KR101633128B1 - Method and apparatus of allocating ranging channel for synchronized mobile station in wireless communication system - Google Patents

Abstract

A ranging channel allocation method and apparatus for a synchronized mobile station in a wireless communication system are provided. A ranging channel for the synchronous terminal is allocated to the radio resource. The radio resource to which the ranging channel for the synchronous terminal is allocated is determined based on the radio resource to which the ranging channel for the asynchronous terminal is allocated.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ranging channel allocation method and apparatus for a synchronous terminal in a wireless communication system,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to wireless communication, and more particularly, to a ranging channel allocation method and apparatus for a synchronous terminal in a wireless communication system.

The Institute of Electrical and Electronics Engineers (IEEE) 802.16e standard is a sixth standard for IMT (International Mobile Telecommunication) -2000 in ITU-R (ITU-R) under ITU (International Telecommunication Union) OFDMA TDD '. ITU-R is preparing the IMT-Advanced system as the next generation 4G mobile communication standard after IMT-2000. The IEEE 802.16 WG (Working Group) decided to implement the IEEE 802.16m project with the goal of preparing the amendment specification of the existing IEEE 802.16e as the standard for the IMT-Advanced system at the end of 2006. As can be seen from the above objectives, the IEEE 802.16m standard contains two aspects: continuity of the past, which is the modification of the IEEE 802.16e standard, and future continuity of the standards for the next generation IMT-Advanced system. Therefore, the IEEE 802.16m standard is required to satisfy all the advanced requirements for the IMT-Advanced system while maintaining compatibility with the Mobile WiMAX system based on the IEEE 802.16e standard.

In the case of a broadband wireless communication system, effective transmission and reception techniques and utilization methods have been proposed to maximize the efficiency of limited radio resources. One of the systems considered in the next generation wireless communication system is an Orthogonal Frequency Division Multiplexing (OFDM) system capable of attenuating the inter-symbol interference (ISI) effect with low complexity. OFDM converts serial data symbols into N parallel data symbols, and transmits the data symbols on N separate subcarriers. The subcarriers maintain orthogonality at the frequency dimension. Each of the orthogonal channels experiences mutually independent frequency selective fading, thereby reducing the complexity at the receiving end and increasing the interval of transmitted symbols, thereby minimizing intersymbol interference.

Orthogonal frequency division multiple access (OFDMA) refers to a multiple access method in which a part of subcarriers available in a system using OFDM as a modulation scheme is independently provided to each user to realize multiple access. OFDMA provides a frequency resource called a subcarrier to each user, and each frequency resource is provided independently to a plurality of users and is not overlapped with each other. Consequently, frequency resources are allocated mutually exclusively for each user. Frequency diversity for multiple users can be obtained through frequency selective scheduling in an OFDMA system and subcarriers can be allocated in various forms according to a permutation scheme for subcarriers. And the efficiency of spatial domain can be improved by spatial multiplexing technique using multiple antennas.

An uplink control channel for transmitting an uplink control signal may be defined. A variety of types such as a fast feedback control channel, a Hybrid Automatic Repeat reQuest feedback control channel, a sounding channel, a ranging channel, a bandwidth request channel, The uplink control channel of the uplink control channel can be defined. The fast feedback control channel carries feedback of CQI (Channel Quality Indicator) and / or MIMO (Multiple-In Multiple-Out) information, and includes a primary fast feedback channel and a secondary fast feedback channel channel). The HARQ feedback control channel is a channel for transmitting ACK (Acknowledgment) / NACK (Non-acknowledgment) signals in response to data transmission. The sounding channel can be used as an uplink channel response for uplink closed-loop MIMO transmission and uplink scheduling. The bandwidth request channel is a channel for requesting radio resources for transmitting uplink data or control signals to be transmitted by the UE.

The ranging channel may be used for uplink synchronization. The ranging channel can be divided into a non-synchronized MS and a ranging channel for a synchronized MS. The ranging channel for the asynchronous mobile station may be used for initial network entry and for ranging to the target base station during handover. The UE may not transmit any uplink burst or uplink control channel in a subframe in which a ranging channel for an asynchronous mobile station is to be transmitted. The ranging channel for the synchronous terminal can be used for periodic ranging. A terminal already synchronized with the target base station can transmit a ranging signal for the synchronous terminal.

On the other hand, in allocating the ranging channel, the base station needs to consider various frame structures and allocated resources. When allocating a ranging channel for an asynchronous terminal and a ranging channel for a synchronous terminal together, the base station needs to allocate the two channels so that they do not overlap with each other.

There is a need for a method of assigning a ranging channel for an asynchronous terminal and a ranging channel for a synchronous terminal so that the allocated resources do not overlap with each other.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a ranging channel allocation method and apparatus for a synchronous terminal in a wireless communication system.

In an aspect, a ranging channel assignment method for a synchronized mobile station in a wireless communication system is provided. The ranging channel allocation method includes assigning a ranging channel for a synchronous terminal to a first sub-frame and a first sub-band, wherein the index of the first sub-frame and the index of the first sub- The index of the second sub-frame and the index of the second sub-band to which the ranging channel for the second sub-band is allocated. The first sub-frame and the first sub-band may not overlap with the second sub-frame and the second sub-band, respectively. The index of the first ranging subband may be different from the index of the second subband by a subband offset. The index of the first subband may be determined based on the cell ID and the number of allocated subbands and may be determined based on Equation I _SB = mod (IDcell + 1, Y _SB ) have. Where I _SB denotes a subband index, IDcell denotes the cell ID, Y _SB denotes the number of allocated subbands, and mod (a, b) denotes a remainder obtained by dividing a by b. The index of the first subframe may be different from the index of the second subframe by a subframe offset. The index of the first subframe may be determined based on the subframe offset (O _SF ) of the ranging channel for the asynchronous mobile station and the number of uplink subframes (N _UL ) per frame, The index may be mod (O _SF + 1, N _UL ). The index of the first frame including the first sub-frame and the index of the second frame including the second sub-frame may differ by a frame offset. Wherein the second frame is a first frame of a superframe to which a ranging channel for the asynchronous mobile station is allocated and the first frame is a superframe to which a ranging channel for the synchronous terminal is allocated, Th frame. The ranging channel for the synchronous terminal may be allocated to a superframe in which each superframe or superframe index is a multiple of four or a multiple of eight. Wherein the ranging channel for the synchronous terminal is a periodic ranging channel for periodic ranging and the ranging channel for the asynchronous terminal is a ranging channel for initial network entry and association, Or a handover ranging channel for ranging to a target base station during a handover. The first subband or the second subband may each include 72 adjacent subcarriers.

