JP5451642B2 - Communication method using frames - Google Patents

Description

  The present invention relates to wireless communication, and more particularly to a communication method using frames in a wireless communication system.

  The Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard provides techniques and protocols for supporting Broadband Wireless Access. Standardization has been underway since 1999, and IEEE 802.16-2001 was approved in 2001. IEEE 802.16-2001 is based on a single carrier physical layer called “WirelessMAN-SC”. In 2003, the IEEE 802.16a standard was approved. In the IEEE 802.16a standard, in addition to “WirelessMAN-SC”, “WirelessMAN-OFDM” and “WirelessMAN-OFDMA” are further added to the physical layer. After the IEEE 802.16a standard was completed, the revised IEEE 802.16-2004 standard was approved in 2004. IEEE 802.16-2004 / Cor1 (hereinafter IEEE 802.16e) was completed in 2005 in the form of “corrigendum” to correct the IEEE 802.16-2004 standard bugs and errors.

  Currently, standardization for IEEE 802.16m, which is a new technical standard based on IEEE 802.16e, is in progress. The newly developed technical standard, IEEE 802.16m, must be designed to support both the previously designed IEEE 802.16e. That is, the newly designed system technology (IEEE802.16m) must be configured to operate by efficiently including the existing technology (IEEE802.16e). This is called backward compatibility. The backward compatibility considered when designing IEEE 802.16m includes the following.

  First, a new technology terminal should operate with the same performance as an existing technology terminal. Hereinafter, a system (terminal or base station) that employs a new technology is referred to as a new system, and a system that employs an existing technology is referred to as a legacy system. Second, the new system and the legacy system should operate with the same RF (Radio Frequency) subcarrier and the same bandwidth. Third, the new base station should support the case where a new terminal and a legacy terminal coexist on the same RF subcarrier, and the overall system performance should be improved by the ratio of new terminals. Fourth, the new base station should support legacy terminal handover and new terminal handover so as to conform to the handover performance between legacy base stations. Fifth, a new base station should support both new and legacy terminals at the same level as those supported by legacy base stations.

  The new base station schedules radio resources for legacy terminals or new terminals within the bandwidth that it can support. Radio resource scheduling may be performed in a logical frame consisting of multiple OFDM symbols in the time domain and multiple subchannels in the frequency domain. Therefore, research is underway on the structure of a frame that can satisfy backward compatibility with the IEEE 802.16m system in the IEEE 802.16m system.

  In particular, when a frame structure with a time division duplexing (TDD) scheme having a different cyclic prefix (CP) length coexists in adjacent cells, the boundary between the downlink and the uplink Points may overlap and interfere with each other. Therefore, it is necessary to design the TDD frame structure so that interference does not occur between TDD frame structures coexisting in adjacent cells.

  In addition, the system profile based on the IEEE 802.16 standard supports only TDD (time division duplexing), but frequency division duplex (Frequency) in which uplink transmission and downlink transmission are simultaneously performed in different frequency bands is supported. There are attempts to support Division Duplexing (FDD). Therefore, it is necessary to design an FDD frame structure having commonality with the TDD frame structure for the convenience of system design and hardware sharing.

  The technical problem to be solved by the present invention is to provide a TDD frame having CPs of various lengths to mitigate interference between uplink and downlink transmission.

  Another technical problem to be solved by the present invention is to provide a method for transmitting an FDD frame having commonality with the TDD frame.

  In one aspect of the invention, a method is provided for a terminal to communicate with a base station. The method includes exchanging frames of data with a base station, the frames of data comprising: a) a plurality of frames each including a first number of orthogonal frequency division multiple access (OFDMA) symbols. And b) a plurality of second subframes each including a second number of OFDMA symbols different from the first number.

  The step of exchanging data frames with the base station includes at least one of transmitting the data frame to the base station and receiving the data frame from the base station.

  The step of exchanging frames of data with the base station includes exchanging frames over a channel having one bandwidth of 5, 10 and 20 Mhz.

  The step of exchanging data frames with the base station includes constructing a frame from data received from a data buffer in the mobile communication terminal.

  The step of exchanging frames of data with the base station includes decomposing the frames into data stored in a data buffer in the mobile communication terminal.

  The number of the plurality of first subframes and the number of the plurality of second subframes are determined in advance or based on an instruction received from the base station.

  The frame has a CP (cyclic prefix) length of 1/16 of a useful symbol time Tu.

  The first number of OFDMA symbols is 7 symbols, and the second number of OFDMA symbols is 6 symbols.

  In the exchange step, the frame is TDD (time division duplexed) with another frame.

  The plurality of first subframes includes two first subframes, and the plurality of second subframes includes six second subframes.

  One of the six second subframes includes an idle symbol.

  The frame includes the six second subframes following one first subframe and the other second subframe following the six second subframes.

  Of the six second subframes, the fourth second subframe includes an idle symbol.

  The idle symbol is the sixth symbol of the fourth second subframe.

  The frame includes a plurality of downlink subframes followed by a plurality of uplink subframes.

  The plurality of downlink subframes includes at least one of the plurality of first subframes and at least one of the plurality of second subframes, and the plurality of uplink subframes include the At least the remaining one of the plurality of first subframes and at least the remaining one of the plurality of second subframes.

  The ratio of the plurality of downlink subframes to the plurality of uplink subframes is one of 4: 4, 6: 2, 7: 1, and 5: 3.

  The frame includes a transmit / receive transition gap (TTG) between the plurality of downlink subframes and the plurality of uplink subframes.

  In the exchanging step, the frame is subjected to frequency division duplexing (FDD) with another frame.

  The plurality of first subframes includes three first subframes, and the plurality of second subframes includes five second subframes.

  The frame includes one first subframe, three second subframes, one second first subframe, two second subframes, and one third first frame. Includes in order of subframes.

  In another aspect of the present invention, a terminal for communicating with a base station is provided. The terminal includes a display unit, a transceiver, and a processor coupled to the display unit and the transceiver to exchange data frames with a base station, wherein the data frames include a) each of a first number of data frames. A plurality of first subframes including OFDMA (orthogonal frequency division multiple access) symbols; and b) a plurality of second subframes each including a second number of OFDMA symbols different from the first number. Including.

It is a block diagram which shows a radio | wireless communications system. An example of a frame structure is shown. An example of a frame hierarchical structure is shown. When the DL / UL ratio is 4: 4, an example of an existing TDD frame structure in which the CP length is 1/8 Tu is shown. When the DL / UL ratio is 5: 3, an example of an existing TDD frame structure in which the CP length is 1/8 Tu is shown. When the DL / UL ratio is 6: 2, an example of an existing TDD frame structure in which the CP length is 1/8 Tu is shown. When the DL / UL ratio is 7: 1, an example of an existing TDD frame structure in which the CP length is 1/8 Tu is shown. An example of an existing FDD frame structure with a CP length of 1/8 Tu is shown. If the DL / UL ratio is 4: 4, the CP length is 1/4 Tu, 1/16 Tu or 1/32 Tu compared to the 1/8 Tu CP length according to an embodiment of the present invention. It is a figure which shows a TDD frame structure. If the DL / UL ratio is 5: 3, the CP length is 1/4 Tu, 1/16 Tu or 1/32 Tu compared to the 1/8 Tu CP length according to one embodiment of the present invention. It is a figure which shows a TDD frame structure. When the DL / UL ratio is 6: 2, the CP length is 1 / 4Tu, 1 / 16Tu or 1 / 32Tu compared to the CP length of 1 / 8Tu according to one embodiment of the present invention. It is a figure which shows a TDD frame structure. When the DL / UL ratio is 7: 1, the CP length is 1 / 4Tu, 1 / 16Tu or 1 / 32Tu as compared to the CP length of 1 / 8Tu according to one embodiment of the present invention. It is a figure which shows a TDD frame structure. FIG. 4 is a diagram illustrating a TDD frame structure having a length of CP of 1/4 Tu and an FDD frame structure having commonality with the TDD frame structure according to an embodiment of the present invention. According to an embodiment of the present invention, a CP length of 1/4 Tu and a TDD frame composed of basic subframes composed of SFT-2 subframes, and an FDD having commonality with the TDD frame It is a figure which shows a frame. FIG. 5 is a diagram illustrating a TDD frame structure having a CP length of 1/16 Tu and an FDD frame structure having commonality with the TDD frame structure according to an embodiment of the present invention. FIG. 3 is a diagram illustrating a TDD frame structure having a CP length of 1/32 Tu and an FDD frame structure having commonality with the TDD frame structure according to an embodiment of the present invention. It is a block diagram which shows a radio | wireless communication apparatus.

  FIG. 1 is a block diagram illustrating a wireless communication system. Wireless communication systems are widely deployed to provide various communication services such as voice and packet data.

  Referring to FIG. 1, the wireless communication system includes a user terminal (10, User Equipment: UE) and a base station (20, Base Station: BS). The terminal (10) may be fixed or mobile, and may be a mobile station (Mobile Station: MS), a user terminal (User Terminal: UT), a subscriber station (Subscriber Station: SS), a wireless device. Can be called in other terms, such as (Wireless Device). The base station (20) generally refers to a fixed station that communicates with the terminal (10), and other terms such as Node B (Node B), BTS (Base Transceiver System), and access point (Access Point). Can be called at. One base station 20 can have one or more cells.

  Hereinafter, downlink (Downlink, DL) means communication from the base station (20) to the terminal (10), and uplink (Uplink, UL) means communication from the terminal (10) to the base station (20). Means communication. In the downlink, the transmitter is part of the base station (20) and the receiver is part of the terminal (10). In the uplink, the transmitter is part of the terminal (10) and the receiver is part of the base station (20).

  The wireless communication system may be an OFDM (Orthogonal Frequency Division Multiplexing) / OFDMA (Orthogonal Frequency Division Multiple Access) based system. OFDM uses a plurality of orthogonal subcarriers. OFDM uses an orthogonal property between Inverse Fast Fourier Transform (IFFT) and Fast Fourier Transform (FFT). Data in the transmitter is transmitted by executing IFFT. The receiver performs FFT on the received signal to restore the original data. The transmitter uses IFFT to combine multiple subcarriers, and the receiver uses a corresponding FFT to separate multiple subcarriers.

  FIG. 2 shows an example of a frame structure. A frame is a data sequence for a fixed time used by physical specifications. This can be referred to in section 8.4.2.2 of IEEE Standard 802.16-2004 “Part 16: Air Interface for Fixed Broadband Wireless Access Systems”.

  Referring to FIG. 2, the frame includes a downlink (DL) frame and an uplink (UL) frame. In a time division duplex (TDD) scheme, uplink and downlink transmissions share the same frequency band but are performed at different time points. The downlink frame is earlier in time than the uplink frame. The downlink frame starts in the order of preamble (Preamble), FCH (Frame Control Header), DL (Downlink) -MAP, UL (Uplink) -MAP, and burst region. A guard time for distinguishing uplink and downlink frames is inserted in the middle part of the frame (between the downlink and uplink frames) and the last part (after the uplink frame) . TTG (transmit / receive transition gap) is a gap between a downlink burst and a subsequent uplink burst. RTG (receive / transmit transition gap) is a gap between an uplink burst and a subsequent downlink burst.

