JP5289615B2 - Ranging channel transmission method and apparatus in wireless communication system - Google Patents

Description

The present invention relates to wireless communication, and more particularly, to a ranging channel transmission method and apparatus in a wireless communication system.

The IEEE (Institute of Electrical and Electronics Engineers) 802.16e standard is the ITU-R (ITU-Radiocommunication Sector) of the ITU (International Telecommunication Union) of the ITU (International Telecommunications Union) of 2007. And has been adopted under the name 'WMAN-OFDMA TDD'. ITU-R is preparing the IMT-Advanced system as the next-generation 4G mobile communication standard after IMT-2000. The IEEE 802.16WG (Working Group) has decided to promote the IEEE 802.16m project with the goal of creating an amendment standard for the existing IEEE 802.16e as a standard for the IMT-Advanced system at the end of 2006. As can be seen from the above goals, the IEEE 802.16m standard includes two aspects: the past continuity of the modification of the IEEE 802.16e standard and the future continuity of the standard for the next generation IMT-Advanced system. . Accordingly, the IEEE 802.16m standard requires that all advanced requirements for IMT-Advanced systems be met while maintaining compatibility with the Mobile WiMAX system based on the IEEE 802.16e standard.

In the case of a wide area radio communication system, effective transmission / 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) that can reduce the effect of inter-symbol interference (ISI) due to low complexity. ) System. In OFDM, data symbols input in series are converted into N parallel data symbols, and transmitted on N subcarriers that are separated from each other. The subcarriers should maintain orthogonality in the frequency dimension. Each orthogonal channel will experience frequency selective fading, which is independent of each other, thereby reducing the complexity at the receiving stage and increasing the interval between transmitted symbols. Interference can be minimized.

Orthogonal Frequency Division Multiple Access (hereinafter referred to as OFDMA) is a system that uses OFDM as a modulation scheme, and provides each user with a part of available subcarriers independently. A multiple connection method to be realized. OFDMA provides a frequency resource called a subcarrier to each user, and each frequency resource is generally provided to a large number of users independently and does not overlap each other. Eventually, frequency resources are allocated mutually exclusive for each user. In an OFDMA system, frequency diversity for multiple users can be obtained through frequency selective scheduling, and subcarriers can be allocated to various forms according to a permutation scheme for subcarriers. . In addition, the efficiency of the spatial domain can be improved by a spatial multiplexing technique using multiple antennas.

A ranging channel can be used for uplink synchronization. The ranging channel can be divided into a ranging channel for a non-synchronized MS and a synchronized MS. A ranging channel for an asynchronous terminal can be used for initial access and handover. A ranging channel for a synchronous terminal can be used for periodic ranging.

There is a need for a resource allocation method for a ranging channel in consideration of a frequency partition (FP) and a subband (SB) / miniband (MB).

The technical problem of the present invention is to provide a method and apparatus for transmitting a ranging channel in a wireless communication system.

In one aspect, a ranging channel transmission apparatus in a wireless communication system is provided. The apparatus includes a processor and an RF unit that is coupled to the processor, receives a ranging channel frequency resource allocation information, and transmits the ranging channel, and the processor includes the ranging channel frequency resource allocation information. A ranging channel is allocated to one ranging subband on the resource region determined based on the frequency, and the frequency resource allocation information of the ranging channel includes the cell ID to which the terminal belongs and the resource It includes the number of subbands assigned to a region or the number of assigned subband CRUs (Contiguous Resource Units). The ranging subband is a subband having an index calculated according to the formula of I _SB = mod (cellID, X _SB ). I _SB is an index (0,..., X _SB −1) of a subband on the resource area, cellID is a cell ID to which the terminal belongs, and X _SB is a subband assigned to the resource area. Or the number of allocated subband CRUs. The cellID is any one integer from 0 to 767. The number of subbands allocated to the resource area or the number of allocated subband CRUs is broadcast or indicated by other signals. The number of subbands allocated to the resource area varies according to the system bandwidth. The ranging subband includes a plurality of adjacent physical resource units (PRUs). The number of adjacent PRUs is four.

