Signal path searching method and apparatus thereof in mobile communication system provided with plurality of array antenna elements

• US 20030067970A1
• Filed: 10/04/2002
• Published: 04/10/2003
• Est. Priority Date: 10/06/2001
• Status: Active Grant

• Current Assignee: LG-Ericsson Company Limited (Telefonaktiebolaget LM Ericsson)
• Original Assignee: LG Nortel Company Limited (Telefonaktiebolaget LM Ericsson)
• Inventors: Kim, Jeong Ho
• Granted Patent: US 7,411,996 B2
• Time in Patent Office: Days
• US Class Current: 375/148
• CPC Class Codes: H04B 1/70752 Partial correlation
• CPC Class Codes: H04B 1/70755 Setting of lock conditions, e.g. threshold
• 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
• CPC Class Codes: H04B 7/0845 per branch equalization, e.g. by an FIR-filter or RAKE receiver per antenna branch rake receivers as such H04B1/7115
• CPC Class Codes: H04B 7/086 using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming
• CPC Class Codes: H04B 7/0891 Space-time diversity rake receivers H04B1/7115; space-time decoding H04L1/0631
• CPC Class Codes: H04L 1/06 using space diversity

Abstract

Disclosed is a signal path searching method in a mobile communication system provided with a plurality of array antenna elements. According to the method and apparatus, the path search is performed using a signal of a chip level or a signal of a symbol level, and it is decided whether to first perform a temporal process or a spatial process according to the level.

Claims

1. A signal path searching method in a mobile communication system provided with a plurality of array antenna elements, the method comprising the steps of:

(a) applying partial correlation values of despread signals to first phase information values estimated for signal path estimation;

(b) deciding if a first maximum value among the partial correlation values to which the first phase information values are applied exceeds a first threshold value;

(c) if it is decided that the first maximum value exceeds the first threshold value, applying the partial correlation values to second phase information values based on a first phase information value producing the first maximum value; and

(d) searching a new signal path according to the comparison of a second maximum value among the partial correlation values to which the second phase information values are applied and a second threshold value.

2. The method of claim 1, further comprising the steps of:

if the second maximum value exceeds the second threshold value, optionally accumulating the partial correlation values to which the second phase information values are applied during a plurality of time-slots period; and

confirming the new signal path by comparing the accumulated value with a third threshold value.

3. The method of claim 1, wherein the second phase information values are an integer multiples of a certain phase angle.

4. The method of claim 3, wherein the second phase information values are integer multiples of 12 degrees.

5. The method of claim 1, wherein the second phase information values are at intervals of before and after 2 degrees based on a specified phase angle.

7. The method of claim 5, further comprising the steps of:

if the second maximum value exceeds the second threshold value, optionally accumulating the partial correlation values of the spread signals to which the second phase information values are applied during a plurality of time-slots period; and

confirming the new signal path by comparing the accumulated value with a third threshold value.

8. The method of claim 7, wherein the second phase information values are an integer multiples of a certain phase angle.

9. The method of claim 8, wherein the second phase information values are integer multiples of 12 degrees.

10. The method of claim 7, wherein the second phase information values are at intervals of before and after 2 degrees based on a specified phase angle.

6. A signal path searching method in a mobile communication system provided with a plurality of array antenna elements, the method comprising the steps of:

applying spread signals to first phase information values estimated for path estimation;

deciding if a first maximum value among partial correlation values of the spread signals to which the first phase information values are applied exceeds a first threshold value;

if it is decided that the first maximum value exceeds the first threshold value, applying the spread signals to second phase information values based on a first phase information value producing the first maximum value; and

searching a new signal path according to the comparison of a second maximum value among partial correlation values of the spread signals to which the second phase information values are applied and a second threshold value.

