Attorney Ref. No. 681954.0890
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`METHOD FOR CONSTRUCTING FRAME STRUCTURES
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`TITLE
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`CROSS-REFERENCE TO RELATED APPLICATION
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`[0001]
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`This application claims the benefit of U.S. Provisional Application Nos. 60/929,798,
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`5
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`entitled "Frame Structure in Wireless Communication Systems," filed July 12, 2007, and
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`60/973,157, entitled "Bandwidth Scalable OFDMA Frame Structure," filed September 17, 2007.
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`These applications are hereby incorporated by reference in their entirety.
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`BACKGROUND
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`[0002]
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`The present invention generally relates to orthogonal frequency-division multiple
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`10
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`access (OFDMA) systems, and more particularly, the present invention relates to methods for
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`constructing frame structures in OFDMA systems.
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`[0003]
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`Orthogonal Frequency Division Multiple Access (OFDMA) is a multiple access
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`scheme for transmitting data in different subcarriers in a channel, wherein the data may come
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`from different users and may be transmitted in disjoint subsets of sub-channels in a transmission
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`15
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`bandwidth. The orthogonality property among the subcarriers may allow simultaneous
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`transmission of data from different users without interference from one other. The multiple
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`access scheme of the OFDMA may generally be applied in various communication systems, such
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`as those defined in IEEE standard 802.16e ("legacy system" hereafter) and IEEE standard
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`802.16m ("new system" hereafter). The new system defined in the IEEE standard 802.16m may
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`20
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`be required to provide enhanced spectrum efficiency, higher speed tolerance and full backward
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`compatibility with the legacy system defined in the IEEE standard 802.16e.
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`[0004]
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`FIG. 1 is a diagram illustrating an OFDMA frame structure under the IEEE 802.16
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`standard. Referring to FIG. 1, the frame structure may include a downlink sub-frame (DL sub(cid:173)
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`frame) 16 and an uplink sub-frame (UL sub-frame) 18. The UL sub-frame 18 may follow the
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`25 DL sub-frame 16 in time domain with a transmit/receive transmission gap (TTG) 17 from the DL
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`sub-frame 16. Moreover, the frame structure may be separated from the next frame structure, led
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`by a preamble 10-2, by a receive/transmit transmission gap (RTG) 19.
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`[0005]
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`The DL sub-frame 16 may include a preamble 10-1, a frame control header (FCH) 11,
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`a downlink map (DL-MAP) 12, a downlink burst (DL burst#l) 13 and a data region (DATA) 14-
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`Attorney Ref. No. 681954.0890
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`1. The UL sub-frame 18 may include a ranging sub-channel 15 and a data region (DATA) 14-2.
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`Since the DL-MAP 12 may be used to identify the division or structure of the DATA 14-1 in the
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`DL sub-frame 16, it may be desirable to integrate the OFDMA frame structure of an old
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`OFDMA system with that of a new OFDMA system by using the DL-MAP 12 to define different
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`5
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`zones in the DATA 14-1 and DATA 14-2 of the frame structure for data of the old OFDMA
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`system and data of the new OFDMA system.
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`[0006]
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`FIG. 2 is a diagram illustrating a placement of guiding signals (or pilot symbols) 24-1
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`for time-domain and frequency-domain OFDMA signals under the IEEE 802.16 standard.
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`Referring to FIG. 2, upper and lower frequency bands may serve as guard bands 22-1 and 22-2,
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`10
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`respectively, which may not be used to carry information. The placement of information may
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`include a first part and a second part. For example, the first part of the placement includes a
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`preamble 10' -1 having a fixed length, and the second part of the placement includes data and
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`guard intervals between an upper row and a lower row of the data interlaced with the pilot
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`symbols 24-1, represented by blocks marked with "X". In some applications such placement of
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`information may be inflexible to bandwidth scaling due to the fixed-length preambles 10 '-1
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`and/or 10'-2 and the often unusable guard bands 22-1 and 22-2. Moreover, the placement may
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`be susceptible to a Doppler effect in a high mobility scenario because the placement may be
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`usually designed with a relatively large symbol period, which in tum may induce relatively short
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`carrier spacing and less dense pilot symbol placement. Moreover, the limitation on pilot symbol
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`20
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`placement may cause channel estimation error at a receiving end because of insufficient
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`information provided for channel estimation.