In another aspect, a ranging channel transmission method in a wireless communication system is provided. The method receives the frequency resource allocation information of the ranging channel, and assigns the ranging channel to one ranging subband on the resource region determined based on the frequency resource allocation information of the ranging channel. Allocation, transmitting the ranging channel, and the frequency resource allocation information of the ranging channel includes a cell ID to which a terminal belongs and the number of subbands allocated to the resource region or an allocated subband CRU (Contiguous). Number of Resource Units). The ranging subband is a subband having an index calculated according to the formula of I _SB = mod (cellID, X _SB ). I _SB is an index (0,..., X _SB −1) of a subband on the resource area, cellID is an ID to which the terminal belongs, and X _SB is a subband assigned to the resource area. Or the number of allocated subband CRUs. The cellID is any one integer from 0 to 767. The number of subbands allocated to the resource area or the number of allocated subband CRUs is broadcast or indicated by other signals. The number of subbands allocated to the resource area varies according to the system bandwidth. The ranging subband includes a plurality of adjacent physical resource units (PRUs). The number of adjacent PRUs is four.
This specification provides the following items, for example.
(Item 1)
In a ranging channel transmission apparatus in a wireless communication system,
A processor; and
An RF unit coupled to the processor, receiving frequency resource allocation information of a ranging channel, and transmitting the ranging channel;
The processor allocates a ranging channel to one ranging subband on a resource region determined based on frequency resource allocation information of the ranging channel,
The ranging resource frequency resource allocation information includes a cell ID to which a terminal belongs and the number of allocated subbands or the number of allocated subband CRUs (Contiguous Resource Units).
(Item 2)
The apparatus of claim 1, wherein the ranging subband is a subband having an index calculated by the following equation.
I _SB = mod (cellID, X _SB )
I _SB is an index (0,..., X _SB −1) of a subband on the resource area . The cell ID is a cell ID to which the terminal belongs. X _SB is the number of allocated subbands or the number of allocated subband CRUs. mod (cellID, X _SB ) is the remainder obtained by dividing the cell ID by X _SB .
(Item 3)
The apparatus according to Item 2, wherein the cellID is an integer of any one of 0 to 767.
(Item 4)
The apparatus of claim 1, wherein the number of allocated subbands or the number of allocated subband CRUs is broadcasted or indicated by other signals.
(Item 5)
The apparatus of claim 1, wherein the number of allocated subbands varies according to a system bandwidth.
(Item 6)
The apparatus of claim 1, wherein the ranging subband includes a plurality of adjacent physical resource units (PRUs).
(Item 7)
The apparatus according to item 6, wherein the number of the plurality of adjacent PRUs is four.
(Item 8)
In a ranging channel transmission method in a wireless communication system,
Receive the frequency resource allocation information of the ranging channel,
A ranging channel is allocated to one ranging subband on a resource region determined based on the frequency resource allocation information of the ranging channel,
Transmitting the ranging channel,
The ranging channel frequency resource allocation information includes a cell ID to which a terminal belongs and the number of allocated subbands or the number of allocated subband CRUs (Contiguous Resource Units).
(Item 9)
The method of claim 8, wherein the ranging subband is a subband having an index calculated by the following equation.
I _SB = mod (cellID, X _SB )
I _SB is an index (0,..., X _SB −1) of a subband on the resource area . The cell ID is a cell ID to which the terminal belongs. X _SB is the number of allocated subbands or the number of allocated subband CRUs. mod (cellID, X _SB ) is the remainder obtained by dividing the cell ID by X _SB .
(Item 10)
10. The method according to item 9, wherein the cellID is any one integer from 0 to 767.
(Item 11)
The method of claim 8, wherein the number of allocated subbands or the number of allocated subband CRUs is broadcast or indicated by other signals.
(Item 12)
9. The method of item 8, wherein the number of allocated subbands varies according to a system bandwidth.
(Item 13)
9. The method of claim 8, wherein the ranging subband includes a plurality of adjacent physical resource units (PRUs).
(Item 14)
14. The method according to item 13, wherein the number of adjacent PRUs is four.

When the resource region is divided into a subband (SB) and a miniband (MB) and is divided into a plurality of frequency partitions, a ranging channel resource to which a ranging channel is allocated without separate signaling is allocated. A subband index can be determined.

1 shows a wireless communication system. It is a block diagram which shows the terminal by which the Example of this invention is implemented. An example of a frame structure is shown. An example of a method for dividing the entire frequency band into a plurality of frequency partitions will be described. 2 shows an example of a cellular system in which the FFR technique is used. An example of an uplink resource structure is shown. An example of a subband partitioning process is shown. An example of a mini-band permutation process is shown. An example of a frequency partitioning process is shown. An example of the proposed ranging channel transmission method is shown. The case where the physical subband allocated for the ranging channel is allocated to the subband CRU is shown. An example of a resource region according to the proposed ranging channel transmission method is shown. The case where the physical subband allocated for the ranging channel is allocated to the miniband CRU is shown. Fig. 4 shows an example of ranging channel resource allocation according to the proposed invention.

The following technology, CDMA (Code Division Multiple Access), FDMA (Frequency Division Multiple Access), TDMA (Time Division Multiple Access), OFDMA (Orthogonal Frequency Division Multiple Access), SC-FDMA (Single Carrier Frequency Division Multiple Access), etc. It can be used for various wireless communication systems. The CDMA can be implemented by a radio technology such as UTRA (Universal Terrestrial Radio Access) or CDMA2000. The TDMA may be implemented by a radio technology such as GSM (Global System for Mobile Communications) / GPRS (General Packet Radio Service) / EDGE (Enhanced Data Rates for GSM Evolution). OFDMA can be implemented with a wireless technology such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (Evolved UTRA), and the like. IEEE 802.16m is an evolution of IEEE 802.16e and provides backward compatibility with systems based on IEEE 802.16e. UTRA is a part of UMTS (Universal Mobile Telecommunication Systems). 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) is an E-UMTS (Evolved UMTS) that uses E-UTRA (Evolved-UMTS Terrestrial Radio Access) and a part of E-UMTS (Evolved UMTS) Adopt SC-FDMA in the uplink. LTE-A (Advanced) is an evolution of 3GPP LTE.

In order to clarify the explanation, IEEE 802.16m is mainly described, but the technical idea of the present invention is not limited to this.

