RU2486705C1 - Ranging by mobile station in legacy support mode - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: method involves receiving secondary superframe header (S-SFH) information from a base station; determining whether the mobile communication system supports WirelessMAN OFDMA technology; obtaining ranging channel information for performing an initial ranging, a handover ranging and a periodic ranging from the S-SFH, when the mobile communication system supports WirelessMAN OFDMA technology; and performing at least one of the initial ranging, the handover ranging and the periodic ranging with the base station using the ranging channel information.

EFFECT: efficient control of mobile station ranging and reducing undesirable overheads.

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Description

FIELD OF THE INVENTION

The present invention relates to a ranking method (ranging; time-frequency synchronization and power adjustment) of a mobile station in support mode for legacy systems. Although the present invention is suitable for a wide range of applications, in particular, it is suitable for implementation by a mobile ranking station in a mobile communication system having a legacy system and an improved system coexisting therein, using a frame supporting legacy systems.

BACKGROUND

Typically, a base station in a system capable of supporting both an inherited mobile station and a mobile station with an advanced system operates in a mixed mode. The following description explains such mixed mode operation under the assumption that the legacy system is an IEEE 802.16e system and the advanced system is an IEEE 802.16m system.

The mixed mode is divided into a WirelessMAN OFDMA region (hereinafter referred to as an L region) supporting an inherited mobile station (i.e., an IEEE 802.16e mobile station) and an advanced wireless interface region (hereinafter referred to as an M region) supporting an IEEE 802.16m mobile station . In mixed mode, the uplink (UL) region is configured such that the L and M regions are separated by time division multiplexing (TDM) or frequency division multiplexing (FDM). The ranking channel of the legacy IEEE 802.16e system uses a sub-channel partial use structure (PUSC) in diversity mode. In contrast, the IEEE 802.16m system ranking channel uses a solid resource block (CRU) subband structure.

FIG. 1 is a diagram of a TDD frame structure for supporting WirelessMAN OFDMA frequency division uplink (FDM) operation.

As shown in FIG. 1, the frame structure includes a WirelessMAN OFDMA downlink area and an advanced wireless interface downlink area. In the downlink, the WirelessMAN OFDMA area and the advanced wireless interface area are separated by TDM. In addition, in the uplink, region L and region M are separated by FDM. In particular, in the time domain, the WirelessMAN OFDMA downlink area, the advanced wireless interface downlink area, and the FDM uplink area correspond to a 5M WirelessMAN frame. In the case of an advanced wireless interface frame, the WirelessMAN ODFM downlink area is considered as a frame offset, and the duration of 5 ms from the frame offset is considered as a frame.

Since a system configured to operate via FDM is structurally incapable of using other permutations, the IEEE 802.16m mobile station must use the IEEE 802.16e system ranking channel structure as it is. In particular, an appropriate system can be developed as follows. First of all, the ranking channel is allocated only to the area L, taking into account overhead. And the corresponding ranking channel is configured to be used in conjunction with IEEE 802.16m mobile stations. Alternatively, a ranking channel may be allocated to region M along with region L.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a method for ranking a mobile station in a legacy system support mode, which substantially eliminates one or more problems due to limitations and disadvantages of the prior art.

Typically, a base station capable of supporting IEEE 802.16m-only mobile stations informs the mobile stations of the ranking channel information, information necessary for generating the code, and the number of codes to use in each case (e.g., for initial ranking, ranking of handover, etc. d.) through the S-SFH header (secondary superframe header). However, since the base station of the mixed-mode system described above uses other ranking channel structures and code generation schemes, S-SFH header information must be transmitted by including information suitable for the used ranking channel structure and code generation scheme. And the corresponding mobile station must also interpret the S-SFH header differently than when only the IEEE 802.16m standard mobile station is supported.

Thus, this disclosure explains the configuration of S-SFH header information transmitted by a base station in a mixed mode system, and a method for a mobile station to perform ranking by interpreting the S-SFH header differently according to the presence or absence of the mixed mode .

Additional functions and advantages of the invention will be set forth in the following description, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be achieved through the structure set forth in the description and claims, as well as in the attached drawings.

In order to achieve these and other advantages, and in accordance with the object of the present and thoroughly described invention, a method for ranking in a mobile station that performs ranking on a base station in a mobile communication system including an inherited system and an improved system, comprises the steps of: S-SFH (secondary superframe header) header information from a base station determines whether the frame configuration used by the mobile communication system supports a fixed system, if the frame configuration supports the legacy system, ranking channel information is obtained for performing initial ranking, handover ranking and periodic ranking from the S-SFH header, and at least one ranking selected from the group consisting of initial ranking, handover ranking is performed and periodically ranking, over a base station using ranking channel information.

Preferably, the ranking channel information includes ranking channel allocation information, ranking channel starting code information, ranking code separation information, and uplink permutation base information (UL_Permbase).

More preferably, the frame includes a ranking subframe having a first ranking interval for the synchronized mobile station and a second ranking interval for the unsynchronized mobile station, each ranking from the initial ranking and handover ranking is performed using the second ranking interval, and periodic ranging is performed using the first interval ranking.

