Patent Application
20170201994
This application claims priority to and the benefit of Korean Patent Application No. 10-2016-0003578 filed in the Korean Intellectual Property Office on Jan. 12, 2016, the entire contents of which are incorporated herein by reference.
The present invention relates to a subframe structure and an HARQ operating method of a wireless communication system.
In the future, it is predicted that various real-time interactive multimedia services including augmented reality, virtual reality, a real-time online game, and the like will increase. Users who use the services need to provide a low-delay 5G wireless communication service in order to experience natural interaction. In general, auditory information which human feels at the time of receiving visual and auditory information through media needs to be transferred within approximately 100 ms and visual information needs to be transferred within a permissible delay time of approximately 10 ms. When a longer delay time is generated in transferring the information, people feel unnaturalness for the corresponding service.
It is also predicted that new wireless communication services requiring end-to-end latency within a maximum of several ms will be created in various wireless communication application areas including traffic, sports, education, a medical service, manufacturing, and the like. For example, V2V communication and V2I communication require extremely short wireless communication latency in order to provide a traffic safety service. Further, wireless communication technology is required to be provided, which can guarantee very short latency similarly to the traffic safety service in order to guarantee high reliability and stability of a remote operation through a robot, and the like when an injured person moves under an emergency situation.
The present invention has been made in an effort to provide a subframe structure and an HARQ operating method of a wireless communication system, which can guarantee low latency characteristics.
The technical objects of the present invention are not limited to the aforementioned technical objects, and other technical objects, which are not mentioned above, will be apparently appreciated to a person having ordinary skill in the art from the following description.
An exemplary embodiment of the present invention provides a subframe structure of a wireless communication system, including a plurality of short frames defined as n (n<12, n is a natural number) OFDM symbol periods, wherein a transmission time interval (TTI) is determined based on the plurality of short frames.
The n may be 2.
The subframe may include a downlink subframe or an uplink subframe.
The downlink subframe may include 6 data short frames and 1 legacy short frame.
A first OFDM symbol of two OFDM symbols included in each of 6 data short frames may include control information of a corresponding data short frame.
The uplink subframe may include 7 data short frames.
Each of 7 data short frames may include information for transferring uplink control information (UCI).
The subframe may be defined in a partial area in an available channel bandwidth.
The subframe may be defined as a time period of 1 ms.
Another exemplary embodiment of the present invention provides an HARQ operating method of a wireless communication system using a subframe structure including a plurality of short frames defined as 2 OFDM symbol periods, in which a transmission time interval (TTI) is determined based on the plurality of short frames, the method including: receiving first downlink data through the physical downlink shared channel (PDSCH) at a first short frame among a plurality of short frames; transmitting an ACK/NACK message corresponding to the first downlink data through the physical uplink control channel (PUCCH) at a second short frame at which a four-short frame interval elapsed from the first short frame; and receiving second downlink data through the PDSCH at a third short frame at which the four-short frame interval elapsed from the second short frame, wherein when the third short frame is a legacy short frame, a next short frame is set as the third short frame.
The subframe may be a downlink subframe.
The downlink subframe may include 6 data short frames and 1 legacy short frame.
A first OFDM symbol of two OFDM symbols included in each of 6 data short frames may include control information of a corresponding data short frame.
Yet another exemplary embodiment of the present invention provides an HARQ operating method of a wireless communication system using a subframe structure including a plurality of short frames defined as 2 OFDM symbol periods, in which a transmission time interval (TTI) is determined based on the plurality of short frames, including: transmitting first uplink data through a physical uplink shared channel (PUSCH) at a first short frame among a plurality of short frames; and receiving a downlink control information (DCI) message or an ACK/NACK message corresponding to the first uplink data through a physical uplink control channel (PDCCH) or a physical HARQ indicator channel (PHICH) at a second short frame at which a four-short frame interval elapsed from the first short frame, wherein when the second short frame is a legacy short frame, a next short frame is set as the second short frame.
The subframe may be an uplink subframe.
The uplink subframe may include 7 data short frames.
Each of 7 data short frames may include information for transferring uplink control information (UCI).
According to exemplary embodiments of the present invention, a subframe structure and an HARQ operating method of a wireless communication system can guarantee low latency characteristics of the wireless communication system.
Meanwhile, effects which can be obtained in the present invention are not limited to the aforementioned effects and other unmentioned effects will be clearly understood by those skilled in the art from the following description.
