Transmitting Data with Multiple Priorities as OFDM Symbols

Abstract

A transmitter transmits data having a set of two or more priorities on subcarriers using orthogonal frequency division multiplexing (OFDM) symbols. The transmitter includes a media access (MAC) layer, wherein the MAC layer further includes a queue for storing data at each priority, a rate control block connected to each queue, and a physical (PHY) layer. The PHY layer further includes a channel coder for each priority, wherein each channel coder is connected to the corresponding queue to receive data, and to the rate control block to send coding information.

1 . A transmitter for transmitting data having a set of two or more priorities on subcarriers using orthogonal frequency division multiplexing (OFDM) symbols, comprising:
 a media access (MAC) layer, wherein the MAC layer further comprises:
 a queue for storing data at each priority; and 
 a rate control block connected to each queue; 
   a physical (PHY) layer, wherein the PHY layer further comprises:
 a channel coder for each priority, wherein each channel coder is connected to the corresponding queue to receive data, and to the rate control block to send coding information. 
   
     
     
         2 . The transmitter of  claim 1 , wherein the PHY layer further comprises:
 a symbol to subcarrier mapping block connected to each channel coding block; and   means for transmitting the ODM symbols connected to the symbol to carrier block;   means for determining channel-over-interference ratios   
       
         
           
             
               
                 
                   ξ 
                   i 
                 
                 = 
                 
                   
                     H 
                     i 
                   
                   
                     I 
                     i 
                   
                 
               
               , 
             
           
         
       
       where I i  is an interference power at a subcarrier i, and H i  is a channel response. 
     
     
         3 . The transmitter of  claim 2 , wherein the symbol to subcarrier mapping is adaptive and depends on an interference location or channel quality. 
     
     
         4 . The method of  claim 2 , wherein the channel-over-interference ratios are sorted in a high to low order, and data with high to low priorities are assigned to the sub-carriers according to the high to low order of the channel-over-interference ratios. 
     
     
         5 . The method of  claim 2 , wherein the subcarrier mapping block uses a permutation function to account for channel diversity. 
     
     
         6 . The method of  claim 4 , wherein a number of subcarriers assigned for each priority is 
       
         
           
             
               
                 
                   S 
                   i 
                 
                 = 
                 
                   
                     D 
                     i 
                   
                   
                     
                       WR 
                       i 
                     
                      
                     
                       
                         log 
                         2 
                       
                        
                       
                         ( 
                         
                           Q 
                           i 
                         
                         ) 
                       
                     
                   
                 
               
               , 
             
           
         
       
       where D i  is a number of bits sent to the PHY layer, W is a number of symbols in a frame, R i  is a data rate, and Q i  is a quality of service, and S 1 +S 2 + . . . +S N =M, where M is a number of subcarriers. 
     
     
         7 . A method for transmitting data having a set of two or more priorities on subcarriers using orthogonal frequency division multiplexing (OFDM) symbols, comprising the steps of
 storing the data at each priority in a corresponding queue in a medium (MAC) layer of a transmitter;   sending the data in each queue to a corresponding coding block in a physical (PHY) layer according to a rate control in the MAC layer depending on each priority.