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`SUMMARY
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`[0007]
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`Examples of the present invention may provide a method for constructing a frame
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`structure for data transmission, the method comprising generating a first section comprising data
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`configured in a first format compatible with a first communication system, generating a second
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`section following the first section comprising data configured in a second format compatible
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`with a second communication system, wherein the second format is different from the first
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`format, generating at least one non-data section containing information describing an aspect of
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`data in at least one of the first section and the second section, and combining the first section, the
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`30
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`second section and the at least one non-data section to form the frame structure.
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`[0008]
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`Examples of the present invention may provide a method of generating a frame for
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`transferring data in a communication system. The communication system may include a first
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`system and a second system. The method may include generating a first sub-frame for downlink
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`transmission, wherein the first sub-frame comprises a first region comprising first mapping
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`5
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`information, a second region comprising second mapping information, and a third region
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`carrying data to be transferred in the downlink transmission, the third region comprising a first
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`sub-region and a second sub-region, wherein the first sub-region and second sub-region are
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`defined by the first mapping information, the first sub-region being capable of carrying first data
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`of the first system and the second sub-region being capable of carrying second data of the second
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`system in the downlink transmission, and generating a second sub-frame for uplink transmission,
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`wherein the second sub-frame comprises a fourth region carrying data to be transferred in the
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`uplink transmission, the fourth region comprising a third sub-region and a fourth sub-region,
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`wherein the third sub-region and the fourth sub-region are defined by the second mapping
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`information, the third sub-region being capable of carrying third data of the first system and the
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`15
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`fourth sub-region being capable of carrying fourth data of the second system in the uplink
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`transmission.
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`[0009]
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`Examples of the present invention may also provide a method of generating a frame
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`for transferring data in a communication system. The communication system may include a first
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`system and a second system. The method may include generating a first frame comprising a first
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`20
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`sub-frame for downlink transmission and a second sub-frame for uplink transmission in a first
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`band, generating a second frame comprising a third sub-frame for downlink transmission and a
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`fourth sub-frame for uplink transmission in a second band, identifying a guard band between the
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`first band and the second band, and generating a third frame comprising a fifth sub-frame for
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`downlink transmission and a sixth sub-frame for uplink transmission in the guard band.
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`[0010]
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`Examples of the present invention may provide a method for allocating information in
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`a frame of a communication system. The communication system may include a first system and
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`a second system. The frame may be used for first data transmission of the first system and
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`second data transmission of the second system. The method may include allocating data of the
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`first system and the second system in first mapping information, dividing a data region of the
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`frame to form a first sub-region and a second sub-region according to the first mapping
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`information, performing the first data transmission of the first system by using the first sub-
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`Attorney Ref. No. 681954.0890
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`region and performing the second data transmission of the second system by using the second
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`sub-region.
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`[0011]
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`Examples of the present invention may provide another method for allocating
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`information in a frame of a communication system. The frame may include a first frame, a
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`5
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`second frame and a band between the first frame and the second frame. The communication
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`system may include a first system and a second system. The frame may be used for first data
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`transmission of the first system and second data transmission of the second system. The method
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`may include allocating data of the first system and the second system in first mapping
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`information or second mapping information, dividing a data region of the first frame or the
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`10
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`second frame to form a first sub-region, a second sub-region, a third sub-region or a second sub(cid:173)
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`region in the data region of the first frame or the second frame according to the first mapping
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`information or the second mapping information, performing the first data transmission of the first
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`system by using the first sub-region or the third sub-region and performing the second data
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`transmission of the second system by using the second sub-region or the fourth sub-region.
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`[0012]
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`Additional features and advantages of the present invention will be set forth in part in
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`the description which follows, and in part will be obvious from the description, or may be
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`learned by practice of the invention. The features and advantages of the invention will be
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`realized and attained by means of the elements and combinations particularly pointed out in the
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`appended claims.
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`[0013]
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`It is to be understood that both the foregoing general description and the following
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`detailed description are exemplary and explanatory only and are not restrictive of the invention,
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`as claimed.
