METHODS FOR FLEXIBLE REFERENCE SIGNAL TRANSMISSION WITH SINGLE CARRIER FREQUENCY DOMAIN MULTIPLE ACCESS (SC-FDMA) AND OFDMA
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)