KR101094489B1 - The uplink sleep mode control method for saving power of wireless communication system - Google Patents

Abstract

The present invention checks the existence of an uplink signal through UL MAP analysis of a downlink channel descriptor (DCD) and transitions the uplink to a sleep mode to reduce power consumption of a repeater. An object of the present invention is to provide an uplink sleep mode control method for reducing power in a wireless communication system.

To this end, the present invention, in the uplink sleep mode control method for power saving in a wireless communication system, the synchronization information is detected from the signal of the downlink interval, and the uplink map (DCD) message from the downlink channel descriptor (DCD) message Detecting a UL MAP); Analyzing the detected uplink map (UL MAP) to predict whether an uplink signal exists; And controlling a sleep mode of an uplink based on the uplink signal presence prediction result.

Repeater, Power Savings, Uplink, High Power Amplifier (HPA), Sleep Mode, Downlink Channel Descriptor (DCD) Messages, Uplink Map (UL MAP)

Description

The uplink sleep mode control method for saving power of wireless communication system

The present invention relates to a method for controlling uplink sleep mode for power saving in a wireless communication system. More specifically, the present invention relates to an uplink signal through UL MAP analysis of a downlink channel descriptor (DCD). The present invention relates to an uplink sleep mode control method for reducing power consumption in a wireless communication system for reducing power consumption of a repeater by shifting an uplink to a sleep mode by checking the presence.

The present invention is derived from the research conducted as part of the IT industrial source technology development project of the Ministry of Knowledge Economy and the Ministry of Information and Telecommunications Research and Development. [Task management number: 2007-S-029-03, Project name: Development of home / company WiBro system technology] ].

Recently, the high-speed data communication network has been used such as portable Internet [WiBro, WiMAX, Mobile WiMAX (M-WiMAX)], LTE (Long Term Evolution, 3rd generation mobile communication evolution technology), etc. System 'is in the spotlight.

Meanwhile, in a wireless communication system, a repeater is installed in an area where radio waves (signals) between a base station and a terminal are difficult to reach, thereby ensuring service coverage through signal amplification and relay.

In addition, in a wireless communication system, an Orthogonal Frequency Division Multiple Access (OFDMA) scheme is used as a multiple access scheme, and a time division duplex (TDD) scheme or a frequency division duplex (FDD) scheme is used as a duplex scheme. Frequency Division Duplex) method is used. Here, the TDD scheme refers to a bidirectional transmission scheme in which uplinks and downlinks are alternately assigned in time in the same frequency band, and the FDD scheme is a bidirectional scheme in which different frequencies are allocated to the uplink and the downlink, respectively. The transmission method.

In general, the TDD scheme is mainly applied to a wireless communication system such as a base station, a repeater, and a terminal. The TDD scheme has higher transmission efficiency than the FDD scheme, and asymmetric or bursty data due to dynamic allocation of time slots. This is because it is suitable for transmission.

In implementing a repeater using the TDD scheme as described above, a first RF part receiving and processing a signal from a base station, a second RF part processing and transmitting a signal to be provided to a terminal, and an oscillation It is largely implemented as an IF part that changes the frequency in the middle to prevent the problem.

In particular, since the TDD repeater can share most of the RF paths of the uplink and the downlink, most internal RF devices are shared and implemented to reduce manufacturing costs.

By the way, the TDD repeater can reduce the manufacturing cost by sharing the RF elements, but the uplink high output amplifier is required even when the uplink and the downlink are not always active, that is, the uplink signal relay is not required. There is a problem that (HPA; High Power Amplifier) should always be operated. According to the operation of the high-power amplifier of the uplink, unnecessary power consumption of the repeater occurs.

Meanwhile, in the conventional WCDMA repeater, a power detection method is used to check whether a relay signal exists based on signal power, and thus, a technique for reducing power consumption by implementing uplink deactivation is known.

However, channel information is included in every frame of the signal relayed by the repeater, and since uplink is always operated because active power is detected for all such frames, uplink deactivation is not possible with the conventional power detection method. There is a problem that is not actually implemented.