The exemplary embodiments of the present invention are illustrative only, and various modifications, changes, substitutions, and additions may be made without departing from the technical spirit and scope of the appended claims by those skilled in the art, and it will be appreciated that the modifications and changes are included in the appended claims.
It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment.
In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.
Hereinafter, some exemplary embodiments of the present invention will be described in detail with reference to the exemplary drawings. When reference numerals refer to components of each drawing, it is noted that although the same components are illustrated in different drawings, the same components are designated by the same reference numerals as possible. In describing the exemplary embodiments of the present invention, when it is determined that the detailed description of the known components and functions related to the present invention may obscure understanding of the exemplary embodiments of the present invention, the detailed description thereof will be omitted.
Terms such as first, second, A, B, (a), (b), and the like may be used in describing the components of the exemplary embodiments of the present invention. The terms are only used to distinguish a component from another component, but nature or an order of the component is not limited by the terms. Further, if it is not contrarily defined, all terms used herein including technological or scientific terms have the same meanings as those generally understood by a person with ordinary skill in the art. Terms which are defined in a generally used dictionary should be interpreted to have the same meaning as the meaning in the context of the related art, and are not interpreted as an ideal meaning or excessively formal meanings unless clearly defined in the present application.
In the following description, it is assumed that mobile or fixed user terminal apparatuses including user equipment (UE), a mobile station (MS), and the like and may include devices including a tablet personal computer (PC), a smart phone, a digital camera, a portable multimedia player (PMP), a media player, a portable game terminal, and a personal digital assistant (PDA) in addition to a mobile communication terminal are collectively called a terminal. It is assumed that predetermined nodes of a network end, which communicate with the terminal, such as Node B, eNode B, Base Station, and the like are collectively called a base station.
In a wireless communication system, the terminal (user equipment) may receive information from the base station through a downlink and the terminal may also transmit information to the base station through an uplink. Information transmitted or received by the terminal may include data and various control information and various physical channels are present according to a type and a purpose of the information transmitted or received by the terminal.
Various exemplary embodiments of the present invention may be developed based on a long term evolution (LTE) communication system. Therefore, hereinafter, first, a frame configuration of the LTE communication system will be described.
Referring to
One slot includes a plurality of orthogonal frequency division multiplexing (OFDM) symbols in a time domain and includes multiple resource blocks (RBs) in a frequency domain. The OFDM symbol is used for expressing one symbol period in a 3GPP LTE system using an orthogonal frequency division multiplexing access (OFDMA) scheme in a downlink. That is, the OFDM symbol may be referred to as an SC-FDMA symbol or symbol period according to a multiple-access scheme. The RB includes a plurality of consecutive subcarriers in one slot per resource allocation.
The structure of the radio frame of
Referring to
Each element on a resource grid is referred to as a resource element (RE) and one resource block (RB) includes 12×7 resource elements (REs). NDL which is the number of resource blocks included in the downlink slot depends on a downlink transmission bandwidth set in a cell.
Referring to
In
The downlink subframe may be defined as a time interval of 1 ms (msec). The downlink subframe may include 14 OFDM symbols and when n is 2 and the downlink subframe may be constituted by 7 short frames.
7 short frames may include 6 data short frames and 1 legacy short frame. For example, the data short frame may mean a short frame for data transmission and the legacy short frame may mean a short frame for downlink control.
Each data short frame may include 2 OFDM symbols and include control information of the data short frame corresponding to a first OFDM symbol among two OFDM symbols. Herein, the corresponding data short frame may mean the data short frame including the first OFDM symbol.
Referring to
The uplink subframe may be defined as a time interval of 1 ms (msec). The uplink subframe may include 14 OFDM symbols and when n is 2 and the uplink subframe may be constituted by 7 data short frames. For example, the data short frame may mean a short frame for data transmission.
Each data short frame may include 2 OFDM symbols and the two OFDM symbols may include information for uplink control information transmission. Herein, the corresponding data short frame may mean the data short frame including two OFDM symbols.
Referring to
First, referring to
First, when HARQ transmission is described, in the case where the wireless communication system 100 transmits and receives data, a receiving end needs to notify to a transmitting end whether to successfully receive the data. When the data is successfully received, the transmitting end transmits new data by transmitting an acknowledgment (ACK) and when the data is unsuccessfully received, the transmitting end retransmits the data by transmitting a negative acknowledgment (NACK). Such an operation is referred to as an automatic repeat and request (ARQ). Hybrid ARQ (HARQ) is proposed by combining the ARQ operation and a channel coding technique.