In this case, the ranking channel allocation information includes a frequency of allocating a ranking subframe and location information in a time domain of the ranking subframe.

The ranking code separation information includes information on the number of codes (N) of a group of codes for initial ranking, the number of codes (O) of a group of codes for ranking a handover, and the number of codes (M) for a group of codes for periodic ranking.

In addition, the mobile station generates codes corresponding to the number of codes (N) of a group of codes for initial ranking, the number of codes (O) of a group of codes for ranking a handover, and the number of codes (M) of a group of codes for periodic ranging from an initiating code (S) of a ranking channel in accordance with the initial ranking, handover ranking and periodic ranking, respectively, using a code generator having a sequence corresponding to the base of permutations sunrise communication lines, as an initiating sequence.

Preferably, the legacy system is a WirelessMAN OFDMA system, and the enhanced system is an IEEE 802.16m system.

Additionally, to achieve these and other advantages, and in accordance with an object of the present invention, a mobile station device that performs ranking on a base station in a mobile communication system including a legacy system and an improved system, comprises an antenna configured to receive a signal from the femto base stations, the antenna is configured to transmit the signal of the base femto station, and a processor configured to process the signal received through the antenna and the signal l transmitted through antennas, the processor determines whether the frame configuration used by the mobile communication system supports the legacy system, if it receives S-SFH (secondary superframe header) information from the base station, the processor receives ranking channel information to perform initial ranking, transmission ranking serving and periodically ranking from the S-SFH header, if the frame configuration supports the legacy system, the processor controls at least one ranking in selected from the group consisting of initial ranking, handover ranking, and periodic ranking that will be performed on the base station using the ranking channel information.

Preferably, the ranking channel information includes ranking channel allocation information, ranking channel starting code information, ranking code separation information, and uplink permutation base information (UL_Permbase).

More preferably, the frame includes a ranking subframe having a first ranking interval for the synchronized mobile station and a second ranking interval for the non-synchronized mobile station, each ranking from the initial ranking and handover ranking is performed using the second ranking interval, and periodic ranking is performed using the first interval ranking.

In this case, the ranking channel allocation information includes a frequency of allocating a ranking subframe and location information in a time domain of the ranking subframe.

The ranking code separation information includes information on the number of codes (N) of a group of codes for initial ranking, the number of codes (O) of a group of codes for ranking a handover, and the number of codes (M) for a group of codes for periodic ranking.

In addition, if the mobile station device further comprises a code generator having a sequence corresponding to the base of uplink permutations as an initiating sequence, the processor generates codes corresponding to the number of codes (N) of the code group for initial ranking, the number of codes (0) of the code group for ranking the handover and the number of codes (M) of the group of codes for periodic ranking, from the initiating code (S) of the ranking channel in accordance with the initial ranking Handling, handover ranking and periodic ranking, respectively, using a code generator.

Preferably, the legacy system is a WirelessMAN OFDMA system, and the enhanced system is an IEEE 802.16m system.

It should be understood that the foregoing general description and the following detailed description are illustrative and explanatory and are intended to provide further clarification of the claimed invention.

In accordance with embodiments of the present invention, S-SFH header information transmitted by a base station in a mixed mode system is performed differently from the mixed mode. The mobile station performs ranking by different interpretations of the S-SFH overhead according to the presence or absence of a mixed mode. Thus, the present invention effectively manages the ranking of the mobile station and reduces unnecessary overhead.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, intended to provide an additional understanding of the invention, included in the present description and constituting a part thereof, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

In the drawings:

FIG. 1 is a diagram of a TDD frame structure for supporting UL FDM WirelessMAN-OFDMA mode operation;

FIG. 2 and 3 are diagrams of the ranking channel formats used in the mode to support only the IEEE 802.16m standard;

FIG. 4 is a configuration diagram of a ranking channel used in mixed mode in accordance with one embodiment of the present invention;

FIG. 5 is a diagram for explaining a transmission periodicity relationship of subpackets of an S-SFH header;

FIG. 6 is a PRBS generator configuration diagram using an uplink permutation base value as an initiating sequence; and

FIG. 7 is a block diagram of a configuration of a mobile station device in accordance with one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The following detailed description of the invention includes details to aid in a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these details. Sometimes, in order to avoid fuzzy descriptions of the present invention, well-known structures and / or devices are omitted or may be presented as block diagrams focused on the basic functions of structures and / or devices. Wherever possible, the same numbers will be used throughout the drawings to refer to the same or similar parts.

In this description, if the described part “includes” the described element, this means that another element may be further included, and not the elimination of other elements, unless expressly stated otherwise. In addition, terminology such as “part”, “functionality”, “module”, etc. means a unit for processing at least one function or operation that may be implemented by software, hardware, or a combination thereof.

As mentioned in the previous description, in the case of a mixed mode operation, in order to explain the S-SFH header information to be transmitted as the ranking channel information by the base station and the corresponding ranking method in the mobile station, the differences in the structure and properties of the ranking channel are described below. in case of support only of the above-mentioned IEEE 802.16m system and differences in the structure and properties of the ranking channel in the case of mixed mode.

