APPARATUS AND METHOD FOR RANDOM ACCESS WITH MULTIPLE ANTENNAS IN A WIRELESS NETWORK

• US 20140016573A1
• Filed: 03/15/2013
• Published: 01/16/2014
• Est. Priority Date: 07/12/2012
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Nuggehalli, Pavan, Li, Ying, Pi, Zhouyue, Stirling-Gallacher, Richard
• Granted Patent: US 9,699,811 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H01Q 1/242 specially adapted for hand-held use
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 3/36 with variable phase-shifters
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

A base station enables a mobile station to employ a random access retransmission scheme in a wireless communication network. The mobile station includes a plurality of antennas configured to communicate with the base station. The mobile station also includes a processing circuitry coupled to the plurality of antennas. The processing circuitry is configured to perform a random access during a random access channel (RACH) burst. The processing circuitry also is configured to at least one of: transmit a random access signal with at least one of an initial transmit power level and an initial transmit beamwidth, and, in response to a random access attempt failure, change at least one of a transmit (Tx) power level and a Tx beamwidth and retransmit the random access signal.

Claims

1. A mobile station comprising:

a plurality of antennas configured to communicate with at least one base station; and

a processing circuitry coupled to the plurality of antennas, the processing circuitry configured to perform a random access during a random access channel (RACH) burst, wherein the processing circuitry is configured to, at least one of;

transmit a random access signal with at least one of an initial transmit power, level and an initial transmit beamwidth, and

in response to a random access attempt failure, change at least one of a transmit (Tx) power level and a Tx beamwidth and retransmit the random access signal.

2. The mobile station as set forth in claim 1, wherein the mobile station is configured to receive a configuration from the at least one base station, wherein the configuration can include at least one of:

a mapping from a path loss to at least one of;

an initial Tx beamwidth (W₁),

an initial Tx power level (P₁),

a Tx beamwidth for a retransmission,

a Tx power level for a retransmission,

an adjusted Tx beamwidth Δ

W for a retransmission, and

an adjusted Tx power level Δ

P for a retransmission,

wherein the path is in-between the mobile station and the base station and the path loss can be measured and estimated by the mobile station;

a mapping from a set of beamwidth that the mobile station is capable to support to at least one of;

an initial Tx power level (P₁),

a Tx power level for a retransmission, and

an adjusted Tx power level Δ

P for a retransmission;

an initial Tx beamwidth (W₁);

an initial Tx power level (P₁);

a Tx beamwidth for a retransmission;

a Tx power level for a retransmission;

an adjusted Tx beamwidth Δ

W for a retransmission; and

an adjusted Tx power level Δ

P for a retransmission.

3. The mobile station as set forth in claim 1, wherein the processing circuitry is configured to set at least an initial Tx beamwidth (W₁) and an initial Tx power level (P₁), as a function of at least one of:

a path loss of a path in-between the mobile station and the base station, wherein the path loss can be measured and estimated by the mobile station; and

a set of beamwidth that the mobile station is capable to support.

4. The mobile station as set forth in claim 1, wherein the processing circuitry is configured to at least one of:

decrease the Tx beamwidth by a Δ

W in successive iterations until the random access is successful or a minimum Tx beamwidth, W_min, is achieved, and

in response to achieving the minimum Tx beamwidth, the processing circuitry is configured to boost the Tx power level by a Δ

P in successive iterations until the random access is successful or a maximum Tx power level, P_max, is achieved.

5. The mobile station as set forth in claim 1, wherein the processing circuitry is configured to at least one of:

boost the Tx power level by a Δ

P in successive iterations until the random access is successful or the maximum Tx power level, P_max, is achieved, and

in response to achieving the maximum Tx power level, the processing circuitry is configured to decrease the Tx beamwidth by a Δ

W in successive iterations until the random access is successful or the minimum Tx beamwidth, W_min, is achieved.

