizer coupled between the sliding-window transform and the CI decoder.

25. The receiver recited in claim 23 wherein the at least one received signal includes at least one of a set of signal types, including single-carrier signals and multi-carrier signals.

26. The receiver recited in claim 23 further including a multiple-access processor adapted to provide for multiple access with respect to at least one multiple-access technique, including time division multiple access, frequency division multiple access, code division multiple access, and space division multiple access.

27. The receiver recited in claim 23 further including a plurality of receiver inputs, the sliding-window transform including a plurality of sliding window transform modules, and the CI decoder being configured to perform a frequency-domain processing and a spatial processing of the sets of frequency-domain components.

28. The receiver recited in claim 27 wherein the CI decoder is configured to perform at least one of optimal combining, multi-user detection, and interference cancellation.

29. The receiver recited in claim 27 wherein the CI decoder is configured to combine the frequency-domain processing and the spatial processing into a unified spectral/spatial calculation.

30. The receiver recited in claim 23 further including a channel analyzer coupled to at least one of the CI decoder and the sliding-window transform, the channel analyzer adapted to enhance combining performance in the CI decoder by compensating for channel distortions.

31. The receiver recited in claim 23 further including a channel analyzer coupled to at least one of the CI decoder and the sliding-window transform, the channel analyzer adapted to estimate performance on the frequency-domain components transmitted by a plurality of base stations and select a preferential set of frequency-domain component/base station combinations therefrom.