  The preamble is used for initial synchronization, cell search, frequency offset, and channel estimation between the base station and the terminal. The FCH includes the length of the DL-MAP message and the DL-MAP coding scheme information.

  DL-MAP is an area where a DL-MAP message is transmitted. The DL-MAP message defines the downlink channel connection. The DL-MAP message includes a configuration change count of a downlink channel descriptor (DCD) and a base station identifier (ID). The DCD describes a downlink burst profile that is applied to the current map. The downlink burst profile refers to the characteristics of the downlink physical channel, and the DCD is periodically transmitted by the base station via the DCD message.

  UL-MAP is an area in which a UL-MAP message is transmitted. The UL-MAP message defines the uplink channel connection. The UL-MAP message includes a configuration change count of an uplink channel descriptor (UCD) and a valid start time of uplink allocation defined by the UL-MAP. The UCD describes an uplink burst profile. The uplink burst profile refers to characteristics of the uplink physical channel, and the UCD is periodically transmitted by the base station via the UCD message.

  FIG. 3 shows an example of a frame hierarchical structure.

  Referring to FIG. 3, each superframe is divided into four radio frames (hereinafter referred to as frames) having the same size. The super frame may include a super frame header. The super frame header can be assigned to the first frame among a plurality of frames constituting the super frame. A common control channel can be assigned to the superframe header. The common control channel is used to transmit control information that can be commonly used by all terminals, such as information on frames constituting a superframe or system information. System information is essential information that the terminal must know in order to communicate with the base station, and the base station periodically transmits the system information. The system information can be periodically transmitted every 20 to 40 ms, and the size of the superframe can be determined by reflecting the transmission period of the system information. In FIG. 3, the size of each superframe is 20 ms, and the size of each frame is 5 ms. However, the present invention is not limited to this.

  One frame is composed of eight subframes. One subframe may be allocated for uplink or downlink transmission. Each subframe for downlink transmission may include a signal for resource allocation. The subframe can include, for example, 6 OFDM symbols. This is merely an example and not a limitation.

  Hereinafter, a TDD frame structure and an FDD frame structure that satisfy backward compatibility with a legacy system will be described. Here, a TDD (time division duplexing) frame refers to a frame that uses the entire frequency band for the uplink or the downlink and divides the uplink and the downlink in the time domain. An FDD (Frequency Division Duplexing) frame means that uplink transmission and downlink transmission occupy different frequency bands and are performed simultaneously. A frame that satisfies backward compatibility with a legacy system is called a dual frame. The dual frame includes a resource region that supports a legacy system and a resource region that supports a new / evolved system. The legacy system means the IEEE 802.16e system, and the new system means IEEE 802.16m. The terms used in the IEEE 802.16e frame structure described with reference to FIG. 2 may be defined and used in the same manner in the IEEE 802.16m frame structure, or may be partially modified and defined.

  Table 1 below shows the frame parameters.

  New system parameters (eg, Transmission Bandwidth, Sampling frequency, FFT size, subcarrier spacing, etc. to satisfy backward compatibility for frames in legacy systems (ie, IEEE 802.16e system) (Subcarrier Spacing, etc.) can follow IEEE 802.16e frame parameters. In the legacy legacy system mode that supports IEEE 802.16e, the CP length can be set to 1/8 effective symbol time (Tu), and one frame can contain 48 OFDM symbols. In legacy Legacy Support Disabled Mode, which does not support legacy systems, the new CP length can be set to 1/4 Tu, 1/16 Tu or 1/32 Tu, and one frame For the CP length, it can contain 43, 51 or 53 OFDM symbols, respectively. For example, when one subframe is composed of 6 OFDM symbols, a frame having a CP length of 1/4 Tu has 7 subframes, 1 residual OFDM symbol, and a CP length of 1/16 Tu. Can be composed of 8 subframes and 3 residual OFDM symbols, and a frame with a CP length of 1/32 Tu can be composed of 8 subframes and 5 residual OFDM symbols.

  Here, CP is a copy of the last useful symbol period (Used Symbol Period) Tg, and can be expressed as a ratio to the useful symbol time (Used symbol time: Tu).

  Table 2 below shows the TTG and RTG lengths in the IEEE 802.16e standard TDD structure. Hereinafter, the TTG may be expressed in terms such as a switching point or an idle frame. This is merely an example and not a limitation. The switching point of the new system may be longer or shorter than the IEEE 802.16e standard.

  FIG. 4 shows a case where the downlink / uplink (DL / UL) ratio is 4: 4, FIG. 5 shows a case where the DL / UL ratio is 5: 3, and FIG. 6 shows a case where the DL / UL ratio is 6: 4. In the case of 2, FIG. 7 shows an example of a TDD frame structure in which the CP length is 1/8 Tu when the DL / UL ratio is 7: 1.

  4 to 7, the new TDD frame satisfying the backward compatibility is based on the existing TDD frame structure, the values of Table 1 and Table 2. That is, the new TDD frame is 5 ms long, the CP length is 1/8 Tu, has a bandwidth of 10 MHz, and includes 48 OFDM symbols. Further, basic control information such as preamble, FCH, and MAP can be defined according to the IEEE 802.16e standard. Table 2 shows the sizes of TTG and RTG.

  4 to 7, one TDD frame is composed of 8 subframes. Here, the subframe is a basic unit of data allocation and scheduling, and generally includes six OFDM symbols. This is a value determined in consideration of the bandwidth to the time axis and the pilot allocation pattern when considering the size of data allocated via MAC and PHY encoding and modulation and the characteristics of the radio channel. When one subframe is composed of 6 OFDM symbols, the DL / UL ratio can be set efficiently, and the number of OFDM symbols in the UL section is adjusted to a multiple of 3 in a dual frame. And delay performance of data can be improved. However, the number of OFDM symbols constituting one subframe is not limited to this.

  A TTG (Transmit / receive transition gap) is located between the DL area and the UL area, and an RTG (Receive / transmit transition gap) is located between the UL area and the subsequent frame. The TTG or RTG may include an idle time (Idle Time) according to the size of the CP in order to prevent intersymbol interference.

  Specifically, referring to FIG. 4, from the start point of a frame to a 2364.86 μs point including 23 OFDM symbols having a length of 1/8 Tu, a DL interval is set, and from a 2364.86 μs point. Up to 247.22 μs points including the TTG interval and 107.46 μs interval corresponding to a part of the idle time in Table 2, the TTG interval is set to 24 pieces having a CP length of 1/8 Tu from the 2247.32 μs point. Up to 4940 μs points including the OFDM symbol are set in the UL interval, and from the 4940 μs point to the last point of the frame including the 60 μs interval corresponding to the RTG interval in Table 2, is set in the RTG interval.

  Referring to FIG. 5, a DL interval is set from the start point of a frame to a 2981.78 μs point including 29 OFDM symbols having a CP length of 1/8 Tu, and the TTG of Table 2 is set from the 2981.78 μs point. Up to 3089.24 μs points including 107.46 μs corresponding to a part of the interval and idle time, 18 OFDM symbols having a length of 1/8 Tu from the 3089.24 μs point are set as TTG intervals. Up to the included 4940 μs point is set as the UL interval, and from the 4940 μs point to the last point of the frame including the 60 μs interval corresponding to the RTG interval in Table 2, is set as the RTG interval.

  Referring to FIG. 6, from the start point of the frame to the 3598.7 μs point including 35 OFDM symbols having a length of 1/8 Tu, the DL period is set, and from the 3598.7 μs point to the TTG of Table 2 Up to 3706.16 μs point including 107.46 μs corresponding to a part of the interval and idle time, it is set as TTG interval, and 12 OFDM symbols having a length of 1/8 Tu from the 3706.16 μs point are obtained. Up to the included 4940 μs point is set as the UL interval, and from the 4940 μs point to the last point of the frame including the 60 μs interval corresponding to the RTG interval in Table 2, is set as the RTG interval.

  Referring to FIG. 7, the DL interval is set from the start point of the frame to the 42215.62 μs point including 41 OFDM symbols having a CP length of 1/8 Tu, and the TTG of Table 2 is set from the 42215.62 μs point. Up to 4323.08 μs points including 107.46 μs corresponding to a part of the interval and idle time, 6 OFDM symbols having a length of 1/8 Tu from the 4323.08 μs point are set as TTG intervals. Up to the included 4940 μs point is set as the UL interval, and from the 4940 μs point to the last point of the frame including the 60 μs interval corresponding to the RTG interval in Table 2, is set as the RTG interval.

  4 to 7, RTG is set to 60.0 μs, and TTG is set to 107.46 μs by allowing most of the idle time to belong to TTG. However, as shown in Table 2 above, it is possible to set the TTG to 105.71 μs and the RTG to 61.77 μs by allowing most of the idle time to belong to the RTG.

  FIG. 8 shows an example of an FDD frame structure in which the CP length is 1/8 Tu.

  Referring to FIG. 8, when the total length of the frame is 5 ms, 48 OFDM symbols are included in one frame. One frame is composed of 8 subframes, and one subframe is composed of 6 OFDM symbols. The idle time at the end of the frame is 64.64 μs as shown in Table 1 above.

  4 to 8 show TDD and FDD frame structures in which the CP length is 1/8 Tu. However, when TDD frame structures with different CP lengths coexist in neighboring cells, mutual interference may occur in data transmission due to mis-alignment between DL and UL transmission. The present invention provides a TDD frame structure having various CP lengths that do not interfere with a TDD frame having a CP length of 1/8 Tu, and an FDD frame structure having a commonality with the TDD frame. .

  <Frame structure in which switching points overlap between frames having different CP lengths>

  FIG. 9 is a diagram illustrating a TDD frame structure with a CP length of 1/4 Tu, 1/16 Tu or 1/32 Tu according to an embodiment of the present invention when the DL / UL ratio is 4: 4. .

  Referring to FIG. 9, the reference frame has an existing structure as shown in FIG. 4, the entire frame length is 5 ms, the CP length is 1/8 Tu, and 8 subframes are used. It has become.