Accordingly, the present invention has been proposed to solve the above problems and meet the above requirements, and whether there is an uplink signal through UL MAP analysis of a downlink channel descriptor (DCD). The purpose of the present invention is to provide an uplink sleep mode control method for reducing power consumption in a wireless communication system for reducing power consumption of a repeater by shifting the uplink to a sleep mode.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention which are not mentioned can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

According to an aspect of the present invention, there is provided a method for controlling uplink sleep mode for power saving in a wireless communication system, the method comprising: detecting synchronization information from a signal in a downlink period and using a downlink channel descriptor (DCD) message; Detecting an uplink map (UL MAP); Analyzing the detected uplink map (UL MAP) to predict whether an uplink signal exists; And controlling a sleep mode of an uplink based on the uplink signal presence prediction result.

In addition, the present invention further includes the step of confirming the existence of an uplink signal through signal power level detection at the intermediate frequency conversion module in parallel with the uplink map (UL MAP) analysis.

The present invention as described above can predict (confirm) the presence of an uplink signal without a power detector through UL MAP analysis, thereby implementing an uplink sleep mode, and a wireless communication system (eg, a repeater). Etc.), it is possible to prevent unnecessary power consumption.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, It can be easily carried out. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a configuration diagram of an embodiment of a wireless communication repeater according to the present invention.

The wireless communication repeater to which the present invention is applied is largely composed of an RF front-end module (100) and an intermediate frequency conversion module (IF converter) 200. As mentioned in the background section, the TDD scheme The internal RF device is shared and implemented.

For example, the RF front-end module 100 may include a donor antenna 11 for signal transmission and reception with a base station, a serving antenna 12 for signal transmission and reception with a terminal, two band pass filters 13, Two circulators 14, two low noise amplifiers (LNA) 15, two switches 16, a downlink high power amplifier (DL) 17, uplink A high power amplifier (HPA for UL) 18, etc., and the intermediate frequency conversion module 200 includes two amplifiers 21, an oscillator 22, an intermediate frequency filter (IF Filter 23), and the like.

Then, the wireless communication repeater proposed in the present invention will be described.

As shown in FIG. 1, the wireless communication repeater according to the present invention includes a synchronization extractor 51 and an UL MAP detector 52 on a downlink path.

Preferably, the synchronization extractor 51 and the uplink map detector 52 of the present invention are implemented on the processing path of the base station signal received through the donor antenna 11 on the downlink path. In addition, the sync extractor 51 controls two switches 16 to control the signal processing path inside the repeater, and the uplink map detector 52 controls the uplink high power amplifier (HPA for UL) 18. To perform the control regarding the sleep mode operation.

In addition, the sync extractor 51 and the uplink map detector 52 may be equipped with algorithm logic of the present invention to be described in detail below to control the internal RF element and signal processing of the repeater, or a separate controller (MCU) to the repeater. , CPU, etc.) to control the synchronous extractor 51 and the uplink map detector 52 to control the repeater internal RF elements and signal processing by mounting the algorithm logic of the present invention. The detailed description thereof will be omitted.

In the present invention, the repeater checks whether an uplink signal exists through an uplink map (UL MAP) analysis of a downlink channel descriptor (DCD) received from a base station through a donor antenna 11, and an uplink signal exists. The power consumption is reduced by transitioning the uplink to the sleep mode during the period not to be used.

To this end, the present invention performs UL MAP analysis through the above-described uplink map detector 52, and an uplink high power amplifier (HPA for UL) 18 based on the uplink map analysis result. The sleep mode of the uplink is implemented by controlling the operation of [ON / OFF].

In addition, in the present invention, in parallel with the above-described uplink map analysis, the presence or absence of an uplink signal is determined by detecting a power level of a signal, and the uplink is sleeped during a period in which there is no uplink signal. mode to reduce power consumption.

To this end, in the present invention, the base station signal received through the donor antenna 11 on the downlink path of the intermediate frequency conversion module 200, for example, is an IF filter 23 of the intermediate frequency conversion module 200. A power detector 61 is further provided on the path processed by the controller to check whether an uplink signal exists.

Then, the 'uplink sleep mode control method for power saving' of the present invention will be described in detail. For example, the following description will be given using a wireless communication repeater as an example, a micro base station (femtocell) and a picocell base station. Note that the present invention can be selectively applied to (picocell), conventional base stations (BS, RAS, etc.).

In general, the repeater performs power amplify multiple times not only in the RF front-end module 100 but also in the intermediate frequency conversion module 200, and detecting signal power in the intermediate frequency conversion module 200. It is more suitable for detecting signal power in a desired signal band than for detecting in the RF front-end module 100.