In another aspect, a ranging channel allocation apparatus for an asynchronous mobile station in a wireless communication system is provided. The ranging channel assigning apparatus includes an RF unit for transmitting or receiving a radio signal, and a processor for receiving a ranging channel for a synchronous terminal in a first sub-frame and a first sub- The index of the first sub-frame and the index of the first sub-band are determined based on the index of the second sub-frame and the index of the second sub-band to which the ranging channel for the asynchronous mobile station is allocated, respectively . The index of the first subband may be determined based on an equation of I _SB = mod (IDcell + 1, Y _SB ). I _SB denotes a subband index, IDcell denotes a cell ID, Y _SB denotes the number of allocated subbands, and mod (a, b) denotes a remainder obtained by dividing a by b. The index of the first subframe may be mod (O _SF + 1, N _UL ). O _SF denotes a subframe offset of the ranging channel for the asynchronous mobile station, and N _UL denotes the number of uplink subframes per frame. A second frame including the second subframe is a first frame of a superframe to which a ranging channel for the asynchronous mobile station is allocated and a first frame including the first subframe includes a synchronous terminal May be the second frame of the superframe to which the ranging channel for the superframe is allocated. Wherein the ranging channel for the synchronous terminal is a periodic ranging channel for periodic ranging and the ranging channel for the asynchronous terminal is a ranging channel for initial network entry and association, Or a handover ranging channel for ranging to a target base station during a handover.

The uplink resources allocated to the ranging channel for the asynchronous MS and the ranging channel for the synchronous MS can be prevented from overlapping with each other.

1 shows a wireless communication system.
2 to 6 show an example of a frame structure.
Fig. 7 shows an example of a method of dividing the entire frequency band into a plurality of frequency partitions.
Figure 8 shows an example of a cellular system in which the FFR scheme is used.
9 shows an example of an uplink resource structure.
10 shows an example of a subband partitioning process.
11 is an example of a structure of a ranging channel for an asynchronous terminal.
12 is an example of a structure of a ranging channel for a synchronous terminal.
13 shows an embodiment of a ranging channel allocation method for the proposed synchronous terminal.
14 is a block diagram illustrating a base station and a terminal in which an embodiment of the present invention is implemented.

The following description will be made on the assumption that the present invention is applicable to a CDMA system such as Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Orthogonal Frequency Division Multiple Access (OFDMA), and Single Carrier Frequency Division Multiple Access And can be used in various wireless communication systems. CDMA may be implemented in radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. The TDMA may be implemented in a wireless technology such as Global System for Mobile communications (GSM) / General Packet Radio Service (GPRS) / Enhanced Data Rates for GSM Evolution (EDGE). OFDMA may be implemented in wireless technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and Evolved UTRA (E-UTRA). IEEE 802.16m is an evolution of IEEE 802.16e, providing backward compatibility with systems based on IEEE 802.16e. UTRA is part of the Universal Mobile Telecommunications System (UMTS). The 3rd Generation Partnership Project (3GPP) LTE (Long Term Evolution) is a part of E-UMTS (Evolved UMTS) using Evolved-UMTS Terrestrial Radio Access (E-UTRA). It adopts OFDMA in downlink and SC -FDMA is adopted. LTE-A (Advanced) is the evolution of 3GPP LTE.

For clarity of description, IEEE 802.16m is mainly described, but the technical idea of the present invention is not limited thereto.

1 shows a wireless communication system.

The wireless communication system 10 includes at least one base station 11 (BS). Each base station 11 provides a communication service to a specific geographical area (generally called a cell) 15a, 15b, 15c. The cell may again be divided into multiple regions (referred to as sectors). A user equipment (UE) 12 may be fixed or mobile and may be a mobile station, a mobile terminal, a user terminal, a subscriber station, a wireless device, a PDA The base station 11 generally refers to a fixed station that communicates with the terminal 12, and may be referred to as a " mobile station " an eNB (evolved-NodeB), a base transceiver system (BTS), an access point, and the like.

A UE belongs to one cell, and a cell to which the UE belongs is called a serving cell. A base station providing a communication service to a serving cell is called a serving BS. Since the wireless communication system is a cellular system, there are other cells adjacent to the serving cell. Another cell adjacent to the serving cell is called a neighbor cell. A base station that provides communication services to neighbor cells is called a neighbor BS. The serving cell and the neighboring cell are relatively determined based on the terminal.

This technique can be used for a downlink or an uplink. Generally, downlink refers to communication from the base station 11 to the terminal 12, and uplink refers to communication from the terminal 12 to the base station 11. In the downlink, the transmitter may be part of the base station 11, and the receiver may be part of the terminal 12. In the uplink, the transmitter may be part of the terminal 12 and the receiver may be part of the base station 11.

Fig. 2 shows an example of a frame structure.

Referring to FIG. 2, a superframe (SF) includes a superframe header (SFH) and four frames (F0, F1, F2, F3). The length of each frame in a superframe may be the same. The size of each super frame is 20 ms, and the size of each frame is 5 ms, but the present invention is not limited thereto. The length of the superframe, the number of frames included in the superframe, the number of subframes included in the frame, and the like can be variously changed. The number of subframes included in the frame may be variously changed according to the channel bandwidth and the length of the cyclic prefix (CP).

The SFH can carry essential system parameters and system configuration information. The SFH may be located in the first subframe within the superframe. SFH may occupy the last 5 OFDMA symbols of the first subframe. The superframe header can be classified into a primary SFH (P-SFH) and a secondary SFH (S-SFH). P-SFH and S-SFH can be transmitted every super frame. The S-SFH can be transmitted in two consecutive super frames. Information transmitted to the S-SFH can be divided into three sub-packets: S-SFH SP1, S-SFH SP2, and S-SFH SP3. Each subpacket can be transmitted periodically with different periods. SF-SPH SP1, S-SFH SP2, and S-SFH SP3 may have different importance of information to be transmitted, and the S-SFH SP3 may be transmitted in the shortest cycle and the S-SFH SP3 may be transmitted in the longest cycle. The S-SFH SP1 includes information about network re-entry. The S-SFH SP1 includes information on the ranging channel, resource mapping information such as subband partitioning and frequency partitioning, legacy support information for supporting the 802.16e terminal, and the like can do. The S-SFH SP2 includes information about an initial network entry and network discovery. S-SFH SP3 contains the remaining important system information.

One frame includes a plurality of subframes (subframes SF0, SF1, SF2, SF3, SF4, SF5, SF6, SF7). Each subframe may be used for uplink or downlink transmission. One subframe includes a plurality of orthogonal frequency division multiplexing (OFDM) symbols or orthogonal frequency division multiple access (OFDMA) in a time domain and includes a plurality of subcarriers in a frequency domain. do. An OFDM symbol is used to represent one symbol period and may be called another name such as an OFDMA symbol and an SC-FDMA symbol according to a multiple access scheme. The subframe may be composed of 5, 6, 7 or 9 OFDMA symbols, but this is only an example and the number of OFDMA symbols included in the subframe is not limited. The number of OFDMA symbols included in the subframe may be variously changed according to the channel bandwidth and the length of the CP. The type of the subframe can be defined according to the number of OFDMA symbols included in the subframe. For example, a Type-1 subframe may be defined as including 6 OFDMA symbols, a Type-2 subframe as 7 OFDMA symbols, a Type-3 subframe as 5 OFDMA symbols, and a Type-4 subframe as 9 OFDMA symbols have. One frame may include all subframes of the same type. Or one frame may include different types of subframes. That is, the number of OFDMA symbols included in each subframe in one frame may be the same or different from each other. Alternatively, the number of OFDMA symbols in at least one subframe in one frame may be different from the number of OFDMA symbols in the remaining subframes in the frame.

