Circuit for signal processing and method performed by such circuit
A method includes receiving a signal transmitted by a transmitter, wherein the transmitter transmits with a transmit power and the signal includes a pilot signal transmitted by the transmitter with a fraction of the transmit power. The method further includes equalizing the received signal, determining a despread pilot signal based on the equalized signal, and determining the fraction of the transmit power based on the despread pilot signal.
1. A method, comprising:
receiving a signal transmitted by a transmitter wherein the transmitter transmits with a transmit power and the signal comprises a pilot signal transmitted by the transmitter with a fraction of the transmit power;
equalizing the received signal;
determining a despread pilot signal based on the equalized signal; and
determining the fraction of the transmit power based on the despread pilot signal.
2. The method of claim 1 , further comprising:
determining a noise power based on the despread pilot signal, wherein determining the fraction of the transmit power is further based on the determined noise power.
3. The method of claim 1 , further comprising:
determining a signal power based on the equalized signal, wherein determining the fraction of the transmit power is further based on the determined signal power.
4. The method of claim 1 , further comprising:
averaging the despread pilot signal; and
determining a scaling factor based on the averaged despread pilot signal, wherein determining the fraction of the transmit power is further based on the scaling factor.
5. The method of claim 4 , wherein equalizing the received signal depends on the scaling factor.
6. The method of claim 1 , wherein the fraction of the transmit power is determined for each of a plurality of subsequent time slots.
7. The method of claim 6 , further comprising:
filtering the determined fraction of the transmit power over the plurality of time slots.
8. The method of claim 1 , further comprising:
low pass filtering the determined fraction of the transmit power.
9. The method of claim 1 , further comprising:
determining at least one channel estimation value based on the received signal; and
scaling the at least one channel estimation value based on the determined fraction of the transmit power.
10. The method of claim 1 , wherein:
the signal is received at a receiver circuit; and
the transmit power is the total power of all signals transmitted by the transmitter.
11. A circuit, comprising:
an input configured to receive a signal transmitted by a transmitter, wherein the transmitter transmits with a transmit power and the signal comprises a pilot signal transmitted by the transmitter with a fraction of the transmit power;
an equalizer arranged downstream of the input, and configured to equalize the received signal;
a despreader arranged downstream of the equalizer, and configured to despread the pilot signal based on the equalized signal; and
an estimation unit configured to determine the fraction of the transmit power based on the despread pilot signal.
12. The circuit of claim 11 , further comprising:
a noise power estimator arranged downstream of the despreader, and configured to estimate a noise power associated with the received signal, wherein the determined fraction of the transmit power is based on the noise power, and wherein the noise power is based on the despread pilot signal.
13. The circuit of claim 11 , further comprising:
a signal power estimation unit arranged downstream of the equalizer and configured to determine a signal power based on the equalized signal, wherein the determined fraction of the transmit power is based on the determined signal power.
14. The circuit of claim 11 , further comprising:
a further estimation unit configured to average a despread pilot signal and configured to determine a scaling factor based on the averaged despread pilot signal, wherein the determined fraction of the transmit power is further based on the scaling factor.
15. The circuit of claim 11 , further comprising:
a channel estimator coupled to an input of the equalizer and to an output of the estimation unit, and configured to receive the determined fraction of the transmit power, and further configured to scale at least one channel estimation value based on the received determined fraction of the transmit power.
16. The circuit of claim 11 , further comprising:
a filter arranged downstream of the estimation unit and configured to filter the determined fraction of the transmit power over multiple time slots.
17. The circuit of claim 11 , further comprising:
a low pass filter arranged downstream of the estimation unit.
18. A method, comprising:
receiving a signal transmitted by a transmitter, wherein the transmitter transmits with a transmit power and the signal comprises a pilot signal transmitted by the transmitter with a fraction of the transmit power;
equalizing the received signal;
determining a signal power based on the equalized signal; and
determining the fraction of the transmit power based on the equalized signal and the determined signal power.
19. The method of claim 18 , further comprising:
determining a despread pilot signal based on the equalized signal; and
determining a noise power based on the despread pilot signal, wherein determining the fraction of the transmit power is further based on the determined noise power.
20. A circuit, comprising:
an input configured to receive a signal transmitted by a transmitter, wherein the transmitter transmits with a transmit power and the signal comprises a pilot signal transmitted by the transmitter with a fraction of the transmit power;
an equalizer arranged downstream of the input, and configured to equalize the received signal;
an estimation unit arranged downstream of the equalizer and configured to determine the fraction of the transmit power based on the equalized signal; and
a signal power estimation unit arranged downstream of the equalizer and in parallel with the estimation unit, and configured to determine a signal power based on the equalized signal and the determined fraction of the transmit power, an output of the signal power estimation unit being coupled to an input of the estimation unit.
21. The circuit of claim 20 , further comprising:
a despreader arranged downstream of the equalizer, and configured to despread the pilot signal based on the equalized signal; and
a noise power estimator arranged downstream of the despreader and configured to determine a noise power based on the despread signal.
22. A method, comprising:
receiving a signal transmitted by a transmitter, wherein the transmitter transmits with a transmit power and the signal comprises a pilot signal transmitted by the transmitter with a fraction of the transmit power;
equalizing the received signal;
determining a signal power based on the equalized signal;
determining a despread pilot signal based on the equalized signal;
determining a noise power based on the despread pilot signal; and
determining the fraction of the transmit power based on the determined noise power and based on the determined signal power.
23. The method of claim 22 , further comprising:
averaging the despread pilot signal; and
determining a scaling factor based on the averaged despread pilot signal, wherein equalizing the received signal is based on the scaling factor, and wherein determining the fraction of the transmit power is further based on the scaling factor.