KR20170025219A - Methods for performing machine type communication for the purpose of coverage enhancement, apparatuses and systems for performing the same - Google Patents

Abstract

The MTC (Machine Type Communication) communication method for expanding coverage includes allocating a system bandwidth larger than a bandwidth of 1.4 MHz for transmission and allocating system information excluding a master information block (MIB) using a system bandwidth larger than the 1.4 MHz bandwidth At least one of system information and data except for the MIB (Master Information Block) is frequency hopped using a periodic hopping pattern, send. The coverage can be extended while maintaining low power.

Description

TECHNICAL FIELD The present invention relates to a MTC (Machine Type Communication) communication method for expanding coverage, a device and system for performing the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a MTC (Machine Type Communication) communication method, and more particularly, to a MTC (Machine Type Communication) communication method for expanding coverage and an apparatus and system for performing the same.

The object communication terminals (for example, MTC (Machine Type Communication) terminals) are arranged in a very large number and lowering the prices of the object communication terminals such as the MTC terminals is a key element in implementing the Internet of Things to be.

MTC terminals can be used in various applications, require low power consumption, and are expected to communicate for infrequent small burst transmissions.

In the case of M2M applications, object communication terminals such as MTC terminals, for example electricity, water, and gas meters, can be deployed deep within a building and coverage improvements compared to previously defined LTE cell coverage May be required.

Some MTC (Machine Type Communication) terminals are installed in a place or building basement that is insulated with metal flakes or shielded by metal windows or thin walled buildings. For this installation reason, the MTC terminal experiences penetration losses on a wireless interface rather than a general LTE terminal.

MTC terminals in extreme coverage scenarios can have characteristics such as very low data rate, large delay tolerance, and no-mobility, so that when communicating using the MTC terminal, some messages and / Channels may not be needed.

Techniques for improving the coverage of such MTC terminals should include consideration of coverage, power consumption, cell frequency efficiency, impact on standards, manufacturing cost, and complexity.

In particular, in the case of MTC (Machine Type Communication), a method is required to greatly increase the coverage while maintaining low power at the MTC terminal because the data transfer rate is approximately 100 kbps (the bandwidth is fixed at 1.4 MHz).

Not all terminals require coverage improvement, and the extent of coverage improvement may vary from terminal to terminal, and the techniques for improving coverage need to be enabled only for the terminals that need it.

a technique for improving the coverage of the MTC terminal by 20 dB compared to the category 1 UE (User Equipment) is required.

As the amount of the coverage improvement of the MTC terminal increases, the physical channels to be used should be improved. To improve the physical channel to about 20 dB, a shared channel (SCH), a broadcast channel (BCH), a physical downlink control channel PDCCH (Physical Downlink Control Channel)) and the downlink physical channel should be improved.

If a single receive radio frequency (RF) and bandwidth reduction technique is applied to the MTC terminals, this single receive RF and bandwidth reduction technique will reduce downlink coverage, and additional coverage enhancement techniques do.

Specifically, when a single receive RF chain is applied to the MTC terminal, additional coverage needs to be supplemented for all downlink channels. When the maximum bandwidth is reduced, (E) Enhanced Physical Downlink (PDCCH) Control Channel) and PDSCH (Physical Downlink Shared Channel).

In addition, such a coverage supplementing technique should be applied to low cost MTC techniques. Allowing cost reduction and coverage expansion at the same time can lead to reduced performance of Long Term Evolution (LTE) systems.

On the other hand, although it is necessary to extend the coverage by more than 20 dB for the MTC terminals, only a bandwidth of 1.4 MHz should be used, and only one reception RF chain can be used. . Therefore, a variety of advanced technologies are needed to increase performance even in such environments and to achieve coverage over 20dB.

Also, one of the most important roles in the coverage enhancement technique is the RACH (Random Access Channel) operation of the uplink. The RACH, which is a kind of data request signal transmitted by the terminal to the base station at a certain time for connection and data transmission of the terminal, serves as a start of communication starting from all the terminals. Therefore, a very far MTC terminal It is required that the base station can successfully receive the RACH signal transmitted from the base station and that the base station can successfully transmit the response signal to the corresponding long distance MTC terminal.

In this overall operation, if the terminal can distinguish between the MTC coverage extended terminal and the general mobile communication terminal in advance, it is possible to enhance the efficiency in MTC coverage extended communication. Therefore, a technology capable of distinguishing the MTC coverage extended terminal from the general terminal in the RACH process in which the terminal attempts initial access is also required.

It is an object of the present invention to provide an MTC communication method for expanding coverage that can expand coverage while maintaining low power, and an apparatus and system for performing the MTC communication method.

According to an aspect of the present invention, there is provided a MTC (Machine Type Communication) communication method for extending coverage, the method comprising: allocating a system bandwidth larger than a 1.4 MHz bandwidth for transmission; And transmitting at least one of system information and data excluding a master information block (MIB) using a larger system bandwidth, wherein at least one of system information and data except for the MIB (Master Information Block) A frequency hopping is performed using a hopping pattern. At least one of the system information and the data excluding the MIB (Master Information Block) is frequency hopped using a periodic hopping pattern to transmit the system information and data except for the MIB (Master Information Block) At least one of the information and data can transmit data by frequency hopping the 1.4 MHz band using a periodic hopping pattern. The system information includes SIB, and can perform frequency hopping and transmission by using a periodic hopping pattern for paging. As the information for the frequency hopping, user information for frequency hopping in the uplink or system information for frequency hopping in the downlink can be used. The frequency hopping pattern can be generated by directly or indirectly using the base station ID and the terminal ID.

According to another aspect of the present invention, there is provided an MTC (Machine Type Communication) communication method for extending coverage, comprising the steps of: allocating a reserved N-bit unused bit in a MIB (Master Information Bit) It is possible to transmit additional information. The additional information includes information on whether the base station supports the MTC terminal, the number of repeated transmissions for the performance, the start point of the MTC PDCCH, frequency hopping on / off state, repetition pattern, Whether or not to use persistent scheduling for fixedly transmitting a location of a resource, and resource location information for persistent scheduling.

According to another aspect of the present invention, there is provided an MTC (Machine Type Communication) communication method for expanding coverage, which can transmit at least one of system information and data using a repetition pattern. The repetition transmission may include one of a method of transmitting the same signal and a method of transmitting the same data but transmitting the signal in a different form. At least one of SIB, PDCCH, EPDCCH, PUSCH, PUCCH, PBCH, and PRACH may be transmitted using a repetition pattern, or may be transmitted by performing bundling.

According to another aspect of the present invention, there is provided an MTC (Machine Type Communication) communication method for extending a coverage using a PRACH signal to distinguish between an MTC coverage extension terminal and a general terminal.

In order to distinguish between the MTC coverage extension terminal and the general terminal, a PRACH preamble can be distinguished.

In order to distinguish the MTC coverage extension terminal from the general terminal, the time and frequency resource positions can be distinguished.

In order to distinguish the MTC coverage extension terminal from the general terminal, the MTC coverage extension terminal can be distinguished by a specific pattern designating the MTC terminal.

In order to distinguish between the MTC coverage extension terminal and the general terminal, a specific pattern indicating the MTC terminal and the existing PRACH preamble may be combined and combined to generate a pattern.

A method for distinguishing an MTC coverage extension terminal from a general terminal using a pattern generated by combining and combining a specific one of the patterns indicating the MTC terminal and the existing PRACH preamble is repeatedly performed when repetition of the existing PRACH preamble is performed Without changing the code values of the TDM, FDM pattern, or CDM.

In order to distinguish the MTC coverage extension terminal from the general terminal, it is possible to distinguish the MTC coverage improvement terminal from the general terminal by combining the CDM with the repetitive transmission pattern.

According to the MTC communication method for expanding the coverage as described above and the apparatus and system for performing the MTC communication method, the coverage can be greatly increased while maintaining low power.

According to the multi-sub-frame scheduling method in the frequency hopping of the object communication terminal as described above and the apparatus and system for performing the same, it is possible to increase the data rate and greatly increase the coverage while reducing the number of switching of the sub- have.

1 shows an example of a frequency hopping pattern according to an embodiment of the present invention.
2 is a schematic block diagram of an MTC terminal according to an embodiment of the present invention.
3 is a schematic block diagram of an MTC communication system according to an embodiment of the present invention.
4 is a conceptual diagram illustrating a case where a narrow band having a 6PRB size according to an embodiment of the present invention is arranged to be aligned with existing legacy PRB mapping.
5 is a conceptual diagram illustrating a case where a narrow band having a 5PRB size according to another embodiment of the present invention is arranged to align with existing legacy PRB mapping.
FIG. 6 is a conceptual diagram illustrating a pattern in which frequency hopping occurs between narrow bands having a 6PRB size using a total system bandwidth larger than a 1.4 MHz bandwidth according to another embodiment of the present invention.
7 and 8, if the PUSCH transmission according to an embodiment of the present invention a multi-is a conceptual diagram showing a sub-frame scheduling (Cross-subframe scheduling) by way of example - the sub-frame scheduling (Multi-subframe scheduling) or a cross.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail.