  In the first TDD frame structure of the present embodiment, the CP length is 1/4 Tu. The total frame length is 5 ms, and the DL interval is set from the start point of the frame to the 2399.25 μs point including 21 OFDM symbols having a length of 1/4 Tu, and the table starts from the 2399.25 μs point. Up to 2540.75 μs points including 2 TTG intervals and 141.5 μs intervals corresponding to a part of idle time are set as TTG intervals, and 21 pieces of CP having a length of 1/4 Tu from 2540.75 μs points are set. The UL section is set up to the 4940 μs point including the OFDM symbol, and the RTG section is set from the 4940 μs point to the last point of the frame including the 60 μs section corresponding to the RTG section in Table 2. Each point can be changed according to the TTG interval and the RTG interval. Therefore, when one subframe is composed of five OFDM symbols, one residual OFDM symbol is further allocated to the DL section, one residual OFDM symbol is further allocated to the UL section, and the remaining one residual OFDM symbol is allocated. Symbols are assigned to TTG and RTG intervals. That is, the last DL subframe is composed of 6 OFDM symbols in FDD, and the last OFDM symbol of this subframe is punctured and converted into 5 OFDM symbol subframes in TDD for the TTG period. In the first TDD frame structure of FIG. 9, the first subframe of the DL section and the last subframe of the UL section are configured by six OFDM symbols, but any one subframe belonging to the DL section is Instead of the first frame, it may be composed of 6 OFDM symbols, and instead of any one of the last frames belonging to the UL interval, it may be composed of 6 OFDM symbols. Also, the DL section can be composed of a plurality of subframes composed of five OFDM symbols and the remaining one independent OFDM symbol, and the UL section is composed of a plurality of subframes composed of five OFDM symbols and the remaining one. It can also consist of two independent OFDM symbols. Such a subframe configuration is merely an example. That is, a subframe belonging to the DL section may be configured with an arbitrary number of OFDM symbols, a subframe belonging to the UL section may be configured with an arbitrary number of OFDM symbols, and each subframe has a different size. You may have.

  In the second TDD frame structure of the present embodiment, the CP length is 1/16 Tu. The entire frame length is 5 ms, and from the start point of the frame to the 2427.8 μs point including 25 OFDM symbols having a CP length of 1/16 Tu is set as the DL section, and the table starts from the 2427.8 μs point. Up to 2511.6 μs points including 24.5 TGS intervals and 84.5 μs intervals corresponding to a part of idle time are set as TTG intervals, and 25 pieces of CP having a length of 1/16 Tu from 2511.6 μs points are set. The UL section is set up to the 4940 μs point including the OFDM symbol, and the RTG section is set from the 4940 μs point to the last point of the frame including the 60 μs section corresponding to the RTG section in Table 2. Each point can be changed according to the TTG interval and the RTG interval. Therefore, when one subframe is composed of 6 OFDM symbols, 3 residual OFDM symbols remain, and one OFDM symbol among the 3 residual OFDM symbols is further allocated to the DL section, The OFDM symbol is further allocated to the UL section, and the remaining one OFDM symbol is further allocated to the TTG and RTG sections. That is, the last DL subframe is composed of 7 OFDM symbols by FDD, the last OFDM symbol of this subframe is punctured, and is converted to a subframe of 6 OFDM symbols by TDD for the TTG period. In the second TDD frame structure of FIG. 9, the first subframe in the DL section is configured with seven OFDM symbols, and the last subframe in the UL section is configured with seven OFDM symbols. However, any one subframe belonging to the DL section may be composed of 7 OFDM symbols instead of the first frame, and 7 instead of any one last frame belonging to the UL section. Of OFDM symbols. Also, the DL section can be composed of a plurality of subframes composed of six OFDM symbols and the remaining one independent OFDM symbol, and the UL section is composed of a plurality of subframes composed of six OFDM symbols and the remaining one. It can also consist of two independent OFDM symbols. Such a subframe configuration is merely an example. That is, a subframe belonging to the DL section may be configured with an arbitrary number of OFDM symbols, a subframe belonging to the UL section may be configured with an arbitrary number of OFDM symbols, and each subframe has a different size. You may have.

  In the third TDD frame structure of the present embodiment, the CP length is 1/32 Tu. The total frame length is 5 ms, and the DL section is set from the start point of the frame to the 2450.76 μs point including 26 OFDM symbols having a CP length of 1/32 Tu, and the table starts from the 2450.76 μs point. Up to 2583.5 μs points including the TTG interval of 2 and the 132.22 μs interval corresponding to a part of the idle time, 25 TGS intervals are set to the TTG interval, and 25 CPs having a length of 1/32 Tu from the 2583.5 μs point are set. The UL section is set up to the 4940 μs point including the OFDM symbol, and the RTG section is set from the 4940 μs point to the last point of the frame including the 60 μs section corresponding to the RTG section in Table 2. Each point can be changed according to the TTG interval and the RTG interval. Therefore, when one subframe is composed of 6 OFDM symbols, 5 residual OFDM symbols remain, and 2 OFDM symbols among the 5 residual OFDM symbols are further allocated to the DL section, and 1 OFDM Symbols are further allocated to the UL section, and the remaining two OFDM symbols are further allocated to the TTG and RTG sections. In the third TDD frame structure of FIG. 9, the first subframe and the last subframe of the DL section are configured by seven OFDM symbols, and the last subframe of the UL section is configured by seven OFDM symbols. doing. However, any two subframes belonging to the DL period may be configured with 7 OFDM symbols instead of the first and last subframes, and any one subframe belonging to the UL period may be configured as the last UL frame. Instead of a subframe, it can be composed of 7 OFDM symbols. Also, the DL section can be composed of a plurality of subframes composed of six OFDM symbols and the remaining two independent OFDM symbols, and the UL section is composed of a plurality of subframes composed of six OFDM symbols and the remaining subframes. It can also be composed of one independent OFDM symbol. Such a subframe configuration is merely an example. That is, a subframe belonging to the DL section may be configured with an arbitrary number of OFDM symbols, a subframe belonging to the UL section may be configured with an arbitrary number of OFDM symbols, and each subframe has a different size. You may have.

  As shown in FIG. 9, when a TDD frame is configured, mutual interference does not occur even when frame structures having different CP lengths coexist in adjacent cells. That is, the DL section of a frame having a CP length of 1/8 Tu and the UL section of a frame having a CP length of 1/4 Tu, 1/16 Tu, or 1/32 Tu do not overlap, and the CP length is 1 Since the UL section of a frame with / 8 Tu and the DL section of a frame with a CP length of 1/4 Tu, 1/16 Tu, or 1/32 Tu do not overlap, mutual interference does not occur.

  FIG. 10 illustrates that when the DL / UL ratio is 5: 3, the CP length is 1/4 Tu, 1/16 Tu or 1 vs. 1/8 Tu CP length according to an embodiment of the present invention. It is a figure which shows the TDD frame structure which is / 32Tu.

  Referring to FIG. 10, the reference frame (Reference Frame) has an existing structure as shown in FIG. 5, the entire frame length is 5 ms, the CP length is 1/8 Tu, and is composed of 8 subframes. ing.

  In the first TDD frame structure of the present embodiment, the CP length is 1/4 Tu. The total frame length is 5 ms, and from the start point of the frame to the 2856.25 μs point including 25 OFDM symbols having a length of 1/4 Tu, the DL period is set, and the table starts from the 2856.25 μs point. Up to 2997.75 μs points including 2 TTG intervals and 141.5 μs intervals corresponding to a part of idle time are set to TTG intervals, and 17 CPs having a length of 1/4 Tu from the 2997.75 μs points are set. The UL section is set up to the 4940 μs point including the OFDM symbol, and the RTG section is set from the 4940 μs point to the last point of the frame including the 60 μs section corresponding to the RTG section in Table 2. Each point can be changed according to the TTG interval and the RTG interval. Accordingly, when one subframe is composed of 6 OFDM symbols, one residual OFDM symbol is further allocated to the DL section, and the first subframe of the UL section is composed of 5 OFDM symbols, and the UL One OFDM symbol positioned in front of the first subframe of the interval is punctured. In the first TDD frame structure of FIG. 10, the first subframe of the DL section is composed of seven OFDM symbols. However, any one subframe belonging to the DL section can be composed of seven OFDM symbols instead of the first subframe. Also, the DL section can be composed of a plurality of subframes composed of six OFDM symbols and the remaining one independent OFDM symbol. Such a subframe structure is merely an example. That is, a subframe belonging to the DL section may be configured with an arbitrary number of OFDM symbols, a subframe belonging to the UL section may be configured with an arbitrary number of OFDM symbols, and each subframe has a different size. You may have.

  As another example, in the case of a TDD frame structure having a CP length of 1/4 Tu and one subframe is composed of five OFDM symbols, one remaining OFDM symbol is further allocated to the DL section, The remaining OFDM symbols may be further allocated to the UL interval, and the remaining one OFDM symbol may be allocated to the TTG interval. This structure is the same as the case of 1/4 Tu in which the DL / UL ratio in FIG. 9 is described as 4: 4.

  In the second TDD frame structure of the present embodiment, the CP length is 1/16 Tu. The entire frame length is 5 ms, and the DL section is set from the start point of the frame to the 3010.41 μs point including 31 OFDM symbols having a CP length of 1/16 Tu. 19 points having a length of 1/16 Tu from the 3094.91 μs point to the 3094.91 μs point including the 24.5 TGS interval and the 84.5 μs interval corresponding to a part of the idle time. The UL section is set up to the 4940 μs point including the OFDM symbol, and the RTG section is set from the 4940 μs point to the last point of the frame including the 60 μs section corresponding to the RTG section in Table 2. Each point can be changed according to the TTG interval and the RTG interval. Therefore, when one subframe is composed of 6 OFDM symbols, 3 residual OFDM symbols remain, and one OFDM symbol among the 3 residual OFDM symbols is further allocated to the DL section, The OFDM symbol is further allocated to the UL section, and the remaining one OFDM symbol is further allocated to the TTG and RTG sections. That is, the last DL subframe is composed of 7 OFDM symbols by FDD, and the last OFDM symbol of this subframe is punctured and converted into 6 OFDM symbol subframes by TDD for the TTG period. In the second TDD frame structure of FIG. 10, the first subframe in the DL section is composed of seven OFDM symbols, and the last subframe in the UL section is composed of seven OFDM symbols. However, any one subframe belonging to the DL section may be composed of 7 OFDM symbols instead of the first subframe, and any one subframe belonging to the UL section may be configured as the last subframe. Instead, it can be composed of 7 OFDM symbols. Also, the DL section can be composed of a plurality of subframes composed of six OFDM symbols and the remaining one independent OFDM symbol, and the UL section is composed of a plurality of subframes composed of six OFDM symbols and the remaining one. It can also consist of two independent OFDM symbols. The remaining one independent OFDM symbol may be followed by a subframe composed of 6 OFDM symbols, or may be a symbol (7th or last symbol) of a subframe composed of 7 OFDM symbols. it can. Such a subframe structure is merely an example. That is, a subframe belonging to the DL section may be configured with an arbitrary number of OFDM symbols, a subframe belonging to the UL section may be configured with an arbitrary number of OFDM symbols, and each subframe has a different size. You may have.

