Synchronous CDMA communication system

1. A method of processing a signal received using a wireless communication channel by a receiver in a wireless cellular network, the method comprising:

receiving signal samples of a signal to be processed from a serving cell;

identifying a set of dominant interfering cells generating an interfering signal above a level;

using a number of cells in the set to select an interference scenario; and

using the selected interference scenario and at least one parameter related to the serving cell and the interfering cells to select a processing function for processing the signal.

2. A method according to claim 1 , comprising:

determining from the signal samples a serving cell power for the signal;

determining the total interference power from the cells in the set, and

comparing the ratio of the serving cell power and the total disturbance power with a threshold value defined by the selected interference scenario to select the processing function.

3. A method according to claim 2 , wherein the threshold value varies with the number of dominant cells.

4. A method according to claim 1 , wherein the processing function is an equalizer function.

5. A method according to claim 2 , wherein the ratio is used to select an equalizer type in dependence on the threshold value.

6. A method according to claim 5 , wherein the selection also depends from the value of at least one additional channel parameter.

7. A method according to claim 1 , wherein the number of dominant cells is selected from a group of cells detected by a cell search function.

8. A method according to claim 5 , wherein the equalizer type is selected from an Least Squares (LS) equalizer and an Minimum Mean-Square Error (MMSE) equalizer.

9. A method according to claim 1 , wherein an equalizer parameter for the equalizer is determined based on at least one estimated channel condition.

10. A method according to claim 9 , wherein the equalizer parameter is the time averaging interval.

11. A method according to claim 9 , wherein the channel condition is an estimate of the relative mobile speed.

12. A computer program product comprising program code means stored on a non-transitory computer-readable medium which, when executed by a processor, implements a method according to claim 1 .

13. A base station comprising a wireless interface for receiving and transmitting signals, said base station operable to implement a method according to claim 1 .

14. A receiver for use in a wireless cellular network for processing digital samples, the receiver comprising:

means for receiving signal samples;

means for identifying a set of dominant interfering cells generating an interfering signal above a level;

means for selecting an interference scenario using a number of cells in the set; and

means for selecting a processing function for processing the digital samples based on the selected interference scenario and at least one parameter related to a serving cell and the interfering cells.

15. A receiver according to claim 14 , further comprising a store holding a plurality of equalizer functions, wherein the selected interference scenario is used to select one of said equalizer functions as said processing function.

16. A receiver according to claim 14 , comprising:

means for determining from the signal samples a serving cell power for the signal;

means for determining the total interference power from the cells in the set; and

means for comparing the ratio of the serving cell power and the total disturbance power with a threshold value defined by the selected interference scenario to select the processing function.

17. A receiver according to claim 15 , wherein the equalizer functions include Least Squares (LS) and Minimum Mean-Square Error (MMSE) equalizers.

18. A mobile terminal comprising a wireless interface for receiving signals and providing said signal samples to a receiver in accordance with claim 14 .

19. A receiver for use in a wireless cellular network for processing digital samples, the receiver comprising:

a processor arranged to receive a sequence of digital samples corresponding to symbols transmitted in a cell of the wireless network, and for implementing an interference scenario selection routine which uses an identified set of dominant interfering cells above signal level to select said interference scenario, said processor being further operable to implement one of a plurality of processing routines for processing the digital samples;

a memory holding said plurality of processing routines;

wherein the processor implements a selection routine which uses the selected interfering scenario to select one of the plurality of processing routines in the memory for processing the digital samples.

20. A method of processing digital samples in a cellular wireless network, the method comprising:

receiving a sequence of samples corresponding to symbols transmitted in a signal in a cell of the wireless network;

using said received sequence to generate an estimate of cell geometry, being an estimate of a ratio between received signal power of signals of that cell and disturbance power where disturbance power is a measure of disturbance introduced from signals of other cells and noise; and

using said estimate to select one of a plurality of processing routines for processing the digital samples.

21. A method according to claim 20 comprising identifying a set of dominant interfering cells generating an interfering signal above a level; and

determining the disturbance power from the cells in the set.

22. A method according to claim 21 wherein the number of cells in the set is used to select an interference scenario and comprising using the interference scenario and at least one additional parameter to select said processing routine.

23. A receiver for use in a wireless cellular network for processing digital samples, the receiver comprising:

a processor arranged to receive a sequence of digital samples corresponding to symbols transmitted in a cell of the wireless network and for implementing an estimation routine which uses the received sequence to generate an estimate of a ratio between received signal power of signals of that cell and disturbance power where disturbance power is a measure of disturbance introduced from signals of other cells and noise, and one of a plurality of processing routines for processing the digital samples;

a memory holding said plurality of processing routines;

wherein the processing implements a routine which uses said estimate to select one of the plurality of processing routines in the memory for processing the digital samples.

24. A receiver according to claim 23 , wherein the plurality of algorithms includes equalizer algorithms with different equalizer cost functions.

25. A receiver according to claim 24 , wherein the cost functions are based on at least an Minimum Mean-Square Error (MMSE) criterion and a Least Squares (LS) criterion.

26. A method of processing radio communication signals in a radio receiver, the method comprising:

receiving digital samples of an incoming radio communication signal and processing those samples in accordance with an equalizer algorithm;

estimating at least one parameter of a channel over which the incoming signal has been transmitted;

selecting said equalizer algorithm from a plurality of equalizer algorithms based on at least one said estimated channel parameter;

wherein the plurality of equalizer algorithms include algorithms with different equalizer cost functions, and the step of selecting said equalizer algorithm comprises selecting one of said different equalizer cost functions; and

wherein the step of selecting one of said equalizer cost functions is based on a parameter indicative of a signal to disturbance ratio.

27. A method of processing radio communication signals in a radio receiver, the method comprising:

receiving digital samples of an incoming radio communication signal and processing those samples in accordance with an equalizer algorithm;

estimating at least one parameter of a channel over which the incoming signal has been transmitted;

selecting said equalizer algorithm from a plurality of equalizer algorithms based on at least one said estimated channel parameter;

wherein the plurality of equalizer algorithms include algorithms with different equalizer cost functions, and the step of selecting said equalizer algorithm comprises selecting one of said different equalizer cost functions; and

wherein the step of selecting one of said equalizer cost functions is based on a channel parameter indicative of statistical distribution of disturbance.