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`BRIEF DESCRIPTION OF THE DRAWINGS
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`[0014]
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`The foregoing summary, as well as the following detailed description of the
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`25
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`invention, will be better understood when read in conjunction with the appended drawings. For
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`the purpose of illustrating the invention, there are shown in the drawings examples which are
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`presently preferred. It should be understood, however, that the invention is not limited to the
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`precise arrangements and instrumentalities shown.
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`[0015]
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`In the drawings:
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`[0016]
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`FIG. 1 is a diagram illustrating an orthogonal frequency-division multiple access
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`(OFDMA) frame structure under the IEEE 802.16 standard;
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`[0017]
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`FIG. 2 is a diagram illustrating a placement of guiding signals for OFDMA signals
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`under the IEEE 802.16 standard;
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`5
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`[0018]
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`FIG. 3 is a diagram illustrating an OFDMA frame structure according to an example
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`of the present invention;
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`[0019]
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`FIG. 4 is a diagram illustrating an OFDMA frame structure supporting high mobility
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`according to an example of the present invention;
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`[0020]
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`FIG. 5 is a diagram illustrating an OFDMA frame structure with a scalable bandwidth
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`10
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`according to an example of the present invention;
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`[0021]
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`FIG. 6A is a diagram illustrating an OFDMA frame structure supporting high
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`mobility and having a scalable bandwidth according to an example of the present invention;
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`[0022]
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`FIG. 6B is a diagram illustrating an OFDMA frame structure supporting high
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`mobility and having a scalable bandwidth according to another example of the present invention;
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`15
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`and
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`[0023]
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`FIG. 7 is a diagram illustrating an exemplary placement of signals and pilots in time-
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`domain and frequency-domain of an OFDMA system supporting high mobility and having a
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`scalable bandwidth.
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`DETAILED DESCRIPTION
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`20
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`[0024]
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`Reference will now be made in detail to various embodiments of the invention,
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`examples of which are illustrated in the accompanying drawings. Wherever possible, the same
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`reference numbers will be used throughout the drawings to refer to the same or like parts.
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`[0025]
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`Exampls of the present invention may allow data of an old orthogonal frequency-
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`division multiple access (OFDMA) system (hereinafter a legacy system) and data of a new
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`25
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`OFDMA system to co-exist in an OFDMA frame by changing a frame structure of the OFDMA
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`frame. The new OFDMA system may have a larger bandwidth and support higher mobility, and
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`may use an updated transmission technology. In order to be backward compatible with the old
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`OFDMA system, the new OFDMA system may be developed based on the old OFDMA system.
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`Throughout the specification, a “new” or “extended” system or standard mayrefer to an
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`“updated,” “evolved”or “next-generation” system or standard, while a “legacy” system or
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`standard may refer to an “‘old”or “current” system or standard. For example, a “new” standard
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`may bea standard that is in use as ofthe date of the filing of this application, and a “legacy”
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`standard may be a standard that is in use prior to the date of the filing of this application and may
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`be still in use for some timeafter the filing of this application.
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`[0026]
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`FIG. 3 is a diagram illustrating an OFDMAframestructure according to an example
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`of the present invention. Referring to FIG. 3, the OFDMAframestructure may include a
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`downlink sub-frame (DL sub-frame) 16 and an uplink sub-frame (UL sub-frame) 18. The DL
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`sub-frame 16 may include a preamble 10-1, an FCH 11, a DL-MAP12, a DL burst #1 13 with an
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`UP-MAP(not shown), and a data region including DATA 30-1 (zone 1) and DATA 30-2 (zone
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`2). The UL sub-frame 18 may include a ranging sub-channel 15 and a data region including
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`DATA34-1 (zone 1) and DATA 34-2 (zone 2).