  In the third TDD frame structure of the present embodiment, the CP length is 1/32 Tu. The entire frame length is 5 ms, and the DL section is set from the start point of the frame to the 3016.32 μs point including 32 OFDM symbols having a CP length of 1/32 Tu, and is displayed from the 3016.32 μs point. Up to 3054.80 μs points including 2 TTG intervals and 38.48 μs interval corresponding to a part of idle time, 20 TGS intervals are set as TTG intervals and have a CP length of 1/32 Tu from 3054.80 μs points. The UL section is set up to the 4940 μs point including the OFDM symbol, and the RTG section is set from the 4940 μs point to the last point of the frame including the 60 μs section corresponding to the RTG section in Table 2. Each point can be changed according to the TTG interval and the RTG interval. Accordingly, when one subframe is composed of 6 OFDM symbols, 5 residual OFDM symbols remain, and 2 OFDM symbols among the 5 residual OFDM symbols are further allocated to the DL interval, The OFDM symbol is further allocated to the UL section, and the remaining one OFDM symbol is further allocated to the TTG and RTG sections. In the third TDD frame structure of FIG. 10, the first subframe and the last subframe in the DL section are configured by seven OFDM symbols, and the first subframe and the last subframe in the UL section are seven. OFDM symbols. However, any two subframes belonging to the DL interval may be configured with 7 OFDM symbols instead of the first and last DL subframes, and any two subframes belonging to the UL interval may be configured as the first and last subframes. Instead of the last UL subframe, it can be composed of 7 OFDM symbols. Also, the DL section can be composed of a plurality of subframes composed of six OFDM symbols and the remaining two independent OFDM symbols, and the UL section is composed of a plurality of subframes composed of six OFDM symbols and the remaining subframes. It can also consist of two independent OFDM symbols. Such a subframe structure is merely an example. That is, a subframe belonging to the DL section may be configured with an arbitrary number of OFDM symbols, a subframe belonging to the UL section may be configured with an arbitrary number of OFDM symbols, and each subframe has a different size. You may have.

  If the TTG interval requires an interval longer than 38.48 μs, one of the OFDM symbols additionally allocated to the DL interval or the UL interval can be further allocated for the TTG interval. For example, one OFDM symbol additionally allocated to the UL interval may be further allocated for the TTG interval, and the TTG interval may be set to 132.74 μs.

  When a TDD frame is configured as shown in FIG. 10, mutual interference does not occur even when frame structures having different CP lengths coexist in adjacent cells. That is, the DL section of a frame having a CP length of 1/8 Tu and the UL section of a frame having a CP length of 1/4 Tu, 1/16 Tu, or 1/32 Tu do not overlap, and the CP length is 1 Since the UL section of a frame with / 8 Tu and the DL section of a frame with a CP length of 1/4 Tu, 1/16 Tu, or 1/32 Tu do not overlap, mutual interference does not occur.

  FIG. 11 shows that when the DL / UL ratio is 6: 2, the CP length is 1/4 Tu, 1/16 Tu or 1 compared to the 1/8 Tu CP length according to an embodiment of the present invention. It is a figure which shows the TDD frame structure which is / 32Tu.

  Referring to FIG. 11, the reference frame has a total frame length of 5 ms and a CP length of 1/8 Tu as in the existing structure of FIG. 6, and is composed of 8 subframes. ing.

  In the first TDD frame structure of the present embodiment, the CP length is 1/4 Tu. The entire frame length is 5 ms, and the DL section is set from the start point of the frame to the 3541.8 μs point including 31 OFDM symbols having a length of 1/4 Tu, and the table starts from the 3541.8 μs point. 11 points having a length of 1/4 Tu from the 368.25 μs point to the 368.25 μs point including the TTG interval of 2 and the 141.45 μs point corresponding to a part of the idle time. The UL section is set up to the 4940 μs point including the OFDM symbol, and the RTG section is set from the 4940 μs point to the last point of the frame including the 60 μs section corresponding to the RTG section in Table 2. Each point can be changed according to the TTG interval and the RTG interval. Accordingly, when one subframe is composed of 6 OFDM symbols, one residual OFDM symbol is further allocated to the DL section, and the first subframe of the UL section is composed of 5 OFDM symbols, and the UL One OFDM symbol positioned in front of the first subframe of the interval is punctured. In the first TDD frame structure of FIG. 11, the first subframe of the DL section is composed of seven OFDM symbols. However, any one subframe belonging to the DL section can be composed of seven OFDM symbols instead of the first subframe. Also, the DL section can be composed of a plurality of subframes composed of six OFDM symbols and the remaining one independent OFDM symbol. Such a subframe structure is merely an example. That is, a subframe belonging to the DL section may be configured with an arbitrary number of OFDM symbols, a subframe belonging to the UL section may be configured with an arbitrary number of OFDM symbols, and each subframe has a different size. You may have.

  As another example, in the case of a TDD frame structure having a CP length of 1/4 Tu and one subframe is composed of five OFDM symbols, one remaining OFDM symbol is further allocated to the DL section, The remaining OFDM symbols may be further allocated to the UL interval, and the remaining one OFDM symbol may be allocated to the TTG interval. This structure is the same as the case of 1/4 Tu in which the DL / UL ratio in FIG. 9 is described as 4: 4.

  In the second TDD frame structure of the present embodiment, the CP length is 1/16 Tu. The total frame length is 5 ms, and from the start point of the frame to the 3593.07 μs point including 37 OFDM symbols having a CP length of 1/16 Tu is set as the DL section, and the table starts from the 3593.07 μs point. 2 TTG sections and 136.7.57 μs points including 84.5 μs section corresponding to a part of idle time are set as TTG sections, and 13 pieces of CP having a length of 1/16 Tu from 3677.57 μs points are set. The UL section is set up to the 4940 μs point including the OFDM symbol, and the RTG section is set from the 4940 μs point to the last point of the frame including the 60 μs section corresponding to the RTG section in Table 2. Each point can be changed according to the TTG interval and the RTG interval. Therefore, when one subframe is composed of 6 OFDM symbols, 3 residual OFDM symbols remain, and one OFDM symbol among the 3 residual OFDM symbols is further allocated to the DL section, The OFDM symbol is further allocated to the UL section, and the remaining one OFDM symbol is further allocated to the TTG and RTG sections. That is, the last DL subframe is composed of 7 OFDM symbols by FDD, and the last OFDM symbol of this subframe is punctured and converted into 6 OFDM symbol subframes by TDD for the TTG period. In the second TDD frame structure of FIG. 11, the first subframe in the DL section is composed of seven OFDM symbols, and the last subframe in the UL section is composed of seven OFDM symbols. However, any one subframe belonging to the DL section may be composed of 7 OFDM symbols instead of the first subframe, and any one subframe belonging to the UL section may be configured as the last subframe. Instead, it can be composed of 7 OFDM symbols. Also, the DL section can be composed of a plurality of subframes composed of six OFDM symbols and the remaining one independent OFDM symbol, and the UL section is composed of a plurality of subframes composed of six OFDM symbols and the remaining one. It can also consist of two independent OFDM symbols. Such a subframe structure is merely an example. That is, a subframe belonging to the DL section may be configured with an arbitrary number of OFDM symbols, a subframe belonging to the UL section may be configured with an arbitrary number of OFDM symbols, and each subframe has a different size. You may have.

  In the third TDD frame structure of the present embodiment, the CP length is 1/32 Tu. The entire frame length is 5 ms, and from the start point of the frame to the 3581.88 μs point including 38 OFDM symbols having a CP length of 1/32 Tu is set in the DL section, and the table starts from the 3581.88 μs point. Up to 3620.36 μs points including 2 TTG intervals and 38.48 μs corresponding to a part of idle time are set as TTG intervals, and 14 CPs having a length of 1/32 Tu from the 3620.36 μs point are set. The UL section is set up to the 4940 μs point including the OFDM symbol, and the RTG section is set from the 4940 μs point to the last point of the frame including the 60 μs section corresponding to the RTG section in Table 2. Each point can be changed according to the TTG interval and the RTG interval. Accordingly, when one subframe is composed of 6 OFDM symbols, 5 residual OFDM symbols remain, and 2 OFDM symbols among the 5 residual OFDM symbols are further allocated to the DL interval, The OFDM symbol is further allocated to the UL section, and the remaining one OFDM symbol is further allocated to the TTG and RTG sections. In the third TDD frame structure of FIG. 11, the first subframe and the last subframe of the DL section are configured by seven OFDM symbols. However, any two subframes belonging to the DL section can be composed of seven OFDM symbols instead of the first and last subframes. Also, the DL section can be composed of a plurality of subframes composed of six OFDM symbols and the remaining two independent OFDM symbols, and the UL section is composed of a plurality of subframes composed of six OFDM symbols and the remaining subframes. It can also consist of two independent OFDM symbols. Such a subframe structure is merely an example. That is, a subframe belonging to the DL section may be configured with an arbitrary number of OFDM symbols, a subframe belonging to the UL section may be configured with an arbitrary number of OFDM symbols, and each subframe has a different size. You may have.

  In addition, when a TTG period is requested to be longer than 38.48 μs, one of OFDM symbols additionally allocated to the DL period or the UL period can be further allocated for the TTG period. For example, one OFDM symbol additionally allocated to the UL interval may be further allocated for the TTG interval, and the TTG interval may be set to 132.74 μs.

  When a TDD frame is configured as shown in FIG. 11, mutual interference does not occur even when frame structures having different CP lengths coexist in adjacent cells. That is, the DL section of a frame having a CP length of 1/8 Tu and the UL section of a frame having a CP length of 1/4 Tu, 1/16 Tu, or 1/32 Tu do not overlap, and the CP length is 1 Since the UL section of a frame with / 8 Tu and the DL section of a frame with a CP length of 1/4 Tu, 1/16 Tu, or 1/32 Tu do not overlap, mutual interference does not occur.

  FIG. 12 shows that when the DL / UL ratio is 7: 1, the CP length is 1/4 Tu, 1/16 Tu or 1 vs. 1/8 Tu CP length according to an embodiment of the present invention. It is a figure which shows the TDD frame structure which is / 32Tu.

  Referring to FIG. 12, the reference frame has a total frame length of 5 ms and a CP length of 1/8 Tu as in the existing structure of FIG. 7, and is composed of 8 subframes. ing.

  In the first TDD frame structure of the present embodiment, the CP length is 1/4 Tu. The total frame length is 5 ms, and from the start point of the frame to the 4227.25 μs point including 37 OFDM symbols having a length of 1/4 Tu, the DL period is set, and the table starts from the 4227.25 μs point. Up to 4368.75 μs points including 2 TTG intervals and 141.5 μs intervals corresponding to a part of idle time are set as TTG intervals, and five CPs having a length of 1/4 Tu from 4368.75 μs points are set. The UL section is set up to the 4940 μs point including the OFDM symbol, and the RTG section is set from the 4940 μs point to the last point of the frame including the 60 μs section corresponding to the RTG section in Table 2. Each point can be changed according to the TTG interval and the RTG interval. Accordingly, when one subframe is composed of 6 OFDM symbols, one residual OFDM symbol is further allocated to the DL section, and the first subframe of the UL section is composed of 5 OFDM symbols, and the UL One OFDM symbol positioned in front of the first subframe of the interval is punctured. In the first TDD frame structure of FIG. 12, the first subframe of the DL section is composed of seven OFDM symbols. However, any one subframe belonging to the DL section can be composed of seven OFDM symbols instead of the first subframe. Also, the DL section can be composed of a plurality of subframes composed of six OFDM symbols and the remaining one independent OFDM symbol. Such a subframe structure is merely an example. That is, a subframe belonging to the DL section may be configured with an arbitrary number of OFDM symbols, a subframe belonging to the UL section may be configured with an arbitrary number of OFDM symbols, and each subframe has a different size. You may have.

