Apparatus and method for generating codes in a communications system

Abstract

There is provided an apparatus and method of generating two-dimensional QCTCs. The sub-code sets of QCTCs with given code rates are generated and the sub-codes are rearranged in a sub-code set with a different code rate, for use in the next transmission to a sub-code with a predetermined code rate.

1 - 8 . (canceled)  
   
   
       9 . A method of generating sub-codes of two-dimensional QCTCs, comprising the steps of: 
 generating sub-codes of a QCTC with the highest code rate among QCTCs with code rates in an integer-multiple relation and setting the QCTC with the highest code rate as a primitive code;    determining a number of sub-codes to be grouped in the primitive code to generate each of the other QCTCs; and    generating sub-codes of the other QCTCs by grouping the sub-codes of the primitive code according to grouping numbers.    
   
   
       10 . The method of  claim 9 , further comprising the step of transmitting a sub-code following a previously transmitted sub-code in a sub-code set of a QCTC with a code rate determined for transmission.  
   
   
       11 . A method of transmitting symbols using sub-codes of two-dimensional QCTCs, comprising the steps of: 
 generating sub-codes of a QCTC with the highest code rate among QCTCs with code rates in an integer-multiple relation and setting the QCTC with the highest code rate as a primitive code;    determining a number of sub-codes to be grouped in the primitive code to generate each of the other QCTCs; and    generating a sub-code by grouping as many sub-codes of the primitive code as a grouping number corresponding to a determined code rate for transmission, starting with a sub-code following a previously transmitted sub-code in the primitive code, and transmitting symbols using the generated sub-code.    
   
   
       12 . A method of transmitting symbols using sub-codes of two-dimensional QCTCs, comprising the steps of: 
 generating sub-codes of a QCTC with the highest code rate among QCTCs with code rates in an integer-multiple relation and setting the QCTC with the highest code rate as a primitive code;    generating sub-codes of the other QCTCs by grouping the sub-codes of the primitive code;    determining a sequence number, j_current to be used in transmission by the following equation when a code rate for transmission is given      [(( j   —   pre+ 1)* g   —   premodSp )−1]+1=( j   —   current*g   —   current ) modSp      where j_pre is a sequence number of sub-code used for the previous transmission, g_pre is a grouping number used for the previous transmission, g_current is a determined grouping number and S p  is a set size of the primitive code; and    transmitting symbols using a sub-code corresponding to the determined sequence number among sub-codes of the QCTC according to the determined code rate    
   
   
       13 . A method of generating sub-codes of two-dimensional QCTCs, comprising the steps of: 
 grouping QCTCs according to code rates, each QCTC group including QCTCs with code rates in an integer-multiple relation;    generating sub-codes of a QCTC with the highest code rate in each QCTC group and setting the QCTC with the highest code rate as a primitive code;    determining a number of sub-codes to be grouped in the primitive code to generate each of the other QCTCs in each QCTC group; and    generating a sub-code by grouping as many sub-codes of the primitive code as a grouping number corresponding to a code rate.    
   
   
       14 . A method of transmitting symbols using sub-codes of two-dimensional QCTCs, comprising the steps of: 
 grouping QCTCs according to code rates, each QCTC group including QCTCs with code rates in an integer-multiple relation;    generating sub-codes of a QCTC with the highest code rate in each QCTC group and setting the QCTC with the highest code rate as a primitive code;    determining a number of sub-codes to be grouped in the primitive code to generate each of the other QCTCs in each QCTC group; and    generating a sub-code by grouping as many sub-codes of the primitive code as a grouping number corresponding to a determined code rate for transmission and transmitting symbols using the generated sub-code.    
   
   
       15 - 17 . (canceled)  
   
   
       18 . An apparatus for transmitting symbols using sub-codes of two-dimensional QCTCs, comprising: 
 a turbo encoder for encoding an input information bit stream with a predetermined code rate and generating code symbols;    a controller for storing a set of matrixes from which to generate sub-codes of a QCTC with the highest code rate among QCTCs with code rates in an integer-multiple relation, setting the QCTC with the highest code rate as a primitive code, generating sub-codes of QCTCs by grouping the sub-codes of the primitive code, selecting a sub-code of QCTC according to the determined code rate when the code rate for the transmission is given, and generating a puncturing and repetition control signal according to the selected sub-code; and    a QCTC generator for generating a sub-code to be transmitted by puncturing and repeating the code symbols received from the turbo encoder according to the puncturing and repetition control signal.    
   
   
       19 . The apparatus of  claim 18 , wherein the controller selects a sub-code according to a sequence number, j_current, of sub-code determined by  
       [(( j   —   pre+ 1)* g   —   premodSp )−1]+1=( j   —   current*g   —   current ) modSp    
     where, j_pre is a sequence number of a sub-code used in the previous transmission, g_pre is a grouping number used for the previous transmission, g_current is a determined grouping number and S p  is a set size of the primitive code.  
   
   
       20 . The apparatus of  claim 18 , wherein the controller has a plurality of QCTC groups, each QCTC grouping having QCTCs with code rates in an integer-multiple relation.