Apparatus and method for modulating data message by employing orthogonal variable spreading factor (ovsf) codes in mobile communication system

Abstract

A method for converting source data to a channel-modulated signal having pairs of in-phase (I) and quadrature-phase (Q) data in a mobile station, wherein the mobile station includes: encoding the source data to generate at least one data part and a control pant; generating a spreading code to allocate to a channel, wherein each spreading code is selected on the basis of a data rate of the data part and the control part and spreading codes are selected so two consecutive pairs of I and Q data correspond to two points located on same point or symmetrical with respect to a zero point on a phase domain; and spreading the control part and the data part with the spreading code, to generate the channel-modulated signal. The method is capable of improving a power efficiency of a mobile station of a mobile communication system by reducing a peak-to-average power ratio.

1 . An apparatus for converting source data to a channel-modulated signal having a plurality of pairs of in-phase (I) and quadrature-phase (Q) data in a mobile station, wherein the mobile station uses (N−1) data channels (N is an integer larger than two) and a control channel, the apparatus comprising: 
 channel coding means for encoding the source data to generate (N−1) data parts and a control part, wherein the data parts are allocated to the data channels and the control part is allocated to the control channel;    code generating means for generating spreading codes to be allocated to the channels, wherein each of the spreading codes is selected on the basis of a data rate of the data part and the control part and spreading codes are selected so that two consecutive pairs of the I and Q data are correspondent to two points located on the same point or symmetrical with respect to a zero point on a phase domain; and    spreading means for spreading the control part and the data part by using the spreading codes to thereby generate the channel-modulated signal,    wherein:    the spreading codes correspond to an orthogonal variable spreading factor (OVSF) code,    the spreading code allocated to the control channel is represented by C 256,0,  where 256 denotes the spreading factor and 0 the code number,    the spreading codes allocated to first and second data channels are represented by C 4, 1 ={1, 1 , −1, −1},    when there are more than two data channels, the spreading codes allocated to a third data channel and, when present, a fourth data channel are represented by C 4, 3 ={1, −1, −1, 1}, and    when there are more than four data channels, the spreading codes allocated to a fifth data channel and, when present, a sixth data channel are represented by C 4, 2 ={1, −1, 1, −1}.    
   
   
       2 . The apparatus as recited in  claim 1 , wherein said code generating means comprises: 
 control means responsive to the spreading factor for generating code numbers for the channels; and    spreading code generation means responsive to the spreading factor and the code number for generating the spreading code to be allocated to the channels.    
   
   
       3 . The apparatus as recited in  claim 1 , wherein said mobile station includes two data channels, three data channels, four data channels, five data channels, or six data channels.  
   
   
       4 . The apparatus as recited in  claim 1 , wherein the spreading factor related to the data part is 2 N , where N=2 to 8 and wherein the code number related to the data part is 2 N /4.  
   
   
       5 . The apparatus as recited in  claim 1 , wherein said code generating means further comprises: 
 signature generation means for generating a predetermined signature; and    scrambling code generation means for generating a scrambling code.    
   
   
       6 . The apparatus recited in  claim 5 , wherein the code numbers related to the data part and the control part are dependent on the predetermined signature, if the scrambling code is shared by multiple mobile stations.  
   
   
       7 . The apparatus as recited in  claim 5 , wherein the spreading factor related to the data part is 2 N  where N−5 to 8 and wherein the code number related to the data part is 2 N (S−1)/16.  
   
   
       8 . The apparatus as recited in  claim 1 , further comprising: 
 scrambling means for scrambling the data and control parts and a scrambling code to thereby rotate the two points and generate scrambled signals.    
   
   
       9 . The apparatus as recited in  claim 8 , further comprising: 
 filtering means for pulse-shaping the scrambled signals and generating pulse-shaped signals; and    gain adjusting means for adjusting gain of each of the pulse-shaped signals.    
   
   
       10 . The apparatus as recited in  claim 8 , wherein one of the two points is rotated to clockwise direction and the other is rotated to counterclockwise direction by a phase of 45°.  
   
   
       11 . The apparatus as recited in  claim 10 , wherein a phase difference between the two points after rotation is 90°.  
   
