KR20190106052A - Uplink resource assignment method - Google Patents

Abstract

The present invention relates to an uplink resource allocation method in a narrowband Internet of things (IoT) system. According to the present invention, the uplink resource allocation method comprises the steps of: allocating one or more resource blocks to a terminal using resource blocks in a frequency of a long term evolution (LTE) system; checking whether there is a resource block having a subcarrier spacing of 3.75 kHz among the at least one uplink resource block allocated to the terminal; and if there is a resource block having a subcarrier spacing of 3.75 kHz among the one or more uplink resource blocks allocated to the terminal, reallocating at least a portion of the one or more uplink resource blocks allocated to the terminal to a resource block in a guard band of the LTE system.

Description

How to allocate uplink resources {UPLINK RESOURCE ASSIGNMENT METHOD}

An embodiment of the present invention relates to an uplink resource allocation method, and more particularly, to an uplink resource allocation method in a narrowband IoT system.

Narrow-band Internet of Things (NB-IoT) technology supports Low Power Wide Area (LPWA) communications over Global System for Mobile Communications (GSM) or Long Term Evolution (LTE) networks. One of the Internet of Things (IoT) technologies. NB-IoT technology is well suited for communication between remote and low-power objects, such as water meter reading and location tracking devices.

The NB-IoT standard, defined in 3GPP release-13, was developed with the goal of expanding coverage, longer battery life, easier installation, lower device cost, and a dramatic increase in the number of service devices.

In this standard, the NB-IoT system provides an NB-IoT service using a resource block (RB) of a Long Term Evolution (LTE) frequency band when operating in an in-band mode. At this time, the interval of the uplink subcarrier in the NB-IoT system can be operated at 3.75kHz for the purpose of terminal coverage expansion, etc., unlike the existing LTE uses 15kHz.

On the other hand, when the NB-IoT system operates in the in-band mode and the uplink subcarrier spacing is 3.75 kHz, there is a problem that the NB-IoT signal and the adjacent LTE signal interfere with each other's reception performance.

An object of the present invention is to provide an uplink resource allocation that can reduce the reception performance degradation due to interference with the LTE signal when the NB-IoT system operates in the in-band mode.

According to an aspect of the present invention, there is provided a method for allocating an uplink resource in a narrowband IoT system to allocate at least one uplink resource block to a terminal using resource blocks in a frequency band of an LTE system. Determining whether there is a resource block having a subcarrier spacing of 3.75 kHz among at least one uplink resource block allocated to the terminal, and a subcarrier spacing of 3.75 kHz among at least one uplink resource block allocated to the terminal. If there is a resource block having a, it may include the step of reallocating at least a portion of at least one uplink resource block allocated to the terminal as a resource block in a guard band (guard band) of the LTE system.

According to an embodiment of the present invention, when the NB-IoT system is operated in the in-band mode, reception performance degradation due to interference with the LTE signal may be reduced.

1 schematically illustrates an apparatus for allocating resources in an NB-IoT system according to an exemplary embodiment of the present invention.
2 schematically illustrates an uplink resource allocation method in an NB-IoT system according to an embodiment of the present invention.
3 illustrates a frequency domain reception signal in an LTE system for a case where a guard resource block (Guard RB) is not inserted between an NB-IoT system and an LTE system.
4 illustrates constellations in the LTE system for the case where a guard resource block (Guard RB) is not inserted between the NB-IoT system and the LTE system.
FIG. 5 illustrates a frequency domain reception signal in the NB-IoT system for the case where no guard resource block is inserted between the NB-IoT system and the LTE system.
6 illustrates constellations in the NB-IoT system for the case where no guard resource block is inserted between the NB-IoT system and the LTE system.
FIG. 7 illustrates a frequency domain reception signal in an LTE system for a case where a guard resource block is inserted between an NB-IoT system and an LTE system.
8 illustrates constellations in the LTE system for the case where a guard resource block is inserted between the NB-IoT system and the LTE system.
FIG. 9 illustrates a frequency domain reception signal in the NB-IoT system for the case where a guard resource block is inserted between the NB-IoT system and the LTE system.
10 illustrates constellations in the NB-IoT system for the case where a guard resource block is inserted between the NB-IoT system and the LTE system.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification and claims, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise.

