Method for transmitting and receiving random access preamble and device therefor

• US 9,596,660 B2
• Filed: 10/08/2014
• Issued: 03/14/2017
• Est. Priority Date: 10/14/2013
• Status: Active Grant

• Current Assignee: KT Corporation
• Original Assignee: KT Corporation
• Inventors: Park, Kyujin, Choi, Woo-jin
• Primary Examiner(s): Lee, John J
• Application Number:
  US15/029,265
• Publication Number:
  US 20160255591A1
• Time in Patent Office: 888 Days
• Field of Search: 455/522, 455/434, 455/515, 455/69, 455/509, 455/452.1
• US Class Current: 1/1
• CPC Class Codes: H04W 4/70 Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

Provided are a method and a device for setting a repetition level of a random access preamble and determining transmission power for each random access preamble, when a random access preamble for an MTC terminal is repetitively transmitted and received to increase the transmission and reception performance of a random access preamble for a coverage-restricted MTC terminal. Provided are also a method and a device for controlling transmission power for a random access preamble when a terminal, located in improved coverage compared to the coverage for a general terminal, repetitively transmits the random access preamble. When the terminal repetitively transmits a PRACH through a plurality of uplink subframes, the terminal can determine the repetition number of transmitting the PRACH, determine transmission power for the PRACH based on the determined repetition number, and transmit the PRACH at the transmission power determined for the PRACH.

Claims

1. A method of performing a random access by a terminal, the method comprising:

determining a preamble repetition level based on one of i) at least one of parameters that determine a transmission power of a random access preamble and ii) a coverage level;

repeatedly transmitting a random access preamble to a base station through a predetermined number of subframes corresponding to the determined preamble repetition level; and

receiving, from the base station, a random access response related to the random access preamble,

wherein when the random access response has not been received from the base station, the transmitting of the random access preamble is repeated, and

wherein the coverage level is configured based on a plurality of thresholds of the downlink path loss value received through a cell specific high layer signaling.

2. The method of claim 1, wherein the preamble repetition level is determined based on the downlink path loss value (PL_c).

3. A terminal for performing random access, the terminal comprising:

a transmission unit configured to repeatedly transmit a random access preamble to a base station through a predetermined number of subframes corresponding to a preamble repetition level that is determined according to one of i) at least one of parameters that determine a transmission power of the random access preamble and ii) a coverage level; and

a reception unit configured to receive, from the base station, a random access response related to the random access preamble,

wherein when the reception unit has not received the random access response from the base station, the transmission unit repeats the transmitting of the random access preamble to the base station, and

wherein the coverage level is configured based on a plurality of thresholds of the downlink path loss value received through a cell-specific high layer signaling.

4. The terminal of claim 3, wherein the preamble repetition level is determined based on the downlink path loss value (PL_c).