| 摘要 |
<p>It is an object to provide a delay time estimating method in a distortion compensating device comprised of a pre-distortion unit that carries out distortion compensation processing by applying a distortion compensation coefficient to an input signal, a delay unit that delays the input signal before the distortion compensation, a distortion compensation coefficient renewal unit that renews the distortion compensation coefficient in accordance with the input signal supplied from the delay unit before the compensation and a feedback signal fed back from an output side of a distortion device, and a DLL circuit set in the delay unit that estimates a delay time caused in the distortion device and the feedback loop. If neighboring two input signal are defined as front and rear signals, the DLL circuit extracts amplitudes of the front and rear signals and the feedback signal, respectively, carries out an amplitude product operation of the front and feedback signals, an amplitude product operation of the rear and feedback signals, and outputs a difference between the amplitude products as a delay time estimated value.</p> |