11. A signal path searching method in a mobile communication system provided with a plurality of array antenna elements, the method comprising the steps of:

(a) applying partial correlation values of despread signals to first phase information values estimated for signal path estimation at a specific time;

(b) deciding if a first maximum value among the partial correlation values to which the first phase information values are applied exceeds a first threshold value;

(c) if it is decided that the first maximum value exceeds the first threshold value, applying the partial correlation values to second phase information values based on a first phase information value producing the first maximum value;

(d) deciding if a second maximum value among the partial correlation values to which the second phase information values are applied exceeds a second threshold value;

(e) if it is decided that the second maximum value exceeds the second threshold value, approving the specific time; and

(f) searching a new signal path at the specific time.

12. The method of claim 11, further comprising the steps of:

if the second maximum value exceeds the second threshold value, optionally accumulating the partial correlation values to which the second phase information values are applied during a plurality of time-slots period; and

confirming the new signal path by comparing the accumulated value with a third threshold value.

13. A signal path searching method in a mobile communication system provided with a plurality of array antenna elements, the method comprising the steps of:

(a) applying spread signals to first phase information values estimated for path estimation at a specific time;

(b) deciding if a first maximum value among partial correlation values of the spread signals to which the first phase information values are applied exceeds a first threshold value;

(c) if it is decided that the first maximum value exceeds the first threshold value, applying the spread signals to second phase information values based on a first phase information value producing the first maximum value;

(d) deciding if a second maximum value among the partial correlation values of the spread signals to which the second phase information values are applied exceeds a second threshold value;

(e) if it is decided that the second maximum value exceeds the second threshold value, approving the specific time; and

(f) searching a new signal path at the specific time.

14. The method of claim 13, further comprising the steps of:

if the second maximum value exceeds the second threshold value, optionally accumulating the partial correlation values of the spread signals to which the second phase information values are applied during a plurality of time-slots period; and

confirming the new signal path by comparing the accumulated value with a third threshold value.

15. A signal path searching method in a mobile communication system provided with a plurality of array antenna elements, the method comprising the steps of:

(a) processing temporally despread signals of signals received through the antenna elements at a specific time;

(b) spatially processing the temporally processed signals by using first estimated phase information values and second estimated phase information values;

wherein the second estimated phase information are slightly increasing and/or decreasing for one among the first estimated phase information values,

(c) searching a signal path existing at the specific time where each maximum value for the first and second phase information values among the spatially processed signals'"'"' values exceeds a corresponding threshold value.

16. The method of claim 15, if it is decided that a maximum value among the spatially processed signals'"'"' values for the second phase information values exceeds a predetermined threshold values, optionally accumulating the spatially processed signals'"'"' values for the second phase information during a plurality of time-slots period;

and

confirming the new signal path by comparing the accumulated value with a corresponding threshold value.

17. A signal path searching method in a mobile communication system provided with a plurality of array antenna elements, the method comprising the steps of:

(a) processing spatially chip-level signals of signals received through the antenna elements by using first estimated phase information values and second estimated phase information values at a specific time;

wherein the second estimated phase information are slightly increasing and/or decreasing for one among the first estimated phase information values,

(b) temporally processing the spatially processed signals for each of the first and second phase information values of at the specific time;

(c) searching a signal path existing at the specific time where a maximum value for each of the first and second phase information values among the temporally processed signals'"'"' values exceeds a corresponding threshold value.

18. The method of claim 17, if it is decided that a maximum value among the temporally processed signals'"'"' values for the second phase information values exceeds a predetermined threshold values, optionally accumulating the temporally processed signals'"'"' values for the second phase information during a plurality of time-slots period;

and

confirming the new signal path by comparing the accumulated value with a corresponding threshold value.

19. A signal path searching apparatus in a mobile communication system provided with a plurality of array antenna elements, the apparatus comprising:

a temporal processor for processing temporally despread signals of signals received through the antenna elements at a specific time;

a spatial processor for spatially processing the temporally processed signals by using first estimated phase information values and second estimated phase information values;

wherein the second estimated phase information are slightly increasing and/or decreasing for one among the first estimated phase information values,

a combiner for combing formed beams of signal paths searched at the specific time where each maximum value for the first and second phase information values among the spatially processed signals'"'"' values exceeds a corresponding threshold value.

