Seamless rate adaptive multicarrier modulation system and protocols

Abstract

A DMT system and method with the capability to adapt the system bit rate on-line in a seamless manner. The DMT system provides a robust and fast protocol for completing this seamless rate adaptation. The DMT system also provides a framing and encoding method with reduced overhead compared to conventional DMT systems. The DMT system and method provide seamless rate adaptation with the provision of different power levels. This framing and encoding method enables a system with seamless rate adaptation capability. The system and method of the invention can be implemented in hardware, or alternatively in a combination of hardware and software.

What is claimed is:  
     
         1 . A method for modulating data in a multicarrier transmission system, the method comprising: 
 providing a stream of codewords for transmission to a receiver, each codeword having a specified number of bits; and    modulating the stream of codewords to form discrete multitone (DMT) symbols having a number of bits determined by a transmission rate capability of the multicarrier transmission system, wherein the number of bits in the codewords is a non-integer multiple of the number of bits in the DMT symbols.    
     
     
         2 . A system that modulates data in a multicarrier transmission environment comprising: 
 an encoder that provides a stream of codewords for transmission to a receiver, each codeword having a specified number of bits; and    a modulator that modulates the stream of codewords to form discrete multitone (DMT) symbols having a number of bits determined by a transmission rate capability of the multicarrier transmission system, wherein the number of bits in the codewords is a non-integer multiple of the number of bits in the DMT symbols.    
     
     
         3 . An information storage media comprising information that modulates data in a multicarrier transmission environment comprising: 
 information that provides a stream of codewords for transmission to a receiver, each codeword having a specified number of bits; and    information that modulates the stream of codewords to form discrete multitone (DMT) symbols having a number of bits determined by a transmission rate capability of the multicarrier transmission system, wherein the number of bits in the codewords is a non-integer multiple of the number of bits in the DMT symbols.    
     
     
         4 . A means for modulating data in a multicarrier transmission environment comprising: 
 means for providing a stream of codewords for transmission to a receiver, each codeword having a specified number of bits; and    means for modulating the stream of codewords to form discrete multitone (DMT) symbols having a number of bits determined by a transmission rate capability of the multicarrier transmission system, wherein the number of bits in the codewords is a non-integer multiple of the number of bits in the DMT symbols.    
     
     
         5 . A communications protocol that modulates data in a multicarrier transmission environment comprising: 
 providing a stream of codewords for transmission to a receiver, each codeword having a specified number of bits; and    modulating the stream of codewords to form discrete multitone (DMT) symbols having a number of bits determined by a transmission rate capability of the multicarrier transmission system, wherein the number of bits in the codewords is a non-integer multiple of the number of bits in the DMT symbols.