Method and apparatus for synchronization in an ofdm wireless communication network

Abstract

A method and wireless transmit/receive unit (WTRU) include a WTRU configured to search a frequency bandwidth, out of a set of potential frequency bandwidths, for synchronization signals. The frequency bandwidth includes a secondary synchronization signal in subcarriers. Other subcarriers in the frequency bandwidth outside of the secondary synchronization signal include data. The WTRU is configured to synchronize using the secondary synchronization signal in the frequency bandwidth. The WTRU is configured to recover the data in the frequency bandwidth

What is claimed is: 
     
         1 . A wireless transmit/receive unit (WTRU) comprising:
 a processor; and   a transceiver, wherein:   the processor and the transceiver are configured to search a frequency bandwidth, out of a set of potential frequency bandwidths, for synchronization signals, wherein the frequency bandwidth includes a secondary synchronization signal in subcarriers and wherein other subcarriers in the frequency bandwidth outside of the secondary synchronization signal include data;   the processor and the transceiver are further configured to synchronize using the secondary synchronization signal in the frequency bandwidth; and   the processor and the transceiver are further configured to recover the data in the frequency bandwidth.   
     
     
         2 . The WTRU of  claim 1 , wherein the frequency bandwidth includes subcarriers set to zero surrounding the secondary synchronization signal. 
     
     
         3 . The WTRU of  claim 1 , wherein the set of potential frequency bandwidths is two. 
     
     
         4 . The WTRU of  claim 1 , wherein the secondary synchronization signal is derived from a cell identification. 
     
     
         5 . The WTRU of  claim 1 , wherein the frequency bandwidth for the synchronization signals is less than a cell bandwidth. 
     
     
         6 . The WTRU of  claim 5 , wherein the frequency bandwidth for the synchronization signals is related to the cell bandwidth. 
     
     
         7 . The WTRU of  claim 1 , wherein the frequency bandwidth for the synchronization signals includes a primary synchronization signal in a different orthogonal frequency division multiplex (OFDM) symbol than the secondary synchronization signal. 
     
     
         8 . The WTRU of  claim 1 , wherein a frequency location of the secondary synchronization signal is different than a center of a cell bandwidth. 
     
     
         9 . The WTRU of  claim 8 , wherein the frequency location of the secondary synchronization signal in the cell bandwidth is one out of a plurality of potential frequency locations for secondary synchronization signals. 
     
     
         10 . The WTRU of  claim 1 , wherein the processor is further configured to determine the frequency bandwidth for the synchronization signals out of two potential frequency bandwidths for synchronization signals. 
     
     
         11 . A method, implemented by a wireless transmit/receive unit (WTRU), the method comprising:
 searching a frequency bandwidth, out of a set of potential frequency bandwidths, for synchronization signals, wherein the frequency bandwidth includes a secondary synchronization signal in subcarriers and wherein other subcarriers in the frequency bandwidth outside of the secondary synchronization signal include data;   synchronizing using the secondary synchronization signal in the frequency bandwidth; and   recovering the data in the frequency bandwidth.   
     
     
         12 . The method of  claim 11 , wherein the frequency bandwidth includes subcarriers set to zero surrounding the secondary synchronization signal. 
     
     
         13 . The method of  claim 11 , wherein the set of potential frequency bandwidths is two. 
     
     
         14 . The method of  claim 11 , wherein the secondary synchronization signal is derived from a cell identification. 
     
     
         15 . The method of  claim 11 , wherein the frequency bandwidth for the synchronization signals is less than a cell bandwidth. 
     
     
         16 . The method of  claim 15 , wherein the frequency bandwidth for the synchronization signals is related to the cell bandwidth. 
     
     
         17 . The method of  claim 11 , wherein the frequency bandwidth for the synchronization signals includes a primary synchronization signal in a different orthogonal frequency division multiplex (OFDM) symbol than the secondary synchronization signal. 
     
     
         18 . The method of  claim 11 , wherein a frequency location of the secondary synchronization signal is different than a center of a cell bandwidth. 
     
     
         19 . The method of  claim 18 , wherein the frequency location of the secondary synchronization signal in the cell bandwidth is one out of a plurality of potential frequency locations for secondary synchronization signals. 
     
     
         20 . The method of  claim 11  further comprising determining the frequency bandwidth for the synchronization signals out of two potential frequency bandwidths for synchronization signals.