  As another example, in the case of a TDD frame structure having a CP length of 1/4 Tu and one subframe is composed of five OFDM symbols, one remaining OFDM symbol is further allocated to the DL section, The remaining OFDM symbols may be further allocated to the UL interval, and the remaining one OFDM symbol may be allocated to the TTG and RTG intervals. This structure is the same as the case of 1/4 Tu in which the DL / UL ratio in FIG. 9 is described as 4: 4.

  In the second TDD frame structure of the present embodiment, the CP length is 1/16 Tu. The total frame length is 5 ms, and the DL section is set from the start point of the frame to the 4175.73 μs point including 43 OFDM symbols having a CP length of 1/16 Tu, and the table starts from the 4175.73 μs point. Up to 4260.23 μs point including 24.5 Ts interval and 84.5 μs interval corresponding to a part of idle time, 7 TGS intervals are set to TTG interval, and 7 CPs have a length of 1/16 Tu from 4260.23 μs point The UL section is set up to the 4940 μs point including the OFDM symbol, and the RTG section is set from the 4940 μs point to the last point of the frame including the 60 μs section corresponding to the RTG section in Table 2. Each point can be changed according to the TTG interval and the RTG interval. Therefore, when one subframe is composed of a plurality of OFDM symbols, three residual OFDM symbols remain, and one OFDM symbol among the three residual OFDM symbols is further allocated to the DL section, and one OFDM symbol is assigned. Symbols are further allocated to the UL section, and the remaining one OFDM symbol is further allocated to the TTG and RTG sections. That is, the last DL subframe is composed of 7 OFDM symbols by FDD, and the last OFDM symbol of this subframe is punctured and converted into 6 OFDM symbol subframes by TDD for the TTG period. In the second TDD frame structure of FIG. 12, the first subframe of the DL section is composed of seven OFDM symbols. However, any one subframe belonging to the DL section can be composed of seven OFDM symbols instead of the first subframe. Also, the DL section can be composed of a plurality of subframes composed of six OFDM symbols and the remaining one independent OFDM symbol. Such a subframe structure is merely an example. That is, a subframe belonging to the DL section may be configured with an arbitrary number of OFDM symbols, a subframe belonging to the UL section may be configured with an arbitrary OFDM symbol, and each subframe has a different size. May be.

  In the third TDD frame structure of the present embodiment, the CP length is 1/32 Tu. The entire frame length is 5 ms, and from the start point of the frame to the 4241.7 μs point including 45 OFDM symbols having a CP length of 1/32 Tu is set as the DL section, and the table starts from the 4241.7 μs point. Up to 4280.18 μs point including 2 TTG interval and 38.48 μs interval corresponding to part of idle time, 7 TGS intervals are set to TTG interval, and the length of CP is 1/32 Tu from 4280.18 μs point. The UL section is set up to the 4940 μs point including the OFDM symbol, and the RTG section is set from the 4940 μs point to the last point of the frame including the 60 μs section corresponding to the RTG section in Table 2. Each point can be changed according to the TTG interval and the RTG interval. Therefore, when one subframe is composed of 6 OFDM symbols, 5 residual OFDM symbols remain, and 3 OFDM symbols among the 5 residual OFDM symbols are further allocated to the DL section, The OFDM symbol is further allocated to the UL section, and the remaining one OFDM symbol is further allocated to the TTG and RTG sections. In the third TDD frame structure of FIG. 12, the first subframe and the sixth and seventh subframes of the DL section are composed of seven OFDM symbols. However, any three subframes belonging to the DL section can be composed of seven OFDM symbols instead of the three subframes. Also, the DL section can be composed of a plurality of subframes composed of 6 OFDM symbols and the remaining three independent OFDM symbols, and the UL section is composed of a subframe composed of 6 OFDM symbols and the remaining one It can also be composed of independent OFDM symbols. Such a subframe structure is merely an example. That is, a subframe belonging to the DL section may be configured with an arbitrary number of OFDM symbols, a subframe belonging to the UL section may be configured with an arbitrary number of OFDM symbols, and each subframe has a different size. You may have.

  In addition, when a TTG period is requested to be longer than 38.48 μs, one of OFDM symbols additionally allocated to the DL period or the UL period can be further allocated for the TTG period. For example, one OFDM symbol additionally allocated to the UL interval may be further allocated for the TTG interval, and the TTG interval may be set to 132.74 μs.

  When a TDD frame is configured as shown in FIG. 12, mutual interference does not occur even when frame structures having different CP lengths coexist in adjacent cells. That is, the DL section of a frame having a CP length of 1/8 Tu and the UL section of a frame having a CP length of 1/4 Tu, 1/16 Tu, or 1/32 Tu do not overlap, and the CP length is 1 Since the UL section of a frame with / 8 Tu and the DL section of a frame with a CP length of 1/4 Tu, 1/16 Tu, or 1/32 Tu do not overlap, mutual interference does not occur.

  Table 3 below summarizes the features shown in FIGS. 9 to 12 and shows a frame structure according to an embodiment of the present invention having different CP lengths coexisting with the existing frame structure.

  The TDD frame structure in which the DL / UL ratio in Table 3 is 4: 4 and the CP length is 1/4 Tu, and 1 sub-frame is assumed to be composed of 5 OFDM symbols. In the TDD frame structure, one OFDM symbol is further allocated to the TTG interval. Also, in the TDD frame structure with a DL / UL ratio of 7: 1 and a CP length of 1/32 Tu, since only one subframe is allocated for the DL section, the remaining OFDM symbols are assigned to the UL section. Assign further. In Table 3, the last two rows with (*) indications vary depending on whether one subframe is basically composed of several OFDM symbols. When the configuration of Table 3 is applied to the system, one symbol can be further punctured in the DL section or the UL section as necessary.

  <Subframe type according to the number of OFDM symbols included in the subframe>

  Hereinafter, FIG. 13 to FIG. 16 are as follows: 1) TDD frame structure of FIG. 9 to FIG. 2) An FDD frame structure having commonality with the TDD frame structure is shown. A TDD frame and an FDD frame having a CP length of 1/4 Tu, 1/16 Tu, or 1/32 Tu are composed of three types of subframes.

  Hereinafter, the subframe type composed of 6 OFDM symbols is composed of SFT-1 (Subframe Type-1), the subframe type composed of 5 OFDM symbols is composed of SFT-2, and 7 OFDM symbols. The subframe type is called SFT-3. Here, the SFT-3 type subframe is a form in which one OFDM symbol is added to the SFT-1 type subframe, and the position where the one OFDM symbol is added is the SFT-1 type subframe. It may be before, after or any intermediate position of the frame. The added OFDM symbol may be used for control information such as preamble or sounding, or may be used for data.

  FIG. 13 is a diagram illustrating a TDD frame structure having a CP length of 1/4 Tu and an FDD frame structure in common with the TDD frame structure according to an embodiment of the present invention. In FIG. 13, the remaining subframes excluding the SFT-2 and SFT-3 type subframes are all SFT-1 type subframes.

  Referring to FIG. 13, in the first TDD frame structure of the present embodiment, the DL / UL ratio is 4: 3, and the CP length is 1/4 Tu. The total frame length is 5 ms, and from the start point of the frame to the 2856.25 μs point including 25 OFDM symbols having a length of 1/4 Tu, the DL period is set, and the table starts from the 2856.25 μs point. Up to 2997.75 μs points including 2 TTG intervals and 141.5 μs intervals corresponding to a part of idle time are set to TTG intervals, and 17 CPs having a length of 1/4 Tu from the 2997.75 μs points are set. The UL section is set up to the 4940 μs point including the OFDM symbol, and the RTG section is set from the 4940 μs point to the last point of the frame including the 60 μs section corresponding to the RTG section in Table 2. Each point can be changed according to the TTG interval and the RTG interval.

  Accordingly, the DL section is composed of three SFT-1 subframes and one SFT-3 subframe, and the UL section is composed of two SFT-1 subframes and one SFT-2 subframe. Composed. Here, there is no restriction on the arrangement of subframe types in the UL section and the DL section.

  In the second TDD frame structure of the present embodiment, the DL / UL ratio is 5: 2, and the CP length is 1/4 Tu. The entire frame length is 5 ms, and the DL section is set from the start point of the frame to the 3541.8 μs point including 31 OFDM symbols having a length of 1/4 Tu, and the table starts from the 3541.8 μs point. 11 points having a length of 1/4 Tu from the 368.25 μs point to the 368.25 μs point including the 21.5 TTG interval and the 141.5 μs interval corresponding to a part of the idle time. The UL section is set up to the 4940 μs point including the OFDM symbol, and the RTG section is set from the 4940 μs point to the last point of the frame including the 60 μs section corresponding to the RTG section in Table 2. Each point can be changed according to the TTG interval and the RTG interval.

  Accordingly, the DL section is composed of four SFT-1 subframes and one SFT-3 subframe, and the UL section is composed of one SFT-1 subframe and one SFT-2 subframe. Composed. Here, there is no restriction on the arrangement of subframe types in the UL section and the DL section.

  In the third TDD frame structure of the present embodiment, the DL / UL ratio is 6: 1 and the CP length is 1/4 Tu. The total frame length is 5 ms, and from the start point of the frame to the 4227.25 μs point including 37 OFDM symbols having a length of 1/4 Tu, the DL period is set, and the table starts from the 4227.25 μs point. Up to 4368.75 μs points including 2 TTG intervals and 141.5 μs intervals corresponding to a part of idle time are set as TTG intervals, and five CPs having a length of 1/4 Tu from 4368.75 μs points are set. The UL section is set up to the 4940 μs point including the OFDM symbol, and the RTG section is set from the 4940 μs point to the last point of the frame including the 60 μs section corresponding to the RTG section in Table 2. Each point can be changed according to the TTG interval and the RTG interval.

  Therefore, the DL section is composed of five SFT-1 subframes and one SFT-3 subframe, and the UL section is composed of one SFT-2 subframe. Here, there is no restriction on the arrangement of subframe types in the UL section and the DL section.

  When a TDD frame is configured as described above, there is a system having a CP length of 1/8 Tu in a neighboring cell by matching a DL / UL switching section with a frame structure having a CP length of 1/8 Tu. The interference between downlink and uplink transmissions can also be minimized.