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`[0027]
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`Data of the new OFDMAsystem (the extended system) may be carried in extended
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`zones, that is, the DATA 30-2 and/or the DATA 34-2, allocated to the DL sub-frame 16 and/or
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`the UL sub-frame 18, respectively. Furthermore, the extended system in the data region DATA
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`30-2 and/or the DATA 34-2 may have the same symbolperiod or the same placementofpilot
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`symbols as the old system (the legacy system) in the data region DATA 30-1 and the DATA 34-
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`1, respectively, in the OFDMAframestructure. In one example, the data region including the
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`20
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`two zones DATA 30-1 (zone 1) and DATA 30-2 (zone2), for the old system and the new system,
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`respectively, may be placed according to the mapping information of the two zones defined in
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`the DL-MAP11. Similarly, the data region of the UL sub-frame 18 including the two zoncs
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`DATA34-1 (zone 1) and DATA 34-2 (zone 2), for the old OFDMAsystem and the new
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`OFDMAsystem,respectively, may be placed according to the mapping information of the two
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`25
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`zones defined in the UL-MAPin the DL burst #1 13.
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`[0028]
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`FIG. 4 1s a diagram illustrating an OFDMAframestructure supporting high mobility
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`according to an example of the present invention. Referring to FIG. 4, the OFDMAframe
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`structure may be similar to that described andillustrated with reference to FIG. 3 except that, for
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`example, a DL sub-frame 16-2 may further include a preamble 43, a sub-MAP 42-2 and a data
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`30
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`region DATA 40-3 (zone 3), and a UL sub-frame 18-2 may further include a data region DATA
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`44-3 (zone 3). To support communication in a high-mobility environment, the zones 3 for the
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`new system (the extended system) under high mobility may be allocated to the data region of
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`both the DL sub-frame 16-2 and the UL sub-frame 18-2. The DATA 40-3 and/or 44-3 (zones 3)
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`may have a shorter symbol period or more pilot symbols placed therein than the DATA 40-1, 40-
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`2, 44-1 and 44-2 in order to enhance the performance of channel estimation. Gencrally, a shorter
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`symbol period may be more robust to inter-symbol interference, while denser pilot symbols may
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`achieve better channel estimation accuracy. Moreover, the DATA 40-3 of the DL sub-frame 16-
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`2 for the new system (extended system) under high mobility may be divided based on the
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`mapping information defined in at least one of the DL-MAP 11 and the sub-MAP 42-2 of DATA
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`40-3, and the DATA 44-3 of the UL sub-frame 18-2 for the new system (extended system) under
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`high mobility may be divided based on the mapping information defined in the UL-MAP(not
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`shown) in the DL burst#1 13. Placements of pilot symbols, symbol periods of OFDM symbols
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`and FFT sizes in the zones | for the old (legacy) system and the zones 2 for the new (extended)
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`system may be the same in the DL sub-frame 16-2 and the UL sub-frame 18-2. The preamble 43
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`placed in front of the zone 3 of the DL sub-frame 16-2 for the newsystem (extended system)
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`may be used to support high mobility. As compared to the zones in the data region of the UL
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`sub-frame 18-2 or the DL sub-frame 16-2 of the old/legacy system or the new/extended system,
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`the placements of the pilot symbols may be denser, the symbol periods of OFDM symbols may
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`be shorter and the FFT sizes may be smaller in the DATA 40-3 and/or DATA 44-3 of the DL
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`20
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`sub-frame 16-2 or the UL sub-frame 18-2, respectively, for the extended system under high
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`mobility.
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`[0029]
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`FIG.5 is a diagram illustrating an OFDMAframestructure with a scalable bandwidth
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`according to an example of the present invention. Referring to FIG. 5, the OFDMAframe
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`structure may includea first frame structure 500, a second framestructure 502 and a third frame
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`25
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`structure 504. The first frame structure 500 may include a first DL sub-frame 16-3a anda first
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`UL sub-frame 18-3a, the second frame structure 502 may include a second DL sub-frame 16-3b
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`and a second UL sub-frame 18-3b, and the third frame structure 504 may include a third DL sub-
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`frame 16-3c and a third UL sub-frame 18-3c. Thefirst frame structure 500, which may be
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`allocated to a first band, may be similar to the frame structure described andillustrated with
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`30
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`reference to FIG. 3. Specifically, the first DL sub-frame 16-3a ofthe first frame structure 500
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`may include a preamble 50-1, an FCH, a DL-MAP 54-1, a DL burst #1 55-1 with an UL MAP
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`(not shown), DATA 56-1 (zone 1) for the old OFDMAsystem (legacy system) and DATA 56-3a
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`(zone 2) for the new OFDMAsystem (extended system). The first UL sub-frame 18-3a of the
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`first frame structure 500 may include a ranging sub-channel 58-1, DATA 59-2 (zone 1) in the
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`data region for the old OFDMAsystem (legacy system) and DATA 59-1a (zone 2) in the data
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`region for the new OFDMAsystem (extended system).