A TDD (Time Division Duplex) scheme or an FDD (Frequency Division Duplex) scheme may be applied to the frame. In the TDD scheme, each subframe is used for uplink transmission or downlink transmission at different times at the same frequency. That is, the subframes in the TDD frame are divided into the uplink subframe and the downlink subframe in the time domain. In the FDD scheme, each subframe is used for uplink transmission or downlink transmission at different frequencies of the same time. That is, subframes in a frame of the FDD scheme are divided into an uplink subframe and a downlink subframe in the frequency domain. The uplink transmission and the downlink transmission occupy different frequency bands and can be performed at the same time.

One OFDMA symbol includes a plurality of subcarriers, and the number of subcarriers is determined according to the FFT size. Subcarriers may be divided into data subcarriers for data transmission, pilot subcarriers for various estimation, guard bands, and null subcarriers for DC carriers. The parameters characterizing the OFDMA symbol are BW, N _used , n, G, and so on. BW is the nominal channel bandwidth. N _used is the number of subcarriers _used (including DC subcarriers). n is the sampling coefficient. n is combined with BW and N _used to determine the subcarrier spacing and useful symbol time. G is the ratio of CP time to useful time.

Table 1 below shows the OFDMA parameters.

Channel bandwidth, BW (MHz) 5 7 8.75 10 20 Sampling factor, n 28/25 8/7 8/7 28/25 28/25 Sampling frequency, Fs (MHz) 5.6 8 10 11.2 22.4 FFT size, N _FFT 512 1024 1024 1024 2048 Subcarrier spacing, Δf (kHz) 10.94 7.81 9.77 10.94 10.94 Useful symbol time, Tb (μs) 91.4 128 102.4 91.4 91.4 G = 1/8 Symbol time, Ts (μs) 102.857 144 115.2 102.857 102.857 FDD Number of
ODFMA symbols
per 5ms frame 48 34 43 48 48 Idle time (μs) 62.857 104 46.40 62.857 62.857 TDD Number of
ODFMA symbols
per 5ms frame 47 33 42 47 47 TTG + RTG (μs) 165.714 248 161.6 165.714 165.714 G = 1/16 Symbol time, Ts (μs) 97.143 136 108.8 97.143 97.143 FDD Number of
ODFMA symbols
per 5ms frame 51 36 45 51 51 Idle time (μs) 45.71 104 104 45.71 45.71 TDD Number of
ODFMA symbols
per 5ms frame 50 35 44 50 50 TTG + RTG (μs) 142.853 240 212.8 142.853 142.853 G = 1/4 Symbol time, Ts (μs) 114.286 160 128 114.286 114.286 FDD Number of
ODFMA symbols
per 5ms frame 43 31 39 43 43 Idle time (μs) 85.694 40 8 85.694 85.694 TDD Number of
ODFMA symbols
per 5ms frame 42 30 38 42 42 TTG + RTG (μs) 199.98 200 136 199.98 199.98 Number of Guard subcarriers Left 40 80 80 80 160 Right 39 79 79 79 159 Number of used subcarriers 433 865 865 865 1729 Number of PRU in type-1 subframe 24 48 48 48 96

In Table 1, N _FFT is the most small 2 ⁿ in the water is greater than N _used is the least power (Smallest power of two greater than N _used), sampling factor _{F s = floor (n · BW} / 8000) , and × 8000, The subcarrier spacing? F = Fs / N _FFT , the effective symbol time Tb = 1 /? F, the CP time Tg = G? Tb, the OFDMA symbol time Ts = Tb + Tg, and the sampling time is Tb / N _FFT .

Fig. 3 shows another example of the frame structure. The frame structure of FIG. 3 is a TDD frame structure and G = 1/8. A 20-ms-long superframe consists of four frames (F0, F1, F2, F3) of 5 ms in length. One frame consists of 8 subframes (SF0, SF1, SF2, SF3, SF4, SF5, SF6, SF7), and the ratio of the downlink subframe to the uplink subframe is 5: 3. The last downlink subframe SF4 includes five OFDMA symbols, and the remaining subframes include six subframes. The TDD frame structure of FIG. 3 can be applied when the bandwidth is 5 MHz, 10 MHz, or 20 MHz.

Fig. 4 shows another example of the frame structure. The frame structure of FIG. 3 is an FDD frame structure and G = 1/8. A 20-ms-long superframe consists of four frames (F0, F1, F2, F3) of 5 ms in length. One frame is composed of eight subframes (SF0, SF1, SF2, SF3, SF4, SF5, SF6, SF7), and all subframes include a downlink region and an uplink region. The downlink transmission and the uplink transmission are classified in the frequency domain. The FDD frame structure of FIG. 4 can be applied when the bandwidth is 5 MHz, 10 MHz, or 20 MHz.

Fig. 5 shows another example of the frame structure. The frame structure of FIG. 5 can be applied to both TDD and FDD systems, where G = 1/8. There are eight subframes (SF0, SF1, SF2, SF3, SF4, SF5, SF6, SF7), and the ratio of the DL subframe and the UL subframe is 5: 3. The TDD frame structure of FIG. 5 can be applied when the bandwidth is 5 MHz, 10 MHz, or 20 MHz. Each subframe may contain six or seven OFDMA symbols.

Fig. 6 shows another example of the frame structure. The frame structure of FIG. 6 shows a TDD frame structure in a legacy support mode supporting 802.16e terminals as well as 802.16m terminals.

Referring to FIG. 6, a frame includes a downlink (DL) subframe and an uplink (UL) subframe. The DL sub-frame is temporally ahead of the UL sub-frame. The DL subframe starts in the order of a preamble, a frame control header (FCH), a downlink (DL) -MAP, an uplink (UL) -MAP, and a burst area. The uplink subframe includes an uplink control channel such as a ranging channel and a feedback channel, a burst region, and the like. A guard time for distinguishing the DL subframe and the UL subframe is inserted in the middle part of the frame (between the DL subframe and the UL subframe) and the last part (after the UL subframe). Transmit / Receive Transition Gap (TTG) is a gap between a downlink burst and a subsequent uplink burst. A Receive / Transmit Transition Gap (RTG) is a gap between an uplink burst and a subsequent downlink burst. The downlink and uplink areas are divided into an area for the 802.16e terminal and an area for the 802.16m terminal. The preamble, the FCH, the DL-MAP, the UL-MAP and the DL burst area in the downlink area are areas for the 802.16e terminal and the remaining downlink areas are for the 802.16m terminal. In the uplink area, the uplink control channel and the uplink burst area are areas for the 802.16e terminal, and the remaining uplink areas are for the 802.16m terminal. The region for the 802.16e terminal and the region for the 802.16m terminal in the UL region may be multiplexed in various manners. In FIG. 3, the uplink regions are multiplexed by the TDM scheme, but the present invention is not limited thereto. The uplink regions may be multiplexed by the FDM scheme.