   
       12 . A mobile station for converting source data to a channel-modulated signal having a plurality of pairs of in-phase (I) and quadrature-phase (Q) data, wherein the mobile station uses (N−1) data channels (N is an integer equal to larger than two) and a control channel, the mobile station comprising: 
 channel coding means for encoding the source data to generate (N−1) data parts and a control part, wherein the data parts are allocated to the data channels and the control part is allocated to the control channel;    code generating means for generating N spreading codes to he allocated to the channels, wherein each of the spreading codes is selected on the basis of a data rate of each data part and the control part and the spreading codes are selected so that two consecutive pairs of the I and Q data are correspondent to two points located on the same point or symmetrical with respect to a zero point on a phase domain; and    spreading means for spreading the control part and the data parts by using the spreading codes to thereby generate the channel-modulated signal,    wherein:    the spreading codes correspond to an orthogonal variable spreading factor (OVSF) code,    the spreading code allocated to the control channel is represented by C 256,0 , where 256 denotes the spreading factor and 0 the code number,    the spreading codes allocated to first and second data channels are represented by C 4, 1 ={1, 1, −1, −1},    when there are more than two data channels, the spreading codes allocated to a third data channel and, when present, a fourth data channel are represented by C 4,3 ={1, −1, −1, 1}, and    when there are more than four data channels, the spreading codes allocated to a fifth data channel and, when present, a sixth data channel are represented by C 4, 2 ={1, −1, 1, −1}.    
   
   
       13 . The mobile station as recited in  claim 12 , further comprising: 
 frequency converting means coupled to the spreading means for converting the channel-modulated signal to a radio frequency signal; and    antenna for sending the radio frequency signal to a base station.    
   
   
       14 . A method for converting source data to a channel-modulated signal having a plurality of pairs of in-phase (I) and quadrature-phase (Q) data in a mobile station, wherein the mobile station uses (N−1) data channels (N is an integer larger than two) and a control channel, the method comprising: 
 a) encoding the source data to generate (N−1) data parts and a control part, wherein the data parts are allocated to the data channels and the control part is allocated to the control channel;    b) generating spreading codes to be allocated to the channels, wherein each of the spreading codes is selected on the basis of a data rate of the data part and the control part and spreading codes are selected so that two consecutive pairs of the I and Q data are correspondent to two points located on the same point or symmetrical with respect to a zero point on a phase domain; and    c) spreading the control part and the data part by using the spreading codes to thereby generate the channel-modulated signal,    wherein:    the spreading codes correspond to an orthogonal variable spreading factor (OVSF) codes    the spreading code allocated to the control channel is represented by C 256,0 , where 256 denotes a spreading factor and 0 a code numbers,    the spreading codes allocated to first and second data channels are represented by C 4, 1 ={1, 1, −1, −1},    when there are more than two data channels, the spreading codes allocated to a third data channel and, when present, a fourth data channel are represented by C 4, 3 ={1, −1, −1, 1}, and    when there are more than four data channels, the spreading codes allocated to a fifth data channel and, when present, a sixth data channel are represented by C 4,2 ={1, −1, 1, −1}.    
   
   
       15 . The method as recited in  claim 14 , wherein said step a) comprises: 
 a1) encoding the source data to generate the data part and the control part; and    a2) generating a spreading factor related to the data rate of the data part.    
   
   
       16 . The method as recited in  claim 15 , wherein said step b) comprises: 
 b1) generating code numbers for the channels in response to the spreading factor; and    b2) generating the spreading code to be allocated to the channels in response to the spreading factor and the code number.    
   
   
       17 . The method as recited in  claim 16 , wherein said mobile station includes a data channel and a control channel for PRACH application.  
   
   
       18 . The method as recited in  claim 14 , wherein the mobile station includes two data channels, three data channels, four data channels, five data channels, or six data channels.  
   
   
       19 . The method as recited in  claim 16 , wherein the spreading factor related to the data part is 2 N , where N=2 to 8, and wherein the code number related to the data part is 2 N /4.  
   
   
       20 . The method as recited in  claim 17 , wherein said step b) further comprises: 
 b3) generating a predetermined signature; and    b4) generating a scrambling code.    
   
   
       21 . The method as recited in  claim 20 , wherein the code numbers related to the data part and the control part are dependent on the predetermined signature, if the scrambling code is shared by multiple mobile stations.  
   