6. The mobile station as set forth in claim 1, wherein the processing circuitry is configured to alternate between decreasing the Tx beamwidth by the Δ

W and boosting the Tx power level by the Δ

P in successive iterations until at least one of;

the random access is successful;

or

the minimum Tx beamwidth, W_min, and the maximum Tx power level, P_max, is achieved.

7. The mobile station as set forth in claim 1, wherein the processing circuitry is configured to utilize a preferred random access configuration, the preferred random access configuration comprising at least one of:

an initial Tx beamwidth (W₁), an initial Tx power level (P₁), a specified Δ

W, a specified Δ

P, and a direction determined by the at least one base station;

the initial Tx beamwidth (W₁), the initial Tx power level (P₁), the Δ

W, the Δ

P, and a direction determined by the processing circuitry; and

values for the initial Tx beamwidth (W₁), the initial Tx power level (P₁), the Δ

W, the Δ

P, and the direction based on a configuration discovered when in a connected state involving uplink data transmissions.

8. A method for performing random access, the method comprising:

attempting, by a mobile station, a random access of at least one base station, during a random access channel (RACH) burst;

at least one of;

transmitting a random access signal with at least one of an initial transmit power level and an initial transmit beamwidth, and

in response to a random access attempt failure, changing at least one of a transmit (Tx) power level and a Tx beamwidth and retransmitting the random access signal.

9. The method as set forth in claim 8, further comprising receiving a configuration from the at least one base station, wherein the configuration can include at least one of:

a mapping from a path loss to at least one of;

an initial Tx beamwidth (W₁),

an initial Tx power level (P₁),

a Tx beamwidth for a retransmission,

a Tx power level for a retransmission,

an adjusted Tx beamwidth Δ

W for a retransmission, and

an adjusted Tx power level Δ

P for a retransmission,

wherein the path is in-between the mobile station and the base station and the path loss can be measured and estimated by the mobile station;

a mapping from a set of beamwidth that the mobile station is capable to support to at least one of;

an initial Tx power level (P₁),

a Tx power level for a retransmission, and

an adjusted Tx power level Δ

P for a retransmission;

an initial Tx beamwidth (W₁);

an initial Tx power level (P₁);

a Tx beamwidth for a retransmission;

a Tx power level for a retransmission;

an adjusted Tx beamwidth Δ

W for a retransmission; and

an adjusted Tx power level Δ

P for a retransmission.

10. The method as set forth in claim 8, further comprising setting at least an initial Tx beamwidth (W₁), an initial Tx power level (P₁), as a function of at least one of

a path loss of the path in-between the mobile station and the base station wherein the path loss can be measured and estimated by the mobile station;

and

a set of beamwidth that the mobile station is capable to support.

11. The method as set forth in claim 8, wherein changing comprises at least one of:

decreasing the Tx beamwidth by a Δ

W in successive iterations until the random access is successful or a minimum Tx beamwidth, W_min, is achieved, and

in response to achieving the minimum Tx beamwidth, boosting the Tx power level by a Δ

P in successive iterations until the random access is successful or a maximum Tx power level, P_max, is achieved.

12. The method as set forth in claim 8, wherein changing comprises at least one of:

boosting the Tx power level by the Δ

P in successive iterations until the random access is successful or the maximum Tx power level, P_max, is achieved, and

in response to achieving the maximum Tx power level, decreasing the Tx beamwidth by the Δ

W in successive iterations until the random access is successful or the minimum Tx beamwidth, W_min, is achieved.

13. The method as set forth in claim 8, wherein changing comprises alternating between decreasing the Tx beamwidth by the Δ

W and boosting the Tx power level by the Δ

P in successive iterations until at least one of;

the random access is successful;

or

the minimum Tx beamwidth, W_min, and the maximum Tx power level, P_max, is achieved.

14. The method as set forth in claim 8, further comprising utilizing a preferred random access configuration, the preferred random access configuration comprising at least one of:

an initial Tx beamwidth (W₁), an initial Tx power level (P₁), a specified Δ

W, a specified Δ

P, and a direction determined by the at least one base station;

the initial Tx beamwidth (W₁), the initial Tx power level (P₁), the Δ

W, the Δ

P, and a direction determined by the mobile station; and

values for the initial Tx beamwidth (W₁), the initial Tx power level (P₁), the Δ

W, the Δ

P, and the direction based on a configuration discovered when in a connected state involving uplink data transmissions.