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 coding scheme information of the DL-MAP.

The DL-MAP is an area to which the DL-MAP message is transmitted. The DL-MAP message defines access to the downlink channel. This means that the DL-MAP message defines the indication and / or control information for the downlink channel. The DL-MAP message includes a configuration change count of DCD (Downlink Channel Descriptor) and a base station ID. The DCD describes a downlink burst profile applied to the current map. The downlink burst profile refers to the characteristics of the downlink physical channel, and DCD is periodically transmitted by the base station through the DCD message.

The UL-MAP is an area in which a UL-MAP message is transmitted. The UL-MAP message defines a connection to an uplink channel. This means that the UL-MAP message defines the indication and / or control information for the uplink channel. The UL-MAP message includes a configuration change count of a UCD (Uplink Channel Descriptor), and an allocation start time of UL allocation defined by UL-MAP. The UCD describes an uplink burst profile. The uplink burst profile refers to the characteristics of the uplink physical channel, and the UCD is periodically transmitted by the base station through the UCD message.

The downlink burst is an area to which data transmitted from the base station to the mobile station is transmitted, and an uplink burst is an area to which data transmitted from the mobile station to the base station is transmitted.

The fast feedback region is included in the UL burst region of the OFDM frame. The fast feedback region is used for transmission of information requiring a fast response from the base station. The fast feedback region may be used for CQI transmission. The position of the fast feedback region is determined by the UL-MAP. The position of the fast feedback region may be a fixed position within the OFDM frame and may be a varying position.

Tables 2 to 4 show a frame configuration according to the bandwidth and a set of frame configuration index indicating the frame configuration. The bandwidth, the CP length, the frame configuration information, and the like are indicated by a frame configuration index, and the frame configuration index can be transmitted by the S-SFH SP1.

In the frame configurations supporting the 802.16e system (WirelessMAN-OFDMA) in Table 2 to Table 4, X: Y (Z) of the DL Mix represents the ratio of the 802.16e downlink subframe and the 802.16m downlink subframe. That is, X: Y is an 802.16e downlink subframe: 802.16m downlink subframe. Z in parentheses represents the frame offset. Similarly, X: Y of the UL Mix indicates the ratio of the 802.16e uplink subframe and the 802.16m downlink subframe in the uplink TDM (Time Division Multiplexing) mode or the ratio of the 802.16e uplink subframe to the 802.16e uplink subframe in the uplink FDM (Frequency Division Multiplexing) Represents the ratio of a subchannel to an 802.16m uplink subchannel. On the other hand, in Table 2, the 5 MHz and 20 MHz bandwidths do not support 802.16e systems.

Table 2 shows a frame configuration when the bandwidth is 5/10/20 MHz and an index set indicating the frame configuration.

Table 3 shows a frame configuration when the bandwidth is 8.75 MHz and an index set indicating the frame configuration.

Table 4 shows a frame configuration when the bandwidth is 7 MHz and an index set indicating the frame configuration.

The subframe includes a plurality of physical resource units (PRU) in the frequency domain. The PRU is a basic physical unit for resource allocation, consisting of a plurality of consecutive OFDMA symbols in the time domain, and a plurality of consecutive subcarriers in the frequency domain. The number of OFDMA symbols included in the PRU may be the same as the number of OFDMA symbols included in one subframe. Therefore, the number of OFDMA symbols in the PRU can be determined according to the type of the subframe. For example, when one subframe is composed of 6 OFDMA symbols, the PRU can be defined as 18 subcarriers and 6 OFDMA symbols.

 A logical resource unit (LRU) is a basic logical unit for distributed resource allocation and contiguous resource allocation. The LRU is defined as a plurality of OFDMA symbols and a plurality of subcarriers, and includes pilots used in the PRU. Therefore, the number of suitable subcarriers in one LRU depends on the number of allocated pilots.

A Distributed Logical Resource Unit (DLRU) can be used to obtain a frequency diversity gain. The DLRU includes subcarrier groups distributed in one frequency partition. The size of the DLRU is equal to the size of the PRU. The minimum unit forming the DLRU is a tile and the size of the uplink tile is 6 subcarriers * N _sym OFDMA symbols. N _sym may vary depending on the subframe type.

A contiguous logical resource unit (CLRU) may be used to obtain a frequency selective scheduling gain. The CLRU includes a local subcarrier group. The size of the CLRU is equal to the size of the PRU.

Meanwhile, a fractional frequency reuse (FFR) scheme may be used in a multi-cell cellular system. The FFR technique is a technique of dividing an entire frequency band into a plurality of frequency partitions (FPs) and assigning frequency partitions to each cell. Different frequency partitions may be allocated between adjacent cells through the FFR technique, and the same frequency partitions may be allocated among the far-away cells. Therefore, inter-cell interference (ICI) can be reduced and performance of the cell edge terminal can be enhanced.

Fig. 7 shows an example of a method of dividing the entire frequency band into a plurality of frequency partitions.

Referring to FIG. 7, the entire frequency band is divided into a first frequency partition FP0, a second frequency partition FP1, a third frequency partition FP2, and a fourth frequency partition FP3. Each frequency partition may be partitioned logically and / or physically from the entire frequency band.

Figure 8 shows an example of a cellular system in which the FFR scheme is used.

Referring to FIG. 8, each cell is divided into an inner cell and a cell edge. Each cell is divided into three sectors. The entire frequency band is divided into four frequency partitions (FP0, FP1, FP2, FP3).

A first frequency partition (FP0) is allocated to the inside of the cell. Each sector of the cell edge is assigned either the second frequency partition (FP1) to the fourth frequency partition (FP3). At this time, different frequency partitions are allocated between adjacent cells. Hereinafter, an assigned frequency partition is referred to as an active frequency partition, and an unallocated frequency partition is referred to as an inactive frequency partition. For example, if a second frequency partition FP1 is allocated, the second frequency partition is the active frequency partition, and the third frequency partition FP2 and the fourth frequency partition FP3 are inactive frequency partitions.

The frequency reuse factor (FRF) can be defined as how many cells (or sectors) the entire frequency band can be divided into. In this case, the frequency reuse coefficient inside the cell is 1, and the frequency reuse factor of each sector of the cell edge can be 3.

9 shows an example of an uplink resource structure.