   
       22 . The method as recited in  claim 14 , further comprising: 
 d) scrambling the data and control parts and a scrambling code, to thereby rotate the two points and generate scrambled signals.    
   
   
       23 . The method as recited in  claim 22 , further comprising: 
 e) filtering the scrambled signals and generating pulse-shaped signals; and    f) adjusting gain of the pulse-shaped signals.    
   
   
       24 . The method as recited in  claim 22 , wherein one of the two points is rotated to clockwise direction and the other is rotated to counterclockwise direction by a phase of 45°, respectively.  
   
   
       25 . The method as recited in  claim 24 , wherein a phase difference between the two points after rotation is 90°.  
   
   
       26 . The apparatus as recited in  claim 16 , wherein the mobile station includes a data channel and a control channel for PRACH application.  
   
   
       27 . A method for converting source data to a channel-modulated signal having a plurality of pairs of in-phase (I) and quadrature-phase (Q) data in a mobile station, wherein the mobile station uses (N−1) data channels N is an integer larger than two) and a control channel, the method comprising: 
 a) encoding the source data to generate (N−1) data parts and a control part, wherein the data parts are allocated to the data channels and the control part is allocated to the control channel;    b) generating spreading codes to be allocated to the channels, wherein each of the spreading codes is selected on the basis of a data rate of the data part and the control part and spreading codes are selected so that two consecutive pairs of the I and Q data are correspondent to two points located on the same point or symmetrical with respect to a zero point on a phase domain; and    c) spreading the control part and the data part by using the spreading codes to thereby generate the channel-modulated signal,    wherein:    the spreading codes correspond to an orthogonal variable spreading factor (OVSF) codes    the spreading code allocated to the control channel is represented by C 256,0 , where 256 denotes a spreading factor and 0 the code number,    the spreading codes allocated to first and second data channels are represented by C 4, 1 ={1, 1, −1, −1},    when there are more than two data channels, the spreading codes allocated to a third data channel and, when present, a fourth data channel are represented by C 4, 3 ={1, −1, −1, 1}, and    when there are more than four data channels, the spreading codes allocated to a fifth data channel and, when present, a sixth data channel are represented by C 4, 2 =1, −1, 1, −1}.    
   
   
       28 . An apparatus for converting source data to a channel-modulated signal having a plurality of pairs of in-phase (I) and quadrature-phase (Q) data in a mobile station, wherein the mobile station uses (N−1) data channels (N is an integer larger than two) and a control channel, the apparatus comprising: 
 channel coding means for encoding the source data to generate (N−1) data parts and a control part, wherein the data parts are allocated to the data channels and the control part is allocated to the control channel;    code generating means for generating spreading codes to be allocated to the channels, wherein each of the spreading codes is selected on the basis of a data rate of the data part and the control part and spreading codes are selected so that two consecutive pairs of the I and Q data are correspondent to two points located on the same point or symmetrical with respect to a zero point on a phase domain; and    spreading means for spreading the control part and the data parts by using the spreading codes to thereby generate the channel-modulated signal,    wherein:    the spreading codes correspond to an orthogonal variable spreading factor (OVSF) code,    said channel coding means includes spreading factor generation means for generating a spreading factor related to the data rate of the data part,    the spreading code allocated to the control channel is represented by C 256,0 , where 256 denotes the spreading factor and 0 the code number,    the spreading codes allocated to first and second data channels are represented by C 4, 1 ={1, 1, −1, −1}, and    said code generating means includes control means responsive to the spreading factor for generating code numbers for the channels, and spreading code generation means responsive to the spreading factor and the code number for generating the spreading code to be allocated to the channels, said spreading code generation means including, counting means for consecutively producing a count value in synchronization with a clock signal, first spreading code generation means responsive to the count value and the spreading factor for generating the spreading code to be allocated to the data channel, and second spreading code generation means responsive to the count value and the spreading factor for generating the spreading code to be allocated to the control channel.    
   
   
       29 . The apparatus as recited in  claim 28 , wherein the first spreading code generation means comprises: 
 first logical operation means responsive to the count value for carrying out a logical operation with the spreading factor and the code number related to the data part, to thereby generate the spreading code related to the data part; and    first selection means for outputting the spreading code related to the data part in response to a select signal as the spreading factor related to the data part.    
   