FIG. 1 shows a wireless communication system.

The wireless communication system 10 includes at least one base station (BS) 11. Each base station 11 provides a communication service to a specific geographical area (generally called a cell) 15a, 15b, 15c. The cell is divided into a plurality of regions (referred to as sectors). A user equipment (UE) 12 may be fixed or mobile, and may include a mobile station (MS), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), and a wireless device (wireless device). ), PDA (Personal Digital Assistant), wireless modem, wireless handheld device, and the like. The base station 11 generally means a fixed station (fixed station) that communicates with the terminal 12, and is called by another term such as eNB (evolved-NodeB), BTS (Base Transceiver System), access point (Access Point), etc. be able to.

A terminal belongs to one cell, and a cell to which the terminal belongs is called a serving cell. A base station that provides a communication service to a serving cell is called a serving base station (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 referred to as a neighbor cell. A base station that provides a communication service to an adjacent cell is referred to as an adjacent base station (neighbor BS). The serving cell and the neighboring cell are determined relative to the terminal.

This technique can be used for the downlink or the uplink. In general, the downlink means communication from the base station 11 to the terminal 12, and the uplink means communication from the terminal 12 to the base station 11. On the downlink, the transmitter is part of the base station 11 and the receiver is part of the terminal 12. On the uplink, the transmitter is part of the terminal 12 and the receiver is part of the base station 11.

FIG. 2 is a block diagram illustrating a terminal in which an embodiment of the present invention is implemented. The terminal 900 includes a processor 910, a memory 920, and an RF unit (Radio frequency unit) 930.

The RF unit 930 is connected to the processor 910, receives frequency resource allocation information of the ranging channel from the base station, and transmits the ranging channel. The processor 910 embodies the proposed functions, processes and / or methods. Examples in which the processor implements the proposed function or method are described below. The processor 910 allocates a ranging channel to one ranging subband on the resource region determined based on the frequency resource allocation information of the ranging channel. The ranging channel frequency resource allocation information may include a cell ID to which the UE belongs and the number of subbands allocated to the resource region or the number of allocated subband CRUs (Contiguous Resource Units). The memory 920 is connected to the processor 910 and stores various information for driving the processor 910.

The RF unit 930 may include an encoder, a precoder, a subcarrier mapper, and an OFDM signal generator to transmit the ranging channel. The encoding unit encodes a data string to be transmitted by a predetermined coding method to form encoded data, and modulates the encoded data to express a position on a constellation. To place. There is no limitation on the modulation scheme. The precoder processes the input symbol into a MIMO scheme using multiple transmission antennas, outputs an antenna specific symbol, and distributes the antenna specific symbol to the corresponding subcarrier mapper. The subcarrier mapper assigns each antenna specific symbol to the subcarrier and multiplexes it by the user. An OFDM (Orthogonal Frequency Division Multiplexing) signal generator modulates each antenna specific symbol into an OFDM scheme and outputs an OFDM symbol.

FIG. 3 shows an example of a frame structure.

Referring to FIG. 3, the super frame (SF) includes a super frame header (SFH) and four frames (F0, F1, F2, F3). The length of each frame in the superframe is the same. Although the length of each super frame is 20 ms and the length of each frame is 5 ms, it is not limited to this. 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 a frame can be variously changed according to the channel bandwidth and the length of CP (Cyclic Prepix).

The super frame header may carry essential system parameters and system configuration information. The superframe header can be located in the first subframe in the superframe. Superframe headers can be classified into primary SFH (P-SFH; primary-SFH) and secondary SFH (S-SFH; secondary-SFH). P-SFH and S-SFH can be transmitted every superframe.

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

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

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

A logical resource unit (LRU) is a basic logical unit for distributed resource allocation and continuous resource allocation. The LRU is defined by a plurality of OFDM symbols and a plurality of subcarriers, and includes a pilot used in the PRU. Therefore, the number of appropriate subcarriers in one LRU depends on the number of assigned pilots.

A distributed logical resource unit (DLRU) can be used to obtain a frequency diversity gain. The DRU includes subcarrier groups distributed in one frequency partition. The smallest unit forming the DRU is one subcarrier.

A continuous logical resource unit (CLRU) can be used to obtain a frequency selective scheduling gain. The CRU includes local subcarrier groups.

Meanwhile, a fractional frequency reuse (FFR) technique may be used in a cellular system where multiple cells exist. The FFR technique is a technique in which the entire frequency band is divided into a plurality of frequency partitions (FP) and a frequency partition is assigned to each cell. Different frequency partitions can be assigned between adjacent cells via the FFR technique, and the same frequency partition can be assigned between distant cells. Accordingly, inter-cell interference (ICI) can be reduced, and the performance of the cell edge terminal can be improved.

FIG. 4 shows an example of a method for dividing the entire frequency band into a plurality of frequency partitions.

Referring to FIG. 4, 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). The Each frequency partition may be logically and / or physically divided from the entire frequency band.

FIG. 5 shows an example of a cellular system in which the FFR technique is used.

