Apparatus and method for configurable multi-dwell search engine for spread spectrum applications

• US 20020015435A1
• Filed: 07/31/2001
• Published: 02/07/2002
• Est. Priority Date: 07/31/2000
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Rieken, Keith
• Granted Patent: US 7,003,015 B2
• Time in Patent Office: Days
• US Class Current: 375/130
• CPC Class Codes: H04B 1/70735 Code identification H04B1/7083 takes precedence
• CPC Class Codes: H04B 1/70775 Multi-dwell schemes, i.e. multiple accumulation times
• 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: H04W 48/16 Discovering, processing access restriction or access information

Abstract

This invention provides a configurable multi-dwell search engine for performing automated efficient searches of a known code sequence space. Inputs from a multi-dwell table and a finger control table are multiplexed by a first multiplexer. Output from the first multiplexer is used to generate a threshold comparison signal. The generated threshold comparison signal, the current dwell state signal and inputs from a next dwell look-up table are multiplexed by a second multiplexer. The second multiplexer outputs a hard hit signal and a offset control signal.

Claims

1. An apparatus for performing searches of a known code sequence space in a spread spectrum system, comprising:

a multi-dwell table for storing energy estimates;

a finger control table;

a next dwell table; and

a comparator;

wherein said finger control table selects an energy estimate output from said multi-dwell table;

wherein said comparator compares said energy estimate output from said multi-dwell table to a magnitude of finger value to generate a threshold comparison result; and

wherein said threshold comparison result is used to select a next state output from said next dwell table for input to said finger control table.

2. The apparatus of claim 1, wherein said multi-dwell table is a look-up table including programmable integration length and threshold information for a programmable set of states.

3. The apparatus of claim 1, wherein said finger control table is a look-up table including context information and dwell select information for a set of virtual fingers in said spread spectrum system.

4. The apparatus of claim 1, wherein said next dwell look up table includes next dwell information for a set of virtual fingers in said spread spectrum system.

5. The apparatus of claim 1, wherein said second of said plurality of multiplexers includes select nodes and input nodes.

6. The apparatus of claim 5, wherein said select nodes receive a current state input from said finger control table and said threshold comparison result from said comparator.

7. The apparatus of claim 5, wherein said input nodes receive next dwell information from said next dwell look up table.

8. The apparatus of claim 1, wherein said plurality of output control signals include a hard hit signal and an offset control signal.

9. A method for performing searches of a known code sequence space in a spread spectrum system, comprising the steps of:

selecting an energy estimate from a multi-dwell table using current dwell state information in a finger control table;

generating a threshold comparison signal;

coupling said threshold comparison signal and a current dwell state signal to obtain a coupled signal;

using said coupled signal to select an output from a next dwell table; and

applying the output from the next dwell table to the finger control table to update current dwell state information.

10. The method of claim 9, further comprising the step of:

outputting a hard hit signal from the next dwell table to an external controller for controlling finger allocation.

11. The method of claim 9, further comprising the step of:

outputting an offset control signal from the next dwell table to a searcher control for initiating a next search offset.