Throughout the specification, a terminal may be a mobile terminal (MT), a mobile station (MS), an advanced mobile station (AMS), a high reliability mobile station (HR-MS). May also refer to a subscriber station (SS), a portable subscriber station (PSS), an access terminal (AT), a user equipment (UE), and the like. May include all or part of the functionality of the MS, SS, PSS, AT, UE and the like.

In addition, a base station (BS) may be an advanced base station (ABS), a high reliability base station (HR-BS), a node B (node B), an advanced node B (evolved node B, eNodeB), access point (AP), radio access station (RAS), base transceiver station (BTS), mobile multihoprelay (MMR) -BS, relay station serving as a base station , RS), a relay node (RN) serving as a base station, an advanced relay station (ARS) serving as a base station, and a high reliability relay station (HR-) serving as a base station RS), small base station (femoto BS), home node B (HNB), home eNodeB (HeNB), pico base station (pico BS), metro base station (metro BS), micro base station (micro BS) Etc.), and all or one of ABS, Node B, eNodeB, AP, RAS, BTS, MMR-BS, RS, RN, ARS, HR-RS, small base station, and the like. It may also include negative functions.

Hereinafter, an apparatus and method for allocating an uplink resource in a narrowband Internet of Things (NB-IoT) system will be described in detail before describing an embodiment of the present invention.

1 schematically illustrates an apparatus for allocating resources in an NB-IoT system according to an exemplary embodiment of the present invention.

Referring to FIG. 1, an apparatus 100 for allocating resources according to an embodiment of the present invention includes a processor 110, a transceiver 120, and a memory 130. The resource allocation apparatus 100 may be implemented in a base station (not shown) of the NB-IoT system.

The processor 110 may control the overall operation of the resource allocation apparatus 100.

When the NB-IoT system operates in an in-band mode, the processor 110 uplinks to a terminal (not shown) using a resource block of a Long Term Evolution (LTE) frequency band. You can allocate resources. In-band mode refers to a mode for providing NB-IoT service using resource blocks in the Long Term Evolution (LTE) frequency band.

Meanwhile, when the uplink resource allocated to the terminal includes a resource block having a subcarrier spacing of 3.75 kHz, the NB-IoT signal and the adjacent LTE signal may interfere with each other's reception performance. Accordingly, the processor 110 allocates an uplink resource to the terminal, and if there is a resource block having a subcarrier spacing of 3.75 kHz, the processor 110 reassigns the corresponding resource block within a guard band of the LTE system. Therefore, interference with the LTE signal can be minimized. Here, the guard band means a buffer band provided separately to prevent interference between the frequency band and the band (or between adjacent channels).

The transceiver 120 may transmit and receive data with a terminal (not shown). For example, when the uplink resource is allocated to the terminal, the transceiver 120 may receive data from the terminal through the uplink resource allocated to the terminal.

The memory 130 stores instructions for performing in the processor 110 or temporarily loads instructions from a storage device (not shown), and the processor 110 is stored in the memory 130 or You can execute the loaded command.

The processor 110 and the memory 130 may be connected to each other through a bus (not shown), and an input / output interface (not shown) may also be connected to the bus. In this case, the transceiver 120 may be connected to the input / output interface, and peripheral devices such as an input device, a display, a speaker, and a storage device may be connected.

2 schematically illustrates an uplink resource allocation method in an NB-IoT system according to an embodiment of the present invention. The uplink resource allocation method of FIG. 2 may be performed by the uplink resource allocation apparatus described with reference to FIG. 1.

Referring to FIG. 2, in the NB-IoT system according to an embodiment of the present invention, the resource allocation apparatus 100 allocates an uplink resource to a terminal in an in-band mode (S100). In-band mode refers to a mode for providing NB-IoT service using resource blocks in the Long Term Evolution (LTE) frequency band. Therefore, in step S100, the resource allocation apparatus 100 may allocate an uplink resource to the terminal using a resource block of the LTE frequency band.

When the uplink resource allocation is completed through the step S100, the resource allocation apparatus 100 checks whether there are resource blocks having a subcarrier spacing of 3.75 kHz among the resource blocks allocated to the terminal (S101).

