USER EQUIPMENT AND POWER CONTROL METHOD FOR RANDOM ACCESS

• US 20120214538A1
• Filed: 02/22/2012
• Published: 08/23/2012
• Est. Priority Date: 02/22/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: CHO, Joon Young, KIM, Youngbum, HAN, Jinkyu, KIM, Younsun, LEE, Juho
• Granted Patent: US 9,516,611 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/325 Power control of control or pilot channels
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment

Abstract

An improved power control method and apparatus of a mobile terminal is provided for facilitating random access procedure in a mobile communication system based on a distributed antenna system. A method includes receiving, by the terminal, system information from a base station, the system information including transmit power information for transmitting a random access preamble; calculating a transmit power using the transmit power information; and transmitting the random access preamble using with the calculated transmit power.

Claims

1. A power control method for random access of a terminal in a mobile communication system, the method comprising:

receiving, by the terminal, control information from a base station, the control information including transmit power information for transmitting a random access preamble;

calculating a transmit power using the transmit power information; and

transmitting the random access preamble using with the calculated transmit power.

2. The method of claim 1, wherein the transmit power information includes at least one of a channel state information reference signal pattern for measuring pathloss for each antenna in the mobile communication system and a power control parameter associated with an antenna communicating with the terminal.

3. The method of claim 2, further comprising:

acquiring the channel state information reference signal pattern from the transmit power information;

measuring the pathloss for each antenna using the channel state information reference signal pattern; and

calculating the transmit power using a measured pathloss having a smallest value.

4. The method of claim 2, further comprising:

acquiring the power control parameter from the transmit power information; and

calculating the transmit power using the power control parameter and a pathloss between the terminal and the base station.

5. The method of claim 4, wherein the transmit power information includes a dedicated random access preamble signaled by the base station, and the power control parameter is mapped to the dedicated random access preamble.

6. The method of claim 1, wherein the random access preamble includes a dedicated random access preamble signaled by the base station.

7. The method of claim 1, further comprising:

receiving a channel state information reference signal pattern set for measuring pathloss for each antenna in multiple cells;

receiving a channel state information reference signal pattern of the set for use in measuring the pathloss; and

calculating the transmit power using the channel state information reference signal pattern.

8. An apparatus for controlling transmit power in a mobile terminal, comprising:

a receiver that receives control information from a base station, the control information including transmit power information for transmitting a random access preamble;

a power control controller that controls a random access preamble transmit power using the transmit power information; and

a transmitter that transmits the random access preamble with the controlled random access preamble transmit power.

9. The apparatus of claim 8, wherein the antenna reference transmit power information comprises at least one of:

a channel state information reference signal pattern for measuring pathloss for each antenna in a mobile communication system; and

a power control parameter associated with an antenna communicating with the mobile terminal.

10. The apparatus of claim 9, wherein the power control controller comprises:

a parameter acquirer that acquires a channel state information reference signal pattern from the transmit power information; and

a pathloss measurer that measures the pathloss for each antenna using the channel state information reference signal pattern,

wherein the power controller controls the random access preamble transmit power using a measured pathloss having a smallest value.

11. The apparatus of claim 10, wherein, when the transmit power information includes the power control parameter, the power control controller controls the parameter acquirer to acquire the power control parameter and controls the pathloss measurer to calculate the transmit power using the power control parameter and a pathloss between the mobile terminal and the base station

12. The apparatus of claim 9, wherein the transmit power information comprises a dedicated random access preamble signaled by the base station and the power control parameter is mapped to the dedicated random access preamble, and

wherein the power controller controls the random access preamble transmit power based on the power control parameter mapped to the dedicated random access preamble.

13. The apparatus of claim 8, wherein the transmit power information comprises a dedicated random access preamble signaled by the base station.

14. The apparatus of claim 8, wherein the power control controller receives a channel state information reference signal pattern set for measuring pathloss for each antenna in multiple cells, receives a channel state information reference signal pattern of the set for use in measuring the pathloss, and calculates the transmit power using the channel state information reference signal pattern.

15. A random access method of a base station in a mobile communication system, the method comprising:

transmitting, by the base station to a terminal, control information including transmit power information for transmitting a random access preamble;

receiving a random access preamble from the terminal;

transmitting a random access response to the terminal, in response to the random access preamble;

receiving uplink data including a terminal identifier from the terminal; and

transmitting data including the terminal identifier to the terminal.

16. The method of claim 15, wherein the transmit power information includes at least one of a channel state information reference signal pattern for measuring pathloss for each antenna in the mobile communication system and a power control parameter associated with an antenna communicating with the terminal.

17. The method of claim 15, further comprising:

transmitting a channel state information reference signal pattern set for measuring pathloss for each antenna in multiple cells; and

transmitting a channel state information reference signal pattern of the set for use in measuring a pathloss.

18. A base station that performs random access in a mobile communication system, comprising:

a transceiver that transceives signals with a terminal; and

a power control controller that transmits control information including transmit power information for transmitting a random access preamble, receives the random access preamble from the terminal, transmits, a random access response to the terminal, receives uplink data including a terminal identifier from the terminal, and transmits data including the terminal identifier to the terminal.

19. The base station of claim 18, wherein the antenna reference transmit power information comprises at least one of:

a channel state information reference signal pattern for measuring pathloss for each antenna in the mobile communication system; and

a power control parameter associated with an antenna communicating with the terminal.

20. The base station of claim 18, wherein the power control controller transmits a channel state information reference signal pattern set for measuring pathloss for each antenna in multiple cells, and transmits a channel state information reference signal pattern of the set for use in measuring a pathloss.