Patent ID: 7627055

Claim:
A method, comprising: generating an original complex IQ signal; performing error adjustment on the original complex IQ signal; processing the adjusted complex IQ signal in a signal processing circuitry, thereby obtaining a processed real signal which is proportional to an amplitude of the adjusted complex IQ signal; detecting an envelope of the processed real signal; synchronizing the real signal envelope and the original complex IQ signal; deriving the envelope of the original complex IQ signal; comparing the synchronized real signal envelope with the synchronized original IQ signal envelope at two consecutive time instances; and obtaining a processed complex IQ signal from the real signal envelope based on a comparison result, which processed complex IQ signal is used in performing error adjustment on the original complex IQ signal, wherein comparing the synchronized real signal envelope with the synchronized original IQ signal envelope comprises comparing the synchronized real signal envelope with the synchronized original IQ signal envelope at two consecutive time instances n and n−1: | A real ( n )|=√{square root over ( y I 2 ( n )+ y Q 2 ( n ))}{square root over ( y I 2 ( n )+ y Q 2 ( n ))}=| A original ( n )|=√{square root over ( d I 2 ( n )+ d Q 2 ( n ))}{square root over ( d I 2 ( n )+ d Q 2 ( n ))} | A real ( n −1)|=√{square root over ( y I 2 ( n −1)+ y Q 2 ( n −1))}{square root over ( y I 2 ( n −1)+ y Q 2 ( n −1))}=| A original ( n −1)|=√{square root over ( d I 2 ( n −1)+ d Q 2 ( n −1))}{square root over ( d I 2 ( n −1)+ d Q 2 ( n −1))} wherein A real is the real signal envelope, A original is the original IQ signal envelope, Y I is the processed In-phase signal component to be estimated, y Q is the processed Quadrature-phase signal component to be estimated, d I is the original In-phase signal component, and d Q is the original Quadrature-phase signal component, wherein the squares of the processed IQ signal components at time instance n−1 are derived as: y I 2 ⁡ ( n - 1 ) = y I 2 ⁡ ( n ) [ ⅆ I 2 ⁢ ( n ) / ⅆ I 2 ⁢ ( n - 1 ) ] , ⁢ y Q 2 ⁡ ( n - 1 ) = y Q 2 ⁡ ( n ) [ ⅆ Q 2 ⁢ ( n ) / ⅆ Q 2 ⁢ ( n - 1 ) ] and ⁢ ⁢ with A real 2 ⁡ ( n - 1 ) = y I 2 ⁡ ( n ) [ ⅆ I 2 ⁢ ( n ) / ⅆ I 2 ⁢ ( n - 1 ) ] + y Q 2 ⁡ ( n ) [ ⅆ Q 2 ⁢ ( n ) / ⅆ Q 2 ⁢ ( n - 1 ) ] A real ⁢ 2 ⁡ ( n ) = y I 2 ⁡ ( n ) + y Q 2 ⁡ ( n ) squares of the processed IQ signal components at time instance n are given by: y I 2 ⁡ ( n ) = A real 2 ⁡ ( n ) - y Q 2 ⁡ ( n ) y Q 2 ⁡ ( n ) = [ ⅆ Q 2 ⁢ ( n ) / ⅆ Q 2 ⁢ ( n - 1 ) ] ⁢ ( A real 2 ⁡ ( n - 1 ) ⁡ [ ⅆ I 2 ⁢ ( n ) / ⅆ I 2 ⁢ ( n - 1 ) ] ⁢ A real 2 ⁡ ( n ) ) [ ⅆ I 2 ⁢ ( n ) / ⅆ I 2 ⁢ ( n - 1 ) ] - [ ⅆ Q 2 ⁢ ( n ) / ⅆ Q 2 ⁢ ( n - 1 ) ] and finally processed IQ signal components at time instance n are derived as: y I ( n )=√{square root over ( y 2 I ( n ))}·signum( d I ( n )) y Q ( n )=√{square root over ( y 2 Q ( n ))}·signum( d Q ( n )) wherein signum (d I (n)) and signum (d Q (n)) provides a sign of original complex IQ signal components.