  Regardless of the DL / UL ratio, the DL section includes one SFT-3 type subframe. In FIG. 13, the first subframe (# 1) in the DL section is composed of SFT-3 type subframes, but this is merely an example. That is, when the DL / UL ratio is 4: 3, the SFT-3 type subframe can be located in one of # 1, # 2, # 3, and # 4, and the DL / UL ratio is In the case of 5: 2, the SFT-3 type subframe can be located in one of # 1, # 2, # 3, # 4 and # 5, and the DL / UL ratio is 6: 1. In this case, the SFT-3 type subframe may be located in one of # 1, # 2, # 3, # 4, # 5, and # 6.

  In addition, regardless of the DL / UL ratio, the UL section includes one SFT-2 type subframe. In FIG. 13, the first subframe of the UL section is composed of SFT-2 type subframes, but this is merely an example. That is, when the DL / UL ratio is 4: 3, the SFT-2 type subframe can be located in one of # 5, # 6, and # 7, and the DL / UL ratio is 5: 2. In this case, the SFT-2 type subframe can be located in one of # 6 and # 7, and when the DL / UL ratio is 6: 1, the SFT-2 type subframe is # 7 can be located.

  Next, the FDD frame structure will be described. The FDD frame includes one pivot subframe. The pivot subframe is a subframe at a position corresponding to the TTG section of the TDD frame in order to maintain commonality with the TDD frame. When the CP length is 1/4 Tu, the pivot subframe is an SFT-1 type subframe. When the DL / UL ratio is 4: 3, the TTG section in the TDD frame is located between # 4 and # 5, so that the pivot subframe in the FDD frame can be located in # 5. When the DL / UL ratio is 5: 2, since the TTG section in the TDD frame is located between # 5 and # 6, the pivot subframe in the FDD frame can be located in # 6. In addition, when the DL / UL ratio is 6: 1, the TTG section in the TDD frame is located between # 6 and # 7. Therefore, the pivot subframe in the FDD frame may be located in # 7. it can. In order to maintain commonality with the TDD frame, one SFT-3 type subframe is positioned in front of the pivot subframe. That is, when the DL / UL ratio is 4: 3, the SFT-3 type subframe can be located in one of # 1, # 2, # 3, and # 4, and the DL / UL ratio is In the case of 5: 2, the SFT-3 type subframe can be located in one of # 1, # 2, # 3, # 4 and # 5, and the DL / UL ratio is 6: 1. In this case, the SFT-3 type subframe may be located in one of # 1, # 2, # 3, # 4, # 5, and # 6.

  In FIG. 13, pivot subframes are located in subframes # 5, # 6, and # 7, but this is merely an example. Other FDD frames with pivot subframes at different positions can be considered the same.

  FIG. 13 shows a TDD frame structure having a CP length of 1/4 Tu, and a basic subframe is composed of SFT-1 type subframes. However, the basic subframe may be composed of SFT-2 type subframes.

  FIG. 14 illustrates a TDD frame composed of basic subframes composed of SFT-2 subframes with a CP length of 1/4 Tu according to an embodiment of the present invention, and a commonality with the TDD frames. It is a figure which shows the FDD frame which has. In FIG. 14, the remaining subframes excluding the SFT-1 type subframes are SFT-2 type subframes.

  Referring to FIG. 14, in the first TDD frame structure of the present embodiment, the DL / UL ratio is 4: 4, the CP length is 1/4 Tu, and the basic subframe is an SFT-2 type subframe. It is a frame. This structure is the same as the TDD frame structure in which the CP length in FIG. 9 is 1/4 Tu. Accordingly, the DL section is composed of one SFT-1 subframe and three SFT-2 subframes, and the UL section is composed of one SFT-1 subframe and three SFT-2 subframes. Composed. Here, there is no restriction on the arrangement of subframe types in the UL section and the DL section.

  In the second TDD frame structure of this embodiment, the DL / UL ratio is 5: 3, the CP length is 1/4 Tu, and the basic subframe is an SFT-2 type subframe. The entire frame length is 5 ms, and from the start point of the frame to the 2970.5 μs point including 26 OFDM symbols having a length of 1/4 Tu, the DL period is set, and the table starts from the 2970.5 μs point. Up to 3112 μs point including 2 TTG interval and 141.5 μs interval corresponding to part of idle time is set as TTG interval, and includes 16 OFDM symbols having CP length of 1/4 Tu from 3112 μs point The UL section is set up to the 4940 μs point, and the RTG section is set from the 4940 μs point to the last point of the frame including the 60 μs section corresponding to the RTG section in Table 2. Each point can be changed according to the TTG interval and the RTG interval.

  Accordingly, the DL section is composed of one SFT-1 subframe and four SFT-2 subframes, and the UL section is composed of one SFT-1 subframe and two SFT-2 subframes. Composed. Here, there is no restriction on the arrangement of subframe types in the UL section and the DL section.

  In the third TDD frame structure of this embodiment, the DL / UL ratio is 6: 2, the CP length is 1/4 Tu, and the basic subframe is an SFT-2 type subframe. This structure is the same as the frame structure in which the CP length in FIG. 11 is 1/4 Tu. Accordingly, the DL section is composed of one SFT-1 subframe and five SFT-2 subframes, and the UL section is composed of one SFT-1 subframe and one SFT-2 subframe. Composed. Here, there is no restriction on the arrangement of subframe types in the UL section and the DL section.

  In the fourth TDD frame structure of the present embodiment, the DL / UL ratio is 7: 1, the CP length is 1/4 Tu, and the basic subframe is an SFT-2 type subframe. The total frame length is 5 ms, and the 4113 μs point including 36 OFDM symbols having a length of 1/4 Tu from the start point of the frame is set as the DL period, and the TTG period of Table 2 from the 4113 μs point Up to a point of 4254.5 μs including a 141.5 μs interval corresponding to a part of the idle time is set as a TTG interval, and includes 6 OFDM symbols having a CP length of 1/4 Tu from the 4254.5 μs point. The UL section is set up to the 4940 μs point, and the RTG section is set from the 4940 μs point to the last point of the frame including the 60 μs section corresponding to the RTG section in Table 2. Each point can be changed according to the TTG interval and the RTG interval.

  Accordingly, the DL section is composed of one SFT-1 subframe and six SFT-2 subframes, and the UL section is composed of one SFT-1 subframe. Here, there is no restriction on the arrangement of the subframe types in the UL section and the DL section.

  When a TDD frame is configured as described above, there is a system having a CP length of 1/8 Tu in a neighboring cell by matching a DL / UL switching section with a frame structure having a CP length of 1/8 Tu. The interference between downlink and uplink transmissions can also be minimized.

  When the basic subframe is composed of SFT-2 type subframes, the DL section includes one SFT-1 type subframe regardless of the DL / UL ratio. When the DL / UL ratio is 4: 4, the SFT-1 type subframe can be located in one of # 1, # 2, # 3, and # 4, and the DL / UL ratio is 5: 3, the SFT-1 type subframe can be located in one of # 1, # 2, # 3, # 4, and # 5, and the DL / UL ratio is 6: 2. -1 type subframe can be located in one of # 1, # 2, # 3, # 4, # 5 and # 6, and DL / UL ratio is 7: 1. One type of subframe may be located in one of # 1, # 2, # 3, # 4, # 5, # 6, and # 7.

  When the basic subframe is composed of SFT-2 type subframes, the UL section includes one SFT-1 type subframe regardless of the DL / UL ratio. When the DL / UL ratio is 4: 4, the SFT-1 type subframe can be located in one of # 5, # 6, # 7, and # 8, and the DL / UL ratio is 5: 3, the SFT-1 type subframe can be located in one of # 6, # 7, and # 8, and when the DL / UL ratio is 6: 2, the SFT-1 type subframe is located. The frame can be located in one of # 7 and # 8. When the DL / UL ratio is 7: 1, the SFT-1 type subframe can be located in # 8.

  Next, if the CP length is 1/4 Tu and the basic subframe describes an FDD frame structure composed of SFT-2 subframes, the pivot subframe is located at a position corresponding to the TTG section of the TDD frame. Can be located. Here, the pivot subframe is an SFT-1 type subframe. When the DL / UL ratio is 4: 4, the TTG section in the TTD frame is located between # 4 and # 5, so the pivot subframe in the FDD frame must be located in # 4 or # 5. Can do. When the DL / UL ratio is 5: 3, the TTG section in the TDD frame is located between # 5 and # 6, so the pivot subframe in the FDD frame must be located in # 5 or # 6. Can do. When the DL / UL ratio is 6: 2, the TTG section in the TDD frame is located between # 6 and # 7, so the pivot subframe in the FDD frame must be located in # 6 or # 7. Can do. Also, when the DL / UL ratio is 7: 1, the TTG section in the TDD frame is located between # 7 and # 8, so the pivot subframe in the FDD frame is located in # 7 or # 8. can do. However, since the UL section includes one SFT-1 type subframe, when the DL / UL ratio is 7: 1, the position of the pivot subframe is preferably # 7.

  In order to maintain commonality with the TDD frame, one SFT-1 type subframe is positioned in front of the pivot subframe, and one SFT-1 type subframe is located behind the pivot subframe. Position. That is, when the DL / UL ratio is 4: 4, the SFT-1 type subframe excluding the pivot subframe is one of # 1, # 2, and # 3 when the pivot subframe is located at # 4. Can be located in one of # 5, # 6, # 7 and # 8, or if the pivot subframe is located in # 5, and one of # 1, # 2, # 3 and # 4 It can be located in one of # 6, # 7 and # 8. When the DL / UL ratio is 5: 3, the SFT-1 type subframe excluding the pivot subframe is one of # 1, # 2, # 3, and # 4 when the pivot subframe is located at # 5. One and one of # 6, # 7 and # 8, or if the pivot subframe is located at # 6, one of # 1, # 2, # 3, # 4 and # 5 Can be located in one of # 7 and # 8. When the DL / UL ratio is 6: 2, SFT-1 type subframes excluding the pivot subframe are # 1, # 2, # 3, # 4 and # 4 when the pivot subframe is located at # 6. Can be located in one of 5 and one of # 7 and # 8, or if the pivot subframe is located in # 7, # 1, # 2, # 3, # 4, # 5 and # 6 And # 8. When the DL / UL ratio is 7: 1, the SFT-1 type subframe excluding the pivot subframe is # 1, # 2, # 3, # 4, #, when the pivot subframe is located at # 7. Can be located in one of 5 or # 6 and # 8, or if the pivot subframe is located in # 8, # 1, # 2, # 3, # 4, # 5, # 6 and # 7 Can be located in two of them.

  In FIG. 14, pivot subframes are located in subframes # 5, # 6, # 7, and # 8, but this is merely an example. Other FDD frames with pivot subframes at different positions can be considered the same.

  FIG. 15 is a diagram illustrating a TDD frame structure having a CP length of 1/16 Tu and an FDD frame structure having commonality with the TDD frame structure according to an embodiment of the present invention. In FIG. 15, the remaining subframes excluding the SFT-3 type subframe are SFT-1 type subframes.

