Receiver for wireless telecommunication stations and method

• US 20030157892A1
• Filed: 11/26/2002
• Published: 08/21/2003
• Est. Priority Date: 02/12/2002
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Reznik, Alexander, Grieco, Donald M., Oh, Hyun Seok
• Granted Patent: US 6,748,013 B2
• Time in Patent Office: Days
• US Class Current: 455/65
• CPC Class Codes: H04B 1/70754 Setting of search window, i.e. range of code offsets to be searched H04B1/70758 takes precedence
• CPC Class Codes: H04B 1/7115 Constructive combining of multi-path signals, i.e. RAKE receivers
• CPC Class Codes: H04B 1/7117 Selection, re-selection, allocation or re-allocation of paths to fingers, e.g. timing offset control of allocated fingers

Abstract

The present invention is directed to an improved telecommunication receiver for receiving wireless multi-path communication signals. A novel RAKE receiver and a time diverse integration system for the calculation of the relative power of received signal samples are provided. Preferably, the receiver is embodied in a UE or base station of a CDMA wireless telecommunication system, such as a 3GPP system.

Claims

1. A receiver for processing communication signals, which includes a RAKE receiver having up to a predetermined number of RAKE fingers, for assigning and combining a plurality of different signal paths of received communication signals comprising:

a RAKE locator which determines signal paths based on windows defined by groups of consecutive signal samples in which samples within a window exceed a first power threshold and designates up to said predetermined number of such windows as candidate windows based on relative power of the samples within the determined windows;

window search circuitry which analyzes candidate windows to determine if the power of samples of the candidate windows exceeds a second threshold and designates a Fat finger candidate window when at least one of the candidate windows has a selected number of candidate samples which exceed said second threshold;

a RAKE finger allocator which assigns candidate windows for processing by either a first type of RAKE finger or a different second type of Fat RAKE finger such that candidate windows which are not designated as a Fat finger candidate window are each assigned to a different RAKE finger of said first type.

2. The receiver of claim 1 wherein said RAKE locator defines windows which have a power level, determined by summing power levels of its group of samples, which exceeds said first power threshold and designates up to said predetermined number of such windows as candidate windows based on windows having the highest power levels, but not designating a window if more than a specified number of samples are included in another window having a higher power level.

3. The receiver of claim 2 wherein said predetermined number of RAKE fingers is 5 of which up to one is a FAT finger which comprises an Adaptive Filter.

4. The receiver of claim 2 wherein each said group of samples contains 21 samples and said specified number is 16 whereby said designated windows are separated from each other by at least 5 consecutive samples.

5. The receiver of claim 2 wherein said window search circuitry designates up to one Fat finger candidate window as the candidate window having the greatest power level which also has said selected number of candidate samples having power levels which exceed said second threshold where candidate samples are samples remaining after pruning consecutive samples which exceed said second threshold.

6. The receiver of claim 5 wherein each said group of samples contains 21 samples and said specified number is 16 whereby said designated windows are separated from each other by at least 5 consecutive samples.

7. The receiver of claim 5 wherein said RAKE finger allocator assigns any candidate window designated as a Fat finger candidate window to a Fat RAKE finger which comprises an Adaptive Filter for processing.

8. The receiver of claim 7 wherein each said group of samples contains 21 samples and said specified number is 16 whereby said designated windows are separated from each other by at least 5 consecutive samples.

9. The receiver of claim 8 wherein said predetermined number of RAKE fingers is 5.

10. The receiver of claim 1 wherein said predetermined number of RAKE fingers is 5 of which up to one is a FAT finger which comprises an Adaptive Filter.

21. A User Equipment (UE) for a CDMA wireless communication system comprising the receiver of claim 1.

22. A Base Station for a CDMA wireless communication system comprising the receiver of claim 1.

23. A CDMA wireless communication system comprising User Equipments (UEs) and a Base Station that each comprise the receiver of claim 1.

11. A method for processing communication signals using a RAKE receiver having up to a predetermined number RAKE fingers which combines a plurality of different signal paths of received communication signals comprising:

determining signal paths based on windows defined by groups of consecutive signal samples in which samples within a window exceed a first power threshold;

designating up to said predetermined number of such windows as candidate windows based on relative power of the samples within the determined windows;

analyzing candidate windows to determine if the power of samples of the candidate windows exceeds a second threshold;

designating a Fat finger candidate window when at least one of the candidate windows has a second predetermined number of candidate samples which exceed said second threshold;

assigning candidate windows for processing by either a first type of RAKE finger or a different second type of Fat RAKE finger such that candidate windows which are not designated as a Fat finger candidate window are each assigned to a different RAKE finger of said first type.

12. The method of claim 11 wherein said windows are defined which have a power level, determined by summing power levels of its group of samples, which exceeds said first power threshold and up to said predetermined number of candidate windows are designated based on windows having the highest power levels, but a window is not designated if more than a specified number of samples are included in another window having a higher power level.

13. The method of claim 12 wherein said predetermined number of RAKE fingers is 5 of which up to one is a FAT finger which comprises an Adaptive Filter such that up to 5 candidate windows are assigned.

14. The method of claim 12 wherein each said group of samples contains 21 samples and said specified number is 16 such that only windows which are separated from each other by at least 5 consecutive samples are designated as candidate windows.

15. The method of claim 12 wherein up to one Fat finger candidate window is designated being the candidate window having the greatest power level which also has said selected number of candidate samples having power levels which exceed said second threshold where candidate samples are samples remaining after pruning consecutive samples which exceed said second threshold.

16. The method of claim 15 wherein each said group of samples contains 21 samples and said specified number is 16 such that only windows which are separated from each other by at least 5 consecutive samples are designated as candidate windows.

17. The method of claim 15 wherein any candidate window designated as a Fat finger candidate window is assigned to a Fat RAKE finger which comprises an Adaptive Filter.

18. The method of claim 17 wherein each said group of samples contains 21 samples and said specified number is 16 such that only windows which are separated from each other by at least 5 consecutive samples are designated as candidate windows.

19. The method of claim 18 wherein said predetermined number of RAKE fingers is 5 such that up to 5 candidate windows are assigned.

20. The method of claim 11 wherein said predetermined number of RAKE fingers is 5 of which up to one is a FAT finger which comprises an Adaptive Filter such that up to 5 candidate windows are assigned.