First of all, in the mode for supporting only the IEEE 802.16m standard, the base station transmits the ranking channel information about the initial ranking and the handover ranking, that is, the ranking channel information about the non-synchronized mobile station through the S-SFH header, and also transmits the ranking channel information for the synchronized the mobile station, that is, the ranking channel information about the periodic ranking through the message AAI_SCD. The present invention relates to information that is transmitted in a mixed mode by a base station through an S-SFH header, and to a corresponding ranking method in a mobile station. The following describes in detail initial ranging and ranking of handoff in mode to support the IEEE 802.16m standard.

FIG. 2 and 3 are diagrams of the ranking channel formats used in mode to support only the IEEE 802.16m standard.

The format shown in FIG. 2 may be called format 0, and the format shown in FIG. 3, can be called format 1. In this case, the ranking channel may occupy an adjacent frequency range (i.e., a localized frequency band) corresponding to one subband.

In FIG. 2 and 3, T _RCP denotes a cyclic ranking prefix region, and T _RP denotes a ranking preamble region. The ranking formats shown in FIG. 2 and 3 can be used for ranking a non-synchronized mobile station, that is, for initial ranking and ranking of a handover.

The configuration information of format 0 and format 1 shown in FIG. 2 and 3 are presented as follows.

Table 1 Format number T _RCP T _RP Δf _RP 0 K ₁ × T _g + k ₂ × T _b 2 × T _b Δf / 2 one 3.5 × T _g + 7 × T _b 8 × T _b Δf / 8

In Table 1, Δf denotes the spacing between subcarriers, T _b denotes the useful duration of the OFDMA symbol, i.e., T _b = 1 / Δf, T _g denotes the length of the cyclic prefix (CP) OFDMA, i.e., T _g = G · T _b , and G denotes the ratio of the useful duration of the symbol to the duration of the cyclic prefix. Meanwhile, k ₁ and k ₂ satisfy the following conditions.

Formula 1

K ₁ = (N _sym +1) / 2 and K ₂ = N _sym -4) / 2

In formula 1, N _sym denotes the number of OFDMA symbols in one AAI subframe.

Based on the structure described above, in a mode for supporting only the IEEE 802.16m standard, ranking channel allocation information (i.e., configuration index and subframe offset (O _SF )) is shown in Table 2, ranking code information (i.e., the number of M _ns cyclic shift codes on the root index ZC) is shown in Table 3, and the separation information of the ranking preamble codes (i.e., N _IN and N _HO ) is shown in Table 4.

table 2 Configurations AAI subframe allocating a ranking channel 0 UL AAI subframe with sequence number O _SF in each frame one UL AAI subframes with sequence number O _SF in the first frame in each superframe 2 UL AAI subframe with sequence number O _SF in the first frame in each even superframe, i.e. mod (superframe number, 2) = 0 3 The UL AAI subframe with the sequence number O _SF in the first frame in every fourth superframe, i.e. mod (superframe number, 4) = 0

Table 3 Index 0 one 2 3 M _ns one 2 four 8

Table 4 Division index 0 one 2 3 four 5 6 7 8 9 10 eleven 12 13 fourteen fifteen Number of initial ranking preamble codes, N _IN 8 8 8 8 16 16 16 16 24 24 24 24 32 32 32 32 Number of Handover Ranking Preamble Codes, N _HO 8 16 24 32 8 16 24 32 8 16 24 32 8 16 24 32

The base station may transmit to the mobile station the information shown in tables 2-4 through the S-SFH header. As mentioned in the previous description, in the mode for supporting only the IEEE 802.16m standard, since the base station transmits the ranking channel information about the initial ranking and the handover ranking only through the S-SFH, the ranking preamble code separation information, as shown in Table 4, includes includes only the number (N _IN ) of code group codes for initial ranking and the number (N _HO ) of code group codes for ranking handover.

Meanwhile, in the case of the mixed mode using the frame structure shown in FIG. 1, other structures and properties of the ranking channel are used.

FIG. 4 is a configuration diagram of a ranking channel used in mixed mode, in accordance with one embodiment of the present invention.

It is proposed that the ranking channel used for mixed mode includes an area for ranking a non-synchronized mobile station and an area for ranking a synchronized mobile station. Although FIG. 4 shows that two areas for ranking a non-synchronized mobile station are included and one area for ranking a synchronized mobile station, only one area for ranking a non-synchronized mobile station can be selected.

As shown in FIG. 4, the ranking channel used for mixed mode has one format configured using the ranking channel area for the non-synchronized mobile station (i.e., the initial ranging and handover ranking areas) and the ranking channel area for the synchronized mobile station. Therefore, in accordance with one embodiment of the present invention, although the base station transmits ranking channel information via an S-SFH header, it is proposed that the ranking channel information include periodic ranging information along with initial ranging information and handover ranking information. In addition, since the single format shown in FIG. 4, the base station is not required to transmit ranking channel format information through an S-SFH header.

