Methods for flexible reference signal transmission with single carrier frequency domain multiple access (sc-fdma) and ofdma

Abstract

A method for transmitting a discrete fourier transform (DFT) DFT-S-OFDM signal including frequency domain reference symbols is disclosed. The method comprises: determining to null a plurality of data symbols prior to DFT-spreading; performing DFT-spreading including the determined null data symbols; puncturing an interleaved output of the DFT-spreading; inserting reference symbols in a frequency domain of the punctured and interleaved DFT-S-OFDM signal; and transmitting the DFT-S-OFDM signal with inserted reference symbols to a receiver. The transmitted DFT-S-OFDM signal enables the receiver to apply zeros corresponding to the reference symbols to an interleaved input of DFT-despreading, and cancel interference due to the puncturing by using all outputs of the DFT-despreading.

1 . A method for transmitting a Discrete Fourier Transform-Spread-Orthogonal Frequency Division Multiple Access (DFT-S-OFDM) signal, the method comprising:
 setting at least one input of a DFT to zero;   performing DFT-spreading including the at least one input set to zero;   puncturing an at least one output of the DFT-spreading;   replacing the punctured outputs of the DFT spreading with additional frequency domain symbols; and   transmitting a DFT-S-OFDM signal including the additional frequency domain symbols to a receiver.   
     
     
         2 . The method of  claim 1 , wherein the additional frequency domain symbol is a reference symbol (RS). 
     
     
         3 . The method of  claim 1 , wherein a number of additional frequency domain symbols inserted is based on a channel condition associated with the receiver. 
     
     
         4 . The method of  claim 3 , wherein on a condition that the channel condition is relatively poor, the number of additional frequency domain symbols inserted is increased. 
     
     
         5 . The method of  claim 1 , wherein the punctured output of the DFT spreading is interleaved. 
     
     
         6 . A wireless communication device configured to transmit a discrete Fourier transform (DFT) spread signal (DFT-S-OFDM) signal, the device comprising:
 A processor configured to:
 set at least one input of a DFT to zero; 
 perform DFT-spreading including the at least one input set to zero; 
 puncture an at least one output of the DFT-spreading; 
 replace the punctured outputs of the DFT spreading with additional frequency domain symbols; and 
   a transmitter configured to transmit a DFT-S-OFDM signal including the additional frequency domain symbols to a receiver.   
     
     
         7 . The device of  claim 6 , wherein the additional frequency domain symbol is a reference symbol (RS). 
     
     
         8 . The device of  claim 6 , wherein a number of additional frequency domain symbols inserted is based on a channel condition associated with the receiver. 
     
     
         9 . The device of  claim 8 , wherein on a condition that the channel condition is relatively poor, the number of additional frequency domain symbols inserted is increased. 
     
     
         10 . The device of  claim 1 , wherein the punctured output of the DFT spreading is interleaved. 
     
     
         11 .- 15 . (canceled)