System and method using primary and secondary synchronization codes during cell search

• US 20030133431A1
• Filed: 11/27/2002
• Published: 07/17/2003
• Est. Priority Date: 11/29/2001
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Rudolf, Marian
• Granted Patent: US 7,693,123 B2
• Time in Patent Office: Days
• US Class Current: 370/342
• CPC Class Codes: H04B 1/7077 Multi-step acquisition, e.g. multi-dwell, coarse-fine or validation
• CPC Class Codes: H04B 1/7083 Cell search, e.g. using a three-step approach
• CPC Class Codes: H04B 2201/70701 featuring pilot assisted reception
• CPC Class Codes: H04B 2201/70702 Intercell-related aspects
• CPC Class Codes: H04B 2201/70707 Efficiency-related aspects

Abstract

A system and method for improved cell searching includes a subframe having a Primary Synchronization Code, which is comment to all Node Bs in the system and is used to indicate the positions of a set of Secondary Synchronization Codes. This greatly simplifies the cell searching procedure and improves cell search performance. In one embodiment, the Primary Synchronization Code is sent in the PCCPCH and the Secondary Synchronization Codes the are sent in the DwPTS timeslot.

Claims

1. A method for cell searching in a TDD system having a plurality of Node Bs, the method comprising;

searching for, and synchronizing with, a primary synchronization code (PSC), the PSC being common to all of said plurality of Node Bs;

using the PSC to locate a secondary synchronization code (SSC), which is unique to a specific Node B; and

synchronizing to said SSC.

2. The method of claim 1 wherein data is transmitted within a subframe including a Primary Common Control Physical Channel (P-CCPCH) and a Downlink Pilot Timeslot (DwPTS), and wherein the PSC is sent in the P-CCPCH and the SSC is sent in the DwPTS.

3. The method of claim 2 wherein said PSC indicates the location of said SSC.

4. A method for cell searching in a TDD system having a plurality of Node Bs, the method comprising;

searching for a primary synchronization code (PSC), which is common to all Node Bs in a TDD system;

synchronizing with said PSC when the PSC is detected;

using the PSC to narrow the searching parameters for a secondary synchronization code (SSC), which is unique to a specific Node B;

detecting said SSC; and

synchronizing with said detected SSC.

5. The method of claim 4, wherein the PSC is located in a first timeslot and the SSC is located in a second timeslot.

6. The method of claim 5, wherein the PSC and the SSC are located in the same timeslot.

7. The method of claim 4 wherein data is transmitted within a subframe including a Primary Common Control Physical Channel (P-CCPCH) and a Downlink Pilot Timeslot (DwPTS), and wherein the PSC is sent in the P-CCPCH and the SSC is sent in the DwPTS.

8. The method of claim 7 wherein said PSC indicates the location of said SSC.

9. A Node B for communicating using a wireless time division duplex/code division multiple access (TDD/CDMA) format, the Node B comprising:

a generator for generating a Primary Common Control Physical Channel (P-CCPCH) including a Primary Synchronization Code (PSC), and for generating a Downlink Pilot Timeslot (DwPTS) including at least one Secondary Synchronization Code (SSC) the PSC indicating the location of the subsequent SSC;

a timeslot controller for placing the P-CCPCH and the DwPTS in the proper timeslots and creating a data stream; and

a transmitter for transmitting said data stream.

10. The Node B of claim 9, wherein said P-CCPCH is located in a first timeslot and said DwPTS is located in a second timeslot.

11. A Node B for communicating using a wireless time division duplex/code division multiple access (TDD/CDMA) format, the Node B comprising:

a generator for generating a primary synchronization channel (PSC);

a second generator for generating a Secondary Synchronization Channel (SSC) which is related to said PSC;

a controller for placing the PSC in a first timeslot and the SSC in a second timeslot to create a data stream, said second timeslot being located after said first timeslot; and

a transmitter for transmitting the data stream.

12. The Node B of claim 11, wherein said first timeslot is a Primary Common Control Physical Channel (P-CCPCH).

13. The Node B of claim 11 wherein said second timeslot is a Downlink Pilot Timeslot (DwPTS).

14. A User Equipment (UE) that supports cell searching using a wireless time division duplex/code division multiple access (TDD/CDMA) format, the UE comprising:

means for detecting a received data stream, the data stream comprising a field having a primary synchronization code PSC and a secondary synchronization code (SSC), the SSC being related to the PSC; and

a data recovery device for recovering the SSC.

15. The UE of claim 14, wherein the PSC indicates the location of the SSC.

16. The UE of claim 15, wherein said SSC is subsequent to said PSC.

17. The UE of claim 14, wherein said PSC is located within a Primary Common Control Physical Channel (P-CCPCH).

18. The UE of claim 14, wherein said SSC is located within a Downlink Pilot Timeslot (DwPTS).

19. A User Equipment (UE) that supports cell searching using a wireless time division duplex/code division multiple access (TDD/CDMA) format, the UE comprising:

a data stream detector for detecting a received data stream, the data stream comprising a field having a first code that indicates the location of a second code; and

a data recovery device for processing said first and second codes.

20. A User Equipment (UE) that supports a communication using a wireless time division duplex/code division multiple access (TDD/CDMA) format by selecting and utilizing at least one timeslot from a plurality of available timeslots and at least one code from a plurality of codes, the UE comprising:

a data stream detector for detecting a received data stream, the data stream comprising a Primary Common Control Physical Channel (P-CCPCH) including a primary synchronization code (PSC), and a Downlink Pilot Timeslot (DwPTS) including a secondary synchronization code (SSC), said SSC being related to said PSC; and

a data recovery device for processing the PSC and the SSC.