Thus, it is proposed that the base station in accordance with the present embodiment transmit different S-SFH header information according to whether the UL FDM WirelessMAN-OFDMA mode is supported. And it is proposed that the base station transmit information in the case of periodic ranging through the S-SFH overhead along with information in the case of initial ranging and handover ranking using a single format ranking channel. Accordingly, in the case of receiving an S-SFH, it is proposed that the mobile station determines whether the UL FDM WirelessMAN-OFDMA mode is supported. If the UL FDM WirelessMAN-OFDMA mode is supported, it is proposed that the mobile station obtain initial ranging information, handover ranking information and periodic ranging information from the S-SFH.

The following description explains in detail S-SFH header information in accordance with the present invention.

FIG. 5 is a diagram for explaining a transmission periodicity relationship of subpackets in an S-SFH header.

As shown in FIG. 5, a secondary superframe header (S-SFH) may be transmitted as distributed across three subpackets SP1, SP2, and SP3. In this case, the sub-packet SP1 of the S-SFH header mainly includes information for re-entering the network. Sub-packet SP2 of the S-SFH header mainly includes information for network entry and discovery. And the sub-packet SP3 of the S-SFH header is transmitted by including the rest of the main system information. As shown in FIG. 5, the S-SFH header sub-packet SP1 may be transmitted every 40 ms, the S-SFH header sub-packet SP2 may be transmitted every 80 ms, and the S-SFH header sub-packet SP3 may be transmitted every 160 ms.

As mentioned in the previous description, in accordance with one embodiment of the present invention, it is proposed to enable ranking channel information in a mixed mode to be carried in a sub-packet SP1 of an S-SFH header. In particular, the information of the S-SFH header subpacket SP1 can be transmitted in such a way that the ranking channel information, if only IEEE 802.16m is supported, and the ranking channel information in mixed mode are included in different formats, respectively. Accordingly, the mobile station receives the S-SFH header sub-packet SP1 and can then obtain the ranking channel information in each mode according to whether the UL operational mode supports FDM WirelessMAN-OFDMA.

In particular, the mobile terminal checks the field indicating the MAC version, or the presence or absence of the operation of the UL FDM WirelessMAN-OFDMA mode, which is transmitted in the S-SFH, and then can know whether the base station is operating in the mixed UL FDM mode. If the base station operating mode is not UL FDM mixed mode (for example, 802.16m only mode, UL TDM mixed mode, etc.), the mobile station may determine that the ranking information delivered through sub-packet SP1 of the S-SFH header is configured as shown in table 5.

Table 5 Fields Size (in bits) NS-RCH Channel Allocation Frequency 2 NS-RCH Subframe Offset 2 NS RCH Channel RP Start Code Information four RP Code Separation Information for NS-RCH four The number of cyclically shifted RP codes per root index for the channel NS-RCH 2 Channel Formats NS-RCH one

In Table 5, the NS-RCH (Non-Synchronized Ranking Channel) denotes the channel used for initial ranking and handover ranking.

If the base station operating mode is UL FDM mixed mode, the mobile station in accordance with the present embodiment may determine that the ranking information delivered through the S-SFH header subpacket SP1 is configured as shown in Table 6 or Table 7.

Table 6 Fields Size (in bits) Highlighting the ranking channel (configuration, LRU index, subframe offset) 7 Start of a group of ranking codes four Ranking Code Separation Index four Uplink Permutation Base (UL_Permbase) 7

Table 7 Fields NS-RCH Channel Allocation Frequency NS-RCH Subframe Offset NS RCH Channel RP Start Code Information RP Code Separation Information for NS-RCH The number of cyclically shifted RP codes per root index for the channel NS-RCH Channel Formats NS-RCH

As shown in Table 6, it is assumed that the ranking channel includes an S-RCH (synchronized ranking channel: this channel is used for periodic ranking) along with an NS-RCH (that is, a channel used for initial ranging and handover ranking) .

Table 7 shows the format of an embodiment in the case of using the field name used in IEEE 802.16m only mode as it is. In UL FDM-based mixed mode, the field value may be interpreted in another way. Mixed mode ranking channel information may include S-RCH channel information along with NS-RCH channel information, while ranking channel information in IEEE 802.16m only mode indicates only NS-RCH channel information. In Table 7, the "NS-RCH Channel Initial RP Code Information" field can be described for proper use for each purpose as follows:

to support the UL FDM UL PUSCH region, this field indicates the parameter k _ns for the initial group of codes (s), where S = 4 × k _ns +1 (i.e., 1, 5, 9, ... or 65), and the range k _ns satisfies the constraint 0≤k _ns ≤15.

Meanwhile, the number of cyclic shifted codes of the ranging preamble on the root index for the NS-RCH and the format information of the NS-RCH are unique to the mode to support only the IEEE 802.16m standard. In UL FDM mixed mode, a fixed-value cyclic shift is applied and, as mentioned in the previous description, a single format ranking channel is used. Thus, the mobile station can ignore the "Number of cyclically shifted RP codes per root index for the NS-RCH" field and the "NS-RCH channel formats" field instead of recognizing them as special information.