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`[0030]
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`The second frame structure 502, which maybe allocated to a second band, may be
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`similar to the frame structure described andillustrated with reference to FIG. 3. Similarly, the
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`second DL sub-frame 16-3b of the second framestructure 502 may include a preamble 52-1, an
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`FCH, a DL-MAP54-2, a DL burst #1 55-2 with an UL MAP (not shown), DATA 56-2 (zone 1)
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`in a data region for the old OFDMAsystem (legacy system) and DATA 56-3b (zone 2)in the
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`data region for the new OFDMA system (extended system), and the second UL sub-frame 18-3b
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`of the sccond framestructure 502 may include a ranging sub-channel 58-2, DATA 59-3 (zone 1)
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`in a data region for the old OFDMAsystem (legacy system) and DATA 59-4 (zone 2) in the data
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`region for the new OFDMAsystem (extended system).
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`[0031]
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`The third frame structure 504, which may be allocated to a third band, may be
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`arranged betweenthefirst frame structure 500 and the second frame structure 502. Specifically,
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`a guard band betweenthefirst frame structure 500 and the second framestructure 502 may serve
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`as the third framestructure 504 to facilitate data transmission. Unlike the guard band 22-1 or 22-
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`2 in FIG.2, data to be transmitted in the new (extended) system or a high-mobility system may
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`be allocated to a guard band betweenthe first frame structure 500 and the second framestructure
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`502. The third frame structure 504 may include a third DL sub-frame 16-3c and a third UL sub-
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`frame 18-3c. The DL sub-frame 16-3c may include a preamble 51-1, an FCH, a DL-MAPand a
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`data region DATA 56-3c (zone3) for the new (extended) system. Furthermore, the UL sub-
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`frame 18-3c may include a data region DATA 59-1b for the new (extended) system.
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`[0032]
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`An OFDMAframestructure thus constructed may have a scalable bandwidth. For
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`example, data of the old (legacy) OFDMA system in the zones 1 of the first frame structure 500
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`and the second framestructure 502 maybe transmitted in parallel using the first band and second
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`band, respectively, and data of the new (extended) OFDMAsystem in the third frame structure
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`504 and the zones 2 of the first frame structure 500 and the sccond framestructure 502 may be
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`together transmitted using the first, second and third bands. In one example, the first, second and
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`third bands may be contiguous with one another. Furthermore, upper and a lower guard bands
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`(not shown) may be required to transmit the OFDMAframestructure via the first, second and
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`third bands.
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`[0033]
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`The “zone 1” 56-1 of the first frame structure 500 andthe “zone 1” 56-2 of the
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`second frame structure 502 may be divided from the data region in the DL sub-frame 16-3a of
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`the first frame structure 500 and the data region in the DL sub-frame 16-3b of the second frame
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`structure 502, respectively, according to the mapping information in the DL-MAP 54-1 and the
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`DL-MAP54-2, respectively. Similarly, the UL sub-frame 18-3a ofthefirst frame structure 500
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`and the UL sub-frame 18-3b of the second frame structure 502 may be divided based on the
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`mapping information in the UL-MAPin the DL burst #1 55-1 ofthefirst frame structure 500 and
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`the UL-MAPin the DL burst#1 55-2 of the second framestructure 502, respectively.
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`[0034]
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`The guard band 504, whichis in a frequency spectrum not used in the old or legacy
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`system, may be used to transfer data in the present example, and the data region of the guard
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`band may be divided based on the mapping informationin at least one of the DL-MAP 54-1 or
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`the DL-MAP 54-2. The preamble part of the extended framestructure described and illustrated
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`with reference to FIG. 5 may include the preamble 50-1 and the preamble 52-1. The preamble
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`51-1 maycarry data, or may carry no information. Moreover, the DL-MAPand the FCH in the
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`guard band 504 may be used to divide the data regions 56-3c and 59-1b. In one example, a Sub-
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`MAP(not shown) may be placed in the DATA 56-3c for further description of the extended
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`20
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`system.
