Adaptative Multi-Carrier Code Division Multiple Access

Abstract

A system for performing adaptative multi-carrier code division multiple access (AMC-CDMA) includes first circuitry and modulator circuitry. The first circuitry determines a channel performance metric for each of a plurality of channels. The first circuitry determines at least one parameter of bit loading for each of the channels based on the channel performance metric. The modulator circuitry modulates AMC-CDMA signals using the parameters for bit loading in each of the channels for transmission over a wired connection.

1 . A system comprising:
 first circuitry configured to determine a channel performance metric for each of a plurality of carriers, and further configured to determine, for each carrier of the plurality of carriers, at least one parameter selected from the group consisting of a number of CDMA sequences over the carrier, a length of a CDMA sequence, a length of a chip in a CDMA sequence, and a number of bits of a constellation of modulation, at least one of the selected parameters being determined based on the determined channel performance metric for that carrier;   modulator circuitry configured to modulate AMC-CDMA signals in each carrier of the plurality of carriers using for each carrier the at least one determined parameter for that carrier; and   a coupler configured to couple the modulator circuitry to a wire for transmission of the modulated AMC-CDMA signals over the wire.   
     
     
         2 . The system of  claim 1  wherein the channel performance metric comprises a signal-to-noise ratio. 
     
     
         3 . The system of  claim 1  wherein the channel performance metric comprises a bit error rate. 
     
     
         4 . The system of  claim 1  wherein the coupler comprises a power line connection and the wire comprises a power line. 
     
     
         5 . The system of  claim 1  wherein the coupler comprises a coaxial connection and the wire comprises a coaxial cable. 
     
     
         6 . The system of  claim 1  wherein the at least one parameter comprises the number of CDMA sequences over the carrier and at least one of a length of a CDMA sequence, a length of a chip in a CDMA sequence, and a number of bits of a constellation of modulation. 
     
     
         7 . The system of  claim 6  wherein the at least one parameter further comprises a number of bits of a constellation of modulation. 
     
     
         8 . The system of  claim 7  wherein the at least one parameter further comprises a length of a CDMA sequence. 
     
     
         9 . The system of  claim 7  wherein the at least one parameter further comprises a length of a chip in a CDMA sequence. 
     
     
         10 . The system of  claim 1  further comprising a serial to parallel converter configured to receive a serial signal, convert the serial signal to a parallel signal, and provide the parallel signal to the modulator circuitry. 
     
     
         11 . The system of  claim 1  further comprising a PN code generator configured to generate PN codes for the AMC-CDMA signals. 
     
     
         12 . The system of  claim 1  further comprising inverse fast Fourier transform (IFFT) circuitry configured to perform IFFT functions on the AMC-CDMA signals. 
     
     
         13 . The system of  claim 1  further comprising receiver circuitry configured to receive and decode the AMC-CDMA signals. 
     
     
         14 . A method comprising:
 determining a channel performance metric for each carrier of a plurality of carriers;   determining for each carrier, of the plurality of carriers, at least one parameter from the group consisting of a number of CDMA sequences over the carrier, a length of a CDMA sequence, a length of a chip in a CDMA sequence, and a number of bits of a constellation of modulation, at least one of the determined parameters being determined based on the determined channel performance metric for that carrier;   modulating AMC-CDMA signals in each carrier of the plurality of carriers using for each carrier the at least one determined parameter for that carrier; and   transmitting the AMC-CDMA signals over a wired connection.   
     
     
         15 . The method of  claim 14  wherein the channel performance metric comprises a signal-to-noise ratio. 
     
     
         16 . The method of  claim 14  wherein the channel performance metric comprises a bit error rate. 
     
     
         17 . The method of  claim 14  wherein the wired connection comprises a power line connection. 
     
     
         18 . The method of  claim 14  further comprising generating PN codes for the AMC-CDMA signals. 
     
     
         19 . The method of  claim 14  further comprising performing inverse fast Fourier transform (IFFT) functions on the AMC-CDMA signals. 
     
     
         20 . The method of  claim 14  further comprising receiving a serial signal and converting the serial signal to a parallel signal.