According to one embodiment of the present invention, if the field indicating the presence or absence of an operation of the UL FDM WirelessMAN OFDMA mode is not explicitly included in the S-SFH header sub-packet SP1, the mobile station reads the MAC version (S-SFH header sub-packet SP2) and then knows about configurations corresponding to the ranking fields of the subpacket SP1 of the S-SFH header. In particular, in accordance with the present embodiment, in case other fields are configured behind the ranking information, for the mobile station to interpret the values of other fields (e.g. BS EIRP, Cell bar information, etc.) except for the fields corresponding to the ranking, despite not knowing the MAC version value after receiving subpacket SP1, the total number of bits corresponding to the ranking of fields in subpacket SP1 is preferably the same.

The following description explains a case in which UL FDM mixed mode ranking information, as shown in Table 6, is provided as a separate format. However, as mentioned in the previous description with respect to Table 7, a diagram of another interpretation of the mode ranking channel information to support only the IEEE 802.16m standard is similarly applicable with the exception of special restrictions.

The ranking channel information transmitted in sub-packet SP1 of the S-SFH header in the UL FDM mixed mode, as shown in Table 6, includes: (1) ranking channel allocation information; (2) uplink permutation base information (UL_Permbase); (3) ranking channel starting code information; and (4) ranking code separation information.

The ranking channel allocation information mentioned in the description of Table 6 may include the following information.

(1) Ranking channel allocation information

(1-1) The base station may indicate that a dedicated ranking channel is provided for normal ranking or specialized ranking, through the S-SFH header. If the base station allocates a dedicated ranking channel through the S-SFH, the base station can deliver a field to indicate the appropriate allocation through the S-SFH.

(1-2) The base station may indicate whether the dedicated ranking channel is intended for use for initial ranking / ranking of handover, or for use for periodic ranking, through the S-SFH header. However, as mentioned in the previous description with respect to FIG. 4, since the mixed-mode ranking channel has a single configuration physically divided into a ranking channel for non-synchronized ranking (e.g., initial ranking / handover ranking) and a ranking channel for synchronized ranking (e.g. periodic ranking), the base station need not be separately indicated this configuration.

(1-3) The base station may indicate the resource area on the frequency axis of the dedicated ranking channel through the S-SFH header. Since the ranking channel is allocated based on the logical resource block (hereinafter abbreviated LRU), the base station can transmit the first LRU index from which the corresponding channel starts through the S-SFH header. However, in accordance with another embodiment of the present invention, it is proposed to determine the resource area on the frequency axis of the ranking channel in accordance with a predetermined location or rules. And the base station in accordance with this embodiment may not need to indicate this separately through the S-SFH header. For example, it can determine that a ranking channel is allocated from a given LRU, that a predetermined rule obtained from a cell identifier (IDCell) is used, or that a ranking channel is connected in front of or behind another uplink control channel (for example, a feedback channel , HARQ channel, bandwidth request channel).

(1-4) The base station may indicate the frequency of allocation of the dedicated ranking channel and the location of the resource area (subframe block) or the offset of the subframe through the S-SFH header. The base station can also reuse the fields “ranking channel allocation frequency” and “subframe offset” specified in table 5. In the event that this information is fixed in accordance with the described embodiment, the corresponding base station may not need to separately tell this mobile station information.

Meanwhile, (2) the uplink permutation base information (UL_Permbase) mentioned in Table 6 has the following distinguishing features.

(2-1) The UL_Permbase permutation base is the information used so that the mobile station generates a plurality of ranking codes that will be used by the corresponding base station. The base station can explicitly deliver this information through the S-SFH or the AAI_SCD message. If the mobile station can calculate / get this information from the cell identifier (IDCell) received through the advanced preamble, the base station may not separately transmit the corresponding information. However, the base station must deliver this information to IEEE 802.16e mobile stations in area L via a UCD message. This is true because the subchannel must be configured in accordance with the same permutation rule by which the regions M and L are divided for use by the resource region on the frequency axis. According to the present embodiment, as mentioned in the previous description with respect to table 6, it is proposed that this uplink permutation base information be transmitted in the sub-packet SP1 of the S-SFH header.

(2-2) The uplink permutation base information may be used as the value of the initial sequence of a code generator (e.g., a PRBS generator). In particular, the values of the uplink permutation base field shown in Table 6 can be used as the initial sequences s0-s6 of the PRBS generator, which will be described with reference to FIG. 6 in the following description.

Meanwhile, “(3) ranking channel starting code information” and “(4) ranking code separation information”, which are mentioned in table 6, can be used by the mobile station as follows.

(3-1) The information of the initial code of the ranking channel mentioned in table 6 (i.e., “the beginning of the code group of the ranking and the allocation code index of the ranking codes”) indicates the index (S) of the initial code to be used in the corresponding base station among the generated ranking codes .

(4-1) The ranking code separation information is information generated to indicate the number of (N) code group codes for the initial ranking, the number (O) code group codes for the handover ranking, and the number (M) of code group codes for the periodic ranking among all 256 ranking codes. According to the present embodiment, it is characterized in that the value of O is indicated through the S-SFH header along with the values of N and M.

The following describes a method for generating a ranking code using the above information.

FIG. 6 is a configuration diagram of a PRBS generator using an uplink permutation base value as an initiating sequence.

As shown in FIG. 6, in the initial sequence of the PRBS generator in accordance with the present embodiment, s6, s5, s4, s3, s2 and s1 are used as the least significant bits (LSB), and the sequence “11010100” is used as the rest.

