WO2013082920A1

WO2013082920A1 - Power control method and device in machine to machine communications

Info

Publication number: WO2013082920A1
Application number: PCT/CN2012/075718
Authority: WO
Inventors: 朱昀; 陈薇
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-12-07
Filing date: 2012-05-18
Publication date: 2013-06-13
Also published as: CN103152806A

Abstract

Disclosed are a power control method and device in machine to machine communications. The method includes: a base station acquiring the current transmit power of a machine type communication (MTC) device in a cell and determining the target transmit power of the MTC device according to a preset power control algorithm in accordance with the current transmit power of the MTC device; and the base station broadcasting the determined target transmit power to the MTC device in the cell through a power control message, and commanding the MTC device in the cell to adjust the transmit power thereof as the target transmit power. The present invention can realize effective control of the transmit power of the MTC device.

Description

Power control method and device in machine-machine communication

The present invention relates to the field of machine and machine communication technologies, and more particularly to a power control method and apparatus for machine to machine communication. Background technique

The full name of M2M is Machine to Machine communications, which is used to refer to inter-machine communication. M2M combines sensor networks and wireless communication technologies. With the great enthusiasm of governments in recent years for their investment, M2M technology itself has also achieved rapid development. At present, the wireless sensing technology in M2M has matured, and how to seamlessly connect wireless sensors into existing wireless communication networks as a new type of terminal "terminal" is still not mature and perfect. solution. Among the various wireless communication technologies, especially the third generation represented by General Packet Radio Service (GPRS), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE) The 3GPP (The 3rd Generation Partnership Project) network is the mainstream wireless communication network adopted by national operators. How to introduce M2M technology into the above-mentioned network, realizing the world-wide "Internet of Things" is currently under study. Hot Issues.

The terminal "terminal" with a wireless sensor is called a Machine Type Communication (MTC) device. The power control of MTC devices is significantly different from traditional wireless terminals:

On the one hand, based on the characteristics of low traffic, MTC equipment transmission is often sudden, and it is difficult to last for a long time in most cases. Therefore, it is difficult to use closed-loop power control for MTC equipment; on the other hand, because MTC equipment is massive If using the current open loop power control unit System (currently open loop power estimation accuracy is limited, generally open loop power will be much larger than closed loop power), then a large number of MTC open loop power transmission will cause communication between MTC devices and affect existing wireless terminal communication, such as Increased interference, etc.

Therefore, the power control technique in the existing wireless communication is not suitable for the transmission power control of the MTC device, but the prior art has not provided a solution to the above problem. Summary of the invention

In view of this, it is a primary object of the present invention to provide a power control method and apparatus for machine-to-machine communication to achieve effective control of the transmit power of an MTC device.

In order to achieve the above object, the technical solution of the present invention is achieved as follows:

The present invention provides a power control method in machine-to-machine communication, the method comprising: acquiring, by a base station, a current transmit power of a machine type communication MTC device in a cell, and according to the

The current transmit power of the MTC device determines the target transmit power of the MTC device according to a preset power control algorithm;

The base station broadcasts the determined target transmit power to the MTC device in the cell through a power control message, and commands the MTC device in the cell to adjust the respective transmit power to the target transmit power.

The base station acquires a current transmit power of the MTC device in the cell, which is specifically:

The base station receives the current transmit power reported by the MTC device in the cell;

Or the base station estimates the path loss by measuring the transmit power of the received signal, and obtains the current transmit power of the MTC device in the cell according to the following formula: the transmit power of the base station receiving signal ^=the current transmit power of the MTC device-path loss, that is, The current transmit power of the MTC device is subtracted from the path loss, and the transmit power of the received signal from the base station is obtained.

The power control algorithm is:

Calculating the intra-cell according to a preset specific objective function according to a current transmit power of all MTC devices in the cell and an intra-cell interference situation under the current transmit power distribution. There is a target transmit power of the MTC device.

The specific objective function is:

An objective function that minimizes overall cell interference;

Alternatively, an objective function that ensures that the signal-to-noise ratio of the received signal of the base station is above a preset threshold and minimizes the transmit power of the MTC device.

The power control message is a cell broadcast message;

For a wireless access mode of Global System for Mobile Communications (GSM) or General Packet Radio Service (GPRS), the power control message is set to be broadcast in the broadcast control channel BCCH to the MTC device within the cell;

For the wireless access mode of the Universal Mobile Telecommunications System UMTS or Long Term Evolution LTE, the power control message is set to be broadcast in the system information block SIB to the MTC device in the cell.

The present invention also provides a power control device in machine-to-machine communication, the device comprising: a current transmit power acquisition module, a target transmit power determination module, and a broadcast control module,

The current transmit power acquisition module is configured to acquire a current transmit power of a device type communication MTC device in a cell;

The target transmit power determining module is configured to determine, according to a current transmit power of the MTC device, a target transmit power of the MTC device according to a preset power control algorithm;

The broadcast control module is configured to broadcast the determined target transmit power to the MTC device in the cell by using a power control message, and command the MTC device in the cell to adjust the respective transmit power to the target transmit power.

