KR20160141160A

KR20160141160A - Random access response receiving device for machine type communication

Info

Publication number: KR20160141160A
Application number: KR1020150075257A
Authority: KR
Inventors: 이충구; 이용재; 안준배
Original assignee: (주)휴맥스
Priority date: 2015-05-28
Filing date: 2015-05-28
Publication date: 2016-12-08

Abstract

The present invention is to receive a response on a random access of an IoT terminal from a base station. In other words, the present invention relates to a random access response receiving device of an IoT terminal which repeatedly receives a response of a random access in response to a repeating count of the random access. The random access response receiving device of the present invention comprises the IoT terminal for receiving the response of the random access repeated in the base station.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a random access response

The present invention relates to a random access response reception apparatus for a object communication terminal, and more particularly, to a random access response reception apparatus for a object communication terminal. That is, the present invention relates to a random access response reception apparatus of a subject communication terminal capable of repeatedly receiving a random access response in accordance with the number of repetitions of random access.

In recent years, M2M (Machine-to-Machine) communication, which enables the acquisition and transmission of necessary information anytime and anywhere by connecting all the objects around the network, As a major issue.

On the other hand, in the 3rd Generation Partnership Project (3GPP) which is a mobile communication standardization organization, a standardization work is underway under the name of MTC (Machine Type Communications).

3GPP refers to an entity that does not require the direct manipulation or intervention of a 'machine', and MTC defines it as a form of data communication involving one or more of these 'machines'. That is, the MTC can be defined in the form of data communications associated with one or more entities that do not necessarily require human intervention.

On the other hand, a method for reliably receiving a random access response of a random access of a terminal has been studied.

For example, in Korean Patent Publication No. 2011-0050674, a base station responds with a random access preamble and a random access response (RAR) of a fixed length message to a terminal random access, And how they can be interpreted.

However, in this case as well, since it is not repeatedly transmitted in a plurality of subframes, there is a disadvantage that the reliability of the random access response is lowered.

Korean Patent Publication No. 2011-0050674 (2011.05.16)

An object of the present invention is to provide a random access response receiving apparatus of a receiving object communication terminal that receives a response to a random access of a object communication terminal from a base station.

It is another object of the present invention to provide a random access response reception apparatus of an object communication terminal that repeatedly receives a random access response in accordance with the number of repetitions of random access, thereby enhancing the reception reliability of the random access.

The random access response receiving apparatus of the object communication terminal according to the present invention includes a object communication terminal for receiving a random access response repeated in the base station.

The random access response receiving apparatus of the object communication terminal according to the present invention has an advantage of receiving a response to the random access of the object communication terminal from the base station.

Alternatively, the random access response receiving apparatus of the object communication terminal according to the present invention has an advantage of increasing the reliability of reception of the random access by repeatedly receiving the random access response in accordance with the number of repetitions of the random access.

1 is a block diagram illustrating a random access response receiving apparatus of a subject communication terminal according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

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 that the present invention is not intended to be limited to the specific embodiments but includes all changes, equivalents, and alternatives included in the spirit and scope of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a random access response receiving apparatus of a subject communication terminal according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram illustrating a random access response receiving apparatus of a subject communication terminal according to an embodiment of the present invention. At this time, the random access response receiving apparatus of the object communication terminal includes the object communication terminal 200 receiving the random access response (400) repeated in the base station (100).

In order to extend the coverage of the object communication terminal 200, the base station 100 repeatedly transmits PDCCH or EPDCCH and PDSCH transmissions in units of one downlink subframe through a plurality of downlink subframes, The communication terminal 200 also needs to perform decoding by combining the PDCCH or EPDCCH and PDSCH received through the plurality of downlink subframes.

The PDCCH including the scheduling information for the random access response 400 as well as the random access response 400 for the object communication terminal 200 performing the random access procedure 300 is also transmitted to the plurality of downlink subframes , Which may cause excessive overhead for the PDCCH common search space (CSS).

The preamble format of the random access 300 for the object communication terminal 200 is newly defined or the preamble format of the random access 300 for the object communication terminal 200 is newly defined in order to improve the preamble reception performance of the random access 300 transmitted from the object communication terminal 200 ) May be considered as a method of repetition and transmission of the preamble format.

