Transmission Method Of Mobile Station For Random Access Channel Diversity

• US 20090175161A1
• Filed: 04/19/2007
• Published: 07/09/2009
• Est. Priority Date: 04/19/2006
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Yi, Hyo-Seok, Chang, Kapseok, Park, Hyeong-Geun, Bang, Seung-Chan, Kim, Young-Hoon, Kim, Il-Gyu, Ko, Young-Jo
• Granted Patent: US 8,165,097 B2
• Time in Patent Office: Days
• US Class Current: 370/210
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0623 Auxiliary parameters, e.g. power control [PCB] or not acknowledged commands [NACK], used as feedback information
• CPC Class Codes: H04B 7/0689 using different transmission schemes, at least one of them being a diversity transmission scheme
• CPC Class Codes: H04B 7/12 Frequency diversity
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/0006 by adapting the transmission format
• CPC Class Codes: H04L 1/06 using space diversity
• CPC Class Codes: H04L 1/1867 Arrangements specially adapted for the transmitter end
• CPC Class Codes: H04L 1/188 Time-out mechanisms
• CPC Class Codes: H04L 1/1893 Physical mapping arrangements physical resource mapping in general H04L5/00
• CPC Class Codes: H04L 27/2626 Arrangements specific to the transmitter only
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601
• CPC Class Codes: H04W 52/286 during data packet transmission, e.g. high speed packet access [HSPA]
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity
• CPC Class Codes: H04W 52/48 during retransmission after error or non-acknowledgment
• CPC Class Codes: H04W 74/085 collision avoidance
• CPC Class Codes: H04W 74/0866 using a dedicated channel for access

Abstract

A transmission method performed by a mobile station for random access channel (RACH) burst transmission diversity gain is provided. According to the method, by combining and using switching diversity by beam forming, frequency hopping, and power ramping, the probability that when the speed of a mobile station is low, the mobile station falls into a deep fading environment is lowered, thereby increasing the probability of detecting an RACH signature of the base station. Also, by using the transmission parameters (subbands, precoding matrixes, power, etc.) which are used for successful transmission of an RACH burst, for transmission of a successive user packet data, reliable transmission of the successive user packet data can be performed.

Claims

1. A transmission method performed by a mobile station of obtaining random access diversity, the method comprising:

(a) processing the signal of a random access channel (RACH) burst according to a beam forming pattern set from among a plurality of beam forming patterns, and then, transmitting the RACH burst to a base station through multiple transmission antennas; and

(b) if a non-acknowledgement (NACK) response to the RACH burst from the base station is received, newly setting a beam forming pattern which is different from the set beam forming pattern, to a new RACH burst, and then, returning to the step (a).

2. The method of claim 1, wherein the RACH burst is transmitted by using a subband that is different from a subband allocated to the previous RACH burst.

3. The method of claim 1, further comprising, (c) if a NACK from the base station is received while a predetermined time has elapsed, newly setting a transmission power higher than an previously set transmission power and returning to the step (a).

4. The method of claim 1, further comprising, (d) if an acknowledgement response (ACK) from the base station is received, transmitting the user packet data, by using the beam forming patterns set when the RACH burst, of which the ACK is received, is transmitted.

5. The method of claim 4, wherein in the step (d), a user packet data is transmitted by using a subband in which the RACH burst, of which the ACK is received, is transmitted.

6. The method of claim 4, wherein the transmission power of the user packet data is set based on the power used for the transmission of the RACH burst, of which the ACK is generated.

7. The method of claim 1, wherein the step (a) comprises:

(a1) generating the RACH burst signal, by performing orthogonal frequency division multiple access (OFDMA) modulation of the RACH burst so that the RACH burst can be loaded on a set subband; and

(a2) processing the RACH burst signal according to the set beam forming pattern, and transmitting the RACH burst signal.

8. The method of claim 7, wherein the step (a2) comprises:

processing the RACH burst signal, by applying a precoding matrix corresponding to the set beam forming pattern, to the RACH burst signal; and

amplifying and up-converting each component of the processed RACH burst signal, and then, transmitting the component to a corresponding antenna from among the multiple transmission antennas.

9. The method of claim 1, wherein the RACH burst includes a signature sequence for identifying a mobile station which attempts random access.

10. The method of claim 1, wherein the RACH burst includes information on at least one of a user identifier and a resource request for setting up a call.

11. The method of claim 7, wherein the OFDMA modulation includes discrete Fourier transform-spread (DFT-S) OFDMA modulation.

12. A computer readable recording medium having embodied thereon a computer program for executing the method of claim 1.

13. The method of claim 2, further comprising, (c) if a NACK from the base station is received while a predetermined time has elapsed, newly setting a transmission power higher than an previously set transmission power and returning to the step (a).

14. The method of claim 2, further comprising, (d) if an acknowledgement response (ACK) from the base station is received, transmitting the user packet data, by using the beam forming patterns set when the RACH burst, of which the ACK is received, is transmitted.