Multi-Carrier Communications With Group-Based Subcarrier Allocation

Abstract

A method and apparatus for subcarrier selection for systems is described. In one embodiment, the system employs orthogonal frequency division multiple access (OFDMA). In one embodiment, a method for subcarrier selection comprises a subscriber measuring channel and interference information for subcarriers based on pilot symbols received from a base station, the subscriber selecting a set of candidate subcarriers, providing feedback information on the set of candidate subcarriers to the base station, and receiving an indication of subcarriers of the set of subcarriers selected by the base station for use by the subscriber.

1 . A method for wireless communication, said method comprising:
 allocating a first set of one or more subcarriers to a subscriber to over a wireless link with said subscriber;   receiving information indicative of quality of said allocated subcarriers;   changing said allocation from said first set to a second set; and   transmitting said second set of one or more subcarriers to said subscriber;   wherein said second set is different than said first set.   
     
     
         2 . The method of  claim 1  wherein changing comprises allocating one or more additional subcarriers to said subscriber when said information indicative of quality is below a determined value. 
     
     
         3 . The method of  claim 1  wherein changing comprises removing at least one of said allocated subcarriers from said allocated subcarriers when said information indicative of quality is above a determined value. 
     
     
         4 . The method of  claim 1  wherein changing comprises replacing at least one of said allocated subcarriers with at least one or more other subcarriers. 
     
     
         5 . The method of  claim 1  wherein said information indicative of quality is signal to interference plus noise ratio (SINR) information relating to said one or more allocated subcarriers. 
     
     
         6 . The method of  claim 1  wherein said information indicative of quality is signal to noise ratio (SNR) information relating to said one or more allocated subcarriers. 
     
     
         7 . The method of  claim 1  further comprising comparing said information indicative of quality to a determined value; wherein said changing is further based upon said comparison. 
     
     
         8 . The method of  claim 7  wherein said determined value is dynamic. 
     
     
         9 . The method of  claim 1  further comprising:
 receiving information indicative of quality of said second allocated subcarriers; 
 changing said allocation from said second set to a third set; and 
 transmitting said third set of one or more subcarriers to said subscriber, wherein said third set is different than said second set. 
 
     
     
         10 . The method of  claim 1  wherein changing said allocation is performed after said allocating and receiving and increases communication bandwidth over said wireless link. 
     
     
         11 . The method of  claim 2  wherein allocating one or more additional subcarriers to said subscriber comprises allocating one or more diversity clusters to said subscriber. 
     
     
         12 . The method of  claim 11  wherein the number of diversity clusters allocated to said subscriber increases as the amount at which said information indicative of quality falls below said determined value increases; and
 wherein changing said allocation is performed after said allocating and receiving and increases communication bandwidth over said wireless link. 
 
     
     
         13 . The method of  claim 1  wherein said transmitting a second set of one or more subcarriers to said subscriber comprises transmitting information indicative of the modulation to be used for said wireless link. 
     
     
         14 . The method of  claim 1  wherein said transmitting a second set of one or more subcarriers to said subscriber comprises transmitting information indicative of the coding to be used for said wireless link. 
     
     
         15 . A method for wireless communication, said method comprising:
 receiving, from one or more subscriber stations, information indicative of quality of one or more subcarriers allocated to said one or more subscriber stations;   prioritizing one or more subcarriers for communication with said one or subscribers based on said received information;   transmitting one or more subcarriers to said one or more subscribers according to said priority; and   updating, from time to time, said priority based on additional received information indicative of quality of said one or more subcarriers.   
     
     
         16 . The method of  claim 15  wherein said information indicative of quality said information comprising information sufficient to determine signal to noise plus interference ratio (SINR). 
     
     
         17 . The method of  claim 16  wherein said information indicative of quality further comprises information sufficient to determine received signal strength (RSS). 
     
     
         18 . The method of  claim 17  further comprising:
 summing said RSS and SINR information for said one or more subcarriers; and 
 prioritizing said one or more subcarriers further based on said summing. 
 
     
     
         19 . The method of  claim 15  further comprising analyzing information indicative of quality for said one or more subcarriers, wherein said prioritizing is based on said analyzing. 
     
     
         20 . The method of  claim 16  wherein said information indicative of quality comprises SINR information relating to pilot symbols transmitted over said wireless link. 
     
     
         21 . The method of  claim 16  wherein said information indicative of quality comprises SINR information relating to data symbols transmitted over said wireless link. 
     
     
         22 . The method of  claim 15  further comprising prioritizing said one or more subcarriers based on said analyzing. 
     
     
         23 . A method for wireless communication, said method comprising:
 sending, from a base station, an instruction to a subscriber station to measure channel condition information for one or more subcarriers, said subcarriers available for communication between said base station and said subscriber station;   receiving, at said base station, information indicative of measured channel condition information of said one or more subcarriers; and   allocating one or more subcarriers to said subscriber station.   
     
     
         24 . The method of  claim 23  further comprising:
 comparing said received information to a determined value. 
 
     
     
         25 . The method of  claim 24  wherein said determined value is dynamic. 
     
     
         26 . The method of  claim 23  wherein said instruction to a subscriber station to measure channel condition information for one or more subcarriers comprises an instruction to measure pilot symbol information, said pilot symbols transmitted from said base station. 
     
     
         27 . The method of  claim 26  wherein said instruction further comprises an instruction to determine signal to noise plus interference (SINR) for said one or more subcarriers. 
     
     
         28 . The method of  claim 24  wherein said allocating one or more subcarriers to said subscriber station comprises allocating additional subcarriers if said received information is below said determined value. 
     
     
         29 . The method of  claim 28  wherein allocating one or more subcarriers to said subscriber station comprises allocating a coherence cluster of subcarriers. 
     
