| 摘要 |
<p>A circuit is used for the compensation of echoes due to inadequate simulation in phantom circuits in a non-synchronous carrier frequency system. For adjustment of the frequency correction circuit a correction signal is derived from the output signal (y') of the adder through a regulating circuit which has an input connected to the adder output. The regulating circuit input signals are fed through a further adjusting element (D1) and also through a Hilbert transformer (H) followed by a further adjusting element (D2) directly and with a phase shift to the inputs of a further adder (101) whose output is fed to a subtraction circuit (111) to which the echo signal (y) from the phantom transformer (G) is also applied. The output from the subtraction unit is taken through an amplifier (K) to two multipliers (MU1m MU2) and there multiplied respectively by the signals at the input to the regulating circuit and at the output of the Hilbert transformer, the two output signals being fed to a pair of integrators (IN1, IN2) whose outputs control the adjusting elements (D1, D2).</p> |
