Multicarrier Sub-Layer for Direct Sequence Channel and Multiple-Access Coding

• US 20070211786A1
• Filed: 01/08/2007
• Published: 09/13/2007
• Est. Priority Date: 02/12/1998
• Status: Active Grant

• Current Assignee: Genghiscomm Holdings, LLC
• Original Assignee: Lot 41 Acquisition Foundation LLC (Intellectual Ventures LLC)
• Inventors: Shattil, Steve
• Granted Patent: US 7,593,449 B2
• Time in Patent Office: Days
• US Class Current: 375/141
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 1/7095 Sliding correlator type
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713
• CPC Class Codes: H04J 13/10 Code generation
• CPC Class Codes: H04J 13/18 Allocation of orthogonal codes
• CPC Class Codes: H04J 2013/0037 Multilevel codes
• CPC Class Codes: H04L 1/0056 Systems characterized by the type of code used H04L1/08 takes precedence
• CPC Class Codes: H04L 1/04 using frequency diversity
• CPC Class Codes: H04L 25/0202 Channel estimation
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 27/2637 with direct modulation of individual subcarriers
• CPC Class Codes: H04L 5/0021 in which codes are applied as a frequency-domain sequences, e.g. MC-CDMA

Abstract

Carrier Interferometry (CI) provides wideband transmission protocols with frequency-band selectivity to improve interference rejection, reduce multipath fading, and enable operation across non-continuous frequency bands. Direct-sequence protocols, such as DS-CDMA, are provided with CI to greatly improve performance and reduce transceiver complexity. CI introduces families of orthogonal polyphase codes that can be used for channel coding, spreading, and/or multiple access. Unlike conventional DS-CDMA, CI coding is not necessary for energy spreading because a set of CI carriers has an inherently wide aggregate bandwidth. Instead, CI codes are used for channelization, energy smoothing in the frequency domain, and interference suppression. CI-based ultra-wideband protocols are implemented via frequency-domain processing to reduce synchronization problems, transceiver complexity, and poor multipath performance of conventional ultra-wideband systems. CI allows wideband protocols to be implemented with space-frequency processing and other array-processing techniques to provide either or both diversity combining and sub-space processing. CI also enables spatial processing without antenna arrays. Even the bandwidth efficiency of multicarrier protocols is greatly enhanced with CI. CI-based wavelets avoid time and frequency resolution trade-offs associated with conventional wavelet processing. CI-based Fourier transforms eliminate all multiplications, which greatly simplifies multi-frequency processing. The quantum-wave principles of CI improve all types of baseband and radio processing.

Claims

1. A receiver system including:

a multi-element receiver adapted to receive a plurality of interfering signals,

a sub-space processor coupled to the multi-element receiver, the processor adapted to generate a plurality of sub-space values from a plurality of signal sub-spaces, and

a sub-space decoder coupled to the processor, the decoder adapted to correlate at least one reference code with at least a subset of the plurality of sub-space values to decode at least one data symbol.

2. The receiver system recited in claim 1 wherein the decoder is adapted to decode the at least one data symbol with at least one of the set of codes including a Carrier Interferometry (CI) code, an MC-CDMA code, a direct-sequence code.

3. The receiver system recited in claim 1 wherein the decoder is adapted to decode the at least one data symbol with at least one of the set of codes including a channel code and a multiple-access code.

4. The receiver system recited in claim 1 wherein the decoder is adapted to decode the at least one data symbol with at least one of the set of codes including an orthogonal code and a quasi-orthogonal code.

5. A transmitter system including:

a multi-element transmitter adapted to transmit a plurality of interfering signals,

a sub-space processor coupled to the multi-element transmitter, the processor adapted to generate a plurality of signal sub-spaces, and

a coder coupled to the sub-space processor, the coder adapted to receive at least one code and at least one data symbol to generate at least one encoded data symbol therefrom, the coder adapted to encode the plurality of signal sub-spaces with the at least one encoded data symbol.

6. The transmitter system recited in claim 5 wherein the coder is adapted to encode the at least one data symbol with at least one of a set of codes including a CI code, an MC-CDMA code, and a direct-sequence code.

7. The transmitter system recited in claim 5 wherein the coder is adapted to encode the at least one data symbol with at least one of a set of codes including a channel code, an encryption code, a spreading code, and a multiple-access code.

8. The transmitter system recited in claim 5 wherein the coder is adapted to encode the at least one data symbol with at least one of the set of codes including an orthogonal code and a quasi-orthogonal code.

9. A method for providing communication signals according to operating parameters using CI, said operating parameters including symbol duration, guard time interval, number of CI carriers, carrier-frequency spacing, carrier-frequency offset, and number of bits per symbol per CI carrier, said method comprising the step of:

receiving a feedback signal from a receiver;

determining that an operating characteristic of said method should be scaled from a first level to at least a second level based on said feedback signal received from said receiver, said operating characteristic including at least one of transmission rate, signal-to-noise ratio, probability of error, and delay-spread tolerance; and

dynamically scaling at least one of said operating parameters for said method to achieve an operating characteristic of said second level by adaptively selecting one of a plurality of operating parameter scaling options in accordance with said determining step.