  Referring to FIG. 15, in the first TDD frame structure of the present embodiment, the DL / UL ratio is 4: 4, and the CP length is 1/16 Tu. This structure is the same as the frame structure having a CP length of 1/16 Tu in FIG. Accordingly, the DL section is composed of one SFT-3 subframe and three SFT-1 subframes, and the UL section is composed of one SFT-3 subframe and three SFT-1 subframes. Composed. Here, there is no restriction on the arrangement of the subframe types in the UL section and the DL section.

  In the second TDD frame structure of the present embodiment, the DL / UL ratio is 5: 3, and the CP length is 1/16 Tu. This structure is the same as the frame structure having a CP length of 1/16 Tu in FIG. Accordingly, the DL section is composed of one SFT-3 subframe and four SFT-1 subframes, and the UL section is composed of one SFT-3 subframe and two SFT-1 subframes. Composed. Here, there is no restriction on the arrangement of the subframe types in the UL section and the DL section.

  In the third TDD frame structure of the present embodiment, the DL / UL ratio is 6: 2, and the CP length is 1/16 Tu. This structure is the same as the frame structure having a CP length of 1/16 Tu in FIG. Accordingly, the DL section is composed of one SFT-3 subframe and five SFT-1 subframes, and the UL section is composed of one SFT-3 subframe and one SFT-1 subframe. Composed. Here, there is no restriction on the arrangement of the subframe types in the UL section and the DL section.

  In the fourth TDD frame structure of this embodiment, the DL / UL ratio is 7: 1 and the CP length is 1/16 Tu. This structure is the same as the frame structure having a CP length of 1/16 Tu in FIG.

  Accordingly, the DL section is composed of one SFT-3 subframe and six SFT-1 subframes, and the UL section is composed of one SFT-3 subframe. Here, there is no restriction on the arrangement of the subframe types in the UL section and the DL section.

  When a TDD frame is configured as described above, there is a system having a CP length of 1/8 Tu in a neighboring cell by matching a DL / UL switching section with a frame structure having a CP length of 1/8 Tu. The interference between downlink and uplink transmissions can also be minimized.

  Regardless of the DL / UL ratio, the DL section includes one SFT-3 type subframe. In FIG. 15, the first subframe (# 1) in the DL section is composed of SFT-3 type subframes, but this is merely an example. That is, when the DL / UL ratio is 4: 4, the SFT-3 type subframe can be located in one of # 1, # 2, # 3, and # 4, and the DL / UL ratio is In the case of 5: 3, the SFT-3 type subframe can be located in one of # 1, # 2, # 3, # 4 and # 5, and the DL / UL ratio is 6: 2. In this case, the SFT-3 type subframe can be located in one of # 1, # 2, # 3, # 4, # 5, and # 6, and the DL / UL ratio is 7: 1. The SFT-3 type subframe can be located in one of # 1, # 2, # 3, # 4, # 5, # 6, and # 7.

  Regardless of the DL / UL ratio, the DL section includes one SFT-3 type subframe. In FIG. 15, the last subframe (# 8) of the UL section is composed of SFT-3 type subframes, but this is merely an example.

  That is, when the DL / UL ratio is 4: 4, the SFT-3 type subframe can be located in one of # 5, # 6, # 7, and # 8, and the DL / UL ratio is In the case of 5: 3, the SFT-3 type subframe can be located in one of # 6, # 7, and # 8, and when the DL / UL ratio is 6: 2, the SFT-3 type Can be located in one of # 7 and # 8, and if the DL / UL ratio is 7: 1, the SFT-3 type subframe can be located in # 8. .

  Next, the FDD frame structure will be described. The FDD frame includes one pivot subframe. As shown in FIG. 15, the pivot subframe may be an SFT-3 type subframe. The pivot sub frame may be located at a position corresponding to the TTG section of the TDD frame. That is, when the DL / UL ratio is 4: 4, the TTG section in the TDD frame is located between # 4 and # 5, so the pivot subframe in the FDD frame is located in # 4 or # 5. can do. When the DL / UL ratio is 5: 3, the TTG section in the TDD frame is located between # 5 and # 6, so the pivot subframe in the FDD frame must be located in # 5 or # 6. Can do. When the DL / UL ratio is 6: 2, the TTG section in the TDD frame is located between # 6 and # 7, so the pivot subframe in the FDD frame is located in # 6 or # 7. can do. Also, when the DL / UL ratio is 7: 1, the TTG section in the TDD frame is located between # 7 and # 8, so the pivot subframe in the FDD frame is located in # 7 or # 8. can do. However, since the UL section includes one SFT-3 type subframe, when the DL / UL ratio is 7: 1, the position of the pivot subframe is preferably # 7.

  In order to maintain commonality with the TDD frame, one SFT-3 type subframe is located in front of the pivot subframe, and one SFT-3 type is located behind the pivot subframe. Make subframes located. That is, when the DL / UL ratio is 4: 4, the SFT-3 type subframe excluding the pivot subframe is one of # 1, # 2, and # 3 when the pivot subframe is located at # 4. Can be located in one of # 5, # 6, # 7 and # 8, or if the pivot subframe is located in # 5, and one of # 1, # 2, # 3 and # 4 It can be located in one of # 6, # 7 and # 8. When the DL / UL ratio is 5: 3, the SFT-3 type subframe excluding the pivot subframe is one of # 1, # 2, # 3, and # 4 when the pivot subframe is located at # 5. One (preferably # 1) and one of # 6, # 7 and # 8 (preferably # 8), or if the pivot subframe is located at # 6, # 1, # 2, one of # 3, # 4 and # 5 and one of # 7 and # 8. When the DL / UL ratio is 6: 2, SFT-3 type subframes excluding the pivot subframe are # 1, # 2, # 3, # 4 and # 4 when the pivot subframe is located at # 6. Can be located in one of 5 and one of # 7 and # 8, or if the pivot subframe is located in # 7, # 1, # 2, # 3, # 4, # 5 and # 6 And # 8. When the DL / UL ratio is 7: 1, the SFT-3 type subframe excluding the pivot subframe is # 1, # 2, # 3, # 4, # when the pivot subframe is located at # 7. One of 5 and # 6 and # 8 can be located.

  In FIG. 15, pivot subframes are located in subframes # 4, # 5, # 6, and # 7, but this is merely an example. Other FDD frames with pivot subframes at different positions can be considered the same.

  FIG. 16 is a diagram illustrating a TDD frame structure having a CP length of 1/32 Tu and an FDD frame structure having commonality with the TDD frame structure according to an embodiment of the present invention. In FIG. 16, the remaining subframes excluding the SFT-3 type subframes are SFT-1 type subframes.

  Referring to FIG. 16, in the first TDD frame structure of the present embodiment, the DL / UL ratio is 4: 4 and the CP length is 1/32 Tu. The total frame length is 5 ms, and the DL section is set from the start point of the frame to the 2450.76 μs point including 26 OFDM symbols having a CP length of 1/32 Tu, and the table starts from the 2450.76 μs point. 26 OFDM having a length of 1/32 Tu from the 2489.24 μs point up to 2489.24 μs point including the 38.48 μs interval corresponding to a part of the TTG interval idle time of 2 The UL section is set up to the 4940 μs point including the symbol, and the RTG section is set from the 4940 μs point to the last point of the frame including the 60 μs section corresponding to the RTG section in Table 2.

  Accordingly, the DL section is composed of two SFT-3 subframes and two SFT-1 subframes, and the UL section is composed of two SFT-3 subframes and two SFT-1 subframes. Composed. Here, there are no restrictions on the arrangement of subframe types in the UL section and the DL section.

  In the second TDD frame structure of the present embodiment, the DL / UL ratio is 5: 3, and the CP length is 1/32 Tu. This structure is the same as the frame structure having a CP length of 1/32 Tu in FIG. Accordingly, the DL section is composed of two SFT-3 subframes and three SFT-1 subframes, and the UL section is composed of two SFT-3 subframes and one SFT-1 subframe. Composed. Here, there are no restrictions on the arrangement of subframe types in the UL section and the DL section.

  In the third TDD frame structure of this embodiment, the DL / UL ratio is 6: 2, and the CP length is 1/32 Tu. This structure is the same as the frame structure having a CP length of 1/32 Tu in FIG. Accordingly, the DL section is composed of two SFT-3 subframes and four SFT-1 subframes, and the UL section is composed of two SFT-3 subframes. Here, there are no restrictions on the arrangement of subframe types in the UL section and the DL section.

  In the fourth TDD frame structure of the present embodiment, the DL / UL ratio is 7: 1 and the CP length is 1/32 Tu. This structure is the same as the frame structure having a CP length of 1/32 Tu in FIG. Accordingly, the DL section is composed of three SFT-3 subframes and four SFT-1 subframes, and the UL section is composed of one SFT-3 subframe. Here, there are no restrictions on the arrangement of subframe types in the UL section and the DL section.

  When a TDD frame is configured as described above, there is a system having a CP length of 1/8 Tu in a neighboring cell by matching a DL / UL switching section with a frame structure having a CP length of 1/8 Tu. The interference between downlink and uplink transmissions can also be minimized.

  The DL section includes a plurality of SFT-3 type subframes. When the DL / UL ratio is 4: 4, the SFT-3 type subframe can be located in two of # 1, # 2, # 3, and # 4, and the DL / UL ratio is 5: 3, SFT-3 type subframes can be located in two of # 1, # 2, # 3, # 4 and # 5, and the DL / UL ratio is 6: 2. SFT-3 type subframes can be located in two of # 1, # 2, # 3, # 4, # 5 and # 6, and if the DL / UL ratio is 7: 1, SFT -Three types of subframes can be located in three of # 1, # 2, # 3, # 4, # 5, # 6 and # 7.

  The UL section includes a plurality of SFT-3 type subframes. When the DL / UL ratio is 4: 4, SFT-3 type subframes can be located in two of # 5, # 6, # 7, and # 8, and the DL / UL ratio is 5: 3, SFT-3 type subframes can be located in two of # 6, # 7 and # 8, and when the DL / UL ratio is 6: 2, SFT-3 type subframes. The frames can be located at # 7 and # 8, and if the DL / UL ratio is 7: 1, the SFT-3 type subframe can be located at # 8.

  However, when a TTG interval is required to be longer than 38.48 μs, two OFDM symbols can be assigned to the TTG interval. For example, one of the OFDM symbols in the UL section may be further allocated for the TTG section, and the TTG section may be set to 132.74 μs. Here, when the DL / UL ratio is 4: 4, SFT-3 type subframes include two of # 1, # 2, # 3, and # 4 and # 5, # 6, # 7, and # 8. If the DL / UL ratio is 5: 3, SFT-3 type subframes are # 1, # 2, # 3, # 4 and # 5 and ## 6, # 7 and # 8, and when the DL / UL ratio is 6: 2, SFT-3 type subframes are # 1, # 2, # 3, # 4 , # 5 and # 6 and # 7 and # 8. When the DL / UL ratio is 7: 1, SFT-3 type subframes should be located at # 8 of # 1, # 2, # 3, # 4, # 5, # 6 and # 7 and # 8 Can do.

