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.

1 . A method, comprising 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.  
   
   
       2 . The method of  claim 1 , further comprising individually spread-spectrum modulating at least two of another set of orthogonal frequency division multiplexed carriers, wherein the resulting individually spread-spectrum modulated at least two of the another set of orthogonal frequency division multiplexed carriers are substantially mutually orthogonal with respect to both frequency division multiplexing and spread-spectrum modulation.  
   
   
       3 . The method of  claim 1 , wherein spread-spectrum modulating includes direct-sequence spreading using a pseudorandom maximal linear sequence.  
   
   
       4 . The method of  claim 1 , wherein spread-spectrum modulating includes direct-sequence spreading using at least one code selected from the group consisting of a Gold code derived from combinations of a plurality of maximal linear sequence polynomials and a Kasami code derived from combinations of a plurality of maximal linear sequence polynomials.  
   
   
       5 . The method of  claim 1 , wherein spread-spectrum modulating includes direct-sequence spreading using a fully orthogonal Walsh polynomial code set.  
   
   
       6 . The method of  claim 1 , wherein frequency division adjacent individually spread-spectrum modulated orthogonal frequency division multiplexed carriers are spread-spectrum modulated by at least one member selected from the group consisting of mutually orthogonal Fourier codes and mutually orthogonal wavelet codes.  
   
   
       7 . The method of  claim 1 , further comprising modulating at least one of the individually spread-spectrum modulated orthogonal frequency division multiplexed carriers using at least one modulation technique selected from the group consisting of BPSK, QPSK, OQPSK, MSK, and n-QAM.  
   
   
       8 . The method of  claim 1 , further comprising spread-spectrum demodulating at least two of the set of individually spread-spectrum modulated orthogonal frequency division multiplexed carriers.  
   
   
       9 . The method of  claim 8 , further comprising orthogonal frequency division demultiplexing the demodulated individually spread-spectrum modulated orthogonal frequency division multiplexed carriers.  
   
   
       10 . A method comprising: 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.  
   
   
       11 . The method of  claim 10 , further comprising individually spread-spectrum demodulating at least two of another 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.  
   
   
       12 . The method of  claim 10 , wherein spread-spectrum demodulating includes direct-sequence despreading using a pseudorandom maximal linear sequence.  
   
   
       13 . The method of  claim 10 , wherein spread-spectrum demodulating includes direct-sequence despreading using at least one code selected from the group consisting of a Gold code derived from combinations of a plurality of maximal linear sequence polynomials and a Kasami code derived from combinations of a plurality of maximal linear sequence polynomials.  
   
   
       14 . The method of  claim 10 , wherein spread-spectrum demodulating includes direct-sequence despreading using a fully orthogonal Walsh polynomial code set.  
   
   
       15 . The method of  claim 10 , wherein frequency division adjacent individually spread-spectrum modulated orthogonal frequency division multiplexed carriers are spread-spectrum demodulated by at least one member selected from the group consisting of mutually orthogonal Fourier codes and mutually orthogonal wavelet codes.  
   
   
       16 . The method of  claim 10 , further comprising demodulating at least one of the individually spread-spectrum modulated orthogonal frequency division multiplexed carriers using at least one modulation technique selected from the group consisting of BPSK, QPSK, OQPSK, MSK, and n-QAM.  
   
   
       17 . The method of  claim 10 , further comprising orthogonal frequency division demultiplexing the demodulated individually spread-spectrum modulated orthogonal frequency division multiplexed carriers.  
   
   
       18 . An apparatus, comprising: 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.  
   
   
       19 . The apparatus of  claim 18 , further comprising a radio-frequency power amplifier coupled to the linear summer and an antenna coupled to the radio-frequency power amplifier.  
   
   
       20 . An apparatus, comprising 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.  
   
   
       21 . The apparatus of  claim 20 , wherein each of the demodulator/despreader circuits and the associated low-pass filters composes a digital signal processor.  
   
   
       22 . The apparatus of  claim 21 , further comprising an analog-to-digital converter coupled to the digital signal processor.  
   
   
       23 . The apparatus of  claim 20 , further comprising an intermediate-frequency amplifier chain coupled to the plurality of demodulator/despreader circuits; an intermediate-frequency bandpass filter coupled to the intermediate-frequency amplifier chain; a radio-frequency downconverter coupled to the intermediate-frequency bandpass filter; a low-noise radio-frequency amplifier coupled to the radio-frequency downconverter; and an antenna coupled to the low-noise radio-frequency amplifier.