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`[0035]
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`FIG. 6A is a diagram illustrating an example of an OFDMAframestructure
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`supporting high mobility and having a scalable bandwidth according to an cxample of the present
`
`invention. Referring to FIG. 6A, the frame structure may be similar to the frame structure in
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`FIG. 5 except that, for example, regions related to zones 3 for a high-mobility environment may
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`be added. Specifically, in a DL sub-frame 16-4,a first region may include a preamble 68, a sub-
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`MAP67-2 and DATA 66-4, and in a UL sub-frame 18-4, a second region may include DATA
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`69-3 and 69-6 (zones 3). DATA 66-4, 69-3 and 69-6 may be allocated for the new OFDMA
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`system (extended system) under high mobility. The DL sub-frame 16-4 may be divided
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`according to the mapping information in DL-MAP 1, DL-MAP 2? and DL-MAP3, while the UL
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`sub-frame 18-4 may be divided according to the map information in UL-MAPsin DL burst#1
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`65-1 and/or 65-2. A portion of the guard band that overlaps data zones 69-1 and 69-2 in the UL
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`sub-frame 18-4 may be used to transmit data in the extended system. In one example,
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`placements ofpilot symbols, symbol periods of OFDM symbols and FFTsizes in the zones 1 for
`
`the old (legacy) system and the zones 2 for the new(extended) system may be the samein the
`
`DL sub-frame 16-4 and the UL sub-frame 18-4. As compared to the zonesin the data region of
`
`the DL sub-frame 16-4 or the UL sub-frame 18-4 of the old/legacy system or the new/extended
`
`system, the placementsof the pilot symbols may be denser, the symbol periods of OFDM
`
`symbols maybe shorter and the FFT sizes may be smaller in the zones 3 of the UL sub-frame
`
`18-4 or the DL sub-frame 16-4 for the extended system under high mobility.
`
`[0036]
`
`FIG. 6B is a diagram illustrating an OFDMAframestructure supporting high
`
`mobility and having a scalable bandwidth according to another example of the present invention.
`
`Referring to FIG. 6B, the OFDMAframe structure may be similar to the OFDMAframe
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`structure described or illustrated with reference to FIG. 6A except that, for example, the zone 2
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`in a UL sub-frame 18-4’ using the guard band may betransmitted after the zone 3 in the UL sub-
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`frame 18-4’, and the locations of zones 1 for the legacy system and zones 3 for the new
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`(extended) system for high mobility are swapped.
`
`[0037]
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`FIG. 7 is a diagram illustrating an exemplary placementof signals and pilots in time-
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`domain and frequency-domain of an OFDMA system supporting high mobility and having a
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`scalable bandwidth. Referring to FIG. 7, an upper band and a lower band may be guard bands
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`73-1 and 73-3, respectively.
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`In the prior art, guard bands do not carry any data or signals in a
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`conventional OFDMAsystem. Consistent with some examples of the present invention, the
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`guard bands 73-1 and 73-3 may be used to carry data or signals. Morcover, to satisfy backward
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`compatibility, preambles 70-1 and 72-1 may be similar to those in the conventional OFDMA
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`system. Similar to those described andillustrated with reference to FIG. 6A and 6B, signals,
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`pilot symbols, both, or neither may be placed in a preamble 71-1. The placement may define one
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`or more regions, which may include, for example, regions 74-1, 74-2, 76-1 and 76-2 for the old
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`(legacy) OFDMAsystem, regions 74-3 and 76-3 for the new (extended) OFDMAsystem
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`supporting lower mobility, and regions 74-4 and 76-4 for the new system supporting high
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`mobility. The old OFDMAsystem and the new OFDMAsystem supporting lower mobility may
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`use the same frequency intervals or the placement of pilot symbols. The new OFDMAsystem
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`supporting high mobility may use larger frequency intervals or shorter OFDM symbolperiod to
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`20
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`25
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`30
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`Attorney Ref. No. 681954.0890
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`avoid frequencyjitter. Therefore, the placement of the pilot symbolsin a first region such as one
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`of the regions 74-1, 74-2, 76-1 and 76-2 of a framestructure divided for the old OFDMA system
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`may be the sameasthat in the prior art, the placement of the pilot symbols in a second region
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`such as one of the regions 74-3 and 76-3 of the framestructure divided for the new OFDMA
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`system supporting lower mobility may be the sameor denser than the that in the prior art, and the
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`placementof the pilot symbols in a third region such as one of the regions 74-4 and 76-4 of the
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`frame structure divided for the new OFDMAsystem supporting high mobility may use more
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`denser pilot placement with more pilot symbols for increasing accuracy of the channel estimation.
