WCDMA terminal baseband processing module having multi-path scanner module

• US 20100054311A1
• Filed: 11/13/2009
• Published: 03/04/2010
• Est. Priority Date: 07/28/2005
• Status: Active Grant

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Yang, Baoguo, Hahm, Mark David
• Granted Patent: US 8,571,087 B2
• Time in Patent Office: Days
• US Class Current: 375/148
• CPC Class Codes: H04B 1/70735 Code identification H04B1/7083 takes precedence
• 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

A baseband processing module according to the present invention includes a multi-path scanner module. The multi-path scanner module is operable to receive timing and scrambling code information regarding an expected multi-path signal component of a WCDMA signal. Then, the multi-path scanner module is operable to identify a plurality of multi-path signal components of the WCDMA signal by descrambling, despreading and correlating a known symbol pattern of/with a baseband RX signal within a search window. The multi-path scanner module is operable to determine timing information for the plurality of multi-path signal components of the WCDMA signal found within the search window and to pass this information to a coupled rake receiver combiner module.

Claims

1. An apparatus, comprising:

an input that is operative to receive a radio frequency (RF) signal from a communication channel;

an RF front end that is operative to process the RF signal thereby generating a Wideband Code Division Multiple Access (WCDMA) signal; and

a multi-path scanner module that is operative to;

determine fast path timing information for a plurality of multi-path signal components of the WCDMA signal found within a search window during a first time slot;

determine timing information for the plurality of multi-path signal components of the WCDMA signal found within the search window during a second slot time; and

determine long term timing information for the plurality of multi-path

signal components of the WCDMA signal based upon at least the fast path timing information determined during the first time slot and the timing information determined during the second time slot.

2. The apparatus of claim 1, wherein the multi-path scanner module is operative to:

establish a search window that is centered at a strongest multi-path signal component of the WCDMA signal;

a center of the search window corresponds to an expected multi-path signal component of the WCDMA signal;

the expected multi-path signal component of the WCDMA signal is the strongest multi-path signal component of the WCDMA signal; and

a duration of the search window corresponds to an expected channel length.

3. The apparatus of claim 1, wherein the multi-path scanner module is operative to:

determine signal strength information for each of the plurality of multi-path signal components of the WCDMA signal; and

establish a search window that is centered at a multi-path signal component of the WCDMA signal that has a strongest signal component among the plurality of multi-path signal components of the WCDMA signal.

4. The apparatus of claim 1, wherein the multi-path scanner module is operative to:

determine at least one additional fast path timing information for at least one additional plurality of multi-path signal components of the WCDMA signal found within at least one additional search window during a third time slot; and

determine at least one additional timing information for the at least one additional plurality of multi-path signal components of the WCDMA signal found within the at least one additional search window during a fourth slot time.

5. The apparatus of claim 1, further comprising:

a rake receiver combiner module that is operative to receive at least one of the fast path timing information, the timing information, and the long term timing information.

6. The apparatus of claim 5, wherein the rake receiver combiner module is operative to:

receive control and traffic channel information from a serving cell; and

based on the control and traffic channel information, the apparatus is operative to monitor a carrier signal from the serving cell, and based in the monitoring, to determine whether to continue to receive the RF signal or to terminate receipt of the RF signal.

7. The apparatus of claim 1, wherein the multi-path scanner module is operative to:

determine a noise floor for the WCDMA signal within the search window; and

remove a bias caused by the noise floor from at least one of the plurality of multi-path signal components of the WCDMA signal found within the search window.

8. The apparatus of claim 1, wherein:

the search window includes samples of the baseband RX signal corresponding to a plurality of chip intervals; and

the multi-path scanner module is operable to search for multi-path signal components of the WCDMA signal corresponding to each chip interval.

9. The apparatus of claim 1, wherein:

the apparatus is a cellular telephone, a laptop computer, a desktop computer, or a data terminal.

