Pulse-shaped orthogonal frequency division multiplexing

Abstract

A method and apparatus for performing pulse shaping using different windowing functions for different sub-bands of a transmission is disclosed. A method for use in a wireless transmit/receive unit (WTRU) may include the WTRU receiving data symbols. The WTRU may assign the data symbols to a plurality of subcarriers in different sub-bands and map the data symbols on each of the plurality of subcarriers in the different sub-bands to a plurality of corresponding subcarriers of an inverse fast Fourier transform (IFFT) block. The WTRU may take an IFFT of the block for each sub-band and pad an output of the IFFT block with a prefix and a postfix for each sub-band. The WTRU may apply a windowing function to an output of the padding for each sub-band and form a composite signal for transmission by adding an output of the windowing of each sub-band. The WTRU may transmit the signal.

1 . (canceled) 
     
     
         2 . A method implemented by an 802.11 device for transmitting a signal, the method comprising:
 mapping a plurality of data symbols on each of a plurality of subcarriers in a plurality of sub-bands;   performing an IFFT on each of the plurality of sub-bands to generate an output for each of the plurality of sub-bands;   padding the output with a prefix or a postfix for each sub-band;   applying a windowing function to the padded output for each sub-band;   forming a composite signal for transmission from each of the windowed padded output; and   transmitting the composite signal.   
     
     
         3 . The method of  claim 2 , wherein different windowing functions are applied to different sub-bands. 
     
     
         4 . The method of  claim 2 , wherein the prefix or the postfix is a guard interval. 
     
     
         5 . The method of  claim 2 , wherein the subcarriers in the sub-bands are non-contiguous. 
     
     
         6 . The method of  claim 2 , wherein the prefix for each sub-band is of a different length. 
     
     
         7 . An 802.11 device configured to transmit a signal, the WTRU comprising:
 a processor configured to:
 map a plurality of data symbols on each of a plurality of subcarriers in a plurality of sub-bands; 
 perform an IFFT on each of the plurality of sub-bands to generate an output signal for each of the plurality of sub-bands; 
 padding an output of the IFFT block with a prefix or a postfix for each sub-band; 
 apply a windowing function to the padded output for each sub-band; 
 form a composite signal for transmission from each of the windowed padded output; and 
   a transmitter, operatively coupled to the processor, configured to transmit the composite signal.   
     
     
         8 . The 802.11 device of  claim 7 , wherein different windowing functions are applied to different sub-bands. 
     
     
         9 . The 802.11 device of  claim 7 , wherein the prefix or the postfix is a guard interval. 
     
     
         10 . The 802.11 device of  claim 7 , wherein the subcarriers in the sub-bands are non-contiguous. 
     
     
         11 . The 802.11 device of  claim 7 , wherein the prefix for each sub-band is of a different length.