`
`[0038]
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`It will be appreciated by those skilled in the art that changes could be madeto the
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`examples described above without departing from the broad inventive concept thereof. It is
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`understood, therefore, that this invention is not limited to the particular examples disclosed, but it
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`is intended to cover modifications within the spirit and scope of the present invention as defined
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`by the appended claims.
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`[0039]
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`Further, in describing representative examples of the present invention, the
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`specification may have presented a method and/or process of the present invention as a particular
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`sequence of steps. However, to the extent that the method or process does not rely on the
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`particular order of steps set forth herein, the method or process should not be limited to the
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`particular sequence of steps described. As one of ordinary skill in the art would appreciate, other
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`sequences of steps may be possible. Therefore, the particular order of the steps set forth in the
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`20
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`specification should not be construed as limitations on the claims. In addition, the claims
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`directed to the method and/or process of the present invention should not be limited to the
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`performance oftheir steps in the order written, and one skilled in the art can readily appreciate
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`that the sequences may be varied andstill remain within the spirit and scopeofthe present
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`invention.
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`Attorney Ref. No. 681954.0890
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`CLAIMS
`
`Weclaim:
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`1. A method of constructing a framestructure for data transmission, the method comprising:
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`generating a first section comprising data configured in a first format compatible with a
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`first communication system;
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`generating a second section following thefirst section, the second section comprising
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`data configured in a second format compatible with a second communication system,
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`wherein the second formatis different from the first format;
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`generating at least one non-data section containing information describing an aspect of
`
`10
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`data in at least one of the first section and the second section; and
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`combiningthefirst section, the second section and the at least one non-data section to
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`form the framestructure.
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`The methodof claim 1, wherein the non-data section comprises mapping informationfor at
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`least one of the first section and the second section.
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`15
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`The method of claim 1, wherein the non-data section comprisesat Icast onc of a preamble, a
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`frame control header (FCH), a burst, and a mapofat least oneofthe first section and the
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`second section.
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`The method of claim 3, whercin the sccond scction follows the first scction in at Icast onc of
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`time sequence and frequency spectrum.
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`20
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`The method of claim 3, wherein the second format is compatible with a third system capable
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`of supporting higher mobility than the first and the sccond systems.
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`The method of claim 5, wherein pilots in the third system are denser than thosein at least one
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`of the first or second system.
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`The method of claim 5, wherein each symbolin the third system has a shorter symbol period
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`25
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`than that in at least one ofthe first or second system.
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`12
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`Attorney Ref. No. 681954.0890
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`8. The method of claim 1, wherein a portion of the second section may be in guard bandor non-
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`communicational region ofthe first system.
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`9. The method of claim 1, wherein each ofthe first section and the second section carries at
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`least one of uplink and downlink data.
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`10. The method of claim 1, whercin the second section carrics mapping information for data in
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`the second section.
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`11. A method of generating a frame for a communication system having a first system and a
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`second system, the method comprising:
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`generating a first sub-frame for downlink transmission, wherein the first sub-frame
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`comprises:
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`a first region comprising first mapping information;
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`a second region comprising second mapping information; and
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`a third region carrying data to be transferred in the downlink transmission,the third
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`region comprising a first sub-region and a second sub-region,
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`whercin the first sub-region and second sub-region are defined by the first mapping
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`information,the first sub-region being capable of carryingfirst data ofthe first system
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`and the second sub-region being capable of carrying second data of the second system in
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`the downlink transmission, and
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`generating a second sub-framefor uplink transmission, wherein the second sub-frame
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`comprises:
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`a fourth region carrying data to be transferred in the uplink transmission, the fourth
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`region comprising a third sub-region and a fourth sub-region,
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`wherein the third sub-region and the fourth sub-region are defined by the second
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`mapping in