10. An apparatus, comprising:

a processing module; and

a memory, coupled to the processing module, that is operable to store operational instructions that enable the processing module to;

determine fast path timing information for a plurality of multi-path signal components of a Wideband Code Division Multiple Access (WCDMA) signal found within a search window during a first time slot;

determine timing information for the plurality of multi-path signal components of the WCDMA signal found within the search window during a second slot time; and

determine long term timing information for the plurality of multi-path signal components of the WCDMA signal based upon at least the fast path timing information determined during the first time slot and the timing information determined during the second time slot.

11. The apparatus of claim 10, wherein the memory, coupled to the processing module, is operable to store operational instructions that enable the processing module to:

establish a search window that is centered at a strongest multi-path signal component of the WCDMA signal;

a center of the search window corresponds to an expected multi-path signal component of the WCDMA signal;

the expected multi-path signal component of the WCDMA signal is the strongest multi-path signal component of the WCDMA signal; and

a duration of the search window corresponds to an expected channel length.

12. The apparatus of claim 10, wherein the memory, coupled to the processing module, is operable to store operational instructions that enable the processing module to:

determine signal strength information for each of the plurality of multi-path signal components of the WCDMA signal; and

establish a search window that is centered at a multi-path signal component of the WCDMA signal that has a strongest signal component among the plurality of multi-path signal components of the WCDMA signal.

13. The apparatus of claim 10, wherein the memory, coupled to the processing module, is operable to store operational instructions that enable the processing module to:

determine at least one additional fast path timing information for at least one additional plurality of multi-path signal components of the WCDMA signal found within at least one additional search window during a third time slot; and

determine at least one additional timing information for the at least one additional plurality of multi-path signal components of the WCDMA signal found within the at least one additional search window during a fourth slot time.

14. A method, comprising:

receiving a radio frequency (RF) signal from a communication channel;

employing an RF front end to process the RF signal thereby generating a Wideband Code Division Multiple Access (WCDMA) signal;

determining fast path timing information for a plurality of multi-path signal components of the WCDMA signal found within a search window during a first time slot;

determining timing information for the plurality of multi-path signal components of the WCDMA signal found within the search window during a second slot time; and

determining long term timing information for the plurality of multi-path signal components of the WCDMA signal based upon at least the fast path timing information determined during the first time slot and the timing information determined during the second time slot.

15. The method of claim 14, further comprising:

establishing a search window that is centered at a strongest multi-path signal component of the WCDMA signal; and

wherein;

a center of the search window corresponds to an expected multi-path signal component of the WCDMA signal;

the expected multi-path signal component of the WCDMA signal is the strongest multi-path signal component of the WCDMA signal; and

a duration of the search window corresponds to an expected channel length.

16. The method of claim 14, further comprising:

determining signal strength information for each of the plurality of multi-path signal components of the WCDMA signal; and

establishing a search window that is centered at a multi-path signal component of the WCDMA signal that has a strongest signal component among the plurality of multi-path signal components of the WCDMA signal.

17. The method of claim 14, further comprising:

determining at least one additional fast path timing information for at least one additional plurality of multi-path signal components of the WCDMA signal found within at least one additional search window during a third time slot; and

determining at least one additional timing information for the at least one additional plurality of multi-path signal components of the WCDMA signal found within the at least one additional search window during a fourth slot time.

18. The method of claim 14, further comprising:

determining a noise floor for the WCDMA signal within the search window; and

removing a bias caused by the noise floor from at least one of the plurality of multi-path signal components of the WCDMA signal found within the search window.

19. The method of claim 14, further comprising:

receiving control and traffic channel information from a serving cell;

based on the control and traffic channel information, monitoring a carrier signal from the serving cell; and

based in the monitoring, determining whether to continue to receive the RF signal or to terminate receipt of the RF signal.

20. The method of claim 14, wherein:

the method is performed within a cellular telephone, a laptop computer, a desktop computer, or a data terminal.