If there are resource blocks having a subcarrier spacing of 3.75 kHz among the resource blocks allocated to the terminal, the resource allocation apparatus 100 reassigns a resource block of a guard band of the LTE system to the terminal instead of the corresponding resource block. (S102).

In step S102, the number of resource blocks reallocated to the guard band may be changed depending on how much uplink resources are allocated to the terminal in the NB-IoT system.

Further, in step S102, the number of resource blocks reallocated to the guard band may vary depending on the number of resource blocks remaining in the guard band. If the number of resource blocks to be reallocated to the terminal is larger than the number of resource blocks remaining in the guard band, the resource allocation apparatus 100 may reassign only the number of resource blocks remaining in the guard band to the guard band. .

Meanwhile, in step S101, if there are no resource blocks having a subcarrier spacing of 3.75 kHz among resource blocks allocated to the terminal, the resource allocation apparatus 100 does not use a guard band (S103) and allocates the current terminal. Resource allocation is completed while maintaining the uplink resource (S104). And. Move on to the next resource allocation procedure.

Hereinafter, the effect of the uplink resource allocation method according to an embodiment of the present invention will be described with reference to FIGS. 3 to 10.

3 to 10 illustrate an interference phenomenon in an environment in which an uplink signal of a narrowband Internet of Things (NB-IoT) system and an uplink signal of a long term evolution (LTE) system coexist; Figures for.

Table 1 below shows the experimental parameters used to obtain the experimental results shown in FIGS. 3 to 10.

Table 1. Experimental Parameters

Referring to Table 1, in the NB-IoT system used in the experiment, the subcarrier spacing of the uplink signal is 3.75 kHz, the FFT size is 8192 points, the channel bandwidth is 180 MHz, and the RB (Resource Block) allocated to the uplink signal The index is 45 and a quadrature phase shift keying (QPSK) scheme is used as a modulation scheme.

In addition, the LTE system used in the experiment, the subcarrier spacing of the uplink signal is 15 kHz, the FFT size is 2048 points, the channel bandwidth is 20MHz, the RB index assigned to the uplink signal is 0 ~ 43/44, 46 / 47 ~ 99, QPSK method was used as the modulation method. In addition, the subcarrier power ratio of the NB-IoT system to the LTE system is set to 1.

3 and 4 illustrate a frequency domain received signal and a constellation in an LTE system for a case where a guard resource block is not inserted between the NB-IoT system and the LTE system. Each is shown.

5 and 6 show frequency domain reception signals and constellations in the NB-IoT system, respectively, when a guard resource block (Guard RB) is not inserted between the NB-IoT system and the LTE system.

7 and 8 illustrate a frequency domain received signal and a constellation in an LTE system for a case where a guard resource block (Guard RB) is inserted between an NB-IoT system and an LTE system. Will be shown respectively.

9 and 10 illustrate frequency domain reception signals and constellations in the NB-IoT system, respectively, when a guard resource block (Guard RB) is inserted between the NB-IoT system and the LTE system.

The flattened shape of the received signal indicates that the reception performance of the system is flat, and the constellation indicates that the reception performance of the system is better as the reception data is concentrated around the source data.

In consideration of this feature, referring to FIGS. 3 to 10, when a guard resource block (Guard RB) is inserted between the NB-IoT system and the LTE system (FIGS. 7 to 10), otherwise (FIG. 3 to FIG. It can be seen that the reception performance of the systems is improved compared to 6).

An embodiment of the present invention is not implemented only through the above-described apparatus and / or method, but may be implemented through a program for realizing a function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded. Such an implementation can be easily implemented by those skilled in the art to which the present invention pertains based on the description of the above-described embodiments.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (1)

In the uplink resource allocation method in a narrowband IoT system,
Allocating at least one uplink resource block to a terminal using resource blocks in a frequency band of the LTE system,
Checking whether there is a resource block having a subcarrier spacing of 3.75 kHz among at least one uplink resource block allocated to the terminal; and
If there is a resource block having a subcarrier spacing of 3.75 kHz among at least one uplink resource block allocated to the terminal, at least a portion of the at least one uplink resource block allocated to the terminal is defined as a guard band of the LTE system. Guard band) uplink resource allocation method comprising the step of reallocating to a resource block.

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