   
       30 . An apparatus for converting source data to a channel-modulated signal having a plurality of pairs of in-phase (1) and quadrature-phase (Q) data in a mobile station, wherein the mobile station uses (N−1) data channels (N is an integer larger than two) and a control channel, the apparatus comprising: 
 channel coding means for encoding the source data to generate (N−1) data parts and a control part, wherein the data parts are allocated to the data channel and the control part is allocated to the control channel;    code generating means for generating spreading codes to be allocated to the channels, wherein each of the spreading codes is selected on the basis of a data rate of the data part and the control part and spreading codes are selected so that two consecutive pairs of the 1 and Q data are correspondent to two points located on the same point or symmetrical with respect to a zero point on a phase domain; and    spreading means for spreading the control part and the data part by using the spreading codes to thereby generate the channel-modulated signal,    wherein:    the spreading codes correspond to an orthogonal variable spreading factor (OVSF) code,    said channel coding means includes spreading factor generation means for generating a spreading factor related to the data rate of the data part,    the spreading code allocated to the control channel is represented by C 256,0 , where 256 denotes the spreading factor and 0 the code number,    the spreading codes allocated to first and second data channels are represented by C 4, 1 ={1, 1, −1, −1}, and    said code generating means further including signature generation means for generating a predetermined signature, and scrambling code generation means for generating a scrambling code, wherein said code numbers related to the data part and the control part are dependent on the predetermined signature, if the scrambling code is shared by multiple mobile stations and wherein the data part and the control part are allocated to the data channel and the control channel, respectively, and wherein the spreading factor related to the control part is 256 and wherein the code number related to the control part is 16(S−1)+15 where S=1 to 16 and S is the predetermined signature.    
   
   
       31 . The apparatus as recited in  claim 30 , wherein the spreading factor related to the data part is 2 N , where N=5 to 8, and wherein the code number related to the data part is 2 N (S−1)/16.  
   
   
       32 . A method for converting source data to a channel-modulated signal having a plurality of pairs of in-phase (I) and quadrature-phase (Q) data in a mobile station, wherein the mobile station uses (N−1) data channels (N is an integer larger than two) and a control channel, the method comprising: 
 c) encoding the source data to generate (N−1) data parts and a control part, wherein the data parts are allocated to the data channels and the control part is allocated to the control channel;    b) generating spreading codes to be allocated to the channels, wherein each of the spreading codes is selected on the basis of a data rate of the data parts and the control part and spreading codes are selected so that two consecutive pairs of the I and Q data are correspondent to two points located on the same point or symmetrical with respect to a zero point on a phase domain; and    c) spreading the control part and the data parts by using the spreading codes to thereby generate the channel-modulated signal,    wherein:    the spreading codes correspond to an orthogonal variable spreading factor (OVSF) code,    the spreading code allocated to the control channel is represented by C 256,0 , where 256 denotes the spreading factor and 0 the code number, the spreading codes allocated to first and second data channels are represented by C 4, 1 ={1, 1, −1, −1},    the step a) comprises:    a1) encoding the source data to generate the data part and the control part; and    a2) generating a spreading factor related to the data rate of the data part;    the step b) comprises:    b1) generating code numbers for the channels in response to the spreading factor;    b2) generating the spreading code to be allocated to the channels in response to the spreading factor and the code number;    b3) generating a predetermined signature; and    b4) generating a scrambling code;    the code numbers related to the data parts and the control part are dependent on the predetermined signature, if the scrambling code is shared by multiple mobile stations.    
   
   
       33 . The method as recited in  claim 32 , wherein the spreading factor related to a data part is 2 N , where N=5 to 8, and wherein the code number related to the data part is 2 N (S−1)/16.  
   
   
       34 . The apparatus as recited in  claim 1 , wherein said channel coding means comprises spreading factor generation means for generating a spreading factor related to the data rate of the data part.  
   
   
       35 . The mobile station as recited in  claim 12 , wherein said channel coding means comprises spreading factor generation means for generating a spreading factor related to the data rate of the data part.  
   