For example, in the case of the object communication terminal 200 with limited coverage, the preamble generated based on the preamble format of the random access 300 for the conventional general LTE / LTE-A terminal is repeated M times, (UL subframe # (n-M + 1) to UL subframe #n) may be considered. At this time, the base station 100 repeats the random access response 400 L times to the L sub-frames (DL sub-frames # (n + k) to DL sub-frames # n + k + L-1).

In other words, in the case of the object communication terminal 200 with limited coverage, the length of the preamble format defined in M uplink subframes, i.e., the sum of the CP length and the sequence length of the preamble format, that is, TCP + TSEQ Value, or sequence length, and the length of the TSEQ) is increased, a method of transmitting a preamble generated based on the preamble format of the new random access 300 may be considered.

In addition, the base station 100 does not use a conventional dynamic scheduling method but a quasi-static scheduling method in order to allocate resources for transmission of a random access response message 400 for the object communication terminal 200 with limited coverage. static scheduling method is considered.

In order to apply the quasi-static scheduling to the random access response 400, specifically, one or more downlink subframes to which the corresponding random access response 400 is transmitted and a random access response (400) transmission in the corresponding downlink subframe We need a definition of how to allocate PRBs for

The base station 100 transmits the subframe information indicating the relation between the subframe in which the preamble of the random access 300 is transmitted and the subframe in which the random access response 400 is transmitted to the object communication terminal 200 . The object communication terminal 200 transmits a preamble of the random access 300 to the base station 100 in step S520 and transmits the preamble of the random access 300 through the downlink subframe determined based on the subframe information from the base station 100 And receives a random access response 400 for the preamble.

In one example, the subframe information may be information indicating a subframe difference of a downlink subframe in which the transmission of the random access response 400 starts from the uplink subframe in which the transmission of the preamble of the random access 300 has been completed have. That is, when the transmission of the preamble of the random access 300 in the uplink subframe #n is ended, the transmission of the random access response 400 in the downlink subframe # (n + k) can be set to start , And the subframe information may include a k value. The corresponding k value may be limited to any positive integer.

For example, in the case of an FDD system, the value of k may be four. Further, in the downlink subframe (subframe # (n + 4)) four subframes from the uplink subframe (subframe #n) where the transmission of the preamble of the repeated random access 300 is terminated, 400) can be initiated.

For another example, the value of k in the TDD system is set based on the UL-DL setting (UL-DL configuration) and the subframe number of the uplink subframe in which the transmission of the preamble of the repeated random access 300 ends Lt; / RTI > In addition, the UL-DL setting is 1 and the subframe number of the uplink subframe in which the transmission of the preamble of the repeated random access 300 ends is 3. In this case, the value of k may be determined to be 6, and the transmission of the repeated random access response 400 may start from subframe 9.

Further, the subframe information including the information indicating the value of k may be transmitted from the base station 100 to the object communication terminal 200 through higher layer signaling (e.g., RRC). Alternatively, the value of k may be a value previously set between the base station 100 and the object communication terminal 200.

Meanwhile, the subframe information may be information indicating an index of the starting subframe of the random access response 400 transmission subframe. In the case of the TDD system, a random access response (400) based on the UL-DL setting and the subframe number (#n) of the uplink subframe in which transmission of the preamble of the repeated random access The index #p of the subframe can be determined. The index of the downlink subframe in which transmission of the random access response 400 starts is #p when the transmission of the preamble of the repeated random access 300 is terminated in the subframe # Can be determined. At this time, when the radio frame in which the transmission of the preamble of the repeated random access 300 is terminated is #M, the radio frame in which the transmission of the repeated random access response 400 starts is the radio frame # (M + 1) Lt; / RTI > That is, when the transmission of the preamble of the repeated random access 300 ends in the radio frame #M and the subframe #n, the transmission of the repeated random access response 400 is performed in the radio frame # (M + 1) You can start with #p. At this time, the value of #p may be set to the same value regardless of the UL-DL setting, or may be set to a different value according to the UL-DL setting. On the other hand, the transmission of the repeated random access response 400 may start at the radio frame # (M + N) where N is a positive integer. Although this example has been described with reference to a TDD system, it is also possible to apply it to an FDD system.

subframe information including information indicating the value of p and / or N may be communicated from the base station 100 to the object communication terminal 200 via upper layer signaling (e.g., RRC). Alternatively, the value of p and / or the value of N may be a value previously set between the base station 100 and the object communication terminal 200.

