HIGH SENSITIVITY GNSS RECEIVER PLATFORM WITH SHARED MEMORY

• US 20090002227A1
• Filed: 06/29/2007
• Published: 01/01/2009
• Est. Priority Date: 06/29/2007
• Status: Active Grant

• Current Assignee: CSR Technology Holdings Inc. (Qualcomm, Inc.)
• Original Assignee: CSR Technology Holdings Inc. (Qualcomm, Inc.)
• Inventors: Zhang, Hongyu, Wang, Chi-Shin, Jia, Zhike, Xiong, Lianxue
• Granted Patent: US 7,743,177 B2
• Time in Patent Office: Days
• US Class Current: 342/357.270
• CPC Class Codes: G01S 19/37 Hardware or software details of the signal processing chain

Abstract

Provided herein is multi-function platform comprising a plurality of devices and a large memory that is external to the devices and shared among the devices. In an embodiment, a Direct Memory Access (DMA) controller is provided for each device to efficiently transfer data between the device and the shared memory. More than one DMA may be provided for a device. For example, separate DMAs may be provided for different components of a device that perform different subfunctions enabling efficient transfer of data between the different components of the device and the shared memory. In another embodiment, each device comprises a local embedded memory and is provided with a DMA for transferring data between the local memory and the shared memory. Examples of devices that can be included in the platform include a GNSS receiver, a audio player, a video player, a wireless communication device, a routing device, or the like.

Claims

1. A system platform comprising:

a GNSS receiver, wherein the GNSS receiver device includes internal on-chip memory;

a memory external to the GNSS receiver, wherein the memory is on a separate chip from the GNSS receiver; and

a data transfer module for transferring data between the internal memory of the GNSS receiver and the external memory.

2. The system of claim 1, wherein the data transfer module comprises a DMA controller associated with correlators of the GNSS receiver and the DMA controller is configured to transfer correlation values from the correlators to the external memory.

3. The system of claim 1, wherein the data transfer module comprises a DMA controller associated with a match filter of the GNSS receiver and the DMA controller is configured to transfer the correlation values from the match filer to the external memory.

4. The system of claim 1, wherein the shared memory stores PN sequences for different satellites, the data transfer module comprises a DMA controller associated with a PN code generator of the GNSS receiver, and the DMA controller is configured to transfer a PN sequence from the external memory to the PN code generator of the GNSS receiver.

5. The system of claim 1, wherein the data transfer module comprises a DMA controller associated with a digital signal processor (DSP) of the GNSS receiver, and the DMA controller is configured to transfer data and programs between an internal memory of the DSP and the external memory.

6. The system of claim 1, wherein the data transfer module comprises a DMA controller associated with an FFT engine of the GNSS receiver, and the DMA controller is configured to transfer input data to the FFT engine from the external memory and transfer output results from the FFT engine to the external memory.

7. The system of claim 1, wherein memory space of the external memory used by the GNSS receiver depends on a signal strength of a received signal.

8. The system of claim 1, wherein memory space of the external memory used by the GNSS receiver depends on a required Time to First Fix.

9. The system of claim 1, wherein memory space of the external memory used by the GNSS receiver depends on the dynamics of the GNSS receiver.

10. The system of claim 1, wherein memory space of the external memory used by the GNSS receiver depends on a number of consecutive 30-second data frames needed to be downloaded to decode navigation data bits.

11. The system of claim 1, further comprising:

at least one device, wherein the memory external to the GNSS receiver is also external to and on a separate chip from the at least one device; and

a data transfer module for transferring data between the at least one device and the external memory.

12. The system of claim 11, wherein the at least one device comprises an audio player, a video player, an Internet device, or other wireless communication or multimedia device.

13. The system of claim 11, further comprising a scheduler for dynamically assigning memory space in the external memory to the GNSS receiver and the at least one device.

14. The system of claim 13, wherein the scheduler assigns more memory space in the external memory to the GNSS receiver when a weak signal condition is detected.

15. The system of claim 13, wherein the scheduler assigns more memory space in the external memory to the GNSS receiver when a high dynamic condition is detected.

16. The system of claim 11, wherein the GNSS receiver and at least one device can share the external memory with different portions.

17. The system of claim 1, wherein the data transfer module comprises a DMA controller configured to transfer signal samples from an RF section of the GNSS receiver to the external memory when a baseband section of the GNSS receiver is bypassed.