It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be interpreted in an ideal or overly formal sense unless explicitly defined in the present application Do not.

The terminal may be a mobile station (MS), a user equipment (UE), a user terminal (UT), a wireless terminal, an access terminal (AT), a terminal, a fixed or mobile subscriber unit, A cellular phone, a wireless device, a wireless communication device, a wireless transmit / receive unit (WTRU), a mobile node, a mobile, a mobile station, a personal digital assistant ), A smart phone, a laptop, a netbook, a personal computer, a wireless sensor, a consumer electronics (CE) or other terminology. Various embodiments of the terminal may be used in various applications such as cellular telephones, smart phones with wireless communication capabilities, personal digital assistants (PDAs) with wireless communication capabilities, wireless modems, portable computers with wireless communication capabilities, Devices, gaming devices with wireless communication capabilities, music storage and playback appliances with wireless communication capabilities, Internet appliances capable of wireless Internet access and browsing, as well as portable units or terminals incorporating combinations of such functions However, the present invention is not limited thereto.

A base station generally refers to a fixed point in communication with a terminal and includes a base station, a Node-B, an eNode-B, an advanced base station (ABS) But is not limited to, an HR-BS, a site controller, a base transceiver system (BTS), an access point (AP), or any other type of interfacing device capable of operating in a wireless environment.

The base station may be a RAN that may also include other base stations and / or network elements (not shown) such as a base station controller (BSC), a radio network controller (RNC), relay nodes, It can be a part. The base station may be configured to transmit and / or receive wireless signals within a particular geographic area, which may be referred to as a cell (not shown).

A cell may also be divided into cell sectors. For example, a cell associated with a base station may be divided into three sectors. Thus, in one embodiment, the base station may include three transceivers, one transceiver for each sector of the cell. In another embodiment, the base station may utilize multiple-input multiple output (MIMO) techniques and therefore utilize multiple transceivers for each sector of the cell.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate the understanding of the present invention, the same reference numerals are used for the same constituent elements in the drawings and redundant explanations for the same constituent elements are omitted.

In the case of the MTC terminal, a coverage expansion of 20 dB or more is required, but only a bandwidth of 1.4 MHz should be used, and only one reception RF chain can be used. Therefore, the data reception performance of the MTC terminal is rather lower than that of a conventional mobile communication terminal .

Therefore, in these environments, various advanced technologies are required to increase performance and ensure coverage over 20dB. In this method, there is a method of significantly improving the SNR (Signal to Noise Ratio) through repetitive transmission and a method of securing the diversity gain by hopping the frequency band of 1.4 MHz to the entire system band.

MTC frequency hopping technology

In the case of data transmission in a conventional MTC (Machine Type Communication) terminal, data is transmitted using only a 1.4 MHz bandwidth and -6 PRB (Physical Resource Block), but the actual total system bandwidth is larger than the 1.4 MHz bandwidth.

On the other hand, in the case of the existing LTE, frequency hopping is not applied separately because the resource is distributed and allocated in the frequency domain through the frequency distributed scheduling (FDS) scheduling in the downlink in data transmission. Only the link is applying frequency hopping via PUSCH. That is, in the existing LTE, frequency hopping is not separately applied in downlink data transmission, and frequency hopping through PUSCH is applied only in uplink data transmission.

However, in the case of the LTE downlink, the FDS method can be used only when the entire bandwidth is wide, and in the case of the MTC communication, it is limited to 1.4 MHz (corresponding to 6 PRB).

In case of LTE downlink data transmission in the MTC communication according to an embodiment of the present invention, frequency hopping of the 1.4 MHz band is performed using the periodic hopping pattern using the whole system bandwidth larger than the 1.4 MHz bandwidth, .

First, a data transmission method in a MTC (Machine Type Communication) terminal according to an embodiment of the present invention will be described.

The MTC terminal transmits data using a total system bandwidth larger than the 1.4 MHz bandwidth, and frequency hopping is performed in the 1.4 MHz band using a periodic hopping pattern such as TSTD (Time Switched Transmit Diversity) And transmits the data.

In the case of MTC communication, the data can be transmitted by frequency hopping through the downlink physical layer data transmission channel PDSCH unlike the conventional LTE. Also, in the case of MTC communication, the data can be transmitted by frequency hopping through a physical uplink shared channel (PUSCH).

Also, when transmitting system information such as SIB (system information block), paging signal and the like except MIB (Master Information Block), frequency hopping can be performed using the whole system bandwidth larger than 1.4 MHz bandwidth.

In case of LTE downlink transmission in MTC communication, system information -SIB, PDCCH, (E) PDCCH, PUSCH, PUCCH, PRACH- and paging signal are transmitted by frequency hopping using a total system bandwidth larger than 1.4 MHz bandwidth .

The PBCH indicating the PSS / SSS used for synchronization and the system information can be prevented from performing frequency hopping.

If the coverage extension of the MTC terminal is supported in the network, the SIB-1 message of the MTC terminal can always be used for frequency hopping when the system bandwidth is above 5 MHz or above 5 MHz.

The SIB-1 message of the MTC terminal can be determined based on the subframe index (and / or SFN), the cell ID and the system bandwidth.

The granularity of the frequency hopping pattern for a channel can be determined by one of three options: common, multiple, and variable.

If the frequency hopping granularity is a common value, the common value may be a fixed value, or the common value may be obtained by receiving through the MIB or SIB1 message.

Frequency hopping. If the granularity is a multiple value, it can be different according to the coverage or the repetition level of the base station. That is, the frequency hopping granularity may be changed according to the coverage or repetition level of the base station.

For example, if the channel condition is poor, if the coverage extension is supported, more frequency hopping can be performed to obtain more frequency hopping gain than when coverage extension is not supported. That is, the frequency hopping period may be shortened or the frequency hopping frequency may be increased to obtain more frequency hopping gain.

Conversely, if the channel condition is not good and coverage extension is not supported, frequency hopping can be performed less than when coverage extension is supported. That is, the frequency hopping period can be made longer or the frequency hopping frequency can be reduced.

For example, the higher the repetition level, the less frequency hopping can be performed. Conversely, the smaller the repetition level, the more frequency hopping can be performed.

Frequency hopping: When the granularity is a variable value, the frequency hopping pattern granularity can be determined based on the number of narrow bands used for frequency hopping and the number of iterations. The frequency hopping can be performed with one hopping per narrowband, with one retuning per narrowband.

The common frequency hopping pattern common to SIB-x (where x is 1, 2, 3, 4, 5, 6, 7 or 8) can be cell-specific.

Frequency hopping can also be used for low complexity MTC terminals that do not support coverage extension. Alternatively, a plurality of classes may be divided according to the degree of support of the coverage expansion of the MTC terminal, and the frequency hopping may be performed differently for each class. For example, if the degree of support for coverage extension is lower, the frequency hopping can be performed less than if the degree of support for coverage extension is higher. That is, the frequency hopping period can be made longer or the frequency hopping frequency can be reduced.

The mapping between the channel and the frequency hopping pattern can be implemented in various ways. For example, the same frequency hopping pattern may be used for each channel, or the frequency hopping pattern may be varied for each channel. Alternatively, the frequency hopping pattern may be adaptively used according to channel characteristics (channel state, channel type such as control channel or data channel, number of narrow bands in the channel, etc.). Alternatively, the frequency hopping pattern of the existing legacy PUSCH or PUCCH of the uplink may be used as it is, or a frequency hopping pattern may be set based on the frequency hopping pattern.

According to another embodiment of the present invention, frequency hopping can be performed only when the system bandwidth is 5 MHz or more for the MTC SIB-1 message.

MTC SIB-1 message frequency hopping can leap into Narrowband (6-PRB) units. MTC SIB-1 message frequency hopping can occur between two narrow bands in a cell. For the MTC SIB-1 message, the frequency hopping narrowband number can be informed by MIB (Master Information Block). In this case, for example, two or four frequency hopping narrow bands can be used. That is, MTC SIB-1 message frequency hopping may occur between two or four narrow bands as indicated in the MIB.

The narrow bands may be determined based on cell ID and / or system bandwidth.

The hopping sequence between the narrow bands may be determined based on the cell ID and the subframe index, and / or the SFN. The parameters used to determine the frequency hopping pattern may include an SFN, a subframe index, and / or a cell ID. Frequency hopping may be limited to a specific narrowband set to perform frequency hopping only within the particular narrowband set.

Information about a narrowband set can be sent by MIB, SIB, or by encoding the MIB / SIB encoding into a specific number of codes

For the Rel-13 low complexity MTC terminals of normal coverage, the PUCCH resource is implicitly based on the M-PDCCH / PDSCH narrowband and / or ECCE / PRB resources in the narrowband ) Can be determined.

For MTC terminals operating with coverage enhancement, the PUCCH resources may be determined implicitly and explicitly determined.