Referring to FIG. 9, the uplink subframe may be divided into at least one frequency partition. Here, although the subframe is divided into two frequency partitions FP1 and FP2 by way of example, the number of frequency partitions in a subframe is not limited thereto. The number of frequency partitions can be at most four. Each frequency partition can be used for other purposes such as FFR.

Each frequency partition is composed of at least one PRU. Each frequency partition may include distributed resource allocation and / or contiguous resource allocation. The distributed resource allocation may be a DLRU, and the contiguous resource allocation may be a CLRU. Here, the second frequency partition FP2 includes distributed resource allocation and consecutive resource allocation. 'Sc' means a subcarrier.

When a plurality of cells exist, the uplink resources may be mapped through processes such as subband partitioning, miniband permutation, and frequency partitioning.

10 shows an example of a subband partitioning process. 10 shows a subband partitioning process when the bandwidth is 10 MHz.

A plurality of PRUs are divided into a subband (SB) and a miniband (MB). In FIG. 10- (a), a plurality of PRUs are allocated as subbands, and in FIG. 10- (b), a plurality of PRUs are allocated as mini-bands. The subband includes N1 adjacent PRUs, and the miniband includes N2 adjacent PRUs. N1 = 4, and N2 = 1. The subbands are suitable for frequency selective resource allocation since consecutive PRUs are allocated in the frequency domain. The mini-bands are suitable for frequency-dispersive resource allocation and may be permutated in the frequency domain.

이며, PRU의 총 개수 N_PRU=L_SB+L_MB이다. The number of subbands can be represented by K _SB . The number of PRUs allocated to the subbands can be represented by L _SB , where L _SB = N 1 * K _SB . K _SB can vary depending on the bandwidth. K _SB may be determined by an uplink subband allocation count (USAC). The length of the USAC may be 3 to 5 bits, and may be broadcast through SFH or the like. The remaining PRUs allocated as subbands are allocated as mini-bands. The number of mini-bands can be expressed in K _MB . Number of PRU allocated to the mini-band can be expressed as L _MB, the L _MB = N2 * K _MB. The maximum number of subbands that can be formed in the resource region

, And the total number of _PRUs N _PRU = L _SB + L _MB .

Table 5 shows an example of the relationship between USAC and K _SB when the bandwidth is 20 MHz. The FFT size may be 2048 when the bandwidth is 20 MHz.

USAC K _SB USAC K _SB 0 0 16 16 One One 17 17 2 2 18 18 3 3 19 19 4 4 20 20 5 5 21 21 6 6 22 reserved 7 7 23 reserved 8 8 24 reserved 9 9 25 reserved 10 10 26 reserved 11 11 27 reserved 12 12 28 reserved 13 13 29 reserved 14 14 30 reserved 15 15 31 reserved

Table 6 shows an example of the relationship between USAC and K _SB when the bandwidth is 10 MHz. The FFT size can be 1024 when the bandwidth is 10 MHz.

USAC K _SB USAC K _SB 0 0 8 8 One One 9 9 2 2 10 10 3 3 11 reserved 4 4 12 reserved 5 5 13 reserved 6 6 14 reserved 7 7 15 reserved

Table 7 shows an example of the relationship between USAC and K _SB when the bandwidth is 5 MHz. The FFT size may be 512 when the bandwidth is 5 MHz.

USAC K _SB USAC K _SB 0 0 4 4 One One 5 reserved 2 2 6 reserved 3 3 7 reserved

The plurality of PRUs are divided into subbands and mini-bands, and are rearranged in subbands PRU (PRU _SB ) and miniband PRU (PRU _MB ). The PRUs in the PRU _SB are each indexed from 0 to (L _SB -1), and the PRUs in the PRU _MB are indexed with any one of 0 to (L _MB -1).

In the mini-band permutation process, the PRU _MB is mapped to the permutation PRU (PPRU _MB ). In the frequency partitioning process, PRUs of PRU _SB and PPRU _MB are allocated to at least one frequency partition.

Hereinafter, a ranging channel will be described.

The ranging channel for the asynchronous mobile station may be used as an initial network entry of the mobile station and as a ranging target for a target BS during handover. A ranging channel for the asynchronous mobile station a ranging preamble length T _RP in the time domain may include;; (Ranging Cyclic Prefix RCP) (RP Ranging Preamble) and length ranging T CP of _RCP. T _RP can be varied by? F _RP , which is the spacing of ranging subcarriers. The ranging channel may be assigned to one subband including four adjacent CLRUs.

Table 8 shows an example of the format and parameters of the ranging channel.

Format T _RCP T _RP Δf _RP 0 K1 * Tg + K2 * Tb 2 * Tb Δf / 2 One 3.5 * Tg + 7 * Tb 8 * Tb ? F / 8

Tb, Tg, and? F can be defined as effective symbol time, CP length, and subcarrier interval, respectively, according to Table 1. The T _RCP of the ranging channel format 0 may be varied depending on the OFDMA parameter and the subframe type in Table 1. [ In this case, k1 = (N _sym +1) / 2 and k2 = (N _sym -4) / 2. N _sym is the number of OFDMA symbols included in one subframe.

11 is an example of a structure of a ranging channel for an asynchronous terminal. The ranging channel for the asynchronous mobile station may be allocated to one or three subframes according to the ranging channel format of Table 8. [ For example, when the ranging channel format is 0, the ranging channel for the asynchronous mobile station can be allocated to one subframe and the ranging channel for the asynchronous mobile station can be allocated to the 3 subframes when the ranging channel format is 1. RCP is a copy of the rear part of the RP, and phase discontinuity between RCP and RP does not occur. The starting point of transmission of the ranging channel is aligned with the starting point of the uplink subframe corresponding to the downlink synchronization acquired by the downlink preamble in the UE. The remaining time of the ranging channel in the subframe may be reserved to prevent interference between adjacent subframes. The UE may not transmit any uplink burst or uplink control channel in a subframe in which a ranging channel for an asynchronous mobile station is to be transmitted.

The ranging channel transmits a ranging preamble code. The ranging preamble code transmitted on the ranging channel for the asynchronous mobile station can be divided into an initial ranging ranging preamble code and a handover ranging preamble code according to the usage. In each ranging code opportunity, the UE randomly selects one from a set of ranging preamble codes selectable in the cell. However, in the case of the handover ranging, when the dedicated ranging code is allocated, the terminal must use the allocated dedicated ranging code.

A Zadoff-Chu (ZC) sequence to which a cyclic shift is applied can be used as a ranging preamble code of a ranging channel for an asynchronous mobile station. Equation (1) is an example of a mathematical expression for generating a ranging preamble code.

p is the index of the root index is shifted from the ZC sequence of r _p N _CS cycle by s _p times ranging candidate preamble code determined. r _p and s _p may be defined by Equation (2), respectively.