As mentioned in the previous description, the number of available codes is 256 (i.e., from 0 to 255). The base station uses a subgroup (or code group) of these codes, and each code group is controlled by the value of S (0≤S≤255), namely, each code group has codes between S and ((S + O + N + M) mod 256) . The following explains the code group for each use.

(a) First, N codes are used for initial ranking. Corresponding codes are generated by activating the aforementioned PRBS generator from a value of "144 × (S mod 256)" to a value of "144 × ((S + N) mod 256) -1".

(b) Then O codes are used to rank the handover. Corresponding codes are generated by activating the aforementioned PRBS generator from a value of “144 × ((S + N) mod 256)” to a value of “144 × ((S + N + O) mod 256) -1”.

(c) Then, the following M codes are used for periodic ranking. Corresponding codes are generated by activating the aforementioned PRBS generator from the value "144 × ((S + N + O) mod 256)" to the value "144 × ((S + N + O + M) mod 256) -1".

As mentioned in the description above, the base station in accordance with the present embodiment is to deliver the values of the S, N, O, and M values set above to the mobile station. In this case, the S value is delivered through the “Begin ranking code group” field mentioned in relation to Table 2 The value of S can be determined by the value of the "Begin ranking code group" field in Table 6. And the value of S can be determined as the following formula.

Formula 2

S = A × s + α, (0≤α, 1≤A)

For example, in formula 2, the values of A and α can be defined as given numerical values (for example, 4 and 1), respectively. If the size of the "Start code group of ranking" field is set to x bits, A can be defined as the value obtained by dividing the total number of codes 256 by 2x.

As mentioned in the previous description, the base station in accordance with the present embodiment transmits information about the value of M through the S-SFH header along with the above information about the values of N and O. This information can be transmitted as an information field in addition to information about the values of N and O. However, in accordance with one preferred embodiment of the present invention, information on all values of N, O, and M can be provided as the following table using a ranking code separation index vania.

Table 8 Division index Number of initial ranking preamble codes, N _IN Number of Handover Ranking Preamble Codes, N _HO Number of Periodic Ranking Preamble Codes, N _PE 0 four four four one four 8 four 2 four 16 four 3 four 24 four four 8 four 8 5 8 8 8 6 8 16 8 7 8 24 8 8 16 four 16 9 16 8 16 10 16 16 16 eleven 16 24 16 12 24 four 24 13 24 8 24 fourteen 24 16 24 fifteen 24 24 24

Information related to periodic ranging (for example, allocation of a ranking channel, number of periodic ranging codes, power loss parameter, initial root index of ZC code, etc.) in IEEE 802.16m only mode is delivered via an AAI-SCD message. In this case, the initial root index of the ZC code is necessary for generating codes that will be used for periodic ranking and have a root index value different from that for the initial ranging / handover ranking code. Thus, the base station must separately transmit the initial root index of the ZC code to generate periodic ranging codes.

However, since the periodic ranking code is generated in the mixed mode by the permutation base in accordance with the same method as the initial ranking / handover ranking code, it is not necessary to transmit each different initial information. In addition, the “start of a group of ranking code” field indicating the allocation of a ranking channel including the information of the periodic ranking area along with the information of the initial ranging / handover ranking and the starting point of the used code is already delivered via the S-SFH header, and it is not necessary to deliver this information through an AAI-SCD message.

The RAID (random access identifier) used for such a random access procedure as ranking is designed to include a 5-bit super-frame index, 2-bit frame index, 2-bit random access and a 6-bit code index. Given this configuration, the non-synchronized ranking code (initial / handover) and the synchronized ranking code (periodic) should be indexed accordingly. The range of code (initial ranging / handover ranging code) that will be used for the non-synchronized ranging channel is S≤ × <S + N + O. The non-synchronized ranking code index (0 to N _N + N _O -1) can be sequentially displayed from the starting point of this range (x).

In contrast, the range of code (periodic ranging code) that will be used for the synchronized ranking channel is S + N + O≤y <S + N + O + M. And the synchronized ranking code index (0 to H _M -1) can be sequentially displayed from the starting point of this range (y). If 256 codes are presented without these restrictions, the size of the RAID code index (random access identifier) should be set to 8 bits in the configuration.

In addition, there may be parameters that are optional for transmission in a mixed mode system, such as configuration parameters in a support mode system of only IEEE 802.16m standard. For example, in the case of an UL FDM mode operation, the Sub-Channel Sub-Channel Permutation (PUSC) of the legacy 802.16e system should be applied. Therefore, the following information of the subbands, minipass separation, or CRU / DRU separation, such as CRU, DRU, and the like, is not transmitted or may be ignored.

UCAS _{SB, 0} : Number of sub-band CRUs in FP ₀

UCAS _{MB, 0} : Number of mini-strip CRUs in FP ₀

UCAS _i : Total allocated CRUs per subband block for FP _i (i≥0)

USAC: Subband Number K _SB

UFPC: Frequency Separation Configuration

UFPSC: Number of allocated subbands if FP _i , i> 0

The above content of SFH information in accordance with the presence or absence of an operation of the UL FDM WirelessMAN OFDMA mode operation can be configured as table 9 or table 10.