For example, in an implicit manner, a PUCCH resource may be implicitly determined based on an M-PDCCH / PDSCH narrowband and / or an ECCE / PRB resource in the narrowband have.

For example, in an explicit manner, a PUCCH resource may be explicitly determined based on DCI / RRC / RAR / Msg4.

For MTC terminals operating with coverage enhancement, slot-level hopping over narrow bands may not be supported.

For PUCCH frequency hopping, a hopping interval / gap may be used for a retuning operation of two adjacent X-subframes PUCCH repetitions.

Regarding SR (Scheduling Request) repetition, SR repetition can only be transmitted within SR transmission instances.

The SR repetition may be transmitted in successive UL subframes from the starting subframe.

The SR repetition can be sent in an intermittent repetition based on the SR configuration.

A method of processing a subframe that can not be repeated is described.

If a subframe that can not be repeated due to a TDD, MBSFN, or PRS subframe is known as a cell-wide (cell-specific repetition can not be performed), repetition is performed in the next repeatable sub- You can postpone repeating until the frame.

Before receiving the MTC-SIB1, the UE can not know the TDD configuration. When receiving the MTC-SIB1, the UE can assume the TDD configuration in the worst case.

Before receiving the MTC-SIB2, the UE can not know the MBSFN configuration, and if it receives the MTC-SIB1 / SIB2, it can assume the MBSFN configuration in the worst case.

If UE-specific repetition is not possible due to a measurement gap, iteration can be dropped.

If the base station and the terminal are aware of each other, the repetition repetition transmission is postponed. Otherwise, the repetition can be abandoned without further transmission.

If the subframe that can not be repeated is aligned between the base station and the MTC terminal, iteration of the repetition can be delayed until the next repeatable subframe.

If the base station and the MTC terminal are misaligned with respect to a subframe that can not be repeated (or the base station and the terminal do not know about a subframe in which repetition is impossible), iteration is dropped .

Or, if the base station and the MTC terminal are misaligned with respect to a subframe that can not be repeated (or the base station and the terminal do not know about a subframe in which repetition is impossible) MTC terminals can be forcibly aligned. Here, after forcibly aligning between the base station and the MTC terminal, it is possible to postpone repetition to the next repeatable subframe.

The M-PDCCH search space of the MTC terminal,

If the MTC terminal does not know when to send the PDCCH (M-PDCCH) for MTC, the MTC terminal must search for the PDCCH every subframe. In fact, most of the subframes do not contain M-PDCCH due to repetition And it is a fatal problem for MTC terminals where power consumption is important. To solve this problem, the following method can be used.

Method 1. The RRC signals the actual transmission offset in the position, transmission period, and transmission period of the M-PDCCH transmission.

Method 2. To allow the terminal itself to know the information (the actual transmission offset in the position, transmission period, and transmission period of the M-PDCCH transmission) with the UE ID, SFN, cell ID, subframe index, Way

3. Method of adjusting transmission period and transmission offset according to repetition level because repetition level is changed according to coverage extension level. That is, it can be changed and determined according to the coverage extension level.

For example, a method of determining a coverage extension level may be used to roughly determine the distance to the UE through the RACH at the beginning of LTE and add an estimated SNR to the coverage extension ) level can be determined. That is, the repetition level can be determined by not only determining the distance but also considering the channel state.

The PDCCH for MTC (M-PDCCH)

When Method 1 using the signaling scheme is applied to when to send PDCCH for MTC (M-PDCCH), possible methods for UE-specific MPDCCH initialization are as follows.

That is, information indicating the position at which the M-PDCCH starts to be transmitted, the transmission period, and the actual transmission offset in the transmission period can be informed by using the following method, thereby indicating when to send the PDCCH for MTC (M-PDCCH).

The M-PDCCH common search space is required for at least paging and / or RAR (Random Access Response).

1) Alt. 1A: If the M-PDCCH CSS (common search space) is supported, it can be informed using Dedicated RRC signaling scheduled by the MPDCCH in the M-PDCCH common search space (CSS). At this time, the parameter (s) for the UE-specific EPDCCH set initialization may be included in the Dedicated RRC signaling scheduled by the MPDCCH in the M-PDCCH common search space (CSS). The design and configuration of the M-PDCCH common search space (CSS) can be implemented in a variety of ways.

If an M-PDCCH common search space (CSS) is required, different UEs may monitor the M-PDCCH common search space (CSS) in different subframes and other narrow bands. With respect to the M-PDCCH common search space (CSS) for coverage enhancement terminal, M-PDCCH candidates with different number of repetitions R may be supported.

One or more decoding candidates of the M-PDCCH common search space (CSS) in the narrowband can be supported. If the UE supports one or more decoding candidates of the M-PDCCH common search space (CSS) in the narrowband, the UE may monitor different decoding candidates of the M-PDCCH common search space (CSS) in the narrowband.

2) Alt. 3A: Message in random access process RACH: RAR (random access response) message can be used to inform.

At this time, the parameter (s) for UE-specific MPDCCH set initialization may be included in a random access response (RAR) message.

The scheduling of RAR (Random Access Response) messages can be implemented in various ways.

3) Alt. 3B: Message in the random access procedure RACH: Message 4 can be used to inform the user.

At this time, the parameter (s) for UE-specific MPDCCH set initialization may be included in Message 4. [

If the M-PDCCH common search space (CSS) is supported, it can be notified using Message 4 scheduled by the MPDCCH in the M-PDCCH common search space (CSS). The design and configuration of the M-PDCCH common search space (CSS) can be implemented in a variety of ways.

For coverage enhancement, the M-PDCCH candidate may be composed of consecutive and valid subframes.

At least an M-PDCCH candidate having different aggregated levels with respect to M-PDCCH UE-specific search space for coverage enhancement MTC terminal may be supported .

On the other hand, a diversity gain can be obtained by applying precoding diversity to the frequency hopping pattern.

Specifically, a diversity gain can be obtained by applying a pattern composed of different codes to each repetition block. That is, different encodings may be used for each repetition block.

Coverage improvement (CE) level in PUCCH resource allocation for MTC

The PUCCH PRB location can be indicated by the MTC SIB message and can be configured separately for each of the coverage enhancement (CE) levels.

The PUCCH PRB position may be configured by the network to overlap.

If the PUCCH PRB position is not signaled for a particular coverage enhancement (CE) level in the MTC SIB message, the same PUCCH PRB location may be used as the default values for the next lower coverage enhancement (CE) level.

CDM and / or FDM may be supported for multiplexing PUCCH transmissions between legacy UEs, low cost UEs and coverage enhanced terminals CE UEs.

Normal coverage

"No repetition", "small repetition", "medium repetition", and "large repetitions" are defined as [0, 5, 10, 15] coverage extension.

"Repetition" means that a transport block is transmitted through at least one or a plurality of subframes.

Normal coverage may correspond to the case of "no repetition" or "small repetition ". Or normal coverage may correspond to the case of "no repetition" or "small repetition" or "medium repetition".

"Large coverage" may correspond to " medium repetition "and" large repetitions ".

"Small coverage" may correspond to "medium repetition ".

A method for distinguishing different MPDCCH repetitions within a search region

For a search region having multiple repetitions, an inexpensive (LC) -MTC terminal can decode an MPDCCH with less repetition.

The repetition number used by the MPDCCH can be distinguished (or determined) by the terminal. For example, when determining the starting subframe of the PDSCH / PUSCH, the repetition number used by the MPDCCH can be distinguished (or determined) by the UE.

For the MPDCCH transmitted in the repetition number R, the terminal can determine R. [

Different scrambling codes may be applied to different repetition MPDCCH candidates before convolutional encoding.

At the terminal, descrambling may be performed after (convolutional) channel decoding. These scrambling codes can be specified in the standard specification.

An M-PDCCH scheduled PDSCH that transmits a paging record (s) may be used.

At least one narrowband may be configured by the base station for paging.

The terminal may monitor paging occurrence in one of the narrow bands configured in the first subframe based at least on the terminal ID for the paging record (s).

Indicators for system information update

Indicators for system information update may be included in the M-PDCCH and transmitted.

Alternatively, indicators for system information update may be included in the PDSCH and transmitted.

When paging for system information update occurs, ETWS and / or CMAS may be cell common or cell common.

Additional information (e.g., CFI, TDD configuration) may be included in the associated DCI or paging message.

The M-PDCCH search area for paging may comprise M-PDCCH candidates (candidate (s)) with the highest coverage enhancement (CE) level configured in the cell.

Physical channel timing relationship: timing relationship between M-PDCCH and PDSCH

Within the FDD and HD-FDD with cross-subframe scheduling, the PDSCH may start in subframe n + k, where n may be the subframe where the repetition of the decoded M-PDCCH message ends have.

Physical channel timing relationship: timing relationship between M-PDCCH and PUSCH

Within FDD and HD-FDD, the PUSCH may start in subframe n + k, where n may be the subframe where the repetition of the decoded M-PDCCH message ends.