20. The apparatus of claim 19, if it is decided that a maximum value for the second phase information values among the spatially processed signals'"'"' values exceeds a predetermined threshold values, the spatial processor optionally accumulates the spatially processed signals'"'"' values for the second phase information during a plurality of time-slots period, the combiner combines the formed beams of the signal paths confirmed by comparing the accumulated value with a corresponding threshold value.

21. A signal path searching apparatus in a mobile communication system provided with a plurality of array antenna elements, the apparatus comprising:

(a) a spatial processor processing spatially chip-level signals of signals received through the antenna elements by using first estimated phase information values and second estimated phase information values at a specific time;

wherein the second estimated phase information are slightly increasing and/or decreasing for one among the first estimated phase information values,

(b) a temporal processor for temporally processing the spatially processed signals by using first estimated phase information values and second estimated phase information values at a specific time;

(c) a combiner for combining formed beams of signal paths searched at the specific time where each maximum value for the first and second phase information values among the temporally processed signals'"'"' values exceeds a corresponding threshold value.

22. The apparatus of claim 21, wherein if it is decided that a maximum value for the second phase information values among the temporally processed signals'"'"' values exceeds a predetermined threshold values, the temporal processor optionally accumulates the temporally processed signals'"'"' values for the second phase information during a plurality of time-slots period, the combiner the formed beams of signal paths confirmed at the specific time by comparing the accumulated value with a corresponding threshold value.

23. A signal path searching apparatus in a mobile communication system provided with a plurality of array antenna elements, the apparatus comprising:

(a) a temporal processor for calculating partial correlation values of despread signals of signals received the antenna elements at a specific time;

(a) a spatial processor for applying the partial correlation values to first estimated phase information values and second estimated phase information values estimated for signal path estimation, wherein the second estimated phase information values are slightly increasing and/or slightly decreasing for one among the first estimated phase information values;

(b) a time hypothesis decider for deciding if a maximum value for each of the first and second phase information values among the partial correlation values to which the first estimated phase information values and the second estimated phase information values are respectively applied exceeds a corresponding threshold value; and

(c) a combiner for combining formed beams of the signal paths searched according to a output of the time hypothesis decider at the specific time.

24. The apparatus of claim 23, wherein the spatial processor optionally accumulates the partial correlation values with the second phase information values during a plurality of time-slots period and the time hypothesis decider further decides if the accumulated value exceeds a predetermined threshold value.

25. The apparatus of claim 23, wherein the second phase information values are an integer multiples of a certain phase angle.

26. The apparatus of claim 25, wherein the second phase information values are integer multiples of 12 degrees.

27. The apparatus of claim 23, wherein the second phase information values are at intervals of before and after 2 degrees based on a specified phase angle.

28. A signal path searching apparatus in a mobile communication system provided with a plurality of array antenna elements, the apparatus comprising:

a spatial processor for applying spread signals to first phase information values and second phase information values estimated for path estimation at a specific time, wherein the second estimated phase information values are slightly increasing and/or slightly decreasing for one among the first estimated phase information values;

a temporal processor for obtaining partial correlation values of the spread signals to which the first phase information values and the second phase information values are respectively applied;

a time hypothesis decider for deciding if each maximum value for the first and second phase information values among the temporally processed signals'"'"' values exceeds a corresponding threshold value; and

a combiner for combining formed beams of the signal paths searched according to a output of the time hypothesis decider at the specific time.

29. The apparatus of claim 28, wherein the temporal processor accumulates the partial correlation values of signals with the second phase information values during a plurality of time-slots, the time hypothesis decider further decides if the accumulated value exceeds a prescribed threshold value.

30. The apparatus of claim 28, wherein the second phase information values are an integer multiples of a certain phase angle.

31. The apparatus of claim 30, wherein the second phase information values are integer multiples of 12 degrees.

32. The apparatus of claim 28, wherein the second phase information values are at intervals of before and after 2 degrees based on a specified phase angle.