The p < th > candidate ranging preamble code is determined using the root index r _p and the s _{p <} th > cyclic shift determined from the starting root index r ₀ . N _TOTAL is the total number of candidate ranging preamble codes of the sector-specific initial access ranging channel and the handover ranging channel. N _TOTAL is assumed to include only a contention-based preamble code allocated by the UE for convenience, but may also include a dedicated preamble code assigned by the base station. When N _TOTAL are included only to the preamble code, N _TOTAL can be expressed as the sum of the number of N _dedi dedicated preamble code and _cont N is the number of contention-based preamble code. N _cont can be expressed by the sum of the number N _IN of the candidate ranging preamble codes of the initial ranging ranging channel and the number N _HO of the candidate ranging preamble codes of the handover ranging channel. N _dedi may be up to 32 days.

로 정의될 수 있다. 여기서 M은 ZC 시퀀스의 루트 인덱스당 순환 쉬프트된 코드의 개수를 나타내며, 이는 표 9에 의하여 결정될 수 있다. N _CS is a unit of cyclic shift according to the cell size in the time domain.

. ≪ / RTI > Where M represents the number of cyclically shifted codes per root index of the ZC sequence, which can be determined by Table 9.

Index 0 One 2 3 M One 2 4 8

N _RP is the length of the ranging preamble code, which can be 139 when the format of the ranging channel determined by Table 8 is 0 and 557 when the format of the ranging channel is 1. The r ₀ and M and the ranging preamble code partition information may be broadcast through the SFH. At this time, the starting root index r ₀ of the ZC sequence can be expressed as r ₀ = 4k + 1 or r ₀ = 16k + 1 according to the ranging channel format. k can be broadcast over the S-SFH, and k can be any integer from 0 to 15. [ The ranging preamble code partition information indicates the number of ranging preamble codes of each ranging channel, which can be determined by Table 10.

Partition Index 0 One 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Number of initial ranging preamble codes 8 8 8 8 16 16 16 16 24 24 24 24 32 32 32 32 Number of handover ranging preamble codes 8 16 24 32 8 16 24 32 8 16 24 32 8 16 24 32

The ranging channel for the asynchronous mobile station can be allocated by the ranging channel time resource information indicating the time domain assigned to the ranging channel and the ranging channel frequency resource information indicating the frequency domain assigned to the ranging channel. The ranging channel time resource information may indicate a subframe offset (O _SF ) of the ranging channel allocation in the time domain. The ranging channel time resource information may be broadcast by the S-SFH. Table 11 is an example of a time resource to which a ranging channel according to ranging channel time resource information is allocated.

Configurations The subframe allocating Ranging channel 0 O _SF ^th UL subframe in every frame One O _SF ^th UL subframes in the first frame in every superframe 2 O _SF ^th UL subframe in the first frame in every even numbered superframe, ie, mod (superframe number, 2) = 0 3 O _SF ^th UL subframe of the first frame in every 4 ^th superframes, ie, mod (superframe number, 4) = 0

Referring to Table 11, the ranging channel can be allocated to the O _SF -th uplink subframe of each frame. According to the configuration of the ranging channel for the asynchronous mobile station, the ranging channel for the asynchronous mobile station is allocated to the O _SF -th uplink subframe of each frame, or the O _SF -th uplink of the first frame of each superframe Frame. The ranging channel for the asynchronous mobile station may be allocated to the O _SF -th uplink subframe of the first frame of the superframe in which the superframe index is a multiple of 2 or a multiple of four. When the ranging channel format is 1, the ranging channel for the asynchronous mobile station is allocated to three consecutive subframes starting from the determined subframe in Table 11. [

The ranging channel frequency resource information may be determined by a cell ID (cell ID) and a number K _SB of allocated subbands. The frequency resource to which the ranging channel is allocated may be determined in advance without being transmitted to the terminal. The frequency resource to which the ranging channel is allocated can be determined by Equation (3).

In Equation (3), I _SB is the subband index (I _SB = 0, ..., Y _SB -1), IDCell is the cell ID, and Y _SB is the number of allocated subbands. mod (a, b) represents the remainder obtained by dividing a by b. According to Equation (3), different subbands are allocated to the base stations as ranging channels.

Equation (4) represents a ranging signal transmitted through an antenna as a function of time.

로 정의될 수 있다. NPRU는 PRU의 총 개수이며, k₀는 레인징 채널에 할당되는 PRU 중 가장 작은 PRU 인덱스이다. Psc는 주파수 영역의 하나의 PRU 내에서 연속한 부반송파의 개수이다. Δf_RP는 레인징 부반송파의 간격(spacing)이다.In Equation (4), t is the elapsed time from the start of the ranging channel. N _RP is the length of the ranging preamble code in the frequency domain. x _p (n) is a p-th ranging preamble code of length N _RP . K _offset is a parameter related to a frequency position,

. ≪ / RTI > NPRU is the total number of PRUs, and k ₀ is the smallest PRU index among the PRUs assigned to the ranging channel. Psc is the number of consecutive subcarriers in one PRU in the frequency domain. And? F _RP is the spacing of the ranging subcarriers.

The ranging channel for the synchronous terminal can be used for periodic ranging. A terminal already synchronized with the target base station can transmit a ranging signal for the synchronous terminal. The ranging channel for the synchronous terminal can occupy six OFDMA symbols starting from the first OFDMA symbol of 72 subcarriers and one subframe. A ranging channel for a synchronous terminal occupies 72 subcarriers and 3 OFDMA symbols and may be composed of a basic unit generated from a ranging preamble code and a repeated unit that repeats the same one time.

12 is an example of a structure of a ranging channel for a synchronous terminal. Tb denotes the effective symbol time in Table 1, and Tg denotes the CP length. The first three OFDMA symbols are allocated to the base unit, and the next three OFDMA symbols are allocated to the repeat unit.

The Padded ZC sequence to which the cyclic shift is applied can be used as the ranging preamble code of the ranging channel for the synchronous terminal. Equation (5) is an example of a ranging preamble code used in a ranging channel for a synchronous terminal.

p is the index of the ranging preamble code in the root index is shifted one _cycle, by the ZC sequences from m _'determined n-th OFDMA symbol. ', _' , _' Can be defined by Equation (6).

로 결정될 수 있다. m은 순환 쉬프트 유닛이며, N_RP는 레인징 프리앰블 코드의 길이이다. N_TOTAL은 섹터별 동기 단말을 위한 레인징 채널의 주기적 레인징 프리앰블 코드의 총 개수이며, 표 12에 의해서 결정될 수 있다. The starting root index r _s0 may be broadcast,

. ≪ / RTI > m is a cyclic shift unit, and N _RP is the length of the ranging preamble code. N _TOTAL is the total number of periodic ranging preamble codes of a ranging channel for a sector-by-sector synchronous terminal, and can be determined according to Table 12. [

index 0 One 2 3 Number of periodic ranging preamble codes, N _PE 8 16 24 32

_Cq (n) is a DFT code or a Walsh code used as a ranging preamble covering code, and can be determined by Table 13.

