Terminal Access Method, System and Associated Devices

• US 20120188897A1
• Filed: 08/02/2010
• Published: 07/26/2012
• Est. Priority Date: 08/31/2009
• Status: Active Grant

• Current Assignee: China Mobile Communications Corporation (China Mobile Communications Group Co., Ltd.)
• Original Assignee: China Mobile Communications Corporation (China Mobile Communications Group Co., Ltd.)
• Inventors: Shen, Xiaodong
• Granted Patent: US 8,811,319 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/16 Deriving transmission power values from another channel
• CPC Class Codes: H04W 52/245 taking into account received signal strength
• CPC Class Codes: H04W 52/246 where the output power of a terminal is based on a path parameter calculated in said terminal
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 76/10 Connection setup

Abstract

A terminal access method is disclosed. The method includes the following steps: the terminal receives an auxiliary synchronization signal sent by a base station on a transmission resource which is chosen from an uplink and used for transmitting downlink data; the terminal calculates transmission power according to the auxiliary synchronization signal; and the terminal sends a Random Access Channel (RACH) access preamble code to the base station according to the transmission power and performs a RACH access process. In this technical solution, the auxiliary synchronization signal is transmitted in a special sub-frame selected from the uplink, which makes it possible for the terminal to obtain the channel quality information of the uplink by receiving the auxiliary synchronization signal during a cell synchronization stage, and determine the transmission power according to the channel quality information of the uplink before the RACH process occurs, thereby reducing the step of adjusting the transmission power and shortening the time of the random access of the channel. A terminal access system and associated devices are also provided.

Claims

1. A user equipment access method, comprising:

a user equipment receiving a secondary synchronization signal transmitted from a base station on a transmission resource selected in the uplink for transmission of downlink data;

the user equipment calculating transmission power from the secondary synchronization signal; and

the user equipment transmitting a Physical Random Access Channel, RACH, access preamble to the base station at the transmission power to perform an RACH access process.

2. The method of claim 1, wherein the user equipment calculating transmission power from the secondary synchronization signal comprises:

the user equipment detecting reception power of a pilot sequence of the received secondary synchronization signal;

determining a path loss in the uplink according to the detected reception power and transmission power preset by the base station; and

the user equipment determining the transmission power as the sum of the path loss in the uplink and reception power required for the base station.

3. The method of claim 1, wherein the base station transmitting the secondary synchronization signal on the transmission resource in the uplink for transmission of downlink data comprises:

the base station selecting one of every five adjacent sub-frames in the uplink as a special sub-frame comprising in turn a downlink transmission time slot, a guard period and an uplink special time slot; and

the base station transmitting the secondary synchronization signal to the user equipment in the downlink transmission time slot in the selected special sub-frame.

4. The method of claim 3, wherein the base station transmitting the secondary synchronization signal in the downlink transmission time slot in the uplink comprises:

the base station selecting for transmission of the secondary synchronization signal a time-frequency resource block comprising six resource blocks in the middle of the uplink frequency band in the frequency domain and at the third symbol location in the downlink transmission time slot in the time domain; and

transmitting the secondary synchronization signal on the selected time-frequency resource block.

5. The method of claim 1, wherein the user equipment is a user equipment applicable to a Time Division-Long Term Evolution, TD-LTE, system, and the base station is a base station applicable to the TD-LTE system.

6. (canceled)

7. A user equipment applicable to a Time Division-Long Term Evolution, TD-LTE, system comprising the user equipment and a base station, the user equipment comprising:

a receiving module configured to receive a secondary synchronization signal transmitted from the base station on a transmission resource selected in the uplink for transmission of downlink data;

a power calculating module connected with the receiving module and configured to calculate transmission power from the secondary synchronization signal received by the receiving module; and

a Physical Random Access Channel, RACH accessing module connected with the power calculating module and configured to transmit an RACH access preamble to the base station at the transmission power calculated by the power calculating module to perform an RACH access process.

8. The user equipment of claim 7, wherein:

the power calculating module is configured to detect reception power of a pilot sequence of the secondary synchronization signal received by the receiving module, to acquire a path loss in the uplink according to the detected reception power and transmission power preset by the base station, and to determine the transmission power as the sum of the path loss in the uplink and reception power required for the base station.

9. A base station applicable to a Time Division-Long Term Evolution, TD-LTE, system comprising a user equipment and the base station, the base station comprising:

a selecting module configured to select a transmission resource in the uplink for transmission of downlink data; and

a secondary synchronization signal transmitting module configured to transmit a secondary synchronization signal on the transmission resource selected by the selecting module.

10. The base station of claim 9, wherein the selecting module selects one of every five adjacent sub-frames in the uplink as a special sub-frame comprising in turn a downlink transmission time slot, a guard period and an uplink special time slot and takes the downlink transmission time slot in the selected special sub-frame as the transmission resource for transmission of downlink data.

11. The base station of claim 10, wherein the selecting module selects for transmission of the secondary synchronization signal a time-frequency resource block comprising six resource blocks in the middle of the uplink frequency band in the frequency domain and at the third symbol location in the downlink transmission time slot in the time domain.