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  Multicarrier orthogonal spread-spectrum(moss) data communicationsUSPTO Application #: 20080095214Title: Multicarrier orthogonal spread-spectrum(moss) data communications Abstract: Systems and methods are described for multicarrier orthogonal spread-spectrum (MOSS) data communication. A method includes individually spread-spectrum modulating at least two of a set of orthogonal frequency division multiplexed carriers, wherein the resulting individually spread-spectrum modulated at least two of a set of orthogonal frequency division multiplexed carriers are substantially mutually orthogonal with respect to both frequency division multiplexing and spread-spectrum modulation. (end of abstract) Agent: John Bruckner PC - Flagstaff, AZ, US Inventors: Stephen F. Smith, William B. Dress USPTO Applicaton #: 20080095214 - Class: 375131000 (USPTO) Related Patent Categories: Pulse Or Digital Communications, Spread Spectrum, Hybrid Form The Patent Description & Claims data below is from USPTO Patent Application 20080095214. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a continuation of, and claims a benefit of priority under 35 U.S.C. 120 from copending utility or design patent application U.S. Ser. No. 10/726,475, filed Dec. 3, 2003, the entire contents of which are hereby expressly incorporated herein by reference for all purposes. BACKGROUND OF THE INVENTION [0003] 1. Field of the Invention [0004] The invention relates generally to the field of communications. More particularly, the invention relates to methods of multicarrier orthogonal spread-spectrum communications, and machinery for transmitting and/or receiving such communications. [0005] 2. Discussion of the Related Art [0006] In digital data-transmission systems, the principal goal is generally to maximize the data-transmission rate, consistent with the legally permissible occupied RF (radio frequency) bandwidth for the signal and the available signal-to-noise ratio (SNR) for the selected channel or RF link path. An additional consideration is the maximum transmitted RF power levels allowed in the various bands. For instance, in the 902-928 MHz ISM (Industrial, Scientific, and Medical) band, up to 1 watt of RF power is currently permitted in the U.S., with a maximum isotropic antenna power gain of 4 (6 dBi); for higher antenna gains, the RF power must be reduced linearly to provide no more than 4 W EIRP (effective isotropic radiated power). In the 2.450-2.4835 GHz band, 1/4 watt of power can currently be used, with the same maximum antenna gain of 6 dBi, for a maximum nominal EIRP of 1 W; for higher antenna gains, the RF power must be reduced by 1 dB for every 3 dB of additional antenna gain. In the 5.725-5.825 GHz ISM band (which at present experiences the least RF interference of the three ISM bands and is thus preferred for data-link applications) for FCC-compliant spread-spectrum devices, up to 1 W of RF output power is currently permitted, without regard for antenna gains of greater than 6 dBi, so long as the minimum direct-sequence process gain of 10 dB is maintained. OFDM systems in the U.S. fall under specific Unlicensed National Information Infrastructure (U-NII) as well as ISM regulations. OFDM systems are presently not permitted at all in the 915-MHz ISM band and are limited to a 1/4-watt RF output power level in the 5.8-GHz ISM band (and much lower levels in the 5.1- and 5.3-GHz U-NII bands). SUMMARY OF THE INVENTION [0007] There is a need for the following aspects of the invention. Of course, the invention is not limited to these aspects. [0008] According to an aspect of the invention, a process comprises: individually spread-spectrum modulating at least two of a set of orthogonal frequency division multiplexed carriers, wherein the resulting individually spread-spectrum modulated at least two of a set of orthogonal frequency division multiplexed carriers are substantially mutually orthogonal with respect to both frequency division multiplexing and spread-spectrum modulation. According to another aspect of the invention, a process comprises: individually spread-spectrum demodulating at least two of a set of individually spread-spectrum modulated orthogonal frequency division multiplexed carriers that are substantially mutually orthogonal with respect to both frequency division multiplexing and spread-spectrum modulation. According to another aspect of the invention, a machine comprises: a plurality of orthogonal frequency division multiplex generators; a plurality of data modulators, each of the plurality of data modulators coupled to one of the plurality of orthogonal frequency division multiplex generators; and a linear summer coupled to the plurality of data modulators. According to another aspect of the invention, a machine comprises a plurality of demodulator/despreader circuits; and a plurality of low-pass filters, each of the plurality of low-pass filters coupled to one of the plurality of demodulator/despreader circuits. [0009] These, and other, aspects of the invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating various embodiments of the invention and numerous specific details thereof, is given by way of illustration and not of limitation. Many substitutions, modifications, additions and/or rearrangements may be made within the scope of the invention without departing from the spirit thereof, and the invention includes all such substitutions, modifications, additions and/or rearrangements. BRIEF DESCRIPTION OF THE DRAWINGS [0010] The drawings accompanying and forming part of this specification are included to depict certain aspects of the invention. A clearer conception of the invention, and of the components and operation of systems provided with the invention, will become more readily apparent by referring to the exemplary, and therefore nonlimiting, embodiments illustrated in the drawings. The invention may be better understood by reference to one or more of these drawings in combination with the description presented herein. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale. [0011] FIG. 1 illustrates a spectral plot of a multicarrier orthogonal spread-spectrum (MOSS) carrier set, representing an embodiment of the invention. [0012] FIG. 2 illustrates a block diagram of a MOSS transmitter, representing and embodiment of the invention. [0013] FIG. 3 illustrates a block diagram of a MOSS receiver, representing an embodiment of the invention. [0014] FIG. 4 illustrates a flow diagram of a MOSS multiplexing-modulating process that can be implemented by a computer program, representing an embodiment of the invention. [0015] FIG. 5 illustrates a flow diagram of a MOSS demodulating-demultiplexing process that can be implemented by a computer program, representing an embodiment of the invention. DESCRIPTION OF PREFERRED EMBODIMENTS [0016] The invention and the various features and advantageous details thereof are explained more fully with reference to the nonlimiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well known processing techniques, components and equipment are omitted so as not to unnecessarily obscure the invention in detail. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only and not by way of limitation. Various substitutions, modifications, additions and/or rearrangements within the spirit and/or scope of the underlying inventive concept will become apparent to those skilled in the art from this disclosure. [0017] Within this application several publications are referenced by Arabic numerals within parentheses. Full citations for these, and other, publications may be found at the end of the specification immediately preceding the claims after the section heading References. The disclosures of all these publications in their entireties are hereby expressly incorporated by reference herein for the purpose of indicating the background of the invention and illustrating the state of the art. [0018] The below-referenced U.S. patent applications disclose embodiments that are satisfactory for the purposes for which they are intended. The entire contents of U.S. patent application Ser. No. 10/726,446 (attorney docket number UBAT1420 also known as 2500940.991420), filed Dec. 3, 2003 are hereby expressly incorporated by reference herein for all purposes. The entire contents of U.S. patent application Ser. No. 09/671,636, filed Sep. 27, 2000, by William B. Dress, Stephen F. Smith and Michael R. Moore, entitled Hybrid Spread-Spectrum Technique for Expanding Channel Capacity, are hereby expressly incorporated by reference herein for all purposes. [0019] Several varieties of hybrid spread-spectrum modulation systems are disclosed in U.S. Ser. No. 09/671,636 and in textbook and journal articles (1-3). However, none of these approaches includes spread-spectrum modulating a plurality of OFDM carriers. Further, none of these approaches realize a constant spread-spectrum process gain to uniformly reject cross-user interference and simultaneously meet the specific requirements of the FCC for full-power ISM band devices. [0020] To be operable at the full 1-watt level permitted by the FCC for true spread-spectrum ISM devices, the signal must provide a minimum 10-dB processing gain. Standard orthogonal frequency-division multiplex (OFDM) systems (i.e., typical U-NII devices) are not intrinsically spread-spectrum and, therefore, cannot achieve the required 10-dB minimum processing gain. To realize a long-distance, high data-rate RF link, where the main-beam SNR is critical to achieving maximum data throughput rates with low errors, the need for an FCC-recognized ISM spread-spectrum modulation method is vital, since only through this specific protocol can very high antenna gains be employed without a concurrent reduction in the radiated RF power (and, therefore link SNR). Continue reading... Full patent description for Multicarrier orthogonal spread-spectrum(moss) data communications Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Multicarrier orthogonal spread-spectrum(moss) data communications patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. 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