For HD-FDD, multiple DL ACK / NACK responses may be bundled via the PUSCH.

Physical channel timing relationship: timing relationship between PDSCH and PUCCH

Within the FDD and HD-FDD, the PDSCH transmission may end in subframe n as indicated by the corresponding M-PDCCH, and the PUCCH transmitting the HARQ-ACK may start in subframe n + k.

For HD-FDD, multiple DL ACK / NACK responses may be bundled via the PUCCH.

Narrowband numbering and location of the remaining PRBs

The remaining PRBs may be equally divided across the system band and the remaining odd PRBs for the system bands (e.g., 3, 5, and 15 MHz) It can be located at the center of the band.

Narrow bands can be numbered in order of increasing PRB number.

Different DCI formats for different coverage levels (CE) levels

For unicast, the DCI format for no repetition level and / or low repetition level may be the same (e.g., DCI format M1)

For unicast, the DCI format for medium repetition level, large repetition level may be the same (e.g., DCI format M2)

Here, the DCI format M1 size and the DCI format M2 size may be different.

The terminal can only monitor DCI format M1 or only DCI format M2.

The scheduling PDSCH and DCI format sizes for the PUSCH may or may not be the same.

The DCI format M1 size and / or the DCI format M2 size may be obtained from the conventional DCI format size (s).

Random Access Response (RAR)

The options for RAR and paging for low complexity terminals and coverage enhanced (CE) enabled terminals are:

Option 1: The M-PDCCH-scheduled PDSCH transmits the RAR and paging

Option 2; The M-PDCCH DCI transmits the RAR and the paging.

Option 3: M-PDCCH-less PDSCH sends RAR and paging

With respect to the random access response (RAR)

Option 2 may be used for the single MAC RAR in the narrowband and Option 1 for the multiple MAC RAR in the narrowband.

For a small number of MAC RARs, a portion of the MAC RARs may be included in the DCI message and the remainder of the MAC RARs may be included in the PDSCH.

It can indicate within the SIB message whether the base station supports Option 1 and / or Option 2. Option 1 may also be used for a single MAC RAR if the base station indicates that it only supports Option 1.

The MTC SIBx can indicate whether Option 1 is used for Random Access Response (RAR) or Option 2 is used.

Alt1: Use only Option1

Alt2: Use Option2 only for large coverage enhancement, Option 1 for the remaining coverage enhancement (CE)

MTC-SIB1 repetitions

When transmitting system information (SI), the following may be predetermined or derived from the MIB.

(i) MTC-SIB1 transmission cycle

(ii) Number of repetitions in the MTC-SIB1 transmission cycle

PBCH Repetition

For a subframe with PBCH repetition, the CSI-RS may puncture PBCH repetition REs (Resource elements). For a subframe with PBCH repetition, the PBCH repetition tones may be mapped to allow an effective frequency tracking loop. For a subframe with PBCH repetition, the base station can signal PBCH repetition if it is using R13 or later regular UEs.

Resource allocation (RA) for PDSCH and PUSCH for low-cost MTC terminal,

A resource allocation (RA) for the PDSCH and PUSCH for a low-cost MTC terminal in normal coverage and small coverage is determined by a narrowband index and a resource allocation , RA).

Scheduling flexibility and / or other aspects in case of Resource Allocation (RA) for the PDSCH and PUSCH within normal coverage and small coverage.

Resource Allocation for PUSCH

With respect to PUSCH resource allocation, there may be overhead for indicating narrowband indication or resources in the narrowband.

With respect to PUSCH resource allocation, there may be overhead for uplink resource allocation type 0 of the current standard document.

The scheduling flexibility may be improved by using the legacy uplink resource allocation type 0 at the time of PUSCH resource allocation.

For a low complexity terminal within at least normal coverage, the uplink resource allocation type 0 of the current standard document can be used for resource allocation for the PUSCH.

The RIV formula is as follows.

(LCRBs ≤ 6)

The frequency hopping granularity YCH decision at the frequency hopping of the channel

The frequency hopping granularity YCH can be determined as follows.

Option 1: Frequency Hopping Grain YCH can be used as a common value. At this time, the frequency hopping granularity YCH may be transmitted via MIB / SIB1 or it may be set to a specific value in advance in the specification.

 Option 2: Frequency Hopping The granularity YCH can be a multiple value, for example a single value can be used for each coverage / repeat level.

 Option 3: Variable frequency hopping granularity YCH can be used. At this time, the frequency hopping granularity YCH can be determined based on the number of the narrow bands used for frequency hopping and the number of iterations. One hop per narrowband (one retuning per narrowband) may be used. Hopping patterns of common channels such as SIBx may be cell-specific.

Frequency hopping may also be used for non-coverage enhanced (non-CE) low cost terminals.

The mapping between the hoppen pattern and the channels can be variously implemented.

For different coverage levels, or for different channels, a single value frequency hopping granularity YCH or multiple value frequency hopping granularity YCH may be supported.

The frequency hopping granularity YCH may be configured semi-statistically (not dynamically indicated) or may be predetermined.

For at least the paging and random access response (RAR), if the number of iterations is greater than the frequency hopping granularity YCH, the cell common value of the frequency hopping granularity YCH may be used.

Or if the number of iterations is greater than the frequency hopping granularity YCH, the cell specific value may be used for at least the frequency hopping granularity YCH for paging and random access response (RAR) operations.

Or if the number of iterations is less than or equal to the frequency hopping granularity YCH, the cell specific value may be used for at least the frequency hopping granularity YCH for paging and random access response (RAR) operations.

For the paging and random access response (RAR), if the number of iterations is less than or equal to the frequency hopping granularity YCH, the frequency hopping granularity YCH may not use frequency hopping or may be smaller than the frequency hopping granularity YCH Other frequency hopping granularity YCH1 may be used or discontinuous hopping may be used. Here, discontinuous hopping can be skipped, for example, in the case of frequency hopping granularity YCH 4, three subframes within each one packet transmission.

The frequency hopping function may be obtained based on the hopping in the PUSCH format or may be obtained by hopping with a fixed offset.

Cross-subframe Channel Estimation for PDSCH < RTI ID = 0.0 >

Frequency hopping may be configured for a PDSCH with DMRS-based transmission.

The same precoding matrix may be used for each antenna port for at least the same PRB for at least X consecutive subframes. Where X is the number of consecutive subframes when the PDSCH is transmitted within the same narrowband (excluding retuning time)

The precoding matrix may vary from one set of X subframes to another set of X subframes.

Frequency hopping may not be configured for the PDSCH.

A repetition of unicast M-PDCCH / PDSCH, paging and random access response (RAR)

The set of subframes used for downlink transmission may be explicitly and / or cell-specifically signaled by the base station by MTC-SIB1. If no explicit signaling is present, a default operation may be performed. The default operation may be the default operation defined by RAN1.

The set of subframes used for uplink transmission may be explicitly, implicitly or cell-specifically signaled by the base station by MTC-SIB1.

1 shows an example of a frequency hopping pattern according to an embodiment of the present invention.

In Fig. 1, the abscissa is the time axis, the ordinate is the frequency axis, and? Represents data or system information for MTC communication, paging, and the like. In Fig. 1, & squ & may be 6 PRB (i.e., 1.4 MHz) or may be 1 PRB.

In frequency hopping, hopping can be performed in units of 1.4 MHz, or a bandwidth of 1.4 MHz can be divided to hop within a total of 1.4 MHz.

1 shows an example of a frequency hopping pattern when a base station transmits data and / or system information, a paging signal, and the like to a MTC terminal through a downlink. The frequency hopping pattern is limited to that shown in FIG. 1 And various hopping patterns can be used.

When frequency hopping of data and / or system information for MTC communication, paging, etc., various hopping patterns are possible, not limited to the frequency hopping pattern of FIG.

As shown in FIG. 1, by performing frequency hopping, data and / or system information, paging, and the like can be transmitted using a total system bandwidth larger than the 1.4 MHz bandwidth. In this case, a transmit diversity effect can be obtained, There is an effect that can be improved.

As information for frequency hopping, user information can be used for frequency hopping in uplink, and system information can be used for frequency hopping in downlink.

A technique for preventing collision when a base station transmits data and / or system information in a frequency hopping manner is required. Specifically, in order to prevent collision of data and / or system information, paging, and the like with respect to each base station and each terminal, the above frequency hopping pattern uses a base station ID (Identifier) and a terminal ID (Identifier) . The base station ID may include a cell ID or a sector ID. The terminal ID may include, for example, an International Mobile Subscriber Identity (IMSI), a Temporary Mobile Subscriber Identity (TMSI), a Globally Unique Temporary Identifier (GURI), or a Radio Network Temporary Identifier (RNTI).

A method of indirectly using a base station ID and a terminal ID to generate a hopping pattern includes first generating a first specific sequence with a corresponding base station ID and / or terminal IDs, and then secondarily using the generated first specific sequence And a method of defining or using a hopping pattern or scrambling the same.