C _q ( n ) OFDMA symbol index within a basic unit, n 0 One Covering code index, q 0 One One One One -One

In a contention-based ranging code opportunity, the terminal arbitrarily selects one of the two time-domain covering codes.

Equation (7) is another example of the ranging preamble code used in the ranging channel for the synchronous terminal.

p is an index of a ranging preamble code constituting a basic unit of a ranging channel determined by cyclic shifting from a ZC sequence whose root index is r _p . r _p and s _p can be defined by equation (8).

The p-th candidate ranging preamble code is determined using the root index r _p determined from the starting root index r ₀ . M is the number of cyclically shifted codes per root index of the ZC sequence, and can be defined as M = 1 / G. N _TOTAL is the total number of periodic ranging preamble codes of a ranging channel for a sector-by-sector synchronous terminal, and can be determined according to Table 12. [

N _TCS is a unit of time-domain cyclic shift per OFDMA symbol according to CP length, and can be defined as N _TCS = G * N _FFT . G and N _FFTs can be defined by Table 1. N _RP is the length of the ranging preamble code and can be defined as N _RP = 71 in this embodiment. The starting root index r ₀ and the ranging preamble code information may be broadcast by the base station. The ranging preamble code information can be defined by Table 12. The starting root index r ₀ of the ZC sequence can be expressed as r ₀ = 6k + 1 or r ₀ = 16k + 1 according to the ranging channel format. k may be a cell-specific value.

Similarly to the ranging channel for the asynchronous mobile station, the ranging channel for the synchronous terminal includes ranging channel time resource information for indicating a time domain allocated to the ranging channel and a ranging channel frequency for indicating a frequency domain allocated to the ranging channel Can be allocated by resource information. In this case, the ranging channel for the synchronous terminal needs to be allocated so as not to overlap with the ranging channel for the asynchronous terminal, and accordingly, the frequency domain or the time domain, to which the ranging channel for the synchronous terminal is allocated, It needs to be set differently from the frequency domain or time domain to which the channel is allocated.

Hereinafter, a ranging channel allocation method for a synchronous terminal proposed through embodiments will be described.

13 shows an embodiment of a ranging channel allocation method for the proposed synchronous terminal.

In step S100, the base station allocates a ranging channel for the synchronous terminal to the first sub-frame and the first sub-band. And the index of the first sub-frame and the index of the first sub-band are determined based on the index of the second sub-frame and the index of the second sub-band to which the ranging channel for the asynchronous mobile station is allocated, respectively .

First, a frequency region to which a ranging channel for a synchronous terminal is allocated may be the same as a frequency region to which a ranging channel for an asynchronous mobile station is allocated, and positions to be mutually allocated may be different by assigning offsets in the time domain. At this time, the information on the frequency domain to which the ranging channel for the synchronous terminal is allocated and the information on the ranging channel for the asynchronous terminal can be used without any additional signaling on the offset.

For example, a frequency region to which a ranging channel for a synchronous terminal is allocated is the same as a frequency region to which a ranging channel for an asynchronous terminal is allocated, and a time region to which a ranging channel for a synchronous terminal is allocated is a May be determined by giving an offset of 1 to the subframe index to which the ranging channel is assigned. That is, when a ranging channel for the asynchronous mobile station is allocated to the O _SF -th uplink subframe, a ranging channel for the synchronous mobile station may be allocated to the (O _SF + 1, N _UL ) th uplink subframe . Table 14 is an example of a subframe configuration in which a ranging channel for a synchronous terminal is allocated.

Configurations The subframe allocating Ranging channel 0 mod (O _SF + 1, N _UL ) ^th UL subframe in every frame One mod (O _SF + 1, N _UL ) ^th UL subframes in the first frame in every superframe 2 mod (superframe number, 2) = 0, mod (O _SF + 1, N _UL ) ^th UL subframe in the first frame in every even numbered superframe, 3 mod (superframe number, 4) = 0, mod (O _SF + 1, N _UL ) ^th UL subframe of the first frame in every 4 ^th superframes,

Referring to Table 14, a ranging channel for a synchronous terminal can be allocated to a mod (O _SF + 1, N _UL ) th uplink subframe of each frame. Synchronous ranging channel for the terminal mod of every frame (O _SF + 1, N _UL) -th uplink or allocated to the sub-frame, or the first frame of each superframe (O _SF + 1, N _UL) mod th And may be allocated to an uplink subframe. (O _SF + 1, N _UL ) th uplink subframe of the first frame of the superframe in which the superframe index is a multiple of 2 or a multiple of 4 by increasing the period of the ranging channel for the synchronous terminal Can be assigned. The position of the frequency domain to which the ranging channel for the synchronous terminal is allocated may be the same as the position of the frequency domain to which the ranging channel for the asynchronous terminal is allocated,

Even if a ranging channel for a synchronous terminal is allocated as shown in Table 14, if the number of allocated subbands, Y _SB = 1, and the number of uplink subframes N _UL = 1 in a frame, the ranging channel for the asynchronous terminal The ranging channels for the synchronous terminals are allotted overlappingly. Also, even if the period of the ranging channel is longer than one frame, the same resource can be used for the ranging channel for the asynchronous terminal and the ranging channel for the synchronous terminal.

Accordingly, when the period of the ranging channel is longer than one frame, the ranging channel for the asynchronous terminal and the ranging channel for the synchronous terminal are allocated to different frames, thereby preventing the two channels from overlapping each other. That is, the ranging channel for the asynchronous terminal and the ranging channel for the synchronous terminal may have a frame offset. Table 15 is an example of a subframe configuration in which a ranging channel for a synchronous terminal is allocated.

Configurations The subframe allocating Ranging channel 0 mod (O _SF + 1, N _UL ) ^th UL subframe in every frame One mod (O _SF + 1, N _UL ) ^th UL subframes in the second frame in every superframe 2 mod (superframe number, 4) = 0, mod (O _SF + 1, N _UL ) ^th UL subframe in the second frame in every 4 ^th superframes, 3 mod (superframe number, 8) = 0, mod (O _SF + 1, N _UL ) ^th UL subframe of the second frame in every 8 ^th superframes,

Referring to Table 15, when the period of the ranging channel is longer than one frame as compared with Table 14, the ranging channel for the synchronous terminal is the mod (O _SF + 1, N _UL ) th uplink of the second frame of the superframe Frame. A second frame to which a ranging channel for a synchronous terminal is allocated is merely an example and a ranging channel for a synchronous terminal may be allocated to a frame to which a ranging channel for an asynchronous terminal such as a third or fourth frame is not allocated have. In the case of Y _SB = 1 and N _UL = 1, it is impossible to avoid overlapping of the two channels. Therefore, when Y _SB = 1 and N _UL = 1, ) Can not be used.

Table 16 shows an example of a subframe configuration in which a ranging channel for a synchronous terminal is allocated.

