Time divided pilot channel detection processing in a WCDMA terminal having a shared memory
View Patent ↗A method for operating a Radio Frequency (RF) receiver of a wireless terminal. During a first time interval, an RF front end is enabled and the RF receiver receives and processes an RF signal, e.g., a Wideband Code Division Multiple Access (WCDMA) signal, to produce a baseband signal and to store samples of the baseband signal. During a second time interval that differs from the first time interval, the RF front end is disabled and the RF receiver processes the plurality of samples of the baseband signal of the first time interval to measure signal strengths of a plurality of pilot signals present in the baseband signal of the first time interval. Finally, during a third time interval that differs from the first time interval and the second time interval, the RF front end is enabled and the RF receiver receives and processes an RF signal of the third time interval to extract data there from. Memory is shared between the first, second, and third time intervals for different uses.
1. A method for operating a Radio Frequency (RF) receiver that has an RF front end and a baseband processing module, the method comprising:
during a first time interval:
sampling a baseband signal to produce a plurality of samples of the baseband signal of the first time interval; and
storing the plurality of samples of the baseband signal of the first time interval in a shared memory;
during a second time interval that differs from the first time interval:
processing the plurality of samples of the baseband signal of the first time interval for pilot signal search operations, the shared memory serving as pilot signal search memory during the first and second time intervals;
during a third time interval that differs from both the first time interval and the second time interval:
evicting the plurality of samples of the baseband signal of the first time interval from the shared memory;
sampling a baseband signal of the third time interval to produce a plurality of samples of the baseband signal of the third time interval;
storing the plurality of samples of the baseband signal of the third time interval in the shared memory that serves as interleaver memory during the third time interval; and
processing the plurality of samples of the baseband signal of the third time interval to extract data therefrom.
2. The method of claim 1 , wherein:
the RF signal is a Wideband Code Division Multiple Access (WCDMA) RF signal;
the baseband signal is a WCDMA baseband signal; and
each pilot signal corresponds to a multipath component of the WCDMA RF signal.
3. The method of claim 1 , further comprising:
enabling the RF front end during the first time interval;
disabling the RF front end during the second time interval; and
enabling the RF front end during the third time interval.
4. The method of claim 3 , wherein the first time interval and the second time interval partially overlap such that the RF front end is enabled during a portion of the second time interval.
5. The method of claim 1 , wherein processing the plurality of samples of the baseband signal of the first time interval for pilot strength measurements is performed by a cell searcher module.
6. The method of claim 1 , wherein processing the baseband signal of the third time interval to extract data therefrom is performed by a rake receiver combiner module.
7. The method of claim 1 , wherein:
processing the baseband signal of the third time interval further comprises locating a plurality of multi-path components of the baseband signal of the third time interval; and
processing the baseband signal of the third time interval to extract data therefrom further comprises rake processing the plurality of multi-path components of the baseband signal of the third time interval.
8. A Radio Frequency (RF) receiver comprising:
a RF front end that is operable to produce a baseband signal;
a baseband processing module coupled to the RF front end; and
a shared memory coupled to the baseband processing module, wherein the baseband processing module is operable to:
during a first time interval:
sample the baseband signal to produce a plurality of samples of the baseband signal of the first time interval; and
store the plurality of samples of the baseband signal of the first time interval in the shared memory;
during a second time interval that differs from the first time interval:
process the plurality of samples of the baseband signal of the first time interval for pilot signal search operations, the shared memory serving as pilot signal search memory during the first and second time intervals;
during a third time interval that differs from both the first time interval and the second time interval:
evict the plurality of samples of the baseband signal of the first time interval from the shared memory;
sample a baseband signal of the third time interval to produce a plurality of samples of the baseband signal of the third time interval;
store the plurality of samples of the baseband signal of the third time interval in the shared memory; and
process the plurality of samples of the baseband signal of the third time interval to extract data therefrom.
9. The RF receiver of claim 8 , wherein:
the RF signal is a Wideband Code Division Multiple Access (WCDMA) RF signal;
the baseband signal is a WCDMA baseband signal; and
each pilot signal corresponds to a multipath component of the WCDMA RF signal.
10. The RF receiver of claim 8 , wherein, during operation, the RF front end is:
enabled during the first time interval;
disabled during the second time interval; and
enabled during the third time interval.
11. The RF receiver of claim 8 , wherein, during operation, the RF front end serves as interleaver memory during the third time interval.
12. The RF receiver of claim 8 , wherein the first time interval and the second time interval partially overlap such that the RF front end is enabled during a portion of the second time interval.
13. The RF receiver of claim 8 , wherein the baseband processing module comprises a cell searcher module that is operable to process the plurality of samples of the baseband signal of the first time interval to measure signal strengths of a plurality of pilot signals present in the baseband signal of the first time interval.
14. The RF receiver of claim 8 , wherein the baseband processing module comprises a rake receiver combiner module that is operable to process the baseband signal of the third time interval to extract data therefrom.
15. The RF receiver of claim 8 , wherein the baseband processing module comprises:
a multi-path scanner module that is operable to process the baseband signal of the third time interval to locate a plurality of multi-path components of the baseband signal of the third time interval; and
a rake receiver combiner module that is operable to process the plurality of multi-path components of the baseband signal of the third time interval to extract data therefrom.