10. A CI system adapted to provide communication signals according at least one operating parameter of a set including symbol duration, guard time interval, number of CI carriers, carrier-frequency spacing, carrier frequency offset, and number of bits per symbol per CI carrier, said system comprising:

dynamic control circuitry adapted to receive a feedback signal from a receiver and determine whether at least one operating characteristic of said method should be scaled from a first level to a second level based on said feedback signal, said at least one operating characteristic including at least one of transmission rate, signal-to-noise ratio, probability of error, and delay-spread tolerance, and, after determining that said operating characteristic for providing communication signals should be scaled from said first level to said second level based on said feedback signal, provides at least one control signal, and

signal circuitry adapted to be responsive to the at least one control signal to dynamically scale at least one of said operating parameters to achieve said operating characteristic of said second level, said control circuitry controlling at least one scalable operating characteristic by adaptively selecting at least one of a plurality of operating parameter scaling options.

11. A CI-code generator adapted to generate at least one CI code, the CI-code generator including:

a CI-symbol generator adapted to generate a plurality of CI symbols, and

a symbol combiner coupled to the CI-symbol generator, the symbol combiner adapted to select at least one set of the CI symbols to generate at least one CI code.

12. The CI-code generator recited in claim 11 wherein the CI-symbol generator further includes a code processor adapted to process at least one set of CI-based symbols with at least one other symbol set to generate the plurality of CI symbols.

13. The CI-code generator recited in claim 12 wherein the code processor is adapted to process at least one set of CI-based symbols with at least one code of a code set including spread-spectrum codes, multiple-access codes, channel codes, sub-channel codes, encryption codes, multi-level codes, compression codes, hybrid codes, and CI codes.

14. A CI transmitter adapted to encode at least one information signal with at least one CI code, the CI transmitter including:

a CI-code generator adapted to generate at least one CI code,

a CI encoder coupled to the CI-code generator, the CI encoder adapted to impress at least one information signal onto the at least one CI code to generate at least one CI-encoded signal, and

a transmission system coupled to at least one communication channel and at least one of the CI-code generator and the modulator, the transmission system adapted to process the at least one CI-encoded signal for transmission into the at least one communication channel.

15. The CI transmitter recited in claim 14 wherein the CI-code generator is adapted to generate at least one code of a code set including a multiple-access code, a spreading code, a channel code, an encryption code, a sub-channel code, an error-correction code, a hybrid code, a multi-level code, and a compression code.

16. A transmitter for a communication system including:

a CI coder adapted to generate a plurality of algebraically unique linear combinations of a plurality of information signals, and

a modulator adapted to impress each of the linear combinations onto a plurality of diversity-parameter values.

17. A CI coder including:

a CI-code generator capable of generating a plurality of CI codes,

a modulator adapted to modulate a plurality of information signals onto a plurality of the CI codes, and

a CI symbol generator adapted to combine a plurality of information-modulated CI-code chips to generate a plurality of CI symbols.

18. A CI decoder including:

an input adapted to provide a plurality of received CI symbols,

a CI-code generator capable of generating at least one reference CI code, and

a combiner adapted to combine the received CI symbols relative to the at least one reference CI code to generate at least one estimated information signal.

19. A transmitter system including:

a CI signal generator adapted to produce a plurality of information-bearing CI symbols distributed over at least a first set of diversity-parameter values, and

a multi-element transmitter adapted to distribute the CI symbols over at least a second set of diversity-parameter values.

20. A transmitter system including:

a CI-symbol generator adapted to generate a plurality of information-bearing CI symbols,

a weighting system adapted to provide at least one weight to at least one of the CI symbols to perform at least one of a set of functions including time-domain shaping, frequency-domain shaping, crest-factor reduction, encryption, beam forming, and channel compensation, and

a modulator adapted to impress the weighted CI symbols onto at least one set of diversity-parameter values.

21. A method of generating CI signals including:

providing for channel estimation,

providing for generating a plurality of CI carriers, and

providing for pre-transmission processing of the CI carriers to provide channel compensation.

22. A software-defined CI transmitter including:

at least one hardware component including at least one computer processing unit and at least one memory device adapted to support at least one software application program, and

at least one software module including at least one application program adapted to perform carrier selection and carrier weighting such that a superposition of the weighted carriers is provided with at least one of a set of predetermined signal parameters, the set including formatting, source coding, encryption, sub-channel coding, channel coding, multiplexing, modulation, spread-spectrum coding, and multiple-access coding.

23. A filter including:

a sampler adapted to collect a plurality of samples of at least one band-limited signal, and

a combiner adapted to combine a plurality of the samples with respect to at least one function generated from a superposition of subcarriers.

24. A filter including:

a sampler adapted to generate a plurality of samples of at least one band-limited signal, the sampler provided with at least one predetermined sample rate and at least one predetermined sample width, and

a combiner adapted to combine a plurality of the samples with respect to at least one function representing a superposition of subcarriers, the combiner provided with at least one predetermined time interval over which the samples are combined.

25. A CI transmitter including:

a step-function generator adapted to generate at least one multicarrier signal, a modulator adapted to impress at least one information signal onto at least one multicarrier signal, and

a filter adapted to band-limit the at least one information-modulated multicarrier signal.

26. A CI transceiver including:

a CI transceiver system having at least one controllable transceiver-operation characteristic,

at least one control circuit coupled to the CI transceiver system, the at least one control circuit adapted to control at least one CI signal parameter, the at least one control circuit being responsive to at least one of a set including system requirements and channel characteristics.