The current transmit power acquisition module is configured to receive the current transmit power reported by the MTC device in the cell;

Or, by measuring the transmit power of the received signal, estimating the path loss, and acquiring the current transmit power of the MTC device in the cell according to the following formula: The transmit power of the received signal of the base station = the current transmit power of the MTC device - the path loss, that is, the current MTC device Transmit power minus path loss Consumption, the transmission power of the signal received by the base station.

The power control algorithm is:

The target transmit power of all MTC devices in the cell is calculated according to a preset specific objective function according to a current transmit power of all MTC devices in the cell and an intra-cell interference condition under the current transmit power distribution.

The specific objective function is:

An objective function that minimizes overall cell interference;

The power control message is a cell broadcast message;

A power control method and apparatus for communication between a machine and a machine provided by the present invention acquires a current transmit power of an MTC device in a cell, and determines a target of the MTC device according to a preset power control algorithm according to a current transmit power of the MTC device. Transmit power; the determined target transmit power is broadcast to the MTC device in the cell through the power control message, and the MTC device in the command cell is adjusted to adjust the respective transmit power to the target transmit power.

The invention adopts the method of closed-loop power control, realizes effective control of the transmission power of the MTC device, and avoids the overload of the network caused by the power control of the massive MTC device; in addition, since the base station grasps the current transmission power of the MTC device And according to a certain power control algorithm, the accuracy and accuracy of power control can be greatly improved. DRAWINGS

1 is a flow chart of a power control method in machine-to-machine communication according to an embodiment of the present invention;

2 is a schematic diagram showing the structure of a power control device in communication between a machine and a machine according to an embodiment of the present invention. detailed description

The technical solutions of the present invention are further elaborated below in conjunction with the accompanying drawings and specific embodiments. An embodiment of the present invention provides a power control method in a machine-to-machine communication, which mainly includes: a base station acquires a current transmit power of an MTC device by using an MTC device reporting manner or a base station measurement manner, and the base station calculates the MTC according to a certain power control algorithm. The target transmit power of the device, after which the base station commands the MTC device to set the target transmit power by sending a power control message to the MTC device; after receiving the power control message, the MTC device performs open loop power control according to the set target transmit power. The transmission of the next time slot data.

It should be noted that the power control method provided by the embodiment of the present invention is applicable to a system for communicating between a machine and a machine, where the system includes a plurality of cells, each cell has at least one base station and a plurality of MTC devices, and the MTC device The communication is performed with the base station by means of radio (specifically, cellular mobile communication such as GSM, UMTS, LTE, etc.). The specific implementation process of the power control method is shown in Figure 1, which mainly includes the following steps:

Step 101: The base station acquires a current transmit power of the MTC device in the cell.

The base station can obtain the current transmit power of the intra-cell MTC device in the following two ways: In the first route, the base station receives the current transmit power reported by the MTC device in the cell, that is, the MTC device can carry its current transmit power value in the measurement report, or The level value of the current transmit power is reported to the base station, and the base station performs reception;

In the second way, the base station obtains the current transmit power of the MTC device by using a measurement. Specifically, the signal transmitted by the MTC device reaches the base station through a certain wireless path, and then the base station can pass the test. The received power of the received signal is estimated, the path loss is estimated, and the current transmit power of the MTC device in the cell is obtained according to the following formula: The transmit power of the received signal of the base station = the current transmit power of the MTC device - the path loss, ie, the current transmit power of the MTC device is reduced. The path loss is obtained, and the transmission power of the signal received by the base station is obtained. The base station can accurately measure the transmit power of the received signal, and estimate the path loss through the previous communication process, and then estimate the current transmit power of the MTC device according to the above formula.

Step 102: The base station determines, according to a current transmit power of the MTC device, a target transmit power of the MTC device according to a preset power control algorithm.

The base station determines the target transmit power of the MTC device based on an aspect of the current transmit power of the MTC device obtained in step 101, and on the other hand according to a specific objective function. Specifically, the base station may calculate target transmit power of all MTC devices in the cell according to a preset specific target function according to the current transmit power of all MTC devices in the cell and the intra-cell interference under the current transmit power distribution.

Among them, the specific objective function can be:

An objective function that minimizes overall cell interference;

Step 103: The base station broadcasts the determined target transmit power to the MTC device in the cell by using a power control message, and commands the MTC device in the cell to adjust the respective transmit power to the target transmit power.

The power control message may be a cell broadcast message; specifically,

For the wireless access mode of the Global System for Mobile Communications (GSM) or GPRS, the power control message is set to be broadcasted in the Broadcast Control Channel (BCCH, Broadcast Control Channel) to the MTC device in the cell; For a wireless access mode of UMTS or LTE, the power control message is set to be broadcast in a System Information Block (SIB) to an MTC device within a cell. The existing protocol specifies system message blocks SIB1-SIB7, SIB11, SIB 12 have been occupied by other applications, so the power control message can be set in any of the remaining SIB8~SIB10 SIBs.

