APPARATUS AND METHOD FOR RANDOM ACCESS IN WIRELESS COMMUNICATION SYSTEM

• US 20200137807A1
• Filed: 09/10/2019
• Published: 04/30/2020
• Est. Priority Date: 10/24/2018
• Status: Active Grant

• Current Assignee: Industry Academic Cooperation Foundation
• Original Assignee: Industry Academic Cooperation Foundation
• Inventors: LEE, Jang Won, LEE, Byung Hyun, MOON, Seok Jae, LEE, Hyun Suk
• Granted Patent: US 11,057,945 B2
• Time in Patent Office: Days
• CPC Class Codes: H04W 56/0045 compensating for timing error by altering transmission time
• CPC Class Codes: H04W 74/085 collision avoidance
• CPC Class Codes: H04W 74/0858 collision detection
• CPC Class Codes: H04W 74/0891 for synchronized access
• CPC Class Codes: H04W 76/11 Allocation or use of connection identifiers

Abstract

The present disclosure provides an apparatus and a method for random access in a wireless communication system having a base station and wireless terminals, where the wireless terminal can select a detection sub-segment from a preamble detection segment that is divided into a multiple number of detection sub-segments, transmit a random access preamble with the timing adjusted such that the random access preamble is received at the base station in the selected detection sub-segment, and when a random access response message is received from the base station, transmit a terminal identification message to the base station and receive a contention resolution message from the base station.

Claims

1. A wireless terminal in a wireless communication system having a base station and wireless terminals performing random access, wherein the wireless terminal:

selects a detection sub-segment from a preamble detection segment divided into a plurality of detection sub-segments and transmits a random access preamble by adjusting a timing such that the random access preamble is received at a base station in the selected detection sub-segment, and

when a random access response message is received from the base station, transmits a terminal identification message to the base station and receives a contention resolution message from the base station.

2. The wireless terminal of claim 1, wherein the wireless terminal:

has a TA (timing advance) stored beforehand, the TA acquired during a previous communication with the base station, and

transmits the random access preamble by adjusting the timing such that the random access preamble is received at the base station in the selected detection sub-segment according to the stored TA.

3. The wireless terminal of claim 1, wherein the wireless terminal:

before selecting the detection sub-segment, receives SIB2 (system information block 2) information, the SIB2 information pertaining to system information related to a random access and broadcasted from the base station, and determines the preamble detection segment and the plurality of detection sub-segments of the base station according to detection sub-segment information included in the SIB2 information.

4. A base station in a wireless communication system having a base station and wireless terminals performing random access, wherein the base station:

divides a preamble detection segment into a plurality of detection sub-segments designated beforehand and detects a random access preamble received from at least one wireless terminal in units of the divided detection sub-segments,

transmits a random access response message to the wireless terminal according to the detected random access preamble, and

when a terminal identification message is received from the wireless terminal, transmits a contention resolution message to the wireless terminal.

5. The base station of claim 4, wherein the base station:

assigns different preamble identifiers (RAPID'"'"'s) for identical random access preambles detected in different detection sub-segments of one preamble detection segment.

6. The base station of claim 4, wherein the base station:

before receiving the random access preamble, broadcasts SIB2 (system information block 2) information, the SIB2 information pertaining to system information related to a random access and including detection sub-segment information pertaining to information on the plurality of detection sub-segments.

7. A random access method for a wireless terminal in a wireless communication system, the random access method comprising:

selecting a detection sub-segment from a preamble detection segment, the preamble detection segment divided into a plurality of detection sub-segments;

transmitting a random access preamble by adjusting a timing such that the random access preamble is received at a base station in the selected detection sub-segment;

receiving a random access response message from the base station;

transmitting a terminal identification message to the base station; and

receiving a contention resolution message from the base station.

8. The random access method of claim 7, further comprising, before the selecting of the detection sub-segment:

storing a TA (timing advance) acquired during a previous communication with the base station,

wherein the transmitting of the random access preamble comprises;

transmitting the random access preamble by adjusting the timing such that the random access preamble is received at the base station in the selected detection sub-segment according to the stored TA.

9. The random access method of claim 7, further comprising, before the selecting of the detection sub-segment:

receiving SIB2 (system information block 2) information, the SIB2 information pertaining to system information related to a random access and broadcasted from the base station; and

dividing the preamble detection segment into the plurality of detection sub-segments of the base station according to detection sub-segment information included in the SIB2 information.

10. A random access method for a base station in a wireless communication system, the random access method comprising:

receiving a random access preamble from at least one wireless terminal;

detecting the random access preamble in units of a plurality of detection sub-segments of a preamble detection segment;

transmitting a random access response message to the wireless terminal according to the detected random access preamble;

receiving a terminal identification message from the wireless terminal; and

transmitting a contention resolution message to the wireless terminal.

11. The random access method of claim 10, wherein the detecting of the random access preamble comprises:

dividing a single preamble detection segment into the plurality of detection sub-segments; and

detecting the random access preamble in each unit of the plurality of detection sub-segments.

12. The random access method of claim 10, wherein the detecting of the random access preamble comprises:

assigning different preamble identifiers (RAPID'"'"'s) for identical random access preambles detected in different detection sub-segments of one preamble detection segment.

13. The random access method of claim 10, further comprising, before the receiving of the random access preamble:

broadcasting SIB2 (system information block 2) information, the SIB2 information pertaining to system information related to a random access and including detection sub-segment information pertaining to information on the plurality of detection sub-segments.