Referring to FIG. 5, 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 inside the cell. Any one of the second frequency partition (FP1) to the fourth frequency partition (FP3) is allocated to each sector of the cell edge. 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 a frequency partition that cannot be assigned is referred to as an inactive frequency partition. For example, when the second frequency partition (FP1) is allocated, the second frequency partition is an active frequency partition, and the third frequency partition (FP2) and the fourth frequency partition (FP3) are inactive frequency partitions. It is.

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

FIG. 6 shows an example of an uplink resource structure.

Referring to FIG. 6, the uplink subframe may be divided into at least one frequency partition. Here, although it is described as an example that the subframe is divided into two frequency partitions (FP1, FP2), the number of frequency partitions in the subframe is not limited thereto. The maximum number of frequency partitions is 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 a distributed resource allocation and / or a continuous resource allocation. The distributed resource assignment is DLRU, and the consecutive resource assignment is CLRU. Here, the second frequency partition (FP2) includes distributed resource allocation and continuous resource allocation. 'Sc' means a subcarrier.

When there are multiple cells, uplink resources can be mapped through processes such as subband partitioning, miniband permutation, frequency partitioning, etc. .

First, the subband partitioning process will be described.

FIG. 7 shows an example of a subband partitioning process. FIG. 7 shows a subband partitioning process when the bandwidth is 5 Mhz.

A plurality of PRUs are divided into a subband (SB) and a miniband (MB). In FIG. 7A, a plurality of PRUs are assigned to subbands, and in FIG. 7B, a plurality of PRUs are assigned to minibands. A subband includes N1 adjacent PRUs, and a miniband includes N2 adjacent PRUs. N1 = 4 and N2 = 1. Since subbands are assigned consecutive PRUs in the frequency domain, they are suitable for frequency selective resource allocation. Minibands are suitable for frequency distributed resource allocation and can be permuted in the frequency domain.

The number of subbands can be expressed as _KSB . The number of PRUs allocated to the subband can be expressed as L _SB , and L _SB = N1 * K _SB . K _SB can vary with bandwidth. The K _SB may be determined by an uplink subband allocation count (USAC; Uplink Subband Allocation Count). The length of the USAC is 3 to 5 bits, and can be broadcasted via SFH or the like. The remaining PRUs after being assigned to subbands are assigned to minibands. The number of minibands can be expressed as _KMB . The number of PRUs allocated to the miniband can be expressed as L _MB , and L _MB = N2 * K _MB . The maximum number of subbands that can be formed in the resource region is
And the total number of _PRUs is N _PRU = L _SB + L _MB .

Table 1, when the band width is 20 MHz, an example of the relationship between USAC and _{K SB.} When the bandwidth is 20 MHz, the FFT size is 2048.

Table 2, when the bandwidth of 10 MHz, an example of the relationship between USAC and _{K SB.} When the bandwidth is 10 MHz, the FFT size is 1024.

Table 3, when the bandwidth of 5 MHz, an example of the relationship between USAC and _{K SB.} When the bandwidth is 5 MHz, the FFT size is 512.

Plural PRU is divided into sub-band and mini-band, are rearranged in the sub-band PRU _{(PRU SB)} and miniband PRU _{(PRU MB).} Each PRU in the PRU _SB is indexed by any one of 0 to (L _SB -1), and each PRU in the PRU _MB is indexed by any one of 0 to (L _MB -1). Is done.

FIG. 8 shows an example of a miniband permutation process. PRU _MB is mapped to permutation PRU (PPRU _MB ) in the miniband permutation process. This is to ensure frequency diversity in each frequency partition. FIG. 8 may be performed following the subband partitioning process of FIG. 7 when the bandwidth is 5 MHz. The PRUs in the PRU _MB are permuted and mapped to the PPRU _MB .

FIG. 9 shows an example of the frequency partitioning process. 9 may be performed following the subband partitioning process of FIG. 7 and the miniband permutation process of FIG. 8 when the bandwidth is 5 MHz.

PRUs of PRU _SB and PPRU _MB are allocated to at least one frequency partition. The maximum number of frequency partitions is four. The frequency partition configuration information can be determined by an uplink frequency partition configuration (UFPC). The configuration of UFPC can be changed according to the bandwidth, and can be broadcast via S-SFH or the like. The UFPC can indicate the size of the frequency partition, the number of frequency partitions, and the like. A frequency partition count (FPCT) indicates the number of frequency partitions. FPSi indicates the number of PRUs assigned to the i-th frequency partition (FPi). Further, an uplink frequency partition subband count (UPPSC) defines the number of subbands allocated to FPi (i> 0). The UFPSC can have a length of 1 to 3 bits.

Table 4 shows an example of the relationship between UFPC and frequency partition when the bandwidth is 20 MHz. When the bandwidth is 20 MHz, the FFT size is 2048.

Table 5 shows an example of the relationship between UFPC and frequency partition when the bandwidth is 10 MHz. When the bandwidth is 10 MHz, the FFT size is 1024.

Table 6 shows an example of the relationship between UFPC and frequency partition when the bandwidth is 5 MHz. When the bandwidth is 5 MHz, the FFT size is 512.

K _{SB, FPi} and K _{MB, FPi ,} which are the number of subbands and minibands in the i-th frequency partition, can be determined by Equation 1, respectively.

In each frequency partition, the number of subband PRUs is L _{SB, FPi} = N1 * K _{SB, FPi} , and the number of miniband PRUs is L _{MB, FPi} = N2 * K _{MB, FPi} .

