Method for reducing interference in a receiver
A control for noise attenuation is provided which is based on signals received at a time that is different than the assigned receiving time slot of the receiver. Thus, the control is not affected by payload information.
1. A method for reducing interference in a receiver for receiving information in receiving time slots, in which receiver signals are received with at least a first antenna (ANT 1 ) and a second antenna (ANT 2 ), characterized in that, on the basis of signals received with said first antenna (ANT 1 ) and second antenna (ANT 2 ) at moments of time other than in said receiving time slot, when no information is being received, a reference signal representing interference in said other time slot is formed and used for the tuning of the receiver in said receiving time slots.
2. The method according to claim 1 , characterized in that the reference signal is generated by adjusting the phase of at least one received signal and mixing the signal with other received signals, and the power of the reference signal is determined, wherein the phase is adjusted to minimize the power of said reference signal.
3. The method according to claim 2 , characterized in that a phase control value formed on the basis of the reference signal is used upon receiving information.
4. The method according to claim 2 , characterized in that the phase control value formed on the basis of the reference signal is kept substantially constant at least for the time of the receiving time slot following the setting up of the phase control value.
5. The method according to claim 1 , characterized in that the reference signal is formed on the basis of the signal received in the time slot preceding a receiving time slot.
6. The method according to claim 5 , characterized in that the reference signal is formed less frequently than in every time slot preceding a receiving time slot.
7. A receiver for receiving information in receiving time slots, the receiver comprising at least a first antenna (ANT 1 ) and a second antenna (ANT 2 ) for receiving signals, characterized in that it comprises also means (D, SUM) for forming a reference signal on the basis of signals received with said first antenna (ANT 1 ) and second antenna (ANT 2 ) at moments of time other than in said receiving time slots, when no information is being received and means (D, DSP) for tuning the receiver on the basis of said reference signal to attenuate interference effective in the reception of information in said receiving time slots.
8. The receiver according to claim 7 , characterized in that it is a TDMA receiver.
9. A wireless communication device comprising at least a receiver for receiving information in receiving time slots allocated for said wireless communication device (MS), as well as a first antenna (ANT 1 ) and a second antenna (ANT 2 ) for receiving signals, characterized in that the wireless communication device comprises also means (D, SUM) for forming a reference signal on the basis of signals received with said first antenna (ANT 1 ) and second antenna (ANT 2 ) at moments of time other than in said receiving time slots allocated for the wireless communication device, when no information is being received and means (D, DSP) for tuning the receiver on the basis of said reference signal to attenuate interference effective in the reception of information in said receiving time slots.
10. The wireless communication device according to claim 9 , characterized in that the means for forming the reference signal comprise means for adjusting the phase of at least one received signal, means for mixing the signals received with the first and second antennas, means for determining the power of the mixed signal, and means for performing the adjustment of said phase on the basis of the power determination.
11. The wireless communication device according to claim 9 , characterized in that it comprises a digital signal processing unit (DSP) arranged for performing the power determination.
12. A system comprising at least a data processor (PC), a receiver for receiving information in receiving time slots, and a first antenna (ANT 1 ) and a second antenna (ANT 2 ) for receiving signals, characterized in that the system comprises also means (D, SUM) for forming a reference signal on the basis of signals received with said first antenna (ANT 1 ) and second antenna (ANT 2 ) at moments of time other than in said receiving time slots allocated for the receiver, when no information is being received and means (D, DSP) for tuning the receiver on the basis of said reference signal to attenuate at least interference which is formed in a data processor (PC) and which is effective in the reception of information in said receiving time slots.