Method and circuit arrangement for reducing offset voltage of a signal

A circuit arrangement for reducing the offset voltage of a first signal, comprising:

• separating means having an input for receiving the first signal and an output for providing a second signal, said separating means being for separating out a direct voltage component of the signal;
• means including a high-pass filter for filtering said first signal, to form a third signal;
• summing means for summing said third signal with a reference voltage to produce a forth signal;
• means for connecting said fourth signal to the output of the separating means for a predetermined time.

In a direct conversion receiver for reducing the offset voltage of a baseband signal, a method for reducing offset voltage of a first signal having a direct voltage component, comprising:

• separating the direct voltage component from the first signal to produce a second signal without the direct voltage component;
• high-pass filtering said first signal to produce a third signal;
• summing a reference voltage with the third signal to produce a fourth signal;
• and
• combining the second signal with the fourth signal for a predetermined time.

In a receiver of a mobile station, a method for reducing offset voltage of a first signal having a direct voltage component, comprising:

• separating the direct voltage component from the first signal to produce a second signal without the direct voltage component;
• high-pass filtering said first signal to produce a third signal;
• summing a reference voltage with the third signal to produce a fourth signal;
• and
• combining the second signal with the fourth signal for a predetermined time.

In a digital, time-division mobile communication system, a method for reducing offset voltage, of a first signal having a direct voltage component, in a telephone of said system, the method comprising:

• separating the direct voltage component from the first signal to produce a second signal without the direct voltage component;
• high-pass filtering said first signal to produce a third signal;
• summing a reference voltage with the third signal to produce a fourth signal;
• and
• combining the second signal with the fourth signal for a predetermined time .