On the other hand, the value of k or the value of p described above may not have a single value but may have a plurality of values within a certain range.

For example, the value of k may have a value of all positive integers satisfying k1? K? K2. When the object communication terminal 200 ends the transmission of the preamble of the random access 300 repeated in the uplink subframe #n, the object communication terminal 200 transmits the preamble of the random access 300 to the subframe # it can be expected that the random access response 400 transmission starts from one of subframes included in # (n + k2). That is, in the case of FDD, the object communication terminal 200 can expect to start the transmission of the random access response 400 from one of the k2-k1 + 1 subframes, and in the case of TDD, the k2- It can be expected that the random access response 400 transmission starts from one of the following subframes. The object communication terminal 200 may perform random access response (400) detection for each of the candidates of the start random access response (400) transmission subframe.

On the other hand, k has a range of 4? K? 6. The object communication terminal 200 attempts to detect the random access response 400 in the L subframes starting from the subframe # (n + 4), and detects the random access response 400 in the L subframes starting from the subframe # (n + 5) 400 and attempt to detect the random access response 400 in the L subframes starting from the subframe # (n + 6).

In the above-described embodiments, the object communication terminal 200 receives subframe information including information indicating k, p, and / or N from the base station 100 through upper layer signaling, ) Transmission sub-frames are scheduled to be quasi-static. However, in other embodiments, k, p, and / or N may have a value that is predetermined in the object communication terminal 200 and the base station 100.

On the other hand, the L value, which is the number of times the random access response 400 is repeated, may be defined as a function of the M value which is the number of repetitions of the preamble format of the random access 300 or the preamble format of the random access 300. For example, the L value, which is the number of times the random access response 400 is repeated, may be set to be proportional to the M value, which is the number of repetitions of the preamble format of the random access 300. As another example, the L value, which is the number of times the random access response 400 is repeated, can be set to be proportional to the length of the preamble format of the random access 300 (i.e., the value of TCP + TSEQ in the preamble format).

Alternatively, the base station 100 may set an L value, which is the number of times the random access response 400 is repeated, and transmit the set L value to the object communication terminals 200 in the cell through cell-specific RRC signaling. That is, the base station 100 may include the L value in the system information for the object communication terminal 200 and broadcast it to the object communication terminals 200 in the cell.

The object communication terminal 200 determines a physical resource block (PRB) to which the random access response 400 is allocated. The object communication terminal 200 transmits the preamble of the random access 300 to the base station 100 and receives the random access response 400 for the preamble of the random access 300 through the determined PRB.

In one example, the PRB for the random access response 400 transmission may be allocated in a localized manner.

On the other hand, the number of PRBs (RPRB) allocated for transmission of the random access response (400) in one downlink subframe and the position (frequency position, or PRB index) of the corresponding PRB may be a fixed value. In one example, the value of RPRB may be a natural number less than or equal to 6, and the location of the PRB may be the center frequency of the system band.

In addition, although the number of PRBs allocated for transmission of the random access response 400 (RPRB) is fixed, the position of the PRB allocated for transmission of the corresponding random access response (400) for each downlink subframe is frequency hopping . When the frequency hopping is applied to the random access response 400 transmission, the location of the PRB allocated for transmission of the random access response 400 in each downlink subframe depends on the bandwidth (number of PRBs, NPRB) May be determined as a function of the subframe index or slot number upon transmission of the access response (400).

Here, the PRB allocated for the transmission of the random access response 400 is a predetermined value or determined according to a preset rule. However, in another embodiment, the PRB allocated for the random access response 400 transmission may be set at the base station 100 and broadcast to the object communication terminals 200 in the cell via cell-specific RRC signaling .