Referring to
Hereinafter, steps S110 to S130 will be described in more detail with reference to
In step S110, the terminal 110 may receive the first downlink data to the first short frame (e.g., short frame #6) from the base station 120 through a low latency PDSCH (LL_PDSCH). Herein, the LL_PDSCH may mean that low latency characteristics which the wireless communication system 100 according to the exemplary embodiment of the present invention may obtain by using the subframe structure described with reference to
In step S120, the terminal 110 may transmit the ACK or NACK message to the base station 120 through a low latency PUCCH (LL_PUCCH) as a response to the first downlink data at the second short frame (e.g., short frame #3) at which the fourth short frame interval elapsed from the first short frame (e.g., short frame #6). Herein, the LL_PUCCH may mean that the low latency characteristics which the wireless communication system 100 according to the exemplary embodiment of the present invention may obtain by using the subframe structure described with reference to
In step S130, the terminal 110 may receive the second downlink data through the LL_PDSCH at the third short frame at which the four-short frame interval elapsed from the second short frame (e.g., short frame #3). Herein, the third short frame may be set as short frame #1. That is, the third short frame at which the four-short frame interval elapsed from the second short frame (e.g., short frame #3) is short frame #0, but short frame #0 is the short frame corresponding to the control region of the system as the legacy short frame, and as a result, short frame #0 is not used and short frame #1 which is the next short frame may be used for the HARQ operation.
First, referring to
Hereinafter, steps S210 and S220 will be described in more detail with reference to
In step S210, the terminal 110 may transmit the first uplink data to the base station 120 through the low latency PUSCH (LL_PUSCH) at the first short frame (e.g., short frame #3). Herein, “LL_” may mean that the low latency characteristics which the wireless communication system 100 according to the exemplary embodiment of the present invention may obtain by using the subframe structure described with reference to
In step S220, the terminal 110 may receive the DCI message or the ACK or NACK message from the base station 120 through the low latency PDCCH (LL_PDCCH) or the low latency PHICH (LL_PHICH) as the response to the first downlink data at the second short frame which the four-short frame interval elapsed from the first short frame (e.g., short frame #3). For example, in
Herein, the third short frame may be set as short frame #1. That is, the third short frame at which the four-short frame interval elapsed from the second short frame (e.g., short frame #3) is short frame #0, but short frame #0 is the short frame corresponding to the control region of the system as the legacy short frame, and as a result, short frame #0 is not used and short frame #1 which is the next short frame may be used for the HARQ operation.
Meanwhile, short frame #4 of the uplink subframe illustrated in
Referring to
The processor 1100 may be a semiconductor device that executes processing of commands stored in a central processing unit (CPU) or the memory 1300 and/or the storage 1600. The memory 1300 and the storage 1600 may include various types of volatile or non-volatile storage media. For example, the memory 1300 may include a read only memory (ROM) and a random access memory (RAM).
Therefore, steps of a method or an algorithm described in association with the exemplary embodiments disclosed in the specification may be directly implemented by hardware and software modules executed by the processor 1100, or a combination thereof. The software module may reside in storage media (that is, the memory 1300 and/or the storage 1600) such as a RAM, a flash memory, a ROM, an EPROM, an EEPROM, a register, a hard disk, a removable disk, and a CD-ROM. The exemplary storage medium is coupled to the processor 1100 and the processor 1100 may read information from the storage medium and write the information in the storage medium. As another method, the storage medium may be integrated with the processor 1100. The processor and the storage medium may reside in an application specific integrated circuit (ASIC). The ASIC may reside in the user terminal. As yet another method, the processor and the storage medium may reside in the user terminal as individual components.
The above description just illustrates the technical spirit of the present invention and various changes and modifications can be made by those skilled in the art to which the present invention pertains without departing from an essential characteristic of the present invention.
Therefore, the exemplary embodiments disclosed in the present invention are used to not limit but describe the technical spirit of the present invention and the scope of the technical spirit of the present invention is not limited by the exemplary embodiments. The scope of the present invention should be interpreted by the appended claims and it should be analyzed that all technical spirit in the equivalent range thereto is intended to be embraced by the scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2016-0003578 | Jan 2016 | KR | national |