The relationship in which the PRU _SB and the PRU in the PPRU _MB are mapped to each frequency partition can be defined by Equation 2.

However,
And

It is.

A PRU in PRU _FPi can be mapped to an LRU. Hereinafter, mapping and permutation are limited when performed within a frequency partition.

Each frequency partition can be divided into CRU and DRU and can be implemented on a sector basis. The UCAS _{SB, i} indicating the size of the subband-based CRU represents the number of subband-based CRUs in the i-th frequency partition (FPi) in units of subband size and can be broadcast. The UCAS _MB represents the number of mini-band based CRUs in the first frequency partition (FP0) and can be broadcast. The number of CRUs in each frequency partition can be expressed by _LCRU and _FPi , and can be expressed as Equation 3.

The number of _DRUs in each frequency partition can be expressed by L _{DRU and FPi} , and can be expressed as Equation 4.

PRU in PRU _FPi may be mapped to _{CRU FPi} by Equation 5.

In Equation 5, k = s [j-UCAS _{SB, i} * N1]. s [] is a CRU / DRU assignment sequence, and 0 ≦ s [j] <FPSi * N2-UCAS _{SB, i} * N1.

PRU in PRU _FPi can be mapped by Equation 6 _{DRU FPi.}

k = s ^c [j], and s ^c [] is a sequence obtained by rearranging the remaining PRUs that are not assigned to the CRU.

Also, tile permutation can be performed. Each DRU of the frequency partition can be divided into 3 tiles including 6 adjacent subcarriers. Multiple tiles within the frequency partition are permuted to obtain frequency diversity gain. The assignment of a physical tile of a DRU to a logical tile of a subchannel can be defined by Equation 7.

In Equation 7, Tile (s, n, t) is a tile index of the nth tile of the sth DLRU of the tth subframe. n is any one of 0 to 2. t is a subframe index. s is an index of a DLRU having one of 0 to L _{DRU and FPi} −1. PermSeq () is a permutation sequence whose length is L _{DRU, FPi} , and can be determined by SEED = {IDcell * 1367} mod 2 ¹⁰ . The permutation sequence can be generated by any sequence generation algorithm.

(PermSeq (), s, n, t) = {PermSeq [n + 107 * s + t] mod L _{DRU, FPi} } + UL_PermBase} mod L _{DRU, FPi} .

Of the uplink control channels, a specific control channel may have to be assigned to one or more adjacent PRUs in the frequency domain. For example, a ranging channel can be assigned to one or two subbands in the frequency domain. Also, in the case of a specific channel, when adjacent sectors use the same time and frequency resources, the channel design method can reduce or increase the performance degradation due to interference. Therefore, when a plurality of frequency partitions exist and both subbands and minibands exist in the resource region, a resource allocation method for a specific control channel such as a ranging channel is required. That is, a method for allocating control channels so that the time or frequency domain is not the same or overlaps between adjacent sectors can be proposed.

Hereinafter, the proposed ranging channel transmission method will be described through an embodiment. In this embodiment, a ranging channel for initial access and handover of a terminal is disclosed. However, the present invention is not limited to this, and the present invention may be applied to various types of control channels. it can. Further, in the present embodiment, it is assumed that there are a plurality of frequency partitions, but the present invention can also be applied to a case where there is one frequency partition.

FIG. 10 shows an embodiment of the proposed ranging channel transmission method.

In step S100, the terminal receives ranging channel frequency resource allocation information. In step S110, the UE allocates a ranging channel to one ranging subband on the resource region determined based on the frequency resource allocation information of the ranging channel.

N (N ≧ 1) adjacent subbands may be allocated as resources for the ranging channel. Hereinafter, for convenience of explanation, it is assumed that there are N _sub subbands. When the total number of _PRUs is N _PRU , N _sub = N _PRU / N1. For example, when the bandwidth is 10 MHz, N _PRU = 48 and N _sub = 12.

The resources for the ranging channel may be reserved in advance for the ranging channel in the resource mapping process. The base station can transmit the index of the physical subband to which the ranging channel is allocated to the terminal. The physical subband index refers to indexing for N _sub subbands before performing subband partitioning in the resource mapping process. The subband index can be broadcast. An index of a predetermined number of subbands or an index of logical subbands according to a predetermined specific rule may be broadcast. Alternatively, resources can be allocated based on a predetermined formula based on a cell ID, superframe number, frame number, subframe number, and the like.

Terminal allocates N adjacent subbands for preferentially ranging channel in a subframe to transmit the ranging channel, performing a resource mapping for N _{sub -N} number of remaining subbands Can do. That is, the whole time PRU number is _{N PRU,} it is possible to perform resource mapping for _N PRU -N * N1 amino PRU excluding the N * N1 pieces of PRU allocated to the ranging channel. At this time, when the base station sets the subband to which the ranging channel is allocated to cell specific (cell-specific), the position in the resource region of N _sub -N subbands is different for each cell. There are restrictions on the application of techniques.

Alternatively, the subband for the ranging channel is not reserved separately and can be allocated to the ranging channel. When performing resource mapping, it is possible to know the indices of physical subbands and logical subbands allocated for the ranging channel, and based on this, the resource mapping can be performed excluding the ranging channel resources. it can.