In addition, since IMSI is very important information for security, when the IMSI is used, a method for generating a hopping pattern by allowing a terminal to determine a hopping pattern by itself is also a method for generating a hopping pattern by an indirect method.

A subject that actually generates a hopping pattern and transmits a signal may be a base station in the downlink and a terminal in the uplink.

Information about the hopping pattern can also be sent and received.

Alternatively, since the IDs are known to each other in order to reduce the overhead incurred by exchanging information on the frequency hopping pattern, information on the hopping pattern itself may not be transmitted or received. Therefore, by adding frequency hopping information to the MIB, it can be implemented to reduce the overhead caused by exchanging information about the frequency hopping pattern by informing only the frequency hopping.

MTC system information (MIB) transmission technology

Currently, in the case of MTC (Machine Type Communication), system information for MTC communication such as MTC-MIB (MTC-Master Information Block) / MTC-SIB (MTC-System Information Block) is separately transmitted.

The master information block (MIB) is transmitted in a transmission time interval (TTI) every 40 ms through the PBCH, and the PBCH is composed of four OFDM symbols existing on 72 center subcarriers in each frame Lt; / RTI >

There is a reserved 10-bit unused bit in the general LTE MIB, and it is possible to send additional information (or parameter) for MTC communication using the 10-bit. MIBs can only transmit a few bits in a limited amount and therefore very important parameters must be included.

Additional information transmitted using the reserved 10-bits may include, for example,

- Whether the base station supports MTC terminal (1 bit)

- Whether CE (Consumer Electronics) device is supported (1 bit)

- Time frequency position of MTC-SIB1 (2 to 3 bits)

- whether repetition level of MTC-SIB1 is included

- Transport block size of MTC-SIB1 (2 bits)

- CFI (Control Format Indicator) (2 bits)

- Number of repeated transmissions for performance

- the starting point position or PCFICH position information of the MTC PDCCH

. ≪ / RTI >

The CFI indicates the number of OFDM symbols used for transmitting the control channel (PDCCH, PHICH) in each subframe. The PCFICH indicates the size of the control region by the number of OFDM symbols. When the data area Directly or indirectly.

Further, the additional information transmitted using the reserved 10-bit of the MIB for MTC communication is

- Whether to use frequency hopping (frequency hopping on / off)

- information about the repetition pattern

- Whether to use persistent scheduling to send a fixed location of resources.

- Resource location information for persistent scheduling

And the like.

Here, since the existing MIB is system information, only the information common to all the MTC terminals is included. However, in one embodiment of the present invention, the MTC terminal receives the system information and defines a specific function that receives additional terminal IDs such as RNTI, GUTI, IMSI, and TMSI of the MTC terminal as standards, Different parameters can be set for each terminal. That is, the base station can transmit the system information (MIB or SIB) including the ID information of the specific MTC terminal. For example, a terminal ID such as RNTI, GUTI, IMSI, TMSI of the terminal is added to the system information in the same manner with respect to DRX (Discontinuous Reception) Cycle parameter, and the terminal ID is transmitted using the reserved 10-bit of the MIB Different parameters can be set for each terminal. Specifically, the DRX cycle can be determined by substituting the MMS terminal's own IMSI value into the SFN (System Frame Number) transmitted from the base station to the MIB and SIB1.

As another example, the MTC terminal may be configured to recognize the system frame number (SFN) through reception of the MIB and the SIB1 from the base station, and to set the DRX cycle parameter by applying the IMSI value of the MTC terminal itself to the SFN have.

MTC system information (MIB) repetition transmission technology

Currently, in the case of MTC (Machine Type Communication), system information for MTC communication such as MTC-MIB / MTC-SIB is separately transmitted.

In the case of the MTC terminal, it is preferable that the MIB system information is repeatedly transmitted in order to improve performance.

In the case of the MTC terminal, a coverage expansion of 20 dB or more is required, but only a bandwidth of 1.4 MHz should be used, and only one reception RF chain can be used. Therefore, the data reception performance of the MTC terminal is rather lower than that of a conventional mobile communication terminal . Therefore, in these environments, various advanced technologies are required to increase performance and ensure coverage over 20dB. In this method, there is a method of greatly improving the SNR through repetitive transmission and a method of ensuring the diversity gain by hopping the frequency band of 1.4 MHz to the entire system band.

However, since iterative transmission increases the power consumption, it is necessary to minimize the number of repetitive transmission as much as possible. Therefore, additional performance enhancement techniques such as frequency hopping and beamforming should be used.

However, in the case of the MIB, since the band of 1,4 MHz is fixed at the center frequency of each frame as described above, it is impossible to use the frequency hopping technique. Therefore, it depends on repetitive transmission.

Repeated transmissions include sending the same signal but sending the same data but sending the signal in a different form. However, HARQ can not be applied because the MIB is one-way downlink communication instead of two-way communication.

The repetition transmission method for the MIB can be selected from the following three iterative methods.

The first method is a method in which the base station repeatedly transmits the MIB at a predetermined period (for example, 40 m) at all times.

The second method is a method in which the base station dynamically determines whether the MIB is repeatedly transmitted every predetermined period (for example, 40 ms).

In the third method, the base station repeatedly transmits the MIB according to the pattern. Here, the pattern may be composed of predefined periods. For example, the pattern may comprise a plurality of 40 ms or predefined time intervals.

Repetitive transmission technology of system information or data other than MIB

As a method of repetitive transmission of system information or data other than the MIB, there is a method of transmitting the same signal but a method of transmitting the same data but in a different form of signal.

For repetition transmission of system information or data other than MIB, one of the following repetition methods can be selected.

The first method is a method in which the base station repeatedly transmits system information or data other than the MIB at a predetermined period (for example, 40 m).

In the second method, the base station dynamically determines whether or not system information or data other than MIB is repeatedly transmitted every predetermined period (for example, 40 ms).

In the third method, the base station repeatedly transmits system information or data other than the MIB according to the pattern. Here, the pattern may be composed of predefined periods. For example, the pattern may comprise a plurality of 40 ms or predefined time intervals.

In addition, the MTC communication performs bundling to repetitively or collectively transmit all data or system information (eg, SIB, PDCCH, PDCCH, PUSCH, PUCCH, PBCH, PRACH) can do.

TTI bundling is also a kind of repetition technique. The only difference is that TTI bundling is repeatedly transmitted over successive subframes. The use of TTI bundling for all data or system information can lead to coverage expansion effects.

The MTC repeat transmission technique according to another embodiment of the present invention

The MTC repeat transmission technique according to another embodiment of the present invention can perform repetitive transmission in the downlink. Hereinafter, downlink will be described as an example.

The MTC repeat transmission technique according to another embodiment of the present invention can adaptively control the restriction condition in frequency hopping according to channel state and / or data characteristic / nature.

The MTC repeat transmission technique according to another embodiment of the present invention adaptively adjusts the hopping bandwidth, the forbidden band, the prohibition time / pause time, and the hopping cycle pattern in the frequency hopping according to the channel state and / Or may vary.

The MTC repeat transmission technique according to another embodiment of the present invention can adaptively adjust the frequency hopping pattern according to the channel state and / or the data property / nature.

The MTC repeat transmission technique according to another embodiment of the present invention may adaptively adjust or vary the frequency hopping range according to the channel state and / or the data characteristics / characteristics.

The MTC repeat transmission technique according to another embodiment of the present invention can adaptively adjust the frequency hopping bandwidth according to the channel state and / or the data characteristics / characteristics. A frequency hopping pattern can be selected by selectively selecting a specific band according to channel status and / or data characteristics / characteristics. When the channel state of a specific frequency band is not good, the corresponding frequency band can be implemented not to be used. If the channel state of a specific frequency band is good, frequency hopping can be implemented using only the corresponding frequency band.

The guard band or the prohibition period (or the pause period) can be adaptively adjusted according to the channel status and / or the data characteristics / characteristics. That is, a frequency hopping pattern can be used by designating a specific band as a prohibited band according to the channel state, or designating a specific time as a prohibited time according to the channel state.

The MTC repeat transmission technique according to another embodiment of the present invention can adaptively adjust the frequency hopping period according to the channel state and / or the data property / nature.

The MTC repeat transmission technique according to another embodiment of the present invention can adaptively adjust the length of the frequency hopping pattern according to channel state and / or data property / nature.

The MTC repeat transmission technique according to another embodiment of the present invention can adaptively adjust the frequency hopping pattern repeat count according to the channel state and / or the data property / nature.

The MTC repeat transmission technique according to another embodiment of the present invention can adaptively adjust the frequency hopping pattern repeat count according to the channel state and / or the data property / nature.

In the case where the channel state is excellent, frequency hopping may not be performed. In this case, information on whether frequency hopping is used or not can be transmitted from the base station to the MTC terminal.