Configurations The subframe allocating Ranging channel 0 mod (O _SF , N _UL ) ^th UL subframe in every frame One mod (O _SF , N _UL ) ^th UL subframes in the second frame in every superframe 2 mod (superframe number, 4) = 0, mod (O _SF , N _UL ) ^th UL subframe in the second frame in every 4 ^th superframes, 3 mod (O _SF , N _UL ) ^th UL subframe of the second frame in every 8 ^th superframes, ie, mod (superframe number, 8) = 0

Table 16 compares the ranging region for the asynchronous mobile station and the time region for allocating the ranging channel for the synchronous mobile station by frame offset without subframe offset, compared with Table 15.

Alternatively, a time zone to which a ranging channel for a synchronous terminal is allocated may be determined to be the same as a time domain to which a ranging channel for an asynchronous terminal is allocated, and may be assigned an offset in the frequency domain to be assigned different positions. At this time, the information on the frequency domain to which the ranging channel for the synchronous terminal is allocated and the information on the ranging channel for the asynchronous terminal can be used without any additional signaling on the offset.

For example, a time zone to which a ranging channel for a synchronous terminal is assigned is the same as a time domain to which a ranging channel for an asynchronous terminal is allocated, and a frequency domain to which a ranging channel for a synchronous terminal is allocated, May be determined by giving an offset of 1 to the subband index to which the ranging channel is assigned. That is, the index of the subband to which the ranging channel for the synchronous terminal is allocated can be determined by Equation (9).

In Equation (9), I _SB is a subband index (I _SB = 0, ..., Y _SB -1), IDCell is a cell ID, and Y _SB is the number of assigned subbands. mod (a, b) represents the remainder obtained by dividing a by b. The index of a subband to which a ranging channel for a synchronous terminal is allocated according to Equation (9) has an index of a subband to which a ranging channel for an asynchronous terminal is allocated and an offset of 1.

Table 17 shows an example of a subframe configuration in which a ranging channel for a synchronous terminal is allocated.

Configurations The subframe allocating Ranging channel 0 mod (O _s , _SF , N _UL ) ^th UL subframe in every frame One mod (O _s , _SF , N _UL ) ^th UL subframes in the second frame in every superframe 2 mod (superframe number, 2) = 0, mod (O _s , _SF , N _UL ) ^th UL subframe in the second frame in every even superframes, 3 mod (superframe number, 4) = 0, mod (O _s , _SF , N _UL ) ^th UL subframe of the second frame in every 4 ^th superframes,

In Table 17, O _{s, SF} can be determined by Equation (10).

If the number of subbands allocated by Equation (10) is one, a ranging channel for a synchronous terminal can be allocated with a subframe offset for a ranging channel for an asynchronous terminal.

Alternatively, a time domain and a frequency domain in which a ranging channel for a synchronous terminal is allocated may be allotted to a time domain and a frequency domain to which a ranging channel for an asynchronous terminal is allocated. At this time, the offset in the time domain and the offset in the frequency domain are fixed, so that the information on the frequency domain to which the ranging channel for the synchronous terminal is allocated and the information on the ranging channel for the asynchronous terminal can be used without any additional signaling on the offset have. The position of the frequency domain of the ranging channel for the synchronous terminal can be determined by Equation (9), and the position of the frequency domain can be determined by Table 14.

14 is a block diagram illustrating a base station and a terminal in which an embodiment of the present invention is implemented.

The base station 800 includes a processor 810 and a radio frequency unit 820. The processor 810 allocates a ranging channel for the synchronous terminal to the first sub-frame and the first sub-band. The index of the first sub-frame and the index of the first sub-band are determined based on the index of the second sub-frame and the index of the second sub-band, respectively, to which the ranging channel for the asynchronous mobile station is allocated. The position of the time domain of the ranging channel for the synchronous terminal can be determined by Tables 14 to 17, and the position of the frequency domain can be determined by Equation (9). The RF unit 820 is connected to the processor 810 and transmits and / or receives a radio signal.

The terminal 900 includes a processor 910 and an RF unit 920. The processor 910 processes the ranging signal to be transmitted to the base station. The RF unit 920 is connected to the processor 910 and transmits the ranging signal through a ranging channel for a synchronous terminal.

The present invention may be implemented in hardware, software, or a combination thereof. (DSP), a programmable logic device (PLD), a field programmable gate array (FPGA), a processor, a controller, a microprocessor, and the like, which are designed to perform the above- , Other electronic units, or a combination thereof. In software implementation, it may be implemented as a module that performs the above-described functions. The software may be stored in a memory unit and executed by a processor. The memory unit or processor may employ various means well known to those skilled in the art.

In the above-described exemplary system, the methods are described on the basis of a flowchart as a series of steps or blocks, but the present invention is not limited to the order of the steps, and some steps may occur in different orders . It will also be understood by those skilled in the art that the steps shown in the flowchart are not exclusive and that other steps may be included or that one or more steps in the flowchart may be deleted without affecting the scope of the invention.

The above-described embodiments include examples of various aspects. While it is not possible to describe every possible combination for expressing various aspects, one of ordinary skill in the art will recognize that other combinations are possible. Accordingly, it is intended that the invention include all alternatives, modifications and variations that fall within the scope of the following claims.

Claims (20)

A ranging channel allocation method for a synchronized mobile station by a base station in a wireless communication system,
And allocating a ranging channel for the synchronous terminal to the first sub-frame and the first sub-band,
The first subframe is determined using a mod (O _SF + 1, N _UL ) th uplink sub-frame,
The O _SF denotes a subframe offset of a ranging channel for a non-synchronized mobile station,
And N _UL denotes a number of uplink subframes per frame. delete delete delete The method according to claim 1,
The first subband is determined using mod (IDcell + 1, Y _SB )
The IDCell is a cell ID,
And the Y _SB represents a number of allocated subbands. delete delete delete The method according to claim 1,
And broadcasting synchronous ranging channel assignment information including the sub-frame offset O _SF through a secondary superframe header (S-SFH). The method according to claim 1,
Wherein the first sub-frame is allocated to each frame. The method according to claim 1,
Wherein the first subframe is allocated to a second frame of each superframe or a second frame of a superframe whose superframe index is a multiple of four or a multiple of eight. The method according to claim 1,
Wherein the ranging channel for the synchronous terminal is a periodic ranging channel for periodic ranging. The method according to claim 1,
The ranging channel for the asynchronous mobile station may include a ranging channel for initial network entry and association or a handover ranging for ranging to a target base station during handover, Wherein the ranging channel is one of a first channel and a second channel. delete An apparatus for allocating ranging channels for a synchronous terminal in a wireless communication system,
A radio frequency (RF) unit; And
And a processor coupled to the RF unit,
The processor comprising:
And allocating a ranging channel for the synchronous terminal to the first sub-frame and the first sub-
The first subframe is determined using the (O _SF + 1, N _UL ) th uplink subframe,
The O _SF denotes a subframe offset of a ranging channel for a non-synchronized mobile station,
And N _UL denotes a number of uplink subframes per frame. delete delete delete delete delete

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