Method and an electrical device for efficient generation of multi-rate pseudo random noise (pn) sequence

Abstract

An electrical device for generating a multi-rate pseudo random noise (PN) sequence. A sequence generator is adapted to output a plurality of sequence values based on a step control signal (S t ). A selection system is adapted to select one of a plurality of sequence values based on a select value (M t ). A step control is adapted to provide the step control signal (S t ). Also disclosed is a method of generating a multi-rate PN sequence.

1 . An electrical device for generating a pseudo random noise (PN) output sequence (Z t ) comprising: 
 a sequence generator to output a plurality of sequence values (X Ni  . . . X Ni+N-1 ) based on a step control signal (S t );    a control and selection system coupled to the sequence generator adapted to select one of said plurality of sequence values (X Ni  . . . X Ni+N-1 ) from the sequence generator based on a select value (M t ), wherein said select value (M t ) is calculated as M t =F(C t , M t-1 ) where F is a function such that for each possible clock value C t  the function value runs through all practicable N values of M t  as M t -t runs through the N values with the restriction that all values occur equally often; and    a step control of the control and selection system adapted to provide said step control signal (S t ) to the sequence generator, wherein said step control signal (S t ) is calculated as S t =G(C t , M t-1 ) where G is a function such that for each possible clock value C t  the function value assumes one or two subsequent function values.    
   
   
       2 . The electrical device according to  claim 1 , wherein said sequence generator comprises a windmill polynomial sequence generator.  
   
   
       3 . The electrical device according to  claim 1 , wherein said electrical device is used in a portable device.  
   
   
       4 . The device according to  claim 3 , wherein said portable device is a mobile telephone.  
   
   
       5 . The device according to  claim 3 , wherein said electrical device is used in a stationary communication device.  
   
   
       6 . A method of generating a PN output sequence (Z t ) comprising the steps of: 
 generating a plurality of sequence values (X Ni  . . . X Ni+N-1 ) based on a step control signal (S t ), the method further comprising the steps of:    providing a select value (M t ), wherein said select value (M t ) is calculated as M t =F(C t , M t-1 ) where F is a function such that for each possible clock value C t  the function value runs through all practicable N values of M t  as M t -t runs through the N values with the restriction that all values occur equally often;    providing the step control signal (S t ), wherein said step control signal (S t ) is calculated as S t =G(C t , Mt- 1 ) where G is a function such that for each possible clock value C t  the function value assumes one or two subsequent function values; and    selecting one of said plurality of sequence values (X Ni  . . . X Ni+N-1 ) on the basis of the select value (M t ); and    outputting one of said plurality of sequence values (X Ni  . . . X Ni+N-1 ) as one element of a PN output sequence (Z t ).    
   
   
       7 . The method according to  claim 6 , wherein said plurality of sequence values (X Ni  . . . X Ni+N-1 ) is generated by a windmill polynomial sequence generator.  
   
   
       8 . The method according to  claim 6 , wherein said method is used in a portable device.  
   
   
       9 . The method according to  claim 6 , wherein said method is used in a mobile telephone.  
   
   
       10 . The method according to  claim 6 , wherein said method is used in a stationary communication device.  
   
   
       11 . A pseudo random noise (PN) generator, comprising: 
 a sequence generator module;    a control and select system module coupled to the sequence generator module;    the sequence generator module adapted to provide a plurality of sequence values (X Ni  . . . X Ni+N-1 ) to the control and select system module based on a step control signal (S t ) fed into the sequence generator module from the control and select system module;    the control and select system module adapted to select one of the plurality of sequence values (X Ni  . . . X Ni+N-1 ) based on a select value (M t ) generated by the control and select system module wherein the select value (M t ) is calculated as M t =F(C t , M t -1) where F is a function such that for each possible clock value C t  the function value runs through all practicable N values of M t  as M t -t runs through the N values with the restriction that all values occur equally often;    the control and select system module being adapted to generate the step control signal (S t ) calculated as S t =G(C t , Mt-1) where G is a function such that for each possible clock value C t  the function value assumes one or two subsequent function values; and    the control and select system module adapted to output the selected one of the plurality of sequence values (X Ni  . . . X Ni+N-1 ) as one element of a PN output sequence (Z t ).    
   
   
       12 . The pseudo random noise (PN) generator of  claim 11 , wherein the sequence generator module comprises a windmill polynomial sequence generator.