The MTC repeat transmission technique according to another embodiment of the present invention can adaptively vary the hopping pattern according to the importance of data and the characteristics / characteristics of data. For example, important data such as MIB, SIB, control information, and 119 emergency data are more important than general data. In this case, the hopping pattern repetition frequency (or frequency) is increased to increase the diversity gain, Performance can be improved. Or, it may be difficult to inform the hopping pattern about such important data, so that it may be implemented not to perform frequency hopping.

The MTC repeat transmission technique according to another embodiment of the present invention can adaptively change the hopping pattern according to the amount of data. If there is a large amount of data to be transmitted, frequency hopping may be performed slowly.

The frequency hopping bandwidth may be 6PRB, 5PRB, 4PRB, 3PRB, 2PRB, or 1PRB depending on the amount of data to be transmitted.

The above-mentioned prohibition time, forbidden bandwidth, forbidden bandwidth, frequency hopping start time, frequency hopping end time, and the like can be informed from the base station to the MTC terminal.

The MTC repeat transmission technique according to another embodiment of the present invention can be applied to paging, SIB, and RAR.

The MTC repeat transmission technique according to another embodiment of the present invention can be implemented such that a predefined frequency band is used without using frequency hopping for the PSS, SSS, or PBCH received first by the MTC terminal.

The MTC repeat transmission technique according to another embodiment of the present invention can adaptively adjust the position at which the frequency hopping starts depending on the type of the MTC terminal. The MTC repeat transmission technique according to another embodiment of the present invention can adjust the position where the frequency hopping is started differently for each MTC terminal.

The MTC repeat transmission technique according to another embodiment of the present invention may also be applied to the uplink.

Coverage Enhanced How to operate

The coverage enhancement level can be divided into several stages. For example, the degree of coverage expansion can be divided into two stages.

It is possible to set the same level of coverage enhancement level for all channels in the MTC terminal. A single coverage enhancement level is configured for all channels in the MTC terminal (A single CE level is configured for all channels in a UE). One coverage enhancement level may consist of a set of repetition times for at least PDSCH, PUSCH and / or MPDCCH (one CE level can be configured with a set of repetition numbers at least for PDSCH, PUSCH & MPDCCH ).

It can be known for all channels in the MTC terminal whether mode 1 or mode 2 is used (which modes are used for all UEs).

Here, Mode 1 describes a case where no repetitions and a small number of repetitions are agreed (Mode 1 describes behaviors agreed for no repetitions and small number of repetitions), mode 2 has a large number of repetitions (Mode 2 describes behaviors agreed for large number of repetitions). Here, the information repeatedly transmitted may be system information (MIB), system information other than MIB, or data.

Mapping each Coverage Enhanced level to a mode can inform the RRC or signal.

In addition, the HARQ process number can be adaptively adjusted according to each coverage enhancement level. For example, as the coverage increases (or as the coverage further covers), the HARQ process number can be adjusted to be smaller. The HARQ process number may be up to two, three, or four.

Reception technology at the MTC terminal

The MTC terminal can receive only one information when several pieces of information are simultaneously received.

However, if there is important information such as paging (data arrival notification signal), system information, etc., among the simultaneously received data, it is possible to implement reception by setting priorities.

In the case of receiving multiple pieces of information at the same time in the MTC terminal according to an embodiment of the present invention, a method of prioritizing may be implemented by prioritizing MIB->SIB->Paging-> Data and receiving and decoding.

MTC terminal uplink random access (Uplink Random Access) technology

The RACH process at the MTC terminal is important for coverage improvement.

Currently, in the case of MTC (Machine Type Communication), there is a need for a method capable of greatly expanding coverage while maintaining low power at the MTC terminal because the data transfer rate is about 100 kbps (the bandwidth is fixed at 1.4 MHz).

For repetition of a signal (eg, a PRACH preamble) sent from a terminal to a base station in order to improve the performance of the RACH process in the MTC terminal for coverage improvement,

1) periodic repetition transmission,

2) dynamic repetition transmission or

3) it is possible to repetitively transmit it.

In the case of periodic iteration, a signal (eg, PRACH preamble) can be repeatedly transmitted from the MTC terminal according to a predefined period.

In the case of dynamic iterative transmission, it is possible to dynamically determine whether to transmit a signal (e.g., a PRACH preamble) at every repetition period at the MTC terminal. Here, parameters related to repetitive transmission such as repetition and / or repetition period may be determined in the base station or the network, or may be set in a predetermined or predetermined value in the MTC terminal.

(E.g., a PRACH preamble) according to a repetition pattern composed of a predetermined number of consecutive periods.

The base station determines whether the MTC terminal exists by using the PRACH preamble sent from the MTC terminal. The PRACH preamble is a kind of code, and chadoff chu code can be used. Alternatively, the PRACH preamble is not a binary code, but may be multiplied by a binary code to create a new code.

In particular, with respect to the RACH process in the MTC terminal for coverage improvement, a method of distinguishing between an MTC coverage extension terminal using a PRACH signal and a general terminal is required.

MTC coverage improvement A method for distinguishing between a terminal and a general terminal without separate control signals is as follows.

1) Classification with PRACH preamble (ie code: CDM)

2) Time and frequency division by resource location (FDM, TDM)

3) A method to distinguish between a specific pattern referring to MTC terminal and a generated pattern by combining and combining existing PRACH preamble (similar to CDM, but the difference is to add one code to existing code)

Particularly, in the case of a method of distinguishing with a specific pattern designating the MTC terminal of 3), a new pattern may be added to an existing PRACH preamble code code.

For example, in the case of dividing a MTC terminal of 3) by a specific pattern, the existing PRACH preamble is used as it is, but when repetition of the existing PRACH preamble is performed, the TDM or FDM pattern Or code values of CDM are exchanged to distinguish between MTC coverage improvement terminal and general terminal. Specifically, 100110 is repeatedly sent. As a result, 100110 is sent as it is once according to the index of the repetition pattern (for example, 0 to 5 can be assigned depending on the type of the repetition pattern), and the next is inverted and 011001 is sent The MTC coverage improvement terminal can be distinguished from the general terminal. If this is generalized, it becomes c_i_code (existing PRACH preamble code) + new_code or c_i_code (existing PRACH preamble code) x new_code (in the case of CDM). In the case of CDM, new PRACH preamble codes are combined with various methods to create new PRACH preamble codes. Finally, the final result is another PRACH preamble in the CDM.

Alternatively, based on this new_code, you can change resource allocation patterns such as TDM / FDM. TDM and FDM can be changed by periodically changing the code itself or by TDM and FDM patterns themselves. As a result, the code has a different effect according to the repetitive transmission pattern. Instead, the change pattern has a unique specific pattern representing the MTC CE terminal. Specifically, one specific pattern designating the MTC terminal includes the CRC pattern currently used in the downlink control channel, and can be used by XORing the CRC output with the C-RNTI in the downlink control channel.

Therefore, this can be seen as code change based on ID like C-RNTI. In addition to these IDs, a new code may be defined and XORed, multiplied, or added to the new and existing code. Since the repetition of the same code is repeated several times in any case, when the code is transmitted evenly or oddly, the same code repeatedly transmitted in repetition such as reversing the sign of the code is transmitted You can change it periodically in a certain way. The resource allocation pattern is a method in which the time and frequency location of a resource to be transmitted are changed periodically with a certain pattern when repeatedly transmitting repeatedly transmitted code. Also, when the PRACH code is assigned to a specific time and frequency location, there is a method of recognizing the MTC CE terminal.

The above example is a method for distinguishing between MTC coverage improvement terminal and general terminal by combining CDM and repetitive transmission pattern. That is, as one method of recycling the PRACH code used in the existing LTE, the MTC terminal can combine the repetitive transmission pattern with the existing PRACH code because the PRACH has to be repeatedly transmitted several times. That is, it is possible to distinguish the MTC coverage improvement terminal from the general terminal by simply modifying the existing PRACH preamble code with a specific pattern every time it is repeatedly transmitted. In order to distinguish between MTC coverage improvement terminal and general terminal, it is possible to easily change without changing any existing codes without changing the above example.

Another method is to combine a specific code representing the MTC terminal of the above 3) with the existing PRACH preamble code. In the case of PDCCH, LTE finds out its PDCCH through blind decoding. In this method, a new CRC generated by XORing its own ID (C-RNTI in the case of LTE) with CRC is attached to the DPCCH and transmitted. Therefore, it is possible to distinguish whether the PDCCH is its own PDCCH or not by simply checking the CRC at the receiving end. This way, you will be able to see if any code is fundamentally any code that is not easily transformed or transformed if you use it in a way that is modifiable (eg, XOR) with some other code. This method is used 3) method. That is, a specific code indicating the MTC terminal is determined, and the specific code and the existing PRACH code are combined / modified and used. In the case of LTE, the existing PRACH code is not a binary code, so it can not be simply transformed by XOR, but it must be modified by other methods such as multiplication.

FIG. 2 is a schematic block diagram of an MTC terminal according to an embodiment of the present invention, and FIG. 3 is a schematic block diagram of an MTC communication system according to an embodiment of the present invention.