In addition, the base station can simultaneously broadcast the uplink interference data measured by the base station in addition to the broadcast power control message, especially for a Time Division Duplexing (TDD) system, which can broadcast the interference signal code power (ISCP) in a time slot. The time slot is here because the TDD system is a time division system. Most of the current network is 2: 4 (2 time slot uplink, 4 time slot downlink) configuration. After the M2M communication is introduced, the uplink and downlink time slot configuration can be adjusted to 3: 3, even 4: 2, etc. Broadcast messages can only be sent in the downlink time slot.

Step 104: After receiving the power control message broadcasted by the base station, the MTC device in the cell adjusts the respective transmit power to the target transmit power in the power control message, and then the MTC device performs the next time slot data according to the adjusted target transmit power. Launch.

Corresponding to the power control method in the above-mentioned machine-to-machine communication, an embodiment of the present invention further provides a power control device in a machine-to-machine communication, the device being applicable to a base station, the device mainly comprising: a current transmit power acquisition module 10 The target transmit power determination module 20 and the broadcast control module 30. The current transmit power is used to obtain the current transmit power of the MTC device in the cell. The target transmit power determining module 20 is configured to determine the MTC according to a preset power control algorithm according to the current transmit power of the MTC device. The target transmit power of the device is used by the broadcast control module 30 to broadcast the determined target transmit power to the MTC device in the cell through the power control message, and the MTC device in the command cell adjusts the respective transmit power to the target transmit power.

Preferably, the current transmit power is also used to receive the current transmit power reported by the MTC device in the cell;

Or, by measuring the transmit power of the received signal, estimating the path loss, and according to the following The current transmit power of the MTC device in the cell is obtained: the transmit power of the received signal of the base station = the current transmit power of the MTC device - the path loss.

Preferably, the power control algorithm is: calculating all MTCs in the cell according to a preset specific objective function according to a current transmit power of all MTC devices in the cell and an intra-cell interference situation under the current transmit power distribution. The target transmit power of the device.

Preferably, the specific objective function is:

An objective function that minimizes overall cell interference;

Preferably, the power control message is a cell broadcast message;

For the GSM or GPRS wireless access mode, the power control message is set to be broadcast in the BCCH to the MTC device in the cell;

For the wireless access mode of UMTS or LTE, the power control message is set to be broadcast in the SIB to the MTC device in the cell.

In summary, the embodiment of the present invention adopts a closed-loop power control method to achieve effective control of the transmit power of the MTC device, and avoids overloading of the network caused by massive power control of the MTC device; Master the current transmit power of the MTC device, and according to a certain power control algorithm, the accuracy and accuracy of the power control can be greatly improved.

The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims

A power control method in machine-to-machine communication, the method comprising: acquiring, by a base station, a current transmit power of a machine type communication MTC device in a cell, and according to the

2. The power control method in the machine-to-machine communication according to claim 1, wherein the base station acquires a current transmit power of the MTC device in the cell, specifically:

Or the base station estimates the path loss by measuring the transmit power of the received signal, and obtains the current transmit power of the MTC device in the cell according to the following formula: the transmit power of the received signal of the base station=^11^ the current transmit power of the device-path loss, That is, the current transmit power of the MTC device minus the path loss, and the transmit power of the received signal of the base station is obtained.

3. The power control method in machine-to-machine communication according to claim 1, wherein the power control algorithm is:

4. The power control method in machine-to-machine communication according to claim 3, wherein said specific objective function is:

An objective function that minimizes overall cell interference;

Or, an objective function of ensuring that the signal to noise ratio of the received signal of the base station is above a preset threshold and minimizing the transmit power of the MTC device.

The power control method in the machine-to-machine communication according to any one of claims 1 to 4, wherein the power control message is a cell broadcast message;

6. A power control device for communication between a machine and a machine, the device comprising: a current transmit power acquisition module, a target transmit power determination module, and a broadcast control module,

The power control device in the machine-to-machine communication according to claim 6, wherein the current transmit power acquisition module is configured to receive a current transmit power reported by the MTC device in the cell;

Or, by measuring the transmit power of the received signal, estimating the path loss, and acquiring the current transmit power of the MTC device in the cell according to the following formula: The transmit power of the received signal of the base station = the current transmit power of the MTC device - the path loss, that is, the current MTC device The transmit power is subtracted from the path loss, and the transmit power of the received signal from the base station is obtained.

8. The power control apparatus in machine-to-machine communication according to claim 6, wherein the power control algorithm is: The target transmit power of all MTC devices in the cell is calculated according to a preset specific target function according to a current transmit power of all MTC devices in the cell and an intra-cell interference condition under the current transmit power distribution.

9. The power control apparatus in machine-to-machine communication according to claim 8, wherein said specific objective function is:

An objective function that minimizes overall cell interference;

The power control device in the machine-to-machine communication according to any one of claims 6 to 9, wherein the power control message is a cell broadcast message;