Adaptive puncturing technique for multicarrier systems

Abstract

Various embodiments are described for adaptive puncturing techniques.

1 . An apparatus comprising:
 an adaptive bit loading block to receive channel state information for a plurality of subcarriers and to select a modulation scheme and a puncturing pattern for each of the plurality of subcarriers or for each of a plurality of subbands based on the channel state information;   a puncturing block to puncture a coded bit stream for each of a plurality of subcarriers or subbands in accordance with the selected puncturing pattern;   a mapping block to map a coded and punctured bit stream output from the puncturing block to one or more subcarrier symbols for each of the plurality of subcarriers or subbands.   
     
     
         2 . The apparatus of  claim 1  and further comprising an encoder coupled to the puncturing block to produce the encoded bit stream. 
     
     
         3 . The apparatus of  claim 2  wherein the encoder comprises a convolutional encoder. 
     
     
         4 . The apparatus of  claim 1  wherein each of the subbands comprises a plurality of subcarriers. 
     
     
         5 . The apparatus of  claim 1  wherein the mapping block comprises a mapping block to map a coded and punctured bit stream output from the puncturing block to one or more OFDM subcarrier symbols for each of a plurality of OFDM subcarriers or OFDM subcarrier subbands, where the OFDM subcarrier subbands comprises a plurality of OFDM subcarriers. 
     
     
         6 . The apparatus of  claim 1  and further comprising an OFDM modulator to modulate a selected subcarrier symbol onto a OFDM subcarrier for each of a plurality of OFDM subcarriers. 
     
     
         7 . The apparatus of  claim 1  wherein the puncturing pattern and/or modulation scheme for a subcarrier are selected such that the number of bits in the subcarrier symbol or subband are the same or a multiple of a number of output coded bits in a puncturing pattern. 
     
     
         8 . The apparatus of  claim 1  wherein a puncturing pattern and/or modulation scheme are selected such that one or more sets of output coded bits in a puncturing pattern may map onto one subcarrier or one subband. 
     
     
         9 . The apparatus of  claim 1  wherein a puncturing pattern and/or modulation scheme are selected such that one or more sets of output coded bits in a puncturing pattern may map onto one subcarrier if adaptive bit loading per subcarrier is performed, or map onto one subband if adaptive bit loading per subband is performed. 
     
     
         10 . An apparatus comprising an adaptive bit loading block to select a modulation scheme an/or a puncturing pattern for an OFDM subcarrier or an OFDM subcarrier subband based on subcarrier channel state information. 
     
     
         11 . The apparatus of  claim 10  wherein the modulation scheme and the puncturing pattern are selected such that a number of bits in an OFDM subcarrier symbol or in an OFDM subcarrier subband to be the same or a multiple of the number of output coded bits in the puncturing pattern. 
     
     
         12 . An apparatus comprising an adaptive bit loading block to select a modulation scheme and a puncturing pattern for each of a plurality of OFDM subcarriers or OFDM subcarrier subbands based on subcarrier channel state information, a subcarrier subband comprising a plurality of OFDM subcarriers. 
     
     
         13 . The apparatus of  claim 12  and further comprising a puncturing block to puncture a coded bit stream for each of a plurality of the subcarrier subbands according to the puncturing pattern selected for the subcarrier subband. 
     
     
         14 . The apparatus of  claim 13  and further comprising a mapping block to map coded and punctured bits into OFDM subcarrier symbols according to the selected modulation scheme for each of the subcarrier subbands. 
     
     
         15 . A method comprising:
 receiving channel state information for each of a plurality of subcarriers; and   selecting a modulation scheme and a puncturing pattern for each of a plurality of subcarriers or subcarrier subbands based on the subcarrier channel state information.   
     
     
         16 . The method of  claim 15  and further comprising:
 coding data bits to produce a coded bit stream; 
 puncturing the coded bit stream for each of a plurality of subcarriers according to the selected puncturing pattern for each subcarrier; and 
 mapping bits from the coded and punctured bit stream to subcarrier symbols according to the selected modulation schemes for each subcarrier or subband. 
 
     
     
         17 . The method of  claim 15  wherein the selecting comprises selecting a modulation scheme and a puncturing pattern for each of a plurality of subcarriers or subcarrier subbands such that a number of bits in an OFDM subcarrier symbol or OFDM subcarrier subband is the same or a multiple of the number of output coded bits in a puncturing pattern. 
     
     
         18 . A method comprising:
 receiving channel state information for each of a plurality of subcarriers; and   selecting a modulation scheme and a puncturing pattern for each of a plurality of subcarrier subbands based on the subcarrier channel state information, each subband comprising a plurality of OFDM subcarriers.