Method and Apparatus for Asynchronous OFDMA/SC-FDMA

Abstract

Various disclosed embodiments include methods and systems for communication in a wireless communication system. A method comprises receiving a signal corresponding to a plurality of modulated signals, each of the plurality of modulated signals corresponding to a unique electronic device. The method comprises filtering the received signal with a plurality of filters, each of which is matched to a corresponding filter in a respective electronic device to obtain a filtered signal for the respective electronic device. The method comprises performing a fast Fourier transform (FFT) operation on the filtered signal to obtain demodulated data corresponding to the respective electronic device.

What is claimed is: 
     
         1 . A method of transmitting data, the method comprising:
 performing, by a wireless electronic device, a filtering operation on a signal corresponding to a first plurality of resource blocks with a spectrum shaping filter to produce a filtered signal;   transmitting, by the wireless electronic device, the filtered signal to a receiver over a first plurality of subcarriers,   wherein the first OFDM modulated signal is transmitted asynchronously with a second filtered signal over a second plurality of subcarriers by a second wireless electronic device.   
     
     
         2 . The method of  claim 1 , wherein bandwidth of the first spectrum shaping filter is equal to the total width of the first plurality of resource blocks and bandwidth of the second spectrum shaping filter is equal to the total width of the second plurality of resource blocks. 
     
     
         3 . The method of  claim 1 , wherein time duration of each of the first spectrum shaping filter and the second spectrum shaping filter is equal to half of an OFDM symbol. 
     
     
         4 . The method of  claim 1 , wherein the first spectrum shaping filter is centered at the first plurality of resource blocks, and the second spectrum shaping filter is centered at the second plurality of resources blocks. 
     
     
         5 . The method of  claim 1 , wherein each of the first spectrum shaping filter and the second spectrum shaping filter is a finite impulse response (FIR) filter. 
     
     
         6 . A wireless electronic device comprising:
 a processor; and   a non-transitory computer readable storage medium storing programming for execution by the processor, the programming including instructions to:   perform a filtering operation on a signal corresponding to a first plurality of resource blocks with a spectrum shaping filter to produce a filtered signal;   transmit the filtered signal to a receiver over a first plurality of subcarriers, wherein the first OFDM modulated signal is transmitted asynchronously with a second filtered signal over a second plurality of subcarriers by a second wireless electronic device.   
     
     
         7 . The wireless device of  claim 6 , wherein bandwidth of the first spectrum shaping filter is equal to the total width of the first plurality of resource blocks and bandwidth of the second spectrum shaping filter is equal to the total width of the second plurality of resource blocks. 
     
     
         8 . The wireless device of  claim 6 , wherein time duration of each of the first spectrum shaping filter and the second spectrum shaping filter is equal to half of an OFDM symbol. 
     
     
         9 . The wireless device of  claim 6 , wherein the first spectrum shaping filter is centered at the first plurality of resource blocks, and the second spectrum shaping filter is centered at the second plurality of resources blocks. 
     
     
         10 . The wireless device of  claim 6 , wherein each of the first spectrum shaping filter and the second spectrum shaping filter is a finite impulse response (FIR) filter. 
     
     
         11 . A method of receiving data, the method comprising:
 receiving, by a receiver, a first filtered signal from a first wireless device over a first plurality of subcarriers; and   receiving, by the receiver, a second filtered signal from a second wireless device over a second plurality of subcarriers, wherein the first filtered modulated signal is transmitted asynchronously with the second filtered signal.   
     
     
         12 . The method of  claim 11 , wherein bandwidth of the first spectrum shaping filter is equal to the total width of the first plurality of resource blocks and bandwidth of the second spectrum shaping filter is equal to the total width of the second plurality of resource blocks. 
     
     
         13 . The method of  claim 11 , wherein time duration of each of the first spectrum shaping filter and the second spectrum shaping filter is equal to half of an OFDM symbol. 
     
     
         14 . The method of  claim 11 , wherein the first spectrum shaping filter is centered at the first plurality of resource blocks, and the second spectrum shaping filter is centered at the second plurality of resources blocks. 
     
     
         15 . The method of  claim 1 , wherein each of the first spectrum shaping filter and the second spectrum shaping filter is a finite impulse response (FIR) filter. 
     
     
         16 . A wireless electronic device comprising:
 a processor; and   a non-transitory computer readable storage medium storing programming for execution by the processor, the programming including instructions to:   receive a first filtered signal from a first wireless device over a first plurality of subcarriers; and   receive a second filtered signal from a second wireless device over a second plurality of subcarriers, wherein the first filtered modulated signal is transmitted asynchronously with the second filtered signal.   
     
     
         17 . The receiver of  claim 6 , wherein bandwidth of the first spectrum shaping filter is equal to the total width of the first plurality of resource blocks and bandwidth of the second spectrum shaping filter is equal to the total width of the second plurality of resource blocks. 
     
     
         18 . The receiver of  claim 6 , wherein time duration of each of the first spectrum shaping filter and the second spectrum shaping filter is equal to half of an OFDM symbol. 
     
     
         19 . The receiver of  claim 6 , wherein the first spectrum shaping filter is centered at the first plurality of resource blocks, and the second spectrum shaping filter is centered at the second plurality of resources blocks. 
     
     
         20 . The receiver of  claim 6 , wherein each of the first spectrum shaping filter and the second spectrum shaping filter is a finite impulse response (FIR) filter.