However, in the TDD-based repeater, it is difficult to accurately detect the presence of an uplink signal only by detecting the power level of the signal on the intermediate frequency conversion module 200. For example, in the TDD-based system characteristic, three symbols of an uplink signal are allocated for ranging, and when the uplink transitions to the sleep mode (uplink blocking) without distinguishing the three symbols. This is because the terminal cannot initially connect to the network and maintain an existing connection.

Therefore, in the present invention, the uplink map detector 52 is provided in the repeater, and the uplink map detector 52 uses an uplink map (UL MAP) in which there is no data burst. We confirm (predict) not to do it.

Before describing the present invention with reference to FIG. 4, a frame structure and an uplink map (UL MAP) will be described first for the purpose of technical understanding.

FIG. 2 is a diagram illustrating an embodiment of a frame structure used in a WiBro system, and FIG. 3 is a diagram illustrating an embodiment of an uplink map (UL MAP) used in the present invention.

The frame structure of the WiBro system includes a frame control channel, a downlink subframe channel, and an uplink subframe channel.

One frame is divided into four large sections, such as a downlink section, a TTG, an uplink section, and an RTG, among which frame control information and a downlink map (DL MAP) are included in the downlink section. UL MAP is transmitted. For example, in time, frame control information may be first detected in a downlink period, and then data may be accessed using information contained in a downlink map (DL MAP) and an uplink map (UL MAP).

Meanwhile, the downlink map (DL MAP) and uplink map (UL MAP) are included in a downlink channel descriptor (DCD) message (hereinafter, 'DCD message') and transmitted. The downlink map (DL MAP) and the uplink map (UL MAP) are MAC management messages for notifying a result of dynamically allocating resources to the UE, and each UE in downlink and uplink, respectively. It is used to specify the location and number of dynamically allocated sub-channels.

The DCD message is a MAC layer message that describes the physical layer (PHY) characteristics of the downlink channel. The terminal transmits the base station access information, burst profile information, and power control through the DCD message broadcasted by the base station at initialization. Acquire system operation parameters such as (power control) information, TTG information, RTG information, SISO / MIMO information, and the like.

As described above, downlink map (DL MAP) and uplink map (UL MAP) in a DCD message are information exchanged between a base station and a user equipment. In a general relay, a downlink map (DL MAP) and an uplink map (UL MAP) are used. ) It performs the function of delivering it to the terminal without performing the process of detection, analysis, etc.

Therefore, unlike the conventional repeater, the present invention performs uplink map (UL MAP) detection and analysis among the information contained in the DCD message in the repeater to check the presence of the uplink signal in the uplink sleep mode for power saving We want to implement

As shown in FIG. 3, a downlink map (DL MAP) containing downlink information and an uplink map (UL MAP) containing uplink information are transmitted in a downlink section. (DL MAP) points to the data burst position in the downlink period and its presence as a map, and this uplink map (UL MAP) points to the data burst position in the uplink period and its presence as a map.

Accordingly, in the present invention, when the uplink signal does not exist, the uplink map (UL MAP) arrived before the uplink signal does not contain any information, and thus the UL map detection and analysis in the repeater This is to confirm the existence of the uplink signal. For example, in the present invention, it is possible to check whether an uplink signal exists without a power detector, and thereby implement an uplink sleep mode.

In addition, since a channel such as the CQICH channel and the ranging channel of FIG. 3 exists every frame, the uplink sleep mode cannot be maintained by more than one frame using the conventional power detection method. Since 3 symbols used for ranging, etc. can be ignored, the uplink sleep mode can be maintained for more than one frame.

Then, the flow of the 'uplink sleep mode control method for power saving' of the present invention will be described in detail with reference to FIG. 4.

4 is a flowchart illustrating an uplink sleep mode control method for reducing power of a repeater according to the present invention.

In the downlink period, the sync extractor 51 detects the synchronization information from the signal received from the base station through the donor antenna 11 (401), and the uplink map detector 52 is an UL MAP from the DCD message. ) Is detected (402).

Thereafter, the uplink map detector 52 checks whether the detected uplink map UL MAP contains uplink information (that is, uplink burst position and its existence) (403).

As a result of the inspection, if uplink information is included in the uplink map UL MAP, it is predicted (regarded) that an uplink signal exists in a corresponding frame indicated by the uplink map UL MAP, and an uplink map detector ( 52 always activates (powers on) the uplink high power amplifier 18 for the entire time period corresponding to the corresponding uplink interval (404).