2 and 3, the MTC terminal 100 includes a transceiver 120, a processor 110 and an antenna 130. The MTC terminal 100 includes a base station 120 and the above- MTC frequency hopping, MTC system information (MIB) transmission, and MTC terminal uplink random access.

The transceiver 120 receives data and control signals (such as a downlink data presence message) from the base station 120 through a downlink 152 through an antenna 130 and transmits the uplink data (downlink data transmission request message, etc.) through the uplink, uplink 154, and the like.

The processor 110 may control the transceiver 100 to determine when to transmit a control signal (e.g., a downlink data transmission request message).

The processor 110 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a microprocessor, one or more microprocessors in conjunction with a DSP core, a controller, a microcontroller, specific integrated circuits (ASICs), field programmable gate array (FPGA) circuits, integrated circuits (IC), state machines, and the like. The processor 110 may perform signal coding, data processing, power control, input / output processing, and / or any other function that enables the terminal to operate in a wireless environment. The processor 110 may be coupled to the transceiver 120. Although processor 110 and transceiver 120 are shown as separate components in Figure 2, processor 110 and transceiver 120 may be integrated together in an electronic package or chip. For example, in one embodiment, the antenna 130 may be an antenna configured to transmit and / or receive RF signals. In another embodiment, the antenna 130 may be a radiator / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the antenna 130 may be configured to transmit and receive both RF and optical signals. The antenna 130 may be configured to transmit and / or receive any combination of wireless signals. The transceiver 120 may be configured to modulate the signals to be transmitted by the antenna 130 and to demodulate the signals received by the antenna 130.

A base station may communicate with one or more (e.g., one or more) stations via an air interface, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet And can communicate with the terminal.

The MTC communication system can use channel access schemes such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station and the MTC terminal of the RAN may use a Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), such as the Universal Mobile Telecommunications System (UMTS), which can establish an air interface using Wideband CDMA Radio technology can be implemented. WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA +). The HSPA may include High Speed Downlink Packet Access (HSDPA) and / or High Speed Uplink Packet Access (HSUPA). In another embodiment, the base station and the MTC terminals may use Evolved UTRA (Evolved UTRA), which may establish a public interface using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A). E-UTRA). ≪ / RTI >

In other embodiments, the base station and the MTC terminal may be configured to use IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access), CDMA2000, CDMA2000 1X, CDMA 2000 Evolution-Data Optimized (EV- , Enhanced Data Rate for GSM Evolution, Enhanced Data Rate for GSM Evolution, Enhanced Data Rate for GSM Evolution, Provisional Standard 95 (IS-95), Provisional Standard 856 (IS-856) Data rates for GSM Evolution (EDGE), GSM / EDGE RAN (GERAN), and the like.

The base station of FIG. 3 may be, for example, a wireless router, a HNB, a HeNB, or an AP and may utilize any suitable RAT that facilitates wireless connectivity in localized areas such as a location in a business, home, vehicle, campus, . In one embodiment, the base station and the MTC terminals may implement a radio technology such as IEEE 802.11 to set up a wireless local area network (WLAN). In another embodiment, the base station and terminals may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In another embodiment, the base station and the MTC terminals may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, etc.) to establish a picocell or femtocell. The base station can directly access the Internet. Thus, the base station may not be required to access the Internet through the core network.

How to tell narrowband information when frequency hopping

In LTE downlink frequency hopping for MTC communication, narrow band usage information such as Narrow band set can be informed in the following way.

First, an MTC terminal is informed of an available narrowband set by using system information such as MIB or SIB broadcasted repeatedly by all MTC terminals in the network, and it is common to all MTC terminals in the network Can be used.

In addition, a narrowband set or a frequency hopping pattern allocated to the MTC terminal itself can be determined by substituting the terminal IDs of RNTI, IMSI, and GUTI into a predetermined formula. That is, both the system information and the terminal ID can be used together to define a narrowband set or a frequency hopping pattern assigned to each MTC terminal in the network.

Second, a set of usable narrow bands common to a specific group of users is informed by using a downlink control channel (for example, PDCCH-) delivered to a specific group of users, and the user terminals of a specific group can commonly use the same.

In addition, a narrowband set or a frequency hopping pattern allocated to the MTC terminal itself can be determined by substituting a terminal ID such as RNTI, IMSI, TMSI, or GUTI into a predetermined formula. That is, a narrowband set or a frequency hopping pattern allocated to each MTC terminal in the network can be determined by using a downlink control channel and a terminal ID transmitted to a specific group of users together.

Third, a narrowband set that can be used by a specific user is informed by using a downlink control channel (e.g., UE-specific EPDCCH-) transmitted to a specific user and can be used by a specific user terminal.

Fourth, in determining the usable narrowband set by the three methods described above, not only the terminal IDs such as RNTI, IMSI, TMSI, or GUTI, but also the system frame number (SFN), the subframe index, The slot index can be further utilized to determine the available narrowband set or frequency hopping pattern.

Specifically, the base station substitutes a SFN (System Frame Number) transmitted in system information such as MIB and SIB1 and an IMSI value of the MTC terminal itself into a predetermined equation, and sets a narrow band set allocated to each MTC terminal Or a frequency hopping pattern can be determined. Subframe / slot multi-subframe scheduling information can be adjusted by using a subframe index and a slot index in addition to the SFN and the terminal ID in the same manner, so that independent scheduling for each MTC terminal Allow information to be determined.

In the same manner, not only the SFN and the terminal ID but also the subframe index and the slot index can be adjusted by adjusting the subframe / slot multi-subframe scheduling information for the corresponding slot or the corresponding subframe, So that independent scheduling information can be determined for each UE.

In this way, only the information common to all users or specific groups is communicated to the actual communication, and the remaining steps are decided without the actual communication step, thereby minimizing the overhead and maximizing the system efficiency.

Fifth, the MTC terminal is informed of the frequency hopping period and the narrowband set which can be used in the control information (MIB, SIB, PDCCH or EPDCCH) is informed at the end of the frequency hopping period, and the narrowband set can be used until the next frequency hopping period.

5 is a conceptual diagram illustrating a case where a narrow band having a 6PRB size according to an embodiment of the present invention is arranged to align with existing legacy PRB mapping.

Referring to FIG. 5, the size of the narrow band is 6 PRB. The center frequency of the narrow band corresponds to the center frequency of the system band, and the narrow band ) Is aligned with the existing legacy PRB mapping.

6 is a conceptual diagram illustrating a case where a narrow band having a 5PRB size according to another embodiment of the present invention is arranged to align with existing legacy PRB mapping.

Referring to FIG. 6, the size of the narrow band is 5 PRB. The center frequency of the narrow band corresponds to the center frequency of the system band, and the narrow band ) Is aligned with the existing legacy PRB mapping.

The size of the narrow band according to embodiments of the present invention may have a size smaller than 6 PRB - e.g., 5 PRB, 4 PRB, 3 PRB-, and a size greater than 6 PRB - for example 7 PRB, 8 PRB, 9 PRB, or 12 PRB, which is twice the size, and 18 PRB-, which is 3 times the size. The size of the narrow band may be fixedly selected from a plurality of sizes, or may be adaptively used depending on the situation. For example, if the narrowband size is smaller, the number of narrow bands is increased, and thus it is possible to support a plurality of MTC terminals or to provide more jumpable bandwidth in frequency hopping. If the narrow band size is increased, the transmission data transmission rate can be increased.

FIG. 7 is a conceptual diagram illustrating a pattern in which frequency hopping occurs between narrow bands having a 6PRB size using a total system bandwidth larger than a 1.4 MHz bandwidth according to another embodiment of the present invention.

Referring to FIG. 7, narrow bands NB1, NB2, ..., NB8 each have a size of 6 PRB, and eight narrow bands NB1, NB2, ..., NB8 PRB index 0-5, 6-11, ..., 42-47 for each. For example, the eight narrow bands NB1, NB2, NB3, NB4, NB5, NB6, NB7, and NB8 are NB6, NB5, NB8, NB7, NB1, NB2, NB4, and NB3 hopping patterns.

Multi-Sub-frame Scheduling Method in Frequency Hopping

For an LTE Rel 13 UE supporting enhanced coverage, multi-subframe scheduling may be supported when the unicast PDSCH transmission is scheduled by EPDCCH (PDCCH for MTC communication).

In addition, for LTE Rel 13 Low complexity MTC UE supporting normal coverage, multi-subframe scheduling can be supported when unicast PDSCH transmission is scheduled by EPDCCH (PDCCH for MTC communication) .

Multi-subframe scheduling (Multi-subframe scheduling) or cross-subframe scheduling (Cross-subframe scheduling) is one of the PDSCH (or PUSCH) UE burst can be scheduled within the existing one subframe of, and for the UE burst The scheduling information is a scheduling scheme deviated from a scheme determined by one PDCCH / EPDCCH control information corresponding thereto, and a specific UE burst can be scheduled over several subframes by one PDCCH / EPDCCH control information. That is, in a conventional method in which scheduling information of a PDSCH burst for a UE in a corresponding subframe is determined with one PDCCH / EPDCCH control information for a specific UE in a specific subframe, one PDCCH / EPDCCH control information A PDSCH burst for a specific UE can be allocated through several subframes.

