Method for updating a linear feedback shift register of code generator

A method for updating a Fibonacci-type linear feedback shift register of a code generator to a new state which is at a known offset from a known current state, comprising:

• generating a binary offset number illustrating the offset;
• generating a counter showning the number of bits in the binary offset number;
• initializing a Galois-type temporary state with a unit state;
• iterating as long as the value of the counter is higher than zero:
• applying a Galois Field multiplication to multiply the temporary state by itself;
• shifting the temporary state one state forward from the current temporary state if the value of the binary offset number bit shown by the counter is one;
• and
• decrementing the counter value by one;
• in the end, when the counter has reached the value zero, performing a Galois Field multiplication between the Galois-type temporary state and the Fibonacci-type current state, and setting the state obtained as a result of the multiplication as the new state of the Fibonacci-type.

A code generator in a radio system comprising:

• means for generating a binary offset number illustrating a known offset from a known current state of a Galois-type linear feedback shift register to a new state;
• means for generating a counter showing the number of bits in the binary offset number;
• means for initializing a temporary state with a unit state;
• means for iterating the operation of subsequent means as long as the counter value is higher than zero:
• means for applying a Galois Field multiplication to multiply the temporary state by itself;
• means for shifting the temporary state one state forward from the current temporary state if the value of the binary offset number bit shown by the counter is one;
• and
• means for decrementing the counter value by one;
• means for multiplying the temporary state and the current state by applying the Galois Field multiplication, and for setting the state obtained as a result of the multiplication as the new state when the counter has reached the value zero.

A code generator in a radio system comprising:

• means for generating a binary offset number illustrating a known offset from a known current state of a Fibonacci-type linear feedback shift register to a new state;
• means for generating a counter showing the number of bits in the binary offset number;
• means for initializing a Galois-type temporary state with a unit state;
• means for iterating the operation of subsequent means as long as the counter value is higher than zero:
• means for applying a Galois Field multiplication to multiply the temporary state by itself;
• means for shifting the temporary state one state forward from the current temporary state if the value of the binary offset number bit shown by the counter is one;
• and
• means for decrementing the counter value by one;
• means for multiplying the Galois-type temporary state and the Fibonacci-type current state by applying the Galois Field multiplication, and for setting the state obtained as a result of the multiplication as the new state of the Fibonacci-type when the counter has reached the value zero.