FIG. 11 illustrates a case where physical subbands allocated for the ranging channel are allocated to the subband CRU. That is, each cell allocates a ranging channel to the subband CRU that each cell has. In such a case, the ranging channel resource may be maintained as it is in the resource mapping process and mapped to the logical resource, or may be mapped to the logical area allocated for the subband CRU. The ranging channel resource has no effect on the permutation between the remaining resources when performing resource mapping. The remaining resources except the ranging channel resource may be indexed again in the logical domain, or may have an index like a subframe without a ranging channel.

In allocating the ranging channel to the subband CRU of each cell, the ranging channel resource can be allocated according to ranging channel configuration information (ranging channel configuration information). The ranging channel configuration information may include information about a time domain and information about a frequency domain among resource areas to which a ranging channel is allocated.

Table 7 shows an example of time resource allocation configuration information for the ranging channel. The time resource allocation configuration information can be broadcast.

Information regarding the time resource allocation of the ranging channel can be determined by the cell ID and the N_RCH. The time resource allocation information is any one of a subframe index, a frame index, and a superframe index of a resource to which a ranging channel is allocated.

Formula 8 is an example of a formula for determining a subframe index of a resource to which a ranging channel is allocated.

I _SF (0,..., N _SF * n _F / N_RCH-1) is a resource to which a ranging channel is allocated among n _SF * n _F / N_RCH-1 subframes in a 1 / N_RCH superframe period. Subframe index. n _SF is the number of subframes in one frame, and n _F is the number of frames in one superframe. f (CellID) is a function of the cell ID. The cell ID can be changed to other parameters such as a base station ID. According to Equation 8, I _SF subframe in 1 / N_RCH super frame period is assigned to periodically ranging channel. For example, when n _SF = 8, n _F = 4, and N_RCH = 1/3, one superframe includes 32 subframes, and 3 superframes include 96 subframes. Of the 96 subframes, the I _SF -th subframe can be periodically assigned to the ranging channel once every three superframes.

Equation 9 is another example of the equation for determining the subframe index of the resource to which the ranging channel is assigned.

I _SF (0,..., N _SF −1) is a subframe index of a resource to which a ranging channel is allocated among n _SF −1 subframes in a 1 / N_RCH superframe period. The position of the frame to which the ranging channel is assigned can be predetermined or broadcast. According to Equation 13, I _SF-th subframe in the one frame in 1 / N_RCH super frame period is assigned to periodically ranging channel.

Formula 10 is an example of a formula for determining a frame index of a resource to which a ranging channel is allocated.

_{I F (0, ..., n} F / N_RCH-1) is a frame index of resources ranging channel is allocated among the _n F / N_RCH-1 frames in a super frame period of 1 / N_RCH. Position of I _F th subframe ranging channel is assigned in a frame can be pre-or determined, or broadcast. According to Equation 14, one subframe in the I _F-th frame in 1 / N_RCH super frame period is assigned to periodically ranging channel.

Formula 11 is an example of a formula that determines a superframe index of a resource to which a ranging channel is allocated.

I _SuperF (0,..., / N_RCH-1) is a superframe index of a resource to which a ranging channel is allocated among 1 / N_RCH-1 superframes during a 1 / N_RCH superframe period. The positions of the frames and subframes to which the _ranging channel is allocated in the I _SuperF- th frame can be predetermined or broadcast. According to Equation 15, one subframe in one frame existing in the I _SuperF- th superframe is periodically allocated to the _{ranging channel} during the 1 / N_RCH superframe period.

Information on frequency channel resource allocation of the ranging channel can be determined by the cell ID and the number of allocated subbands K _SB or the number of allocated subband CRUs Y _SB . The information on the frequency resource allocation is a subband index of a resource to which a ranging channel is allocated. The K _SB or Y _SB can be broadcast or indicated by other signals.

Formula 12 is an example of a formula that determines a subband index of a resource to which a ranging channel is allocated.

I _SB (0,..., K _SB −1) is an index of a subband to which resources for the ranging channel are allocated among the K _SB subbands.

Formula 13 is an example of a formula for determining an index of a resource to which a ranging channel is allocated.

I _idx (0,..., N _SF * n _F / N_RCH * K _SB −1) is a value of n _F / N_RCH−1 subframes and K _SB subbands in a 1 / N_RCH superframe period. An index of a resource to which a ranging channel is allocated.

Formula 14 is another example of a formula for determining an index of a resource to which a ranging channel is allocated.

I _idx (0,..., N _SF * K _SB −1) is an index of a resource to which a ranging channel is allocated among n _SF subframes and K _SB subbands in a 1 / N_RCH superframe period. It is.

When the index of the resource to which the ranging channel is allocated is determined according to Equation 13 or 14, the subframe index and subband index to which the ranging channel is allocated can be determined according to Equation 15.

The position of the frame to which the ranging channel is assigned can be predetermined or broadcast.

Equation 16 is another example of the equation for determining the subband index of the resource to which the ranging channel is assigned.

I _idx (0,..., N _F / N_RCH * K _SB −1) is a ranging channel of n _F / N_RCH−1 frames and K _SB subbands during the 1 / N_RCH superframe period. The index of the resource to be allocated.

