Patent ID: 7881402

Claim:
A method of compensating for one or more errors in a transmitter, wherein the transmitter includes a compensator circuit, a quadrature modulator and a feedback path, the method comprising: (a) supplying an orthogonal pair of tones as calibration signals to the compensator circuit; (b) adjusting a delay value of a delay unit in the feedback path in order to approximate the condition that a sum of a first phase lag corresponding to the delay value plus a second phase lag associated with one or more filters in the transmitter is an integer multiple of π; (c) generating an update for one or more parameters of the compensator circuit, wherein said generating includes: capturing a block of samples from the feedback path; computing real and imaginary parts of the complex Fourier transform corresponding to the frequency kf b from the block of samples, wherein f b is the frequency of the orthogonal pair of tones, wherein k is one or two; and computing the update for the one or more parameters using said real and imaginary parts of the complex Fourier transform corresponding to frequency kf b ; (d) supplying the updated one or more parameters to the compensator circuit; and (e) repeating (c) and (d) a number of times until a termination condition is achieved.