Multi-carrier communications with adaptive cluster configuration and switching

Abstract

A method and apparatus for allocating subcarriers in an orthogonal frequency division multiple access (OFDMA) system is described. In one embodiment, the method comprises allocating at least one diversity cluster of subcarriers to a first subscriber and allocating at least one coherence cluster to a second subscriber.

What is claimed is: 
     
         1 . A method for wireless communication in an orthogonal frequency-division multiple access (OFDMA) system, said method comprising:
 allocating, at a base station, a first set of one or more subcarriers to a first subscriber over a first wireless link with said first subscriber, said allocated first set of said one or more subcarriers having at least one of a modulation scheme and a data coding used over said first wireless link;   allocating, at said base station, a second set of one or more subcarriers to said first subscriber over said first wireless link with said first subscriber, said allocated second set of said one or more subcarriers having at least one of a modulation scheme and a data coding used over said first wireless link being different than said at least one of said modulation scheme and said data coding of said allocated first set of said one or more subcarriers; and   allocating, at said base station, a third set of one or more subcarriers to a second subscriber over a second wireless link, said allocating said first set of said one or more subcarriers occurring simultaneously as said allocating said second set of said one or more subcarriers and as said allocating said third set of said one or more subcarriers.   
     
     
         2 . The method of  claim 1 , further comprising:
 allocating, at said base station, diversity clusters of subcarriers to said first subscriber.   
     
     
         3 . A base station for wireless communication in an orthogonal frequency-division multiple access (OFDMA) system, said base station comprising:
 a controller configured to:
 allocate a first set of one or more subcarriers to a first subscriber over a first wireless link with said first subscriber, said allocation of said first set of said one or more subcarriers having at least one of a modulation scheme and a data coding used over said first wireless link; 
 allocate a second set of one or more subcarriers to said first subscriber over said first wireless link with aid first subscriber, said allocation of said second set of said one or more subcarriers having at least one of a modulation scheme and a data coding used over said first wireless link being different than said at least one of said modulation scheme and said data coding of said allocation of said first set of said one or more subcarriers; and 
 allocate a third set of one or more subcarriers to a second subscriber over a second wireless link with said second subscriber, said allocation of said first set of said one or more subcarriers occurring simultaneously as said allocation of said second set of said one or more subcarriers and as said allocation of said third set of said one or more subcarriers. 
   
     
     
         4 . The base station of  claim 3 , wherein said controller is further configured to allocate diversity clusters of subcarriers to said first subscriber. 
     
     
         5 . A method for wireless communication in an orthogonal frequency-division multiple access (OFDMA) system, said method comprising:
 receiving, at a first subscriber, a first allocation of one or more subcarriers from a base station over a first wireless link with said base station, said first allocation of said one or more subcarriers having at least one of a modulation scheme and a data coding used over said first wireless link; and   receiving, at said first subscriber, a second allocation of one or more subcarriers from said base station over said first wireless link, said second allocation of said one or more subcarriers having at least one of a modulation scheme and a data coding used over said first wireless link being different than said at least one of said modulation scheme and said data coding of said first allocation of said one or more subcarriers, said receiving said first allocation of said one or more subcarriers occurring simultaneously as said receiving said second allocation of said one or more subcarriers and as a second subscriber receives a third allocation of one or more subcarriers from said base station over a second wireless link.   
     
     
         6 . The method of  claim 5 , further comprising:
 receiving, at said first subscriber, an allocation of diversity clusters of subcarriers from said base station.   
     
     
         7 . A first subscriber station for wireless communication in an orthogonal frequency-division multiple access (OFDMA) system, said first subscriber station comprising:
 a transceiver configured to:
 receive a first allocation of one or more subcarriers from a base station over a first wireless link with said base station, said first allocation of said one or more subcarriers having at least one of a modulation scheme and a data coding used over said first wireless link; and 
 receive a second allocation of one or more subcarriers from said base station over said first wireless link, said second allocation of said one or more subcarriers having at least one of a modulation scheme and a data coding used over said first wireless link being different than said at least one of said modulation scheme and said data coding of said first allocation of said one or more subcarriers, said receipt of said first allocation of said one or more subcarriers occurring simultaneously as said receipt of said second allocation of said one or more subcarriers and as a second subscriber receives a third allocation of one or more subcarriers from said base station over a second wireless link. 
   
     
     
         8 . The first subscriber station of  claim 7 , wherein said transceiver is further configured to receive an allocation of diversity clusters of subcarriers from said base station.