When the index of the resource to which the ranging channel is allocated is determined according to Equation 16, the frame index and the subband index to which the ranging channel is allocated can be determined according to Equation 17.

Position of I _F th subframe ranging channel is assigned in a frame can be pre-or determined, or broadcast.

Equation 18 is another example of the equation for determining the subband index of the resource to which the ranging channel is assigned.

I _idx (0,..., K _SB / N_RCH-1) is a resource to which a ranging channel is allocated among 1 / N_RCH-1 superframes and K _SB subbands during a 1 / N_RCH superframe period. Is the index of

When the index of the resource to which the ranging channel is assigned is determined according to Equation 18, the superframe index and the subband index to which the ranging channel is assigned can be determined according to Equation 19.

The positions of the frames and subframes to which the _ranging channel is allocated in the I _SuperF- th superframe can be predetermined or broadcast.

By setting N_RCH = 1 in various expressions for determining the index of the frequency resource or time resource to which the ranging channel is allocated, the position of the superframe to which the ranging channel is allocated can be designated in advance. Also, by setting n _F = 1, the position of the frame to which the ranging channel is assigned can be designated in advance. Further, by setting n _SF = 1, the position of the subframe to which the ranging channel is assigned can be designated in advance. The various mathematical formulas described above can be combined in various forms. In addition, as described above, if the allocation of the ranging channel is limited to only the subband CRU, the permutation cannot be affected at all. Therefore, the number K of subbands allocated to all the above equations. it is also possible to change the _{Y SB} is the number of subbands CRU assigned to _SB.

Referring to FIG. 10, in step S120, the UE transmits the ranging channel to the base station.

A terminal in which the embodiment of the present invention of FIG. 2 is implemented can be described using the embodiment of the present invention of FIG.

The RF unit 930 is connected to the processor 910, receives frequency resource allocation information of the ranging channel from the base station, and transmits the ranging channel. The processor 910 allocates a ranging channel to one ranging subband on the resource region determined based on the frequency resource allocation information of the ranging channel. The ranging channel frequency resource allocation information may include a cell ID to which the UE belongs and the number of subbands allocated to the resource region or the number of allocated subband CRUs (Contiguous Resource Units). The number of subbands assigned to the resource region or the number of assigned subband CRUs is broadcast or indicated by other signals, and the number of subbands assigned to the resource region is Variable according to system bandwidth.

The ranging subband is a subband having an index determined by a formula of I _SB = mod (cellID, X _SB ). I _SB is an index (0,..., X _SB −1) of subbands on the resource region, cellID is a cell ID to which the terminal belongs, and X _SB is the number of allocated subbands or This is the number of allocated subband CRUs. mod (cellID, X _SB ) is the remainder obtained by dividing the cell ID by X _SB . The cellID is any one integer from 0 to 767.

FIG. 12 shows an example of a resource region according to the proposed ranging channel transmission method.

Referring to FIG. 12, cell A, cell B, and cell C have a subband region common to cells in an uplink resource region. The cell common subband region is a region allocated to the subband PRU (PRU _SB ) through the subband partitioning process of FIG. In addition, a subband CRU region is assigned to each cell. The size of the subband CRU region allocated to each cell is different. Cell A and cell B have two subband CRUs, and cell C has three subband CRUs. Ranging channels 200, 210, and 220 are allocated to the subband CRU region of each cell. The ranging channels 200, 210, and 220 assigned to each cell transmit ranging channels without overlapping each other in the frequency domain. The subband CRU assigned to the ranging channels 200, 210, and 220 in each cell can be determined based on the cell ID according to Equation 16 described above.

Meanwhile, a miniband CRU may be allocated as a resource for the ranging channel.

FIG. 13 illustrates a case where physical subbands allocated for the ranging channel are allocated to the miniband CRU. In this case, the UE can remove the ranging channel resource in the DRU permutation process. That is, tile permutation can be performed except for the miniband for the ranging channel in the tile permutation process.

If there are m logical minibands for the ranging channel in the frequency partition, Equation 7 can be modified as Equation 20.

In Equation 20, Tile (s, n, t) is a tile index of the nth tile of the sth DLRU of the tth subframe. n is any one of 0 to 2. t is a subframe index. s is an index of a DLRU having any one value of 0 to L _{DRU and FPi} -1-m. That is, tile permutation is performed except for the mini-band CRU assigned to the ranging channel. The remaining resources except for the ranging channel resource may be re-indexed in the logical domain, or may have the same index as a subframe without a ranging channel.

As described above, when the ranging channel resource is not reserved separately, no restriction is imposed on operating a plurality of frequency partitions by applying the FFR technique or the like. Alternatively, the resources can be reserved so that the inter-sector resources do not overlap with each other by applying the FFR technique even when N subbands for the ranging channel are reserved. The ranging channel resource may be limited to any one of the subband CRU and the miniband CRU. That is, a ranging channel can be allocated only within the subband-based CRU that each cell has. Alternatively, ranging channel resources may be limited to some of the subbands reserved for the miniband permutation process in the resource mapping process.

