Uplink synchronization without preamble in SC-FDMA

• US 9,907,092 B2
• Filed: 11/14/2014
• Issued: 02/27/2018
• Est. Priority Date: 10/09/2014
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Wang, Xiao Feng, Li, Junyi
• Primary Examiner(s): LAM, YEE F
• Application Number:
  US14/542,470
• Publication Number:
  US 20160105910A1
• Time in Patent Office: 1,201 Days
• CPC Class Codes: H04W 56/0045 compensating for timing error by altering transmission time
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus may determine an allocated set of resources within a PRACH period. The apparatus may transmit pilot signals in the determined allocated set of resources.

Claims

1. A method of wireless communication by a user equipment (UE), comprising:

determining an allocated set of resources, within a physical random access channel (PRACH) period, designated for uplink synchronization, wherein the PRACH period comprises a set of slots, and each slot of the

set of slots comprises a set of symbols, and wherein the determining the allocated set of resources comprises;

determining a first set of symbols and a second set of symbols within the PRACH period for transmitting pilot signals,

determining a first set of tone indices within the first set of symbols for transmitting a first set of pilot signals, and

determining a second set of tone indices within the second set of symbols for transmitting a second set of pilot signals, wherein the second set of tone indices is determined based on an offset value from the first set of tone indices; and

transmitting the first and second sets of pilot signals in the determined allocated set of resources to a device to enable uplink synchronization with the device.

2. The method of claim 1, wherein each symbol of each set of symbols comprises a set of tones.

3. The method of claim 1, wherein the determining the allocated set of resources further comprises determining a subset of symbols within each slot in the subset of slots in the PRACH period for transmitting the first and second sets of pilot signals, wherein the subset of symbols within each slot is greater than or equal to 2.

4. The method of claim 1, wherein the first set of pilot signals has at least two pilot signals, and the second set of pilot signals has at least two pilot signals.

5. The method of claim 1, further comprising transmitting information in the determined allocated set of resources, wherein the information comprises at least one of an identifier, control information, or a pathloss report.

6. The method of claim 1, wherein the determining the allocated set of resources further comprises:

determining at least a third set of symbols within the PRACH period of transmitting pilot signals;

determining at least a third set of tone indices within the third set of symbols for transmitting a third set of pilot signals, wherein the third set of tone indices is determined based on a second offset value from the second set of tone indices; and

transmitting the third set of pilot signals in the determined allocated set of resources to the device.

7. The method of claim 6, wherein the third set of symbols is different from the second set of symbols.

8. The method of claim 6, wherein the second offset value is the same as or different from the offset value.

9. The method of claim 6, wherein the offset value and the second offset value have values greater than or equal to one.

10. The method of claim 1, wherein only pilot signals are transmitted in the set of symbols or information signals and pilot signals are transmitted in the set of symbols.

11. An apparatus for wireless communication, comprising:

a memory; and

at least one processor coupled to the memory and configured to;

determine an allocated set of resources, within a physical random access channel (PRACH) period, designated for uplink synchronization, wherein the PRACH period comprises a set of slots, and each slot of the set of slots comprises a set of symbols, and wherein the at least one processor is configured to determine the allocated set of resources by;

determining a first set of symbols and a second set of symbols within the PRACH period for transmitting pilot signals,

determining a first set of tone indices within to the first set of symbols for transmitting a first set of pilot signals, and

determining a second set of tone indices within the second set of symbols for transmitting a second set of pilot signals, wherein the second set of tone indices is determined based on an offset value from the first set of tone indices; and

transmit the first and second sets of pilot signals in the determined allocated set of resources to a device to enable uplink synchronization with the device.

12. The apparatus of claim 11, wherein each symbol in each set of symbols comprises a set of tones.

13. The apparatus of claim 11, wherein the at least one processor is configured to determine the allocated set of resources by determining a subset of symbols within each slot in the subset of slots in the PRACH period for transmitting the first and second sets of pilot signals, wherein the subset of symbols within each slot is greater than or equal to 2.

14. The apparatus of claim 11, wherein the first set of pilot signals has at least two pilot signals, and the second set of pilot signals has at least two pilot signals.

15. The apparatus of claim 11, wherein the at least one processor is further configured to transmit information in the determined allocated set of resources, wherein the information comprises at least one of an identifier, control information, or a pathloss report.