Table 9 Syntax The size
(in bits) Description Ranking channel allocation frequency 2 Indicates the frequency of ranking channel allocation Ranking channel subframe offset 2 Indicates the offset channel allocation (O _SF ). Value Range 0≤O _SF ≤3 If (UL FDM PUSC zone support) { Indicates uplink WirelessMAN OFDMA support in FDM mode when the frame configuration index in sub-packet SP2 of the S-SFH is equal to:
- 5 or 7 or 9 for the frequency band of the channel 5/10/20 MHz in accordance with table 765
- 4 or 6 or 8 for the channel bandwidth of 8.75 MHz in accordance with table 766
- 3 (with CP = 1/8) for the channel bandwidth of 7 MHz in accordance with table 767 Ranking Channel Initial Information four Indicates k _ns , which is a parameter for starting a group of codes (S).
S = 16 × k _ns +1
Value Range 0≤k _ns ≤15 Ranking Preamble Code Separation Information four Indicates the number of codes (N, O, and M) for initial ranking, handover ranking, and periodic ranking Frequency domain ranking channel location 3 Indicates the initial distributed LRU index for a ranking channel } else { Ranking channel initial code information for non-synchronized mobile stations four Indicates k _ns , which is the parameter that controls the initial root index of the ranking preamble codes (r _ns0 )
r _ns0 (k _ns ) = 4 × k _ns +1 for ranking channel format 0
r _ns0 (k _ns ) = 16 × k _ns +1 for format 1 ranking channel
Value Range 0≤k _ns ≤15 Ranking preamble code separation information for non-synchronized mobile stations four Indicates the number of initial and handover ranking codes (N _IN and N _HO ) Number of cyclically shifted ranking preamble codes per root index for non-synchronized mobile stations 2 Indicates the number of cyclically shifted codes per root index (M _ns ) for ranking preamble codes Ranking channel formats for non-synchronized mobile stations one Indicates the ranking channel format number }

Table 10 Syntax The size
(in bits) Description S-SFH SP1 Information Element Format ... WirelessMAN OFDMA Support one Indicates if the frame configuration of the WirelessMAN OFDMA system supports
0b0: No WirelessMAN OFDMA Support
0b1: Support WirelessMAN OFDMA if (WirelessMAN OFDMA support with PUSC UL FDM zone) { Indicates WirelessMAN OFDMA support with a PUSC UL FDM zone when WirelessMAN OFDMA support is 0b1 and the frame configuration index is:
- 5, 7, 9, 11, 13 or 15 for the frequency band of the channel 5/10 MHz in accordance with table 780
- 4, 6 or 8 for the channel frequency band of 8.75 MHz in accordance with table 781
- 3 (with CP = 1/8) for the channel bandwidth of 7 MHz in accordance with table 782 RCH Allocation Frequency 2 Indicates the frequency of RCH channel allocation RCH subframe offset 2 Indicates the offset (O _SF ) of the RCH channel allocation. Value Range 0≤O _SF ≤3 RCH R channel start code information four Indicates k _ns , which is a parameter for starting a group of RP codes (r _ns0 ).
r _ns0 (k _ns ) = 16 × k _ns +1
Value Range 0≤k _ns ≤15 RP Code Separation Information for RCH four Indicates the number of codes (N _IN , N _HO, and N _PE ) for initial ranking, handover ranking, and periodic ranking UL_Permbase 7 Specifies the UL_Permbase permutation base used in a WirelessMAN OFDMA system with a PUSC UL FDM zone Reserved 6/3 For FFT size 1024-6 bit
For FFT 512-3 bit size } else { NS-RCH Channel Allocation Frequency 2 Indicates the frequency of allocation of the channel NS-RCH NS-RCH Subframe Offset 2 Indicates the offset (O _SF ) of the allocation of the channel NS-RCH. Value Range 0≤O _SF ≤3 NS RCH Channel RP Start Code Information four Indicates k _ns , which is the parameter that controls the initial root index of the RP codes (r _ns0 )
r _ns0 (k _ns ) = 4 × k _ns +1 for channel NS-RCH format 0
r _ns0 (k _ns ) = 16 × k _ns +1 for format 1 NS-RCH
Value Range 0≤k _ns ≤15 RP Code Separation Information for NS-RCH four Indicates the number of RP codes for initial ranking and handover ranking (N _IN and N _HO ) The number of cyclically shifted RP codes per root index for the channel NS-RCH 2 Indicates the number of cyclically shifted codes per root index (M _ns ) for RP codes Channel Formats NS-RCH one Indicates NS-RCH Channel Format Number UCAS _{SB, 0} 5/4/3 Indicates the number of subband based CRUs in FP ₀
For FFT size 2048-5 bits
For FFT size 1024-4 bit
For FFT 512-3 bit size UCAS _{MB, 0} 5/4/3 Indicates the number of mini-strip CRUs in FP ₀
For FFT size 2048-5 bits
For FFT size 1024-4 bit
For FFT 512-3 bit size UCAS _i 3/2/1 Indicates the total number of allocated CRUs per subband block for FP _i (i≥0)
For FFT size 2048-3 bit
For FFT size 1024-2 bit
For FFT size 512-1 bit } ... }

The following description explains the configuration of a mobile station (or base station) that performs the above operations.