     
         30 . The method of  claim 23  wherein said instruction to a subscriber station to measure channel condition information for one or more subcarriers comprises an instruction to measure data symbol information, said data symbols transmitted from said base station. 
     
     
         31 . The method of  claim 30  wherein said instruction further comprises an instruction to determine signal to noise plus interference (SINR) for said one or more subcarriers. 
     
     
         32 . The method of  claim 28  wherein allocating one or more subcarriers to said subscriber station comprises allocating a diversity cluster of subcarriers. 
     
     
         33 . The method of  claim 23  wherein said instruction to a subscriber station to measure channel condition information for one or more subcarriers comprises an instruction to measure a coherence cluster of subcarriers. 
     
     
         34 . The method of  claim 23  wherein said instruction to a subscriber station to measure channel condition information for one or more subcarriers comprises an instruction to measure a diversity cluster of subcarriers. 
     
     
         35 . The method of  claim 23  wherein said instruction to a subscriber station to measure channel condition information for one or more subcarriers comprises an instruction to measure randomly selected subcarriers. 
     
     
         36 . The method of  claim 23  wherein said transmitting a second set of one or more subcarriers to said subscriber comprises transmitting information indicative of the modulation for communication between said base station and said subscriber station. 
     
     
         37 . The method of  claim 23  wherein said transmitting a second set of one or more subcarriers to said subscriber comprises transmitting information indicative of the coding for communication between said base station and said subscriber station. 
     
     
         38 . The method of  claim 23  wherein said allocating one or more subcarriers to said subscriber station is based, at least in part, on said received information. 
     
     
         39 . A method for wireless communication, said method comprising:
 receiving a first allocation of one or more subcarriers from a base station to establish a wireless communication link with said base station;   transmitting, after receiving said first allocation, information indicative of quality of said one or more subcarriers to said base station; and   receiving a second allocation of one or more subcarriers from said base station;   wherein said second allocation is different than said first allocation.   
     
     
         40 . The method of  claim 39  wherein said transmitting is performed on a periodic basis. 
     
     
         41 . The method of  claim 39  wherein said transmitting is performed on an aperiodic basis. 
     
     
         42 . The method of  claim 39  wherein said second allocation comprises more subcarriers than said first allocation. 
     
     
         43 . The method of  claim 39  wherein said second allocation comprises less subcarriers than said first allocation. 
     
     
         44 . The method of  claim 39  wherein said second allocation comprises at least one different subcarrier from said first allocation. 
     
     
         45 . The method of  claim 39  wherein said information indicative of quality is signal to interference plus noise ratio (SINR) information relating to said one or more allocated subcarriers. 
     
     
         46 . The method of  claim 39  wherein said information indicative of quality is signal to noise ratio (SNR) information relating to said one or more allocated subcarriers. 
     
     
         47 . The method of  claim 39 , further comprising:
 transmitting information indicative of quality of said second one or more subcarriers to said base station; and   receiving a third allocation of one or more subcarriers from said base station;   wherein said third allocation is different than said second allocation.   
     
     
         48 . The method of  claim 39  wherein said second allocation is based, at least in part, on said transmitted information. 
     
     
         49 . The method of  claim 47  wherein transmitting information indicative of quality of said second one or more subcarriers is performed in response to receiving said second allocation; and
 receiving said third allocation of one or more subcarriers from said base station, is based, at least in part, on said second transmitted information. 
 
     
     
         50 . A method for wireless communication, said method comprising:
 receiving, at a subscriber station, an instruction from a base station to measure channel condition information for one or more subcarriers, said subcarriers available for communication between said base station and said subscriber station;   measuring channel condition information for one or more subcarriers in accordance with said instruction;   transmitting information indicative of measured channel condition information of said one or more subcarriers to said base station; and   receiving an allocation of one or more subcarriers from said base station.   
     
     
         51 . The method of  claim 50  wherein said measuring channel condition information for one or more subcarriers comprises measuring pilot symbol information, said pilot symbols transmitted from said base station. 
     
     
         52 . The method of  claim 51  wherein said measured pilot symbol information is used to determine signal to noise plus interference (SINR) for said one or more subcarriers. 
     
     
         53 . The method of  claim 52  wherein said allocation of one or more subcarriers from said base station comprises additional subcarriers if said determined SINR is below a determined value. 
     
     
         54 . The method of  claim 53  wherein receiving an allocation of one or more subcarriers from said base station comprises receiving a coherence cluster of subcarriers. 
     
     
         55 . The method of  claim 50  wherein said measuring channel condition information for one or more subcarriers comprises measuring data symbol information, said data symbols transmitted from said base station. 
     
     
         56 . The method of  claim 55  wherein said measured data symbol information is used to determine signal to noise plus interference SINR for said one or more subcarriers. 
     
     
         57 . The method of  claim 56  wherein said allocation of one or more subcarriers from said base station comprises additional subcarriers if said determined SINR is below a determined value. 
     
     
         58 . The method of  claim 57  wherein receiving an allocation of one or more subcarriers from said base station comprises receiving a diversity cluster of subcarriers. 
     
     
         59 . The method of  claim 50  wherein said measuring channel condition information for one or more subcarriers comprises measuring a coherence cluster of subcarriers. 
     
     
         60 . The method of  claim 50  wherein said measuring channel condition information for one or more subcarriers comprises measuring a diversity cluster of subcarriers. 
     
     
         61 . The method of  claim 50  wherein said measuring channel condition information for one or more subcarriers comprises measuring randomly selected subcarriers. 
     
     
         62 . The method of  claim 50  wherein said receiving an allocation of one or more subcarriers from said base station is based, at least in part, on said transmitted information.