Method of predicting wireless signal power

1. A method of predicting the power of a received wireless signal, the method comprising the steps of:

sampling the power of the received wireless signal over an observation interval to obtain a first series of values representative of the power of the received wireless signal over the observation interval;

performing a smoothing operation on the first series of values to give a series of smoothed samples over the observation interval, wherein the number of smoothed samples is less than the number of values in the first series of values; and

extrapolating the smoothed samples beyond the observation interval to predict the future power of the received wireless signal.

2. A method as claimed in claim 1 , wherein the step of extrapolating comprises:

performing least mean squares curve fitting on the smoothed samples; and then extrapolation of the fitted curve beyond the observation interval.

3. A method as claimed in claim 1 , wherein the step of performing least mean squares curve fitting comprises fitting a polynomial curve to the smoothed samples.

4. A method as claimed in claim 3 , wherein the polynomial curve is a second order polynomial.

5. A method as claimed in claim 1 , wherein the step of performing the smoothing operation comprises performing an additive white gaussian noise smoothing procedure.

6. A method as claimed in claim 5 , wherein the step of performing the additive white gaussian noise smoothing procedure is followed by a further step of removing the bias due to the Influence of the additive white gaussian noise.

7. A method as claimed in claim 1 further comprising the step of excluding any predictions of negative power.

8. A method as claimed in claim 1 performed by signal processing apparatus in a mobile device.

9. A method as claimed in claim 1 performed by signal processing apparatus at a base station.

10. A method of predicting the power of a received wireless signal, the method comprising the steps of:

sampling the power of the received wireless signal over an observation interval to obtain a first series of values representative of the power of the received wireless signal over the observation interval;

performing an additive white gaussian noise smoothing operation on the first series of values to give a series of smoothed samples over the observation interval, and

removing the bias due to the influence of the additive white gaussian noise;

performing least mean squares curve fitting on the smoothed samples;

fitting a second order polynomial curve to the smoothed samples; and

extrapolating the fitted curve beyond the observation interval to predict the future power of the received wireless signal.

11. A wireless device having signal processing apparatus, the signal processing apparatus being operable to predict the power of a wireless signal received by the wireless device, the signal processing apparatus being arranged to:

sample the power of the received wireless signal over an observation interval to obtain a first series of values representative of the power of the received wireless signal over the observation interval;

perform a smoothing operation on the first series of values to give a series of smoothed samples over the observation interval; and

extrapolate the smoothed samples beyond the observation interval to predict the future power of the received wireless signal.

12. A wireless device having signal processing apparatus, the signal processing apparatus being operable to predict the power of a wireless signal received by the wireless device, the signal processing apparatus being arranged to:

sample the power of the received wireless signal over an observation interval to obtain a first series of values representative of the power of the received wireless signal over the observation interval;

perform an additive white gaussian noise smoothing operation on the first series of values to give a series of smoothed samples over the observation interval, and

remove the bias due to the influence of the additive white gaussian noise;

perform least mean squares curve fitting on the smoothed samples;

fit a second order polynomial curve to the smoothed samples; and

extrapolate the fitted curve beyond the observation interval to predict the future power of the received wireless signal.

13. A wireless communications network including a plurality of wireless devices, each wireless device having signal processing apparatus, the signal processing apparatus being operable to predict the power of a wireless signal received by the wireless device, the signal processing apparatus being arranged to:

sample the power of the received wireless signal over an observation interval to obtain a first series of values representative of the power of the received wireless signal over the observation interval;

perform a smoothing operation on the first series of values to give a series of smoothed samples over the observation interval; and

extrapolate the smoothed samples beyond the observation interval to predict the future power of the received wireless signal.

14. Signal processing apparatus arranged to perform a method of predicting the power of a received wireless signal, the method comprising the steps of:

sampling the power of the received wireless signal over an observation interval to obtain a first series of values representative of the power of the received wireless signal over the observation interval;

performing a smoothing operation on the first series of values to give a series of smoothed samples over the observation interval; and

extrapolating the smoothed samples beyond the observation interval to predict the future power of the received wireless signal.

15. A computer program executable to cause signal processing apparatus to perform a method of predicting the power of a received wireless signal, the method comprising the steps of:

sampling the power of the received wireless signal over an observation interval to obtain a first series of values representative of the power of the received wireless signal over the observation interval;

performing a smoothing operation on the first series of values to give a series of smoothed samples over the observation interval; and

extrapolating the smoothed samples beyond the observation interval to predict the future power of the received wireless signal.

16. A computer program stored on a data carrier, the computer program being executable to cause signal processing apparatus to perform a method of predicting the power of a received wireless signal, the method comprising the steps of:

sampling the power of the received wireless signal over an observation interval to obtain a first series of values representative of the power of the received wireless signal over the observation interval;

performing a smoothing operation on the first series of values to give a series of smoothed samples over the observation interval; and

extrapolating the smoothed samples beyond the observation interval to predict the future power of the received wireless signal.

17. A computer program executing on signal processing apparatus, the program causing the signal processing apparatus to perform a method of predicting the power of a received wireless signal, the method comprising the steps of:

sampling the power of the received wireless signal over an observation Interval to obtain a first series of values representative of the power of the received wireless signal over the observation interval;

performing a smoothing operation on the first series of values to give a series of smoothed samples over the observation interval; and

extrapolating the smoothed samples beyond the observation interval to predict the future power of the received wireless signal.