Complex number multiplier

A complex number multiplier, comprising:

• an input for receiving a real part A and an imaginary part B of a first complex number, and a real part C and an imaginary part D of a second complex number, wherein A, B, C, D are binary numbers coded in two's complement form;
• a first processing stage which outputs values representing operations A−B, C−D, and A+B, wherein the A−B and C−D values are each a base two binary number with a redundant binary format and a borrow-save coding, wherein the A+B value is a base two binary number with a redundant format and a carry-save coding;
• a second processing stage comprising a converter configured to convert numbers delivered by the first processing stage into base four coded binary numbers with a redundant format;
• a third processing stage comprising one or more multipliers configured to perform operations (A−B)C, (C−D)B and (A+B)D, wherein results of these operations are base two coded numbers with a redundant format;
• and
• a fourth processing stage comprising two adders configured to compute a real part and an imaginary part of a product of two input complex numbers from numbers delivered by the third processing stage, wherein the real and imaginary parts are base two with a redundant binary format.

A mobile phone comprising a complex number multiplier comprising:

• an input for receiving a real part A and an imaginary part B of a first complex number, and a real part C and an imaginary part D of a second complex number, wherein A, B, C, D are binary numbers coded in two's complement form;
• a first processing stage which outputs values representing operations A−B, A+B, and C−D, wherein the A−B and C−D values are each a base two binary number with a redundant binary format and a borrow-save coding, wherein the A+B value is a base two binary number with a redundant format and a carry-save coding;
• a second processing stage comprising a converter configured to convert numbers delivered by the first processing stage into base four coded binary numbers with a redundant format;
• a third processing stage comprising one or more multipliers configured to perform operations (A−B)C, (C−D)B and (A+B)D, wherein results of these operations are base two coded numbers with a redundant format;
• and
• a fourth processing stage comprising two adders configured to compute a real part and an imaginary part of a product of two input complex numbers from numbers delivered by the third processing stage, wherein the real and imaginary parts are base two with a redundant binary format.