15. A base station comprising:

a plurality of antenna configured to communicate with at least one mobile station;

processing circuitry coupled to the plurality of antennas, the processing circuitry configured to enable the at least one mobile station to perform a random access during a random access channel (RACH) burst, wherein the at least one mobile station is configured to at least one of;

transmit a random access signal with at least one of an initial transmit power level and an initial transmit beamwidth, and

in response to a random access attempt failure, change one of a transmit (Tx) power level and a Tx beamwidth and retransmit the random access signal.

16. The base station as set forth in claim 15, wherein the processing circuitry configured is configured to transmit a configuration to the at least one mobile station, wherein the configuration can include at least one of:

a mapping from a path loss to at least one of;

an initial Tx beamwidth (W₁),

an initial Tx power level (P₁),

a Tx beamwidth for a retransmission,

a Tx power level for a retransmission,

an adjusted Tx beamwidth Δ

W for a retransmission, and

an adjusted Tx power level Δ

P for a retransmission,

wherein the path is in-between the mobile station and the base station and the path loss can be measured and estimated by the mobile station;

a mapping from a set of beamwidth that the mobile station is capable to support to at least one of;

an initial Tx power level (P₁),

a Tx power level for a retransmission, and

an adjusted Tx power level Δ

P for a retransmission;

an initial Tx beamwidth (W₁);

an initial Tx power level (P₁);

a Tx beamwidth for a retransmission;

a Tx power level for a retransmission;

an adjusted Tx beamwidth Δ

W for a retransmission; and

an adjusted Tx power level Δ

P for a retransmission.

17. The base station as set forth in claim 15, wherein the at least one mobile station is configured to set at least an initial Tx beamwidth (W₁), an initial Tx power level (P₁), can be a function of at least one of:

a path loss of the path in-between the mobile station and the base station wherein the path loss can be measured and estimated by the mobile station; and

a set of beamwidth that the mobile station is capable to support.

18. The base station as set forth in claim 15, wherein the at least one mobile station is configured to at least one of:

decrease a Tx beamwidth by a Δ

W in successive iterations until the random access is successful or a minimum Tx beamwidth, W_min, is achieved; and

in response to achieving the minimum Tx beamwidth, the at least one mobile station is configured to boost a Tx power level by a Δ

P in successive iterations until the random access is successful or a maximum Tx power level, P_max, is achieved.

19. The base station as set forth in claim 15, wherein the mobile station is configured to at least one of:

boost the Tx power level by a Δ

P in successive iterations until the random access is successful or the maximum Tx power level, P_max, is achieved; and

in response to achieving the maximum Tx power level, the mobile station is configured to decrease the Tx beamwidth by a Δ

W in successive iterations until the random access is successful or the minimum Tx beamwidth, W_min, is achieved.

20. The base station as set forth in claim 15, wherein the mobile station is configured to alternate between decreasing the Tx beamwidth by a Δ

W and boosting the Tx power level by a Δ

P in successive iterations until at least one of;

the random access is successful;

or

the minimum Tx beamwidth, W_min, and the maximum Tx power level, P_max, is achieved.

21. The base station as set forth in claim 15, wherein the processing circuitry is configured to cause the mobile station to utilize a preferred random access configuration, the preferred random access configuration comprising at least one of:

an initial Tx beamwidth (W₁), an initial Tx power level (P₁), a specified Δ

W, a specified Δ

P, and a direction determined by the at least one base station;

the initial Tx beamwidth (W₁), the initial Tx power level (P₁), the Δ

W, the Δ

P, and a direction determined by the processing circuitry; and

values for the initial Tx beamwidth (W₁), the initial Tx power level (P₁), the Δ

W, the Δ

P, and the direction based on a configuration discovered when in a connected state involving uplink data transmissions.