  Next, the FDD frame structure will be described. The FDD frame includes one pivot subframe. As shown in FIG. 16, the pivot subframe may be an SFT-3 type subframe. The pivot subframe may be located at a position corresponding to a TTG section of the TDD frame. That is, when the DL / UL ratio is 4: 4, the TTG section in the TDD frame is located between # 4 and # 5, so the pivot subframe in the FDD frame is located in # 4 or # 5. can do. Also, when the DL / UL ratio is 5: 3, the TTG section in the TDD frame is located between # 5 and # 6, so the pivot subframe in the FDD frame is located in # 5 or # 6. can do. When the DL / UL ratio is 6: 2, the TTG section in the TDD frame is located between # 6 and # 7, so the pivot subframe in the FDD frame is located in # 6 or # 7. can do. However, since the UL section includes two SFT-3 type subframes, the position of the pivot subframe is preferably # 6. Also, when the DL / UL ratio is 7: 1, the TTG section in the TDD frame is located between # 7 and # 8, so the pivot subframe in the FDD frame is located in # 7 or # 8. can do. However, since the UL section includes one SFT-3 type subframe, the position of the pivot subframe is preferably # 7.

  In order to maintain commonality with the TDD frame, two SFT-3 type subframes are positioned in front of the pivot subframe, and two SFT-3 types are positioned behind the pivot subframe. Make subframes located. That is, when the DL / UL ratio is 4: 4, the SFT-3 type subframe excluding the pivot subframe has two of # 1, # 2, and # 3 when the pivot subframe is located at # 4. And # 5, # 6, # 7 and # 8, or if the pivot subframe is located at # 5, then two of # 1, # 2, # 3 and # 4 If the DL / UL ratio is 5: 3, the SFT-3 type subframe excluding the pivot subframe can be located in two of # 6, # 7 and # 8. When located in # 5, it can be located in two of # 1, # 2, # 3 and # 4 and two of # 6, # 7 and # 8, or the pivot subframe is located in # 6 If # 1, # 2, # 3, # 4 and # 5 and # If the DL / UL ratio is 6: 2, the SFT-3 type subframe excluding the pivot subframe is # 1 when the pivot subframe is located at # 6. , # 2, # 3, # 4 and # 5 and # 7 and # 8, or if the pivot subframe is located at # 7, # 1, # 2, # 3, # 4 and # 5 and # 6 can be located at # 8 and the DL / UL ratio is 7: 1, the SFT-3 type subframe excluding the pivot subframe is the pivot subframe. Can be located at # 7, can be located at # 8 with three of # 1, # 2, # 3, # 4, # 5 and # 6 and # 8, or the pivot subframe is located at # 8 , # 1, # 2, # 3, # 4, # 5, # 6 and # 7 It can be positioned in.

  In FIG. 16, pivot subframes are located in subframes # 4, # 5, # 6, and # 7, but this is merely an example. Other FDD frames with pivot subframes at different positions can be considered the same.

  When the TDD frame structure is configured as shown in FIGS. 13 to 16, mutual interference does not occur even when frame structures having different CP lengths coexist in adjacent cells. That is, the DL section of a frame having a CP length of 1/8 Tu and the UL section of a frame having a CP length of 1/4 Tu, 1/16 Tu, or 1/32 Tu do not overlap, and the CP length is 1 Since the UL section of a frame with / 8 Tu and the DL section of a frame with a CP length of 1/4 Tu, 1/16 Tu, or 1/32 Tu do not overlap, mutual interference does not occur.

  Further, if the FDD frame structure is configured as shown in FIGS. 13 to 16, since it has commonality with the TDD frame, related communication algorithms such as algorithms used in the TDD system and resource allocation methods are used in the FDD system. Can be reused.

  Table 4 below summarizes the features of FIGS. 13-16 and illustrates the features of the TDD frame structure according to one embodiment of the present invention.

  Table 5 below summarizes the features of FIGS. 13-16, where the CP length is 1/4 Tu and the basic subframe is an SFT-2 type subframe according to one embodiment of the present invention. The characteristics of the TDD frame when configured are shown.

  Table 6 below summarizes the features of FIGS. 13-16, where the CP length is 1/32 Tu and two OFDM symbols are assigned to the TTG interval according to one embodiment of the present invention. The characteristics of the TDD frame are shown.

  Table 7 below summarizes the features of FIGS. 13 to 16 and summarizes the features of the FDD frame structure according to one embodiment of the present invention.

  Table 8 below summarizes the additional features of FIGS. 13-16, with a CP length of 1/4 Tu and a basic subframe of SFT-2 type according to one embodiment of the present invention. The characteristics of the FDD frame when composed of subframes are shown.

  Table 9 below summarizes the additional features of FIGS. 13-16, with a CP length of 1/32 Tu and two OFDM symbols in the TTG interval according to one embodiment of the present invention. It is the table | surface which arranged the characteristic of the FDD frame at the time of assigning.

  FIG. 17 is a block diagram showing a wireless communication apparatus used in the above-described embodiment. The wireless device (50) can be part of a terminal. The wireless device (50) includes a processor (51), a memory (52), an RF unit (53), a display unit (54), and a user interface unit (55). The processor (51) sets at least one subframe in the frame. The frame can be configured by the method described above. The memory 52 is connected to the processor 51 and stores various information for setting subframes in the frame. The display unit 54 displays various information of the terminal and can use well-known elements such as an LCD (Liquid Crystal Display) and an OLED (Organic Light Emitting Diodes). The user interface unit 55 may be a combination of well-known user interfaces such as a keypad and a touch screen. The RF unit 53 is connected to the processor and transmits and / or receives subframes in the frame.

  According to the present invention, when frame structures having various CP lengths supporting the IEEE 802.16m format coexist in adjacent cells, mutual interference during data transmission can be reduced.

  In addition, an FDD frame structure having commonality with a TDD frame can be provided, and related communication algorithms such as algorithms used in the TDD system and resource allocation methods can be reused in the FDD system.

  The present invention can be implemented in hardware, software, or a combination thereof. In hardware implementation, ASIC (application specific integrated circuit), DSP (digital signal processing), PLD (programmable logic device), FPGA (field programmable gate array), processor, controller designed to perform the functions described above , A microprocessor, other electronic units, or a combination thereof. In software implementation, it may be implemented by a module that performs the above-described functions. Software can be stored in the memory unit and executed by the processor. For the memory unit and the processor, various means well known to those skilled in the art can be adopted.

  Although the preferred embodiments of the present invention have been described in detail above, those skilled in the art to which the present invention pertains have ordinary skill in the art, which are within the spirit and scope of the present invention as defined in the appended claims. It will be understood that the present invention can be implemented with various modifications or alterations unless otherwise specified. Therefore, future modifications of the embodiments of the present invention cannot deviate from the technology of the present invention.

Claims (3)

In a method in which a terminal communicates with a base station, the method includes:
Transmitting and receiving a signal based on a frame of data with the base station, the frame of data comprising:
A plurality of first type subframes each having a first number of orthogonal frequency division multiple access (OFDMA) symbols;
A plurality of second type subframes each having a second number of OFDMA symbols different from the first number;
The frame of data is configured to support at least one of two different CPs including a first cyclic prefix (CP) and a second CP;
When the first CP is supported , the first number of OFDMA symbols is 7 symbols, the second number of OFDMA symbols is 6 symbols,
When the second CP is supported, the first number of OFDMA symbols is 5 symbols, the second number of OFDMA symbols is 6 symbols,
The step of transmitting and receiving includes the step of time division duplexing the frame with other frames,
When the first CP is supported, the frame includes two first type subframes and six second type subframes;
When the second CP is supported, the frame includes one first-type subframe and seven second-type subframes;
When the first CP is supported, the fourth subframe of the six second type subframes is followed by an idle symbol;
When the second CP is supported, the one first type subframe is followed by an idle symbol;
When the first CP is supported, one of the two first type subframes is followed by at least five of the six second type subframes, followed by the two second type subframes. Followed by one other of one type of subframe,
When the second CP is supported, four second type subframes are followed by the one first type subframe, followed by three second type subframes,
When the first CP is supported, one of the two first type subframes and four of the six second type subframes are grouped into a plurality of downlink subframes; Thereafter, a plurality of uplink subframes follow, the other uplink subframes including the other one of the two first type subframes and the other of the six second type subframes. Two are grouped ,
When the second CP is supported, four of the one first-type subframe and the seven second-type subframes are grouped into a plurality of downlink subframes, and the seven Are grouped into a plurality of uplink subframes,
The downlink section of the frame supporting the first CP does not overlap the uplink section of the frame supporting the second CP;
The downlink section of the frame supporting the second CP does not overlap the uplink section of the frame supporting the first CP .   The method of claim 1, wherein the number of the plurality of first type subframes and the number of the plurality of second type subframes are determined based on an instruction received from the base station. A terminal configured to communicate with a base station,
Display section,
A transceiver, and a processor operatively coupled to the display unit and the transceiver, configured to transmit and receive signals based on the data frame with the base station, the data frame comprising:
A plurality of first type subframes each having a first number of OFDMA symbols;
A plurality of second type subframes each having a second number of OFDMA symbols different from the first number;
The frame of data is configured to support at least one of two different CPs including a first cyclic prefix (CP) and a second CP;
When the first CP is supported , the first number of OFDMA symbols is 7 symbols, the second number of OFDMA symbols is 6 symbols,
When the second CP is supported, the first number of OFDMA symbols is 5 symbols, the second number of OFDMA symbols is 6 symbols,
The frame is a time-division duplexed frame;
When the first CP is supported, the frame includes two first type subframes and six second type subframes;
When the second CP is supported, the frame includes one first-type subframe and seven second-type subframes;
When the first CP is supported, the fourth subframe of the six second type subframes is followed by an idle symbol;
When the second CP is supported, the one first type subframe is followed by an idle symbol;
When the first CP is supported, one of the two first type subframes is followed by at least five of the six second type subframes, followed by the two second type subframes. Followed by one other of one type of subframe,
When the second CP is supported, four second type subframes are followed by the one first type subframe, followed by three second type subframes,
When the first CP is supported, one of the two first type subframes and four of the six second type subframes are grouped into a plurality of downlink subframes; Thereafter, a plurality of uplink subframes follow, the other uplink subframes including the other one of the two first type subframes and the other of the six second type subframes. Two are grouped ,
When the second CP is supported, four of the one first-type subframe and the seven second-type subframes are grouped into a plurality of downlink subframes, and the seven Are grouped into a plurality of uplink subframes,
The downlink section of the frame supporting the first CP does not overlap the uplink section of the frame supporting the second CP;
The downlink section of the frame supporting the second CP does not overlap the uplink section of the frame supporting the first CP .

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