Random access dimensioning methods and procedures for frequency division multiplexing access systems

• US 8,687,564 B2
• Filed: 11/03/2006
• Issued: 04/01/2014
• Est. Priority Date: 11/04/2005
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Vujcic, Dragan, Fischer, Patrick
• Primary Examiner(s): Mesfin, Yemane
• Assistant Examiner(s): DUONG, CHRISTINE T
• Application Number:
  US12/092,705
• Publication Number:
  US 20080279257A1
• Time in Patent Office: 2,706 Days
• Field of Search: None
• US Class Current: 370/329
• CPC Class Codes: H04B 7/2637 for logical channel control
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 74/0866 using a dedicated channel for access

Abstract

A method of determining random access resources performed by a mobile terminal, the method comprising: receiving information on available random access resources from a network; deciding how to derive the random access resources to be allowed based on default values or information received from the network; measuring received signal quality of at least one of a cell to be accessed and a neighboring cell; and deriving the allowed random access resources based on the deciding and the measuring.

Claims

1. A method of determining random access resources performed by a mobile terminal, the method comprising:

receiving information about available random access resources from a network;

selecting a set of allowed random access resources from the available random access resources based on default values or information received from the network;

measuring signal quality of at least one of a cell to be accessed or a neighboring cell; and

deriving a random access resource from the set of allowed random access resources based on the measuring,

wherein each of the set of allowed random access resources comprises a random access channel (RACH) comprising M RACH allowed frequencies mapped on T RACH time offsets, and S time offsets are defined per a RACH allowed frequency, where each of M, T, and S is a positive number, and

wherein a time offset of the derived random access resource is determined by the following formula;

2. The method of claim 1, wherein the information received from the network is received in a broadcast, multicast or dedicated manner.

3. The method of claim 1, wherein the signal quality comprises at least one of energy of carrier, spectral noise density, signal-to-noise ratio, carrier signal level, interference level, or path loss.

4. The method of claim 1, wherein the available random access resources-comprise a set of any combination of time, frequency, or code.

5. The method of claim 1, wherein one or more available random access resources are allowed to be used if the signal quality of at least one of the cell to be accessed or the neighboring cell is larger or smaller than a threshold value.

6. The method of claim 1, further comprising:

performing an access procedure comprising transmitting an access burst, wherein the access burst is re-transmitted based on the set of allowed random access resources and a random access resource chosen for a previous transmission.

7. The method of claim 6, wherein the re-transmitted access burst employs random access channel (RACH) hopping.

17. The method of claim 1, wherein C allowed frequencies are defined per a RACH time offset, where C is a positive number, and

wherein an allowed frequency of the derived random access resource is determined by the following formula:

8. A method of determining random access resources performed by a network, the method comprising:

transmitting information about available random access resources to a terminal; and

transmitting at least one parameter related to a measurement of a downlink radio signal,

wherein a set of allowed random access resources is selected by the terminal from the available random access resources based on the at least one parameter,

wherein signal quality of at least one of a cell to be accessed or a neighboring cell is measured,

wherein a random access resource is derived from the set of allowed random access resources based on the measurement of the signal quality,

wherein each of the set of allowed random access resources comprises a random access channel (RACH) comprising M RACH allowed frequencies mapped on T RACH time offsets, and S time offsets are defined per a RACH allowed frequency, where each of M, T, and S is a positive number, and

wherein a time offset of the derived random access resource is determined by the following formula;

9. The method of claim 8, further comprising:

coordinating at least two cells how the random access resources are to be allocated or how the at least one parameter for each random access resource is set.

10. The method of claim 9, wherein the random access resources are allocated in a localized or distributed manner.

11. The method of claim 8, wherein the random access resources are allocated according to traffic load.

12. The method of claim 8, wherein the information is transmitted in a broadcast, multicast or dedicated manner.

13. The method of claim 8, wherein the signal quality comprises at least one of energy of carrier, spectral noise density, signal-to-noise ratio, carrier signal level, interference level, or path loss.

14. The method of claim 8, wherein the available random access resources comprise a set of any combination of time, frequency, or code.

15. The method of claim 14, wherein each cycle comprises one or more radio frames.

16. The method of claim 8, wherein one or more available random access resources are allowed to be used by the terminal if the signal quality of at least one of the cell to be accessed or the neighboring cell is larger or smaller than a threshold value.

18. The method of claim 8, wherein C allowed frequencies are defined per a RACH time offset, where C is a positive number, and

wherein an allowed frequency of the derived random access resource is determined by the following formula: