Data transmissions device and data transmissions method capable of minimizing delay of fast data

Abstract

A data transmission device for executing data transmission in environments where the noise level changes periodically minimizes delay of fast data. A multiplexing/synchronization control section receives data (in which the ratio between fast data and interleave data is fixed) which are supplied from an upper layer device at a prespecified data rate, and separates the data into fast data and interleave data. The fast data is supplied to a tone ordering section without changing its data rate. Meanwhile, an interleaving section executes interleaving to the interleave data, and a rate converter controls the data rate of the interleave data and supplies the interleave data to the tone ordering section. The tone ordering section assigns the fast data and the interleave data to each carrier of a symbol (frame) to be transmitted, based on preobtained bit distribution with respect to low noise periods or high noise periods, depending on whether the symbol is transmitted in the low noise periods or in periods including the high noise periods. In the data assignment, the amount of fast data included in each symbol is set constant regardless of whether the symbol is transmitted in the low noise periods or in periods including the high noise periods, thereby the amount of fast data transmitted in a fixed time period is made constant, and thus delay of fast data is minimized.

1 . A device comprising: 
 inputting means for inputting a signal that represents a change of the noise level;    first outputting means for outputting first data;    second outputting means for outputting second data;    wherein at least one of the amount of said first data and of said second data changes on the basis of said signal.    
     
     
         2 . The device as claimed in  claim 1 , wherein: 
 the amount of said first data is constant non-zero amount.    
     
     
         3 . The device as claimed in  claim 1 , wherein: 
 said change of the noise level is that high noise period and low noise period change periodically.    
     
     
         4 . The device as claimed in  claim 3 , wherein: 
 the amount of said second data in low noise period is more than that of said first data in high noise period.    
     
     
         5 . The device as claimed in  claim 1 , wherein: 
 said first data are fast data.    
     
     
         6 . The device as claimed in  claim 5 , wherein: 
 said second data are interleave data.    
     
     
         7 . A device comprising: 
 inputting circuit which inputs a signal that represents a change of the noise level;    first outputting circuit for outputting first data;    second outputting circuit for outputting second data;    wherein at least one of the amount of said first data and of said second data changes on the basis of said signal.    
     
     
         8 . The device as claimed in  claim 7 , wherein: 
 the amount of said first data is constant non-zero amount.    
     
     
         9 . The device as claimed in  claim 7 , wherein: 
 said change of the noise level is that high noise period and low noise period change periodically.    
     
     
         10 . The device as claimed in  claim 9 , wherein: 
 the amount of said second data in low noise period is more than that of said first data in high noise period.    
     
     
         11 . The device as claimed in  claim 7 , wherein: 
 said first data are fast data.    
     
     
         12 . The device as claimed in  claim 11 , wherein: 
 said second data are interleave data.    
     
     
         13 . A method for transmitting data, comprises the steps of: 
 a step for inputting a signal that represents a change of the noise level;    a step for controlling at least one of the amount of first data and of second data;    a step for outputting said first and second data on the basis of said signal so that said at least one of the amount of first data and of second data can change.    
     
     
         14 . The method as claimed in  claim 13 , wherein: 
 the amount of said first data is constant non-zero amount.    
     
     
         15 . The method as claimed in  claim 13 , wherein: 
 said change of the noise level is that high noise period and low noise period change periodically.    
     
     
         16 . The method as claimed in  claim 15 , wherein: 
 the amount of said second data in low noise period is more than that of said second data in high noise period.    
     
     
         17 . The method as claimed in  claim 13 , wherein: 
 said first data are fast data.    
     
     
         18 . The method as claimed in  claim 17 , wherein: 
 said second data are interleave data.