METHOD AND APPARATUS FOR PROVIDING DOWNLINK REFERENCE SIGNAL TRANSMISSION POWER INFORMATION IN A WIRELESS COMMUNICATION SYSTEM THAT SUPPORTS MULTIPLE ANTENNAS

• US 20120188988A1
• Filed: 10/12/2010
• Published: 07/26/2012
• Est. Priority Date: 10/12/2009
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Chung, Jae Hoon, Lee, Moon Il, Noh, Min Seok, Ko, Hyun Soo
• Granted Patent: US 8,750,257 B2
• Time in Patent Office: Days
• US Class Current: 370/335
• CPC Class Codes: H04B 1/7073 Synchronisation aspects
• CPC Class Codes: H04B 7/2668 Arrangements for Wireless Code-Division Multiple Access [CDMA] System Synchronisation, for code acquisition H04B1/7075, for code tracking H04B1/7085
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0016 Time-frequency-code
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04W 52/143 Downlink power control

Abstract

The present invention relates to a wireless communication system, and more particularly, to a method and an apparatus for providing downlink reference signal transmission power information in a wireless communication system that supports multiple antennas. A method for providing demodulation reference signal transmission power information according to one embodiment of the present invention comprises: a step of mapping a main synchronous signal onto a predetermined OFDM symbol of a downlink pilot time slot (DwPTS) subframe; a step of mapping, in a code division multiplexing manner, a demodulation reference signal over two or more OFDM symbols containing said predetermined OFDM symbol in the DwPTS subframe; a step of transmitting the DwPTS subframe to which the main synchronous signal and the demodulation reference signal are mapped; and a step of transmitting information on the transmission power for transmitting the demodulation reference signal mapped onto said predetermined OFDM symbol.

Claims

1. A method of providing demodulation reference signal transmission power information, comprising the steps of:

mapping a primary synchronization signal to a prescribed OFDM symbol of DwPTS (downlink pilot time slot) subframe;

mapping the demodulation reference signal across at least 2 OFDM symbols including the prescribed OFDM symbol in the DwPTS subframe by a code division multiplexing scheme;

transmitting the DwPTS subframe to which the primary synchronization signal and the demodulation reference signal are mapped; and

transmitting transmission power information of the demodulation reference signal mapped to the prescribed OFDM symbol.

2. The method of claim 1, wherein the primary synchronization signal is power boosted.

3. The method of claim 1, wherein the demodulation reference signal on the prescribed OFDM symbol is power deboosted.

4. The method of claim 1, wherein the transmission power information of the demodulation reference signal comprises at least one selected from the group consisting of a transmission power level of the demodulation reference signal on the prescribed OFDM symbol, a difference value between a transmission power level of the demodulation reference signal on the prescribed OFDM symbol and a transmission power level of the demodulation reference signal on the rest of the OFDM symbol, and a ratio of the transmission power level of the demodulation reference signal on the prescribed OFDM symbol to the transmission power level of the demodulation reference signal on the rest of the OFDM symbol.

5. The method of claim 1, wherein the code division multiplexing uses an orthogonal cover code (OCC) having a length 2 or more.

6. The method of claim 1, wherein the prescribed OFDM symbol comprises a 3^rd OFDM symbol of the DwPTS subframe.

7. A method of acquiring channel information using a demodulation reference signal, comprising the steps of:

receiving DwPTS (downlink pilot time slot) subframe having the demodulation reference signal mapped by a code division multiplexing scheme across at least 2 OFDM symbols including a prescribed OFDM symbol to which a primary synchronization signal is mapped;

receiving transmission power information of the demodulation reference signal mapped to the prescribed OFDM symbol;

despreading the received demodulation reference signal based on the transmission power information of the demodulation reference signal; and

acquiring the channel information from the despread demodulation reference signal.

8. The method of claim 7, the demodulation reference signal dispreading step comprising the step of normalizing a power of the demodulation reference signal mapped to the at least 2 OFDM symbols from the transmission power information of the demodulation reference signal.

9. The method of claim 7, wherein the primary synchronization signal is power boosted.

10. The method of claim 7, wherein the demodulation reference signal on the prescribed OFDM symbol is power deboosted.

11. The method of claim 7, wherein the transmission power information of the demodulation reference signal comprises at least one selected from the group consisting of a transmission power level of the demodulation reference signal on the prescribed OFDM symbol, a difference value between a transmission power level of the demodulation reference signal on the prescribed OFDM symbol and a transmission power level of the demodulation reference signal on the rest of the OFDM symbol, and a ratio of the transmission power level of the demodulation reference signal on the prescribed OFDM symbol to the transmission power level of the demodulation reference signal on the rest of the OFDM symbol.

12. The method of claim 7, wherein the code division multiplexing uses an orthogonal cover code (OCC) having a length 2 or more.

13. The method of claim 7, wherein the prescribed OFDM symbol comprises a 3^rd OFDM symbol of the DwPTS subframe.

14. A base station for providing demodulation reference signal transmission power information, comprising:

a receiving module receiving an uplink signal from a user equipment;

a transmitting module transmitting a downlink signal to the user equipment; and

a processor connected to the receiving module and the transmitting module, the processor controlling the base station including the receiving module and the transmitting module,

wherein the processor is configured to;

map a primary synchronization signal to a prescribed OFDM symbol of DwPTS (downlink pilot time slot) subframe,

map the demodulation reference signal across at least 2 OFDM symbols including the prescribed OFDM symbol in the DwPTS subframe by a code division multiplexing scheme, and

transmit the DwPTS subframe to which the primary synchronization signal and the demodulation reference signal are mapped and transmission power information of the demodulation reference signal mapped to the prescribed OFDM symbol via the transmitting module.

15. A user equipment for acquiring channel information using a demodulation reference signal, comprising:

a receiving module receiving a downlink signal from a base station;

a transmitting module transmitting an uplink signal to the user equipment; and

a processor connected to the receiving module and the transmitting module, the processor controlling the user equipment including the receiving module and the transmitting module,

wherein the processor is configured to;

receive DwPTS (downlink pilot time slot) subframe having the demodulation reference signal mapped by a code division multiplexing scheme across at least 2 OFDM symbols including a prescribed OFDM symbol to which a primary synchronization signal is mapped via the receiving module, the processor configured to receive transmission power information of the demodulation reference signal mapped to the prescribed OFDM symbol via the receiving module,

despread the received demodulation reference signal based on the transmission power information of the demodulation reference signal, and

acquire the channel information from the despread demodulation reference signal.