Meanwhile, the object communication terminal 200 receives information on a physical resource block (PRB) to which the random access response 400 is allocated from the base station 100. The object communication terminal 200 transmits the preamble of the random access 300 to the base station 100 and receives the random access response 400 for the preamble of the random access 300 through the determined PRB.

In this case, the PRB allocation information for the random access response 400 may be set in a bitmap manner for the PRBs constituting the entire system bandwidth by reusing the PRB allocation signaling format for existing EPDCCH set configuration. Also, the PRB allocation may be allocated in a local or distributed manner.

Alternatively, when the PRB information is allocated through the cell-specific RRC signaling, the value of the number of PRBs allocated for transmission of the random access response 400 (RPRB) and the value of the number of PRBs allocated for the transmission of the first random access response 400 With the RPRB allocation information in the frame, the value of the hopping size of the random access response 400 can be signaled.

The object communication terminal 200 according to another embodiment can know the repetition level of the random access response 400 transmission from the repetition level of the most recent random access 300. [ That is, even if the base station 100 does not repeat the setting of the random access response 400, the object communication terminal 200 can transmit the random access response 400 to the base station 100 based on the repetition level of the random access 300 transmitted by the object communication terminal 200 It is possible to efficiently use the radio resources because the radio resource allocation for the number of repetitions of the random access response 400 is not performed by predicting the number of repetitions of the random access response 400 that can be received from the random access response 400. [ However, the repetition level of the random access response 400 may be larger or smaller than the repetition level of the random access 300 depending on the reception performance of the random access 300 in the base station 100. [

Where the repetition level of the random access response 400 may be a function of the TBS of the random access response 400. Or a modulation coding select (MCS) channel quality indicator (CQI).

On the other hand, the object communication terminal 200 may know in which subframe the transmission of the random access response 400 is to be started from the resource set of the most recent random access 300. For example, at the same point in time as the last sub-frame of the resource set of the random access 300 or after a certain offset. Therefore, by predicting the starting point of the random access response 400 that can be received from the base station 100, it is possible to efficiently use radio resources without allocating radio resources for transmission of the starting point of the random access response 400 There are advantages.

The object communication terminal 200 can know at which frequency to perform the random access response 400 transmission from the resource set of the most recent random access 300. [ For example, if a frequency or frequency hopping that is a pair with the frequency at which the random access 300 is transmitted is generated, it can be predicted as a predetermined frequency hopping frequency. Therefore, by predicting the starting point of the random access response 400 that can be received from the base station 100, it is possible to efficiently use radio resources without allocating radio resources for transmission of the starting point of the random access response 400 There are advantages.

The random access response 400 may be transmitted on the MPDCCH, but may be transmitted on the PDSCH with the schedule of the MPDCCH. That is, it can select whether to transmit on PDSCH or MPDCCH, and can transmit on MPDCCH or PDSCH according to scheduling with MPDCCH.

In addition, when the PDSCH is permanently used, it can be transmitted on MPDCCH or PDSCH with a predetermined schedule without additional scheduling.

The object communication terminal 200 can perform the switching for the above random access response 400 transmission mode. That is, it can receive PDSCH, MPDCCH, and PDSCH without scheduling by scheduling MPDCCH, thereby saving radio resources for scheduling.

Meanwhile, the random access response 400 message may include only one response that corresponds to one random access 300 transmission, or all of the information included in the transmission of the random access 300, . Here, the object communication terminal 200 has an advantage that the object communication terminal 200 can be simply configured by responding only to a part of the random access 300.

On the other hand, the object communication terminal 200 receives the PDSCH scheduled to be M-PDCCH and received by the DCI of the M-PDCCH in order for the object communication terminal 200 to apply the cell extension, PDCCH in the case of a single MAC random access response 400 within a narrow band and may support multiple MAC random access responses 400 in the narrowband ), It can be received on the PDSCH that is scheduled by the M-PDCCH.

In addition, when the MAC random access response 400 is small, a part of the MAC random access response 400 may be received by the DCI and the remaining part may be received by the PDSCH.

Also, if the MAC random access response 400 is large, it may be received on the PDSCH scheduled with the M-PDCCH or only on the PDSCH.

The paging according to another embodiment may be performed in the same manner as the random access response 400.

