Method and device for open loop uplink access power control

• US 9,295,002 B2
• Filed: 03/05/2012
• Issued: 03/22/2016
• Est. Priority Date: 03/31/2011
• Status: Active Grant

• Current Assignee: Nufront Mobile Communications Technology Company Limited
• Original Assignee: Nufront Mobile Communications Technology Company Limited
• Inventors: Bao, Dongshan, Pan, Lijun, Yao, Huijuan, Zhou, Yubao, Yu, Xiaoyan, Lei, Jun, Wang, Jing, Liu, Shenfa, Yan, Zhigang
• Primary Examiner(s): HOANG, THAI D
• Application Number:
  US14/008,616
• Publication Number:
  US 20150085732A1
• Time in Patent Office: 1,478 Days
• Field of Search: 370329-330, 370/335, 370/342, 455/63.1, 455/570
• US Class Current: 1/1
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 52/10 Open loop power control
• CPC Class Codes: H04W 52/12 Outer and inner loops
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/226 using past references to control power, e.g. look-up-table
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/262 taking into account adaptive modulation and coding [AMC] scheme AMC per se H04L1/0001
• CPC Class Codes: H04W 72/0473 the resource being transmission power
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

A method for open loop uplink access power control comprises: estimating the uplink transmission path loss according to received signal power of a station (STA) and the transmit power of a central access point (CAP); determining the transmission bandwidth allocated by the CAP for uplink transmission and deviation adjustment of the CAP; determining a modulation-coding mode and determining requirements of the carrier-to-noise ratio corresponding to the modulation-coding mode; and calculating a target value for adjusting the transmit power of the STA. Also disclosed is a device for open loop uplink access power control.

Claims

1. A method for open loop uplink access power control, comprising:

estimating an uplink transmission path loss according to a received signal power of a station (STA) and a transmit power of a central access point (CAP);

determining a transmission bandwidth allocated by CAP for uplink transmission and deviation adjustment of CAP;

determining a modulation-coding mode and determining requirements of a carrier-to-noise ratio corresponding to modulation-coding mode; and

calculating a target value for adjusting transmit power of the STA by a formula;

P_STA=min{P<sub>STA—

MAX</sub>,PL_OL+C/N+10 log₁₀(BW)+offset_CAP+offset_STA}

wherein, P<sub>STA—

MAX</sub> is a maximum transmission power of said STA, PL_OL is loss of uplink transmission path, C/N is the carrier-to-noise ratio corresponding to modulation and coding scheme, with respect to noise and interference on a receiving terminal, BW is a bandwidth distributed by access point CAP for the uplink transmission, offset_CAP is deviation adjustment of the CAP, and offset_STA is an adjustment of the STA.

2. The method of claim 1, further comprising obtaining a deviation adjustment of CAP by parsing the CAP broadcast message.

3. The method of claim 1, further comprising obtaining a resource indication by the STA by analyzing a control channel (CCH) of currently received physical frame, to determine transmission bandwidth distributed by CAP for the uplink transmission.

4. The method of claim 1, further comprising:

acquiring modulation encoding scheme indication by STA by parsing a CCH of currently received physical frame;

determining a modulation and coding scheme, by using a lookup correspondence table between preset modulation encoding and carrier-to-noise ratio; and

determining a current modulation and coding scheme corresponding to carrier-to-noise ratio.

5. A device of uplink transmission open loop power control, comprising:

first calculating unit that calculates a target value of STA transmission power;

first determining unit that determines CAP for uplink transmission allocation of transmission bandwidth;

second determining unit that determines modulation and coding mode, and carrier-to-noise ratio corresponding to modulation and coding mode;

third determining unit that determines deviation adjustment of the CAP; and

second calculating unit that calculates a target value for adjusting transmit power of the STA by a formula;

P_STA=min{P<sub>STA—

MAX</sub>,PL_OL+C/N+10 log₁₀(BW)+offset_CAP+offset_STA}

wherein, P<sub>STA—

MAX</sub> is a maximum transmission power of the indicated STA, PL_OL is loss of uplink transmission path, C/N is the carrier-to-noise ratio corresponding to modulation and coding scheme, and BW is a bandwidth distributed by access point CAP for the uplink transmission.

6. The device of claim 5, wherein the third determining unit obtains deviation adjustment of CAP by parsing a CAP broadcast message.

7. The device of claim 5, wherein the first computing unit comprises:

a first analysis unit that parses transmitting power of the CAP from a CAP broadcast message; and

an estimating unit that estimates uplink path loss depending on STA received signal power and CAP transmit power.

8. The device of claim 5, wherein the first determination unit comprises:

a second analysis sub-unit that acquires resource indication by parsing control channel CCH of currently received physical frame; and

a first determining sub-unit that utilizes the resource indication for determining transmission bandwidth for uplink transmission allocated by CAP.

9. The device of claim 5, wherein the second determining unit comprises:

a third analysis unit that acquires modulation coding mode indication by parsing CCH of currently received physical frame;

a second determining sub-unit that utilizes the modulation coding scheme indication for determining modulation coding; and

a third determining sub-unit that looks up a preset correspondence table of modulation encoding with carrier-to-noise ratio for determining carrier-to-noise ratio corresponding to modulation coding scheme.