On the other hand, if the uplink map (UL MAP) does not contain uplink information as a result of the test, it is predicted (remembered) that no uplink signal exists in the frame indicated by the uplink map (UL MAP), The link map detector 52 checks the uplink interval start time point in the frame by using the synchronization information detected by the sync extractor 51 (405).

Then, the uplink map detector 52 grasps 3 symbol intervals (ie ranging intervals) of the uplink intervals through the identified uplink interval start time points, and only during a time corresponding to the 3 symbol intervals. Activate [power on] the uplink high power amplifier 18, and deactivate the uplink high power amplifier 18 for a time corresponding to the rest of the uplink period thereafter (i.e., during the period where no up signal is present). Off] to transition the uplink to sleep mode (406). As described above, the activation of the uplink high power amplifier 18 in the three symbol periods is for ensuring the initial connection of the network and the existing connection of the terminal [WiBro system communication guarantee].

Meanwhile, in parallel with the uplink map analysis described above, as an additional embodiment of the present invention, the presence of an uplink signal may be checked through the power detector 61.

That is, in parallel with the process of performing the uplink signal presence prediction in the uplink map detector 52 of the RF front-end module 100, the power detector 61 of the intermediate frequency conversion module 200 performs a signal power level. When the uplink signal is detected through the level), the uplink map detector 52 is notified. Accordingly, the uplink map detector 52 can fully confirm that the uplink signal exists through the power detector 61 as well as the uplink signal prediction.

As described above, in the present invention, uplink signal detection is performed at the intermediate frequency conversion module 200 stage, which is not an intermediate frequency conversion module 200 stage other than the RF front-end module 100 stage so as not to be affected by signals from neighboring base stations and terminals. )

On the other hand, the method of the present invention as described above can be written in a computer program. And the code and code segments constituting the program can be easily inferred by a computer programmer in the art. In addition, the written program is stored in a computer-readable recording medium (information storage medium), and read and executed by a computer to implement the method of the present invention. The recording medium may include any type of computer readable recording medium.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

1 is a configuration diagram of an embodiment of a wireless communication repeater according to the present invention.

2 is a diagram illustrating an embodiment of a frame structure used in a WiBro system.

3 is a diagram illustrating an embodiment of an uplink map (UL MAP) used in the present invention.

4 is a flowchart illustrating an uplink sleep mode control method for reducing power of a repeater according to the present invention.

* Explanation of symbols on the main parts of the drawing

51: Sync Extractor

52: uplink map detector

61: power detector

Claims (5)

In the uplink sleep mode control method for power saving in a wireless communication system, Detecting synchronization information from a signal of a downlink interval, and detecting an uplink map (UL MAP) from a downlink channel descriptor (DCD) message; Analyzing the detected uplink map (UL MAP) to predict whether an uplink signal exists; And Controlling a sleep mode of an uplink based on a result of predicting the presence of an uplink signal Uplink sleep mode control method for power saving in a wireless communication system comprising a. The method of claim 1, Predicting whether the uplink signal is present, If uplink information is not included in the detected UL MAP, power saving in the wireless communication system predicts that there is no uplink signal in the corresponding frame indicated by the UL MAP. Uplink sleep mode control method for the. The method of claim 2, If it is predicted that the uplink signal does not exist, By using the detected synchronization information to determine the start time of the uplink period in the frame, Identifying a ranging period through the identified uplink period start time, and activates the uplink only for a time corresponding to the ranging period, and deactivates the uplink for a time corresponding to the remaining uplink period afterwards. Uplink sleep mode control method for power saving in the system. The method of claim 1, Predicting whether the uplink signal is present, If the detected uplink map (UL MAP) contains uplink information, it is predicted that an uplink signal exists in a corresponding frame indicated by the uplink map (UL MAP). Controlling the sleep mode of the uplink, The uplink sleep mode control method for power saving in the wireless communication system, the uplink active for the entire time corresponding to the uplink interval is expected to exist. The method according to any one of claims 1 to 4, Predicting whether the uplink signal is present, In parallel with the uplink map (UL MAP) analysis, confirming whether an uplink signal is present through signal power level detection at an intermediate frequency conversion module stage. Uplink sleep mode control method for reducing power in a wireless communication system further comprising.

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