8 and 9 are multi for PUSCH transmission in accordance with an embodiment of the present invention is a conceptual diagram showing a sub-frame scheduling (Cross-subframe scheduling) by way of example - the sub-frame scheduling (Multi-subframe scheduling) or a cross.

Multiple PUSCH transmissions (or multiple PDSCH transmissions) in a single downlink control information (DCI) format by using multi-subframe scheduling or cross-subframe scheduling, as shown in FIGS. 8 and 9, The downlink control overhead can be greatly reduced

9, the uplink data rate is increased by 2.33 times as compared with the PUSCH transmission of FIG. Such multi-sub-frame scheduling or cross-sub-frame scheduling can also be applied to downlink PDSCH transmission.

To be used for R12 MTC communicate; (Coverage Enhancement CE) purposes and, EPDCCH for coverage enhancement multi-subframe scheduling (Cross-subframe scheduling) is a coverage improvement sub-frame scheduling (Multi-subframe scheduling) or cross In the case of repetition transmission, since the decoding time of a large amount of control information increases on the UE side, the UE experiences a delay in starting the associated PDSCH. When the MTC terminal supporting the coverage improvement uses the EPDCCH repeated transmission, scheduling (Multi-subframe scheduling) or cross-scheduling the sub-frame (cross-subframe scheduling) is required.

Multi-subframe scheduling (Multi-subframe scheduling) or cross-case of the sub-frame scheduling (Cross-subframe scheduling) can significantly reduce the down-link control overhead (control overhead), which may increase the data rate, power consumption, Can be reduced, and the number of times of sub-frame switching can be reduced.

Hereinafter, a multi-sub-frame scheduling method in frequency hopping will be described.

1) It is possible to inform the common multi-subframe scheduling information using system information such as MIB or SIB repeatedly broadcast to all the MTC terminals in the network repeatedly, and to allow all MTC terminals in the network to commonly use the system information.

Further, it is possible to uniquely determine the multi-subframe scheduling information allocated to the MTC terminal itself by substituting the terminal IDs of RNTI, IMSI, GUTI, etc. into a predetermined formula here. That is, the system information and the terminal ID may be used together to set multi-subframe scheduling information allocated to each MTC terminal in the network.

2) Uses a downlink control channel (for example, PDCCH-) transmitted to a specific group of users to inform us of usable multi-subframe scheduling information common to a specific group of users and can commonly use them by a specific group of user terminals .

Furthermore, it is possible to uniquely determine the multi-subframe scheduling information allocated to the MTC terminal itself by substituting the terminal IDs such as RNTI, IMSI, TMSI, or GUTI into a predetermined formula. That is, it is possible to set multi-subframe scheduling information allocated to each MTC terminal in the network by using common downlink multi-subframe scheduling information delivered to a specific group of users and the terminal ID.

3) A multi-subframe scheduling information may be informed to a specific user by using a downlink control channel transmitted to a specific user (e.g., UE-specific EPDCCH-), and may be used by a specific user terminal.

4) In addition to determining the multi-subframe scheduling information by the above-described three methods, a system frame number (SFN), a subframe index, and a slot index are additionally utilized, subframe scheduling can be determined.

Specifically, the base station substitutes the SFN (System Frame Number) transmitted by the system information such as the MIB and the SIB1 and the IMSI value of the MTC terminal itself into the equation for determining the predetermined multi-subframe scheduling information, Subframe scheduling that is assigned to the MS in itself. Subframe / slot multi-subframe scheduling information can be adjusted by using a subframe index and a slot index in addition to the SFN and the terminal ID in the same manner, so that independent scheduling for each MTC terminal Allow information to be determined. In this way, only the information common to all users or specific groups is communicated to the actual communication, and the remaining steps are decided without the actual communication step, thereby minimizing the overhead and maximizing the system efficiency.

Second, it is possible to send only the scheduling information to the MTC terminal by operating the frequency hopping period and the multi-subframe scheduling in synchronization with each other.

Third, it can inform the start point and the end point of the subframe using the same scheduling with the control information (for example, PDCCH) or the number of multi-subframes using the semi-static scheduling.

Fourth, it is possible to operate two or more of repetition period, multi-subframe scheduling period, and frequency hopping pattern period to coincide with each other.

Fifth, it is better to transmit the frequency hopping pattern and period, the repetition period and frequency, and the multi-subframe scheduling information separately through PBCH, PDCCCH, EPDCCH, etc., It is possible to maximize the system efficiency by reducing the control information to be transmitted. And the simplest form is used so that it coincides with the fourth method.

The above methods can reduce the size of control information to be transmitted in common. If there is information that can be shared among various patterns, the amount of information to be sent can be reduced compared with sending separately, and the overhead can be reduced. Particularly, in the case of the third method, persistent scheduling is a method used in current LTE VoIP. In the case of voice, persistent scheduling is a real time characteristic and data must be constantly transmitted every subframe. For this purpose, it is troublesome to send scheduling information to PDCCH / EPDCCH in each subframe every time, so if PDCCH / EPDCCH is used only once, scheduling information continues to be used from the next subframe. As a technique to recycle it, the MTC terminal is not voice but data, but the amount of data is small. Therefore, only the duration for performing persistent scheduling is known.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. It will be possible.

Claims (16)

A MTC (Machine Type Communication) communication method for extending coverage,
Allocating a system bandwidth greater than a 1.4 MHz bandwidth for transmission; And
Transmitting at least one of system information and data excluding a master information block (MIB) using a system bandwidth larger than the 1.4 MHz bandwidth,
Wherein at least one of system information and data except for the MIB (Master Information Block) is frequency hopped using a periodic hopping pattern and transmitted. Way. The method of claim 1, wherein at least one of the system information and the data excluding the MIB (Master Information Block) is frequency hopped using a periodic hopping pattern and transmitted
Wherein at least one of the system information and the data excluding the MIB (Master Information Block) transmits data by frequency hopping the 1.4MHz band using a periodic hopping pattern. Machine Type Communication. 2. The method of claim 1, wherein the system information comprises SIB and frequency hopping is performed using a periodic hopping pattern to perform paging. Communication method. 2. The method as claimed in claim 1, wherein the information for the frequency hopping includes user information for frequency hopping in uplink or system information for frequency hopping in downlink (MTC) . The MTC (Machine Type Communication) communication method according to claim 1, wherein the frequency hopping pattern is generated by directly or indirectly using a base station ID and a terminal ID. A MTC (Machine Type Communication) communication method for extending coverage,
(MIB) of the MIB (Master Information Bit), and transmits the MIB (Machine Type Communication) communication method. 7. The method of claim 6, wherein the additional information includes at least one of MIB information, whether the base station supports the MTC terminal, the number of repetitive transmissions for performance, the start point of the MTC PDCCH, whether frequency hopping is on / off, (MTC) type information, which includes at least one of information on the pattern, information on whether to use persistent scheduling for fixedly transmitting a location of a resource, and resource location information on persistent scheduling. Communication method. A MTC (Machine Type Communication) communication method for extending coverage,
Wherein at least one of the system information and the data is transmitted using a repetition pattern. 9. The method as claimed in claim 8, wherein the repetition transmission includes one of a method of transmitting the same signal and a method of transmitting the same data but in a different form of a signal. . 9. The method of claim 8, wherein at least one of SIB, PDCCH, EPDCCH, PUSCH, PUCCH, PBCH, and PRACH is transmitted using a repetition pattern or is bundled and transmitted. Communication method. A MTC (Machine Type Communication) communication method for extending coverage,
MTC coverage extension An MTC (Machine Type Communication) communication method characterized by using a PRACH signal to distinguish between a terminal and a general terminal. The MTC (Machine Type Communication) communication method according to claim 11, wherein the MTC coverage extension terminal is divided into PRACH preamble to distinguish the MTC coverage extension terminal from the general terminal. 12. The MTC (Machine Type Communication) communication method according to claim 11, wherein the MTC coverage extension terminal is divided into a time and frequency resource location to distinguish the MTC coverage extension terminal from the general terminal. 12. The MTC (Machine Type Communication) communication method according to claim 11, wherein the MTC coverage extension terminal and the general terminal are distinguished by a specific pattern designating the MTC terminal. 15. The method of claim 14, wherein the CRC pattern is used to distinguish between an MTC coverage extension terminal and a general terminal. The method of claim 14, wherein when the PRACH preamble is repetitively transmitted, the TDM, FDM pattern, (MTC) communication method according to the present invention. 12. The MTC (Machine Type Communication) communication method according to claim 11, wherein the MTC coverage extension terminal and the general terminal are distinguished from each other by combining a CDM and an iterative transmission pattern to distinguish the MTC coverage extension terminal and the general terminal.

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