   
       36 . An apparatus for converting source data to a channel-modulated signal having a plurality of pairs of in-phase (I) and quadrature-phase (Q) data in a mobile station, wherein the mobile station uses (N−1) data channels (N is an integer larger than two) and a control channel, the apparatus comprising: 
 channel coding means for encoding the source data to generate (N−1) data parts and a control part, wherein the data parts are allocated to the data channels and the control part is allocated to the control channel;    code generating means for generating spreading codes to be allocated to the channels; and    spreading means for spreading the control part and the data pall by using the spreading codes to thereby generate the channel-modulated signals,    wherein:    the spreading codes correspond to an orthogonal variable spreading factor (OVSF) code, the spreading code allocated to the control channel is represented by C 256,0 , where 256 denotes the spreading factor and 0 the code number,    the spreading codes allocated to first and second data channels are represented by C 4, 1 ={1, 1, −1, −1},    when there are more than two data channels, the spreading codes allocated to a third data channel and, when present, a fourth data channel are represented by C 4, 3 ={1, −1, −1, 1}, and    when there are more than four data channels, the spreading codes allocated to a fifth data channel and, when present, a sixth data channel are represented by C 4, 2  {1, −1, 1, −1}.    
   
   
       37 . A mobile station for converting source data to a channel-modulated signal having a plurality of pairs of in-phase (I) and quadrature-phase (Q) data, wherein the mobile station uses (N−1) data channels (N is an integer equal to larger than two) and a control channel, the mobile station comprising: 
 channel coding means for encoding the source data to generate (N−1) data parts and a control part, wherein the data parts are allocated to the data channels and the control part is allocated to the control channel;    code generating means for generating N spreading codes to be allocated to the channels; and    spreading means for spreading the control part and the data parts by using the spreading codes to thereby generate the channel-modulated signal,    wherein:    the spreading codes correspond to an orthogonal variable spreading factor (OVSF) code, the spreading code allocated to the control channel is represented by C 256,0 , where 256 denotes the spreading factor and 0 the code number,    the spreading codes allocated to first and second data channels are represented by C 4, 1 ={1, 1, −1, −1},    when there are more than two data channels, the spreading codes allocated to a third data channel and, when present, a fourth data channel are represented by C 4, 3 ={1, −1, −1, 1}, and    when there are more than four data channels, the spreading codes allocated to a fifth data channel and, when present, a sixth data channel are represented by C 4, 2 ={1, −1, 1, −1}.    
   
   
       38 . A method for converting source data to a channel-modulated signal having a plurality of pairs of in-phase (I) and quadrature-phase (Q) data in a mobile station, wherein the mobile station uses (N−1) data channels (N is an integer larger than two) and a control channel, the method comprising: 
 a) encoding the source data to generate (N−1) data parts and a control part, wherein the data parts are allocated to the data channels and the control part is allocated to the control channel;    b) generating spreading codes to be allocated to the channels; and    c) spreading the control part and the data part by using the spreading codes to thereby generate the channel-modulated signal,    wherein:    the spreading codes correspond to an orthogonal variable spreading factor (OVSF) code, the spreading code allocated to the control channel is represented by C 256,0 , where 256 denotes a spreading factor and 0 a code number,    the spreading codes allocated to first and second data channels are represented by C 4, 1 ={1, 1, −1, −1},    when there are more than two data channels, the spreading codes allocated to a third data channel and, when present, a fourth data channel are represented by C 4, 3 ={1, −1, −1, 1}, and    when there are more than four data channels, the spreading codes allocated to a fifth data channel and, when present, a sixth data channel are represented by C 4, 2 ={1, −1, 1, −1}.    
   
   
       39 . A method for converting source data to a channel-modulated signal having a plurality of pairs of in-phase (1) and quadrature-phase (Q) data in a mobile station, wherein the mobile station uses (N−1) data channels (N is an integer larger than two) and a control channel, the method comprising: 
 a) encoding the source data to generate (N−1) data parts and a control part, wherein the data parts are allocated to the data channel and the control part is allocated to the control channel;    b) generating spreading codes to be allocated to the channels; and    c) spreading the control part and the data part by using the spreading codes to thereby generate the channel-modulated signal,    wherein:    the spreading codes correspond to an orthogonal variable spreading factor (OVSF) code, the spreading code allocated to the control channel is represented by C 256,0 , where 256 denotes the spreading factor and 0 the code number,    the spreading codes allocated to first and second data channels are represented by C 4, 1 ={1, 1, −1, −1},    when there are more than two data channels, the spreading codes allocated to a third data channel and, when present, a fourth data channel are represented by C 4, 3 ={1, −1, −1, 1}, and    when there are more than four data channels, the spreading codes allocated to a fifth data channel and, when present, a sixth data channel are represented by C 4, 2 ={1, −1, 1, −1}.    
   