Meanwhile, according to the subband partitioning rule, the subband index in the physical resource before the subband partitioning process and the subband index assigned to the subband PRU (PRU _SB ) after the subband partitioning process are aligned with each other. (Aligned). That is, when it is assumed that the subband includes N1 PRUs, the N1 PRUs constituting a certain subband allocated to the PRU _SB are PRUs that are not adjacent to each other in the physical resource region. For example, the 0th to 3rd PRUs of the PRU _SB in FIG. 7 can be mapped from the 4th, 5th, 8th, and 9th PRUs that are not consecutive resources of the 4th to 7th PRUs of the physical resource. In this case, the ranging channel may be allocated only to subbands in which PRUs included in the corresponding physical resource subband among physical resource subbands are not allocated to a plurality of PRU _SB subbands in the subband partitioning process. it can.

FIG. 14 shows an example of ranging channel resource allocation according to the proposed invention. Each subband of the physical resource region may have 1 to 12 indexes. The subbands of the physical resource region are allocated to the PRU _SB through a subband partitioning process. Some of the PRU _SB subbands allocated by the subband partitioning process are mapped from PRUs to a plurality of subbands in the physical resource region. For example, the first allocation subband 300 is mapped from the index 3 subband and the index 4 subband of the physical resource region. The second allocation subband 310 is mapped from the subband of index 6 and the subband of index 7 in the physical resource area. The third allocation subband 320 is mapped from the subband with index 9 and the subband with index 10 in the physical resource region. The ranging channel can be allocated to the remaining subbands excluding the subbands of the physical resource area over which the allocated subbands are transmitted as described above. That is, subbands with indexes 1, 2, 5, 8, 11, and 12 can be allocated to ranging channel resources. Alternatively, the subband of the physical resource area to which the allocation subband is passed can be regarded as one subband and can be allocated to the ranging channel. In this case, three subbands can be additionally allocated to ranging channel resources. At this time, the sub-band index allocated additionally is a smaller index among the physical sub-band indexes over which the resources are passed. That is, subbands with indexes 1, 2, 3, 5, 6, 8, 9, 11, and 12 can be allocated to ranging channel resources.

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

In the exemplary system described above, the method has been described based on a sequence diagram in a series of steps or blocks, but the present invention is not limited to a sequence of steps, and certain steps may differ from those described above. Can occur in different orders or simultaneously. Also, those skilled in the art are not exclusive of the steps shown in the sequence diagram and include other steps or delete one or more steps of the sequence diagram without affecting the scope of the present invention. I can understand that it is possible.

The embodiments described above include illustrations of various aspects. Although not all possible combinations for describing various aspects can be described, those having ordinary skill in the art can recognize that other combinations are possible. Accordingly, the present invention includes all alterations, modifications, and variations that fall within the scope of the claims.

Claims (12)

An apparatus for transmitting Oite ranging channel in a wireless communication system,
The device is
An RF (Radio Frequency) unit configured to transmit or receive a radio signal;
A processor connected to the RF unit;
With
Wherein the processor is configured to the ranging channelization Le to the assignment so that the one ranging sub-band of a plurality of sub-bands on the frequency domain, the one ranging subbands, cell identifier (ID of the cell ) And the number of subbands, and the number of subbands is determined based on the number of subband CRUs (Contiguous Resource Units) .
The one ranging subband is:
I _SB = mod (cellID, X _SB )
Has an index calculated by
I _SB is the subband index 0 _{X SB} subbands on the frequency domain, _..., represent the _X SB -1,
cellID represents the cell ID of the cell;
X _SB represents the number of the plurality of subbands;
mod (cellID, X _SB ) is the remainder obtained by dividing the cell ID by X _SB . The cellID is any one of integers of from 0 to 767, according to claim 1. Number or the number of pre-hexa subband CRU of the plurality of sub-bands, either broadcast or indicated by other signals, according to claim 1. The apparatus of claim 1, wherein the number of the plurality of subbands varies according to a system bandwidth. The ranging sub-band includes a plurality of adjacent PRU (Physical Resource Unit), Apparatus according to claim 1. The adjacent plural number of PRU is 4, apparatus according to claim 5. A method for transmitting Oite ranging channel in a wireless communication system,
The method
A assign one of ranging the subband ranging channel of a plurality of sub-bands on the frequency domain, the one ranging subband cell identifier of the cell (ID) and the plurality of The number of subbands is determined based on the number of subband CRUs (Contiguous Resource Units);
Transmitting the ranging channel ;
Including
The one ranging subband is:
I _SB = mod (cellID, X _SB )
Has an index calculated by
I _SB is the subband index 0 _{X SB} subbands on the frequency domain, _..., represent the _X SB -1,
cellID represents the cell ID of the cell;
X _SB represents the number of the plurality of subbands;
mod (cellID, X _SB ) is the remainder obtained by dividing the cell ID by X _SB . The cellID is any one of integers of from 0 to 767, The method of claim 7. Number or the number of pre-hexa subband CRU of the plurality of sub-bands, either broadcast or indicated by other signals, The method of claim 7. The method of claim 7 , wherein the number of the plurality of subbands varies depending on a system bandwidth. The ranging sub-band includes a plurality of PRU adjacent (Physical Resource Unit), The method of claim 7. The adjacent plural number of PRU is 4, A method according to claim 11.