Received communication signal processing methods and components for wireless communication equipment

• US 7,593,742 B2
• Filed: 08/27/2007
• Issued: 09/22/2009
• Est. Priority Date: 03/05/2003
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Bohnhoff, Peter
• Primary Examiner(s): Vuong, Quochien B
• Application Number:
  US11/845,514
• Publication Number:
  US 20070293255A1
• Time in Patent Office: 757 Days
• Field of Search: 455/130, 455/313, 455/323, 455/327, 455/334, 455/522, 455/502, 375/147, 375/148, 375/150, 375/224, 375/259, 375/260, 375/325, 375/340, 375/349, 370/335, 370/342
• US Class Current: 455/502
• CPC Class Codes: H04B 1/70735 Code identification H04B1/7083 takes precedence
• CPC Class Codes: H04B 1/70755 Setting of lock conditions, e.g. threshold
• CPC Class Codes: H04B 1/708 Parallel implementation
• CPC Class Codes: H04B 1/7083 Cell search, e.g. using a three-step approach
• CPC Class Codes: H04B 1/7113 Determination of path profile
• 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 17/364 Delay profiles
• CPC Class Codes: H04B 7/08 at the receiving station
• CPC Class Codes: H04J 13/10 Code generation
• CPC Class Codes: H04L 25/0212 of impulse response

Abstract

A wireless transmit receive unit (WTRU) and methods are used in a wireless communication system to process sampled received signals to establish and/or maintain wireless communications. A selectively controllable coherent accumulation unit produces power delay profiles (PDPs). A selectively controllable post processing unit passes threshold qualified magnitude approximation values and PDP positions to a device such as a rake receiver to determine receive signal paths.

Claims

1. A wireless transmit receive unit (WTRU) for use in wireless communications comprising:

a post processing unit configured to process power delay profiles (PDPs) of received wireless signals where each PDP has a selected number of sequential elements that have values representing coherent accumulation of sequential sets of received samples mixed with a known sequence;

the post processing unit configured to select less than half of the PDP elements of each PDP and to store the selected PDP elements'"'"' values and respective PDP position values;

the post processing unit further configured to selectively combine stored PDP values such that the values of elements of each PDP of a set of corresponding PDPs that are stored for the same respective PDP position are combined; and

the post processing unit further configured to evaluate the combined values for respective PDP positions against selected thresholds to pass threshold qualified combined values and respective position values for further signal processing for use in determining received signal paths of signals from which the respective PDP elements are produced.

2. The WTRU of claim 1 wherein the post processing unit is configured to select PDP elements based on highest values of PDP elements of each PDP.

3. The WTRU according to claim 2 where the PDP element values contain in-phase and quadrature components wherein the post processing unit is configured to selectively combine stored PDP element values by coherent combination for threshold evaluation and the post processing unit is further configured to compute a magnitude approximation value for each combined value that is threshold qualified whereby the magnitude approximation value and a respective position value are utilized for further signal processing in determining received signal paths.

4. The WTRU according to claim 2 where the PDP element values contain in-phase and quadrature components wherein the post processing unit is configured to selectively combine stored PDP element values by coherent combination for threshold evaluation and the post processing unit is further configured to:

compute a magnitude approximation value for each stored PDP element value;

noncoherently combine magnitude approximation values corresponding PDP element values that are coherently combined; and

separately evaluate both coherently and noncoherently combined values against thresholds to qualify values of respective PDP positions for further signal processing in determining received signal paths.

5. The WTRU according to claim 1 where the PDP element values processed by the post processing unit are magnitude approximations of coherent accumulations of sequential sets of signal samples wherein the post processing unit is configured to selectively combine stored PDP element values by noncoherent combination for threshold evaluation.

6. The WTRU according to claim 1 wherein the post processing unit is configured to process PDPs in a plurality of groups such that:

a limited number of PDP elements are selected from a first group of PDPs and elements'"'"' values and respective position values of the selected first group PDP elements are stored;

elements'"'"' values and respective position values of respectively positioned elements are stored from each corresponding PDP of a PDP set as each other group of PDPs is processed; and

a limited number of other elements are selected from PDPs which do not match any positions of the elements selected from the PDPs of the first group.

7. The WTRU according to claim 6 wherein the post processing unit is configured to select elements from the first group PDPs based on selecting a selected number of highest values of PDP elements.

8. The WTRU according to claim 6 wherein the post processing unit is configured to select elements from the first group PDPs by threshold qualification where the threshold is set such that less than one-quarter of the elements of a PDP are selected from each of the first group PDPs.

9. The WTRU of claim 6 further comprising:

an interpolation unit configured to operate at a clock speed of at least twice sampling rate of a PDP production unit and to interpolate groups of PDPs produced by the PDP production unit to provide a corresponding number of at least twice as many PDP elements to the post processing unit.

10. The WTRU according to claim 1 wherein the post processing unit comprises:

a hardware unit configured to select the PDP elements of each PDP and to store the selected PDP elements'"'"' values and respective PDP position values; and

a software unit configured to selectively combine and evaluate the stored PDP.

11. The WTRU of claim 10 further comprising:

an interpolation unit configured to operate at a clock speed of at least twice sampling rate of a PDP production unit and to interpolate groups of PDPs produced by the PDP production unit to provide a corresponding number of at least twice as many PDP elements to the post processing unit.

12. The WTRU of claim 1 further comprising:

an interpolation unit configured to operate at a clock speed of at least twice sampling rate of a PDP production unit and to interpolate groups of PDPs produced by the PDP production unit to provide a corresponding number of at least twice as many PDP elements to the post processing unit.

13. The WTRU according to claim 1 wherein the post processing unit comprises:

a hardware unit configured to select the PDP elements of each PDP and to store the selected PDP elements'"'"' values and respective PDP position values and

a software unit configured to selectively combine and evaluate the stored PDP values.

14. The WTRU of claim 13 further comprising:

an interpolation unit configured to operate at a clock speed of at least twice sampling rate of a PDP production unit and to interpolate groups of PDPs produced by the PDP production unit to provide a corresponding number of at least twice as many PDP elements to the post processing unit.