   
       40 . An apparatus for converting source data to a channel-modulated signal having a plurality of pairs of in-phase (I) and quadrature-phase (Q) data in a mobile station, wherein the mobile station uses (N−1) data channels (N is an integer larger than two) and a control channel, the apparatus comprising; 
 a channel coder configured to encode the source data to generate (N−1) data parts and a control part, wherein the data parts are allocated to the data channels and the control part is allocated to the control channel;    a code generator configured to generate spreading codes to be allocated to the channels; and    a spreader configured to spread the control part and the data part by using the spreading codes to thereby generate the channel-modulated signal,    wherein:    the spreading codes correspond to an orthogonal variable spreading factor (OVSF) code, the spreading code allocated to the control channel is represented by C 256,0 , where 256 denotes the spreading factor and 0 the code number,    the spreading codes allocated to first and second data channels are represented by C 4, 1 ={1, 1, −1, −1},    when there are more than two data channels, the spreading codes allocated to a third data channel and, when present, a fourth data channel are represented by C 4, 3 ={1, −1, −1, 1}, and    when there are more than four data channels, the spreading codes allocated to a fifth data channel and, when present, a sixth data channel are represented by C 4, 2  ={1, −1, 1, −1}.    
   
   
       41 . The apparatus as recited in  claim 40 , wherein each of the spreading codes is selected on the basis of a data rate of the data part and the control part and spreading codes are selected so that two consecutive pairs of the I and Q data are correspondent to two points located on the same point or symmetrical with respect to a zero point on a phase domain.  
   
   
       42 . The apparatus as recited in  claim 40 , further comprising a processor that implements the channel coder, the code generator, and the spreader.  
   
   
       43 . The apparatus as recited in  claim 40 , wherein said mobile station includes two data channels, three data channels, four data channels, five data channels, or six data channels.  
   
   
       44 . A mobile station for converting source data to a channel-modulated signal having a plurality of pairs of in-phase (I) and quadrature-phase (Q) data, wherein the mobile station uses (N−1) data channels (N is an integer larger than two) and a control channel, the mobile station comprising: 
 a channel coder configured to encode the source data to generate (N−1) data parts and a control part, wherein the data parts are allocated to the data channels and the control part is allocated to the control channel;    a code generator configured to generate N spreading codes to be allocated to the channels; and    a spreader configured to spread the control part and the data parts by using the spreading codes to thereby generate the channel-modulated signal,    wherein:    the spreading codes correspond to an orthogonal variable spreading factor (OVSF) code, the spreading code allocated to the control channel is represented by C 256,0 , where 256 denotes the spreading factor and 0 the code number,    the spreading codes allocated to first and second data channels are represented by C 4, 1 ={1, 1, −1, −1},    when there are more than two data channels, the spreading codes allocated to a third data channel and, when present, a fourth data channel are represented by C 4, 3 ={1, −1, −1, 1}, and    when there are more than four data channels, the spreading codes allocated to a fifth data channel and, when present, a sixth data channel are represented by C 4, 2 ={1, −1, 1, −1}.    
   
   
       45 . The mobile station as recited in  claim 44 , wherein each of the spreading codes is selected on the basis of a data rate of each data part and the control part and the spreading codes are selected so that two consecutive pairs of the I and Q data are correspondent to two points located on the same point or symmetrical with respect to a zero point on a phase domain.  
   
   
       46 . The mobile station as recited in  claim 44 , further comprising: 
 a processor that implements the channel coder, the code generator, and the spreader.    
   
   
       47 . The mobile station as recited in  claim 44 , wherein said mobile station includes two data channels, three data channels, four data channels, five data channels, or six data channels.