That is, the object communication terminal 200 can know the repetition level of the paging transmission from the repetition level of the most recent random access 300. That is, even if the base station 100 does not repeat the setting for the paging, the object communication terminal 200 can receive the object information from the base station 100 based on the repetition level of the random access 300 transmitted by the object communication terminal 200 It is possible to efficiently use the radio resources because the radio resources are not allocated to the repetition times of the paging. However, the repetition level of the paging may be larger or smaller than the repetition level of the random access 300 depending on the reception performance of the random access 300 in the base station 100. [

Where the repetition level of the paging may be a function of the TBS of the paging. Or a modulation coding select (MCS) channel quality indicator (CQI).

On the other hand, the object communication terminal 200 may know in which subframe the paging transmission starts from the resource set of the most recent random access 300. [ For example, at the same point in time as the last sub-frame of the resource set of the random access 300 or after a certain offset. Therefore, by predicting the starting point of paging that can be received from the base station 100, there is an advantage that radio resources can be efficiently used because the radio resource is not allocated for the transmission of the paging start point.

The object communication terminal 200 can know at what frequency to perform paging transmission from the resource set of the most recent random access 300. [ For example, if a frequency or frequency hopping that is a pair with the frequency at which the random access 300 is transmitted is generated, it can be predicted as a predetermined frequency hopping frequency. Therefore, by predicting the starting point of paging that can be received from the base station 100, there is an advantage that radio resources can be efficiently used because the radio resource is not allocated for the transmission of the paging start point.

The paging may be sent on the MPDCCH, but on the PDSCH with the schedule of the MPDCCH. That is, it can select whether to transmit on PDSCH or MPDCCH, and can transmit on MPDCCH or PDSCH according to scheduling with MPDCCH.

The object communication terminal 200 can perform switching for the above paging transmission mode. That is, it can receive PDSCH, MPDCCH, and PDSCH without scheduling by scheduling MPDCCH, thereby saving radio resources for scheduling.

On the other hand, the paging message may include only one response corresponding to one random access 300 transmission, or all of the information included in the transmission of the random access 300 may be selected or transmitted. Here, the object communication terminal 200 has an advantage that the object communication terminal 200 can be simply configured by responding only to a part of the random access 300.

The object communication terminal 200 according to another embodiment of the present invention may be configured such that the object communication terminal 200 receives the PDSCH scheduled to be M-PDCCH and DCI of the M-PDCCH in order to apply the cell extension, Paging can be received. For example, in the case of a single paging or multiple paging within narrowband, it can be received on PDSCH scheduled with M-PDCCH. In this case, the size of the DCI is smaller than the paging.

In one or more exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, these functions may be stored or transmitted as one or more instructions or code on a computer readable medium. Computer-readable media includes both communication media and computer storage media including any medium that facilitates transfer of a computer program from one place to another.

The storage medium may be any available media that is accessible by a computer. By way of example, and not limitation, such computer-readable media can comprise any computer-readable medium, such as RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, And any other medium that can be used to store and be accessed by a computer. Also, any connection may be properly referred to as a computer-readable medium.

In an implementation in software, the techniques described herein may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The software codes may be stored in memory units and executed by processors. The memory unit may be implemented within the processor and external to the processor, in which case the memory unit may be communicatively coupled to the processor by various means as is known.

In a hardware implementation, the processing units may be implemented as one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays Controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof.

What has been described above includes examples of one or more embodiments. It is, of course, not possible to describe all possible combinations of components or methods for purposes of describing the embodiments described, but one of ordinary skill in the art may recognize that many further combinations and permutations of various embodiments are possible. Accordingly, the described embodiments are intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims.

Furthermore, to the extent that the term "comprising" is used in the detailed description or the claims, such term is intended to be embodied in a manner similar to that which is constructed as interpreted when used in a transitional word in the claims.

As described above, the random access response receiving apparatus of the object communication terminal according to the present invention has an advantage of receiving the response to the random access of the object communication terminal from the base station, repeatedly receiving the random access response according to the number of repetitions of the random access, Thereby improving the reception reliability of the receiver.

Claims

And an object communication terminal for receiving a random access response repeated in the base station.

And an object communication terminal for receiving repeated paging at the base station.