FIG. 7 is a block diagram of a configuration of a mobile station device in accordance with one embodiment of the present invention.

As shown in FIG. 7, a mobile station device that is capable of ranking over a femto base station in accordance with the present invention may include a receiving module 210, a processor 220, a transmitting module 230, and an antenna configured to receive a signal from the base station and transmit her signal. Each of the receiving and transmitting modules 230 and 210 may be part of the processor 220 in accordance with its implementation. This basic configuration is identically applicable to the base femto station.

In addition, the mobile station processor 220 in accordance with one embodiment of the present invention may further include a code generator 240 configured to generate a ranking code. In this case, the code generator 240 may include the previous PRBS generator described in relation to FIG. 6. In particular, the processor 220 may control the PRBS generator to generate a ranking code using the ranking channel information received through the S-SFH header.

Embodiments of the present invention may be implemented using various means. For example, embodiments of the present invention may be implemented using hardware, firmware, software, and / or any combination thereof. In a hardware implementation, the method in accordance with each embodiment of the present invention can be implemented by at least one member selected from the group consisting of specialized integrated circuits (ASICs), digital signal processors (DSP), digital signal processing devices (DSPD ), programmable logic devices (PLDs), programmable gate arrays (FPGAs), processor, controller, microcontroller, microprocessor, etc.

If implemented using firmware or software, the method in accordance with each embodiment of the present invention may be implemented by modules, procedures, and / or functions to perform the functions or operations explained above. The program code is stored in a memory unit and then executed by the processor. A memory block is provided inside or outside the processor for exchanging data with the processor through various well-known means.

Although the present invention has been described and illustrated herein with reference to preferred embodiments thereof, it will be apparent to those skilled in the art that various modifications and changes can be made thereto without departing from the spirit and scope of the invention. Thus, it is intended that the present invention covers modifications and variations of this invention that fall within the scope of the appended claims and their equivalents. Obviously, it is understood that the embodiment is accomplished by combining items that are not explicitly cited in the appended claims or that may be included as new claims by amendment after application.

INDUSTRIAL APPLICABILITY

As described, the present invention is applicable to a mobile communication system.

Claims (12)

1. A method of performing ranking with a base station by means of a mobile station in a mobile communication system, the method comprising the steps of:
receiving secondary header information of a superframe (S-SFH header) from a base station;
determining whether the mobile communication system supports WirelessMAN OFDMA technology;
receiving ranking channel information for performing initial ranking, handover ranking, and periodic ranking from the S-SFH overhead when the mobile communication system supports WirelessMAN OFDMA; and performing at least one ranking of initial ranking, handover ranking, and periodic ranking with the base station using ranking channel information. 2. The method of claim 1, wherein the ranking channel information includes ranking channel allocation information, ranking channel starting code information, ranking code separation information, and uplink permutation base information (UL-Permbase). 3. The method of claim 2, wherein the mobile communication system uses a ranking subframe having a first ranking interval for a synchronized mobile station and a second ranking interval for an unsynchronized mobile station, wherein each ranking from the initial ranking and handover ranking is performed using a second ranking interval , and periodic ranking is performed using the first ranking interval. 4. The method of claim 3, wherein the ranking channel allocation information includes a frequency of allocating a ranking subframe and location information in a time domain of a ranking subframe. 5. The method according to claim 3, in which the information separation code ranking includes information about the number of codes (N) in the group of codes for the initial ranking, the number of codes (O) in the group of codes for ranking the handover and the number of codes (M) in code group for periodic ranking. 6. The method according to claim 5, in which the mobile station generates codes corresponding to the number of codes (N), the number of codes (O) and the number of codes (M) from the initiation code (S) of the ranking channel in accordance with the initial ranking, ranking of the transmission servicing and periodically ranking, respectively, using a code generator having a sequence corresponding to the base of uplink permutations as an initiating sequence. 7. A mobile station device performing ranking with a base station in a mobile communication system, the mobile station device comprising:
an antenna configured to receive or transmit a signal from a base station; and
a processor configured to process a signal received or transmitted through the antenna, the processor determining whether the mobile communication system supports WirelessMAN OFDMA technology, if the antenna receives the secondary superframe header information (S-SFH header) from the base station, the processor obtains ranking channel information for performing initial ranking, handover ranking, and periodic ranking from the S-SFH header, if the mobile communication system supports WirelessMAN OFDMA technology, a process controls at least one of the ranking of the initial ranging, handover ranging and periodic ranging to be performed with the base station using a ranging channel information. 8. The mobile station apparatus of claim 7, wherein the ranking channel information includes ranking channel allocation information, ranking channel starting code information, ranking code separation information, and uplink permutation base information (UL-Permbase). 9. The mobile station apparatus of claim 8, wherein the mobile communication system uses a ranking subframe having a first ranking interval for a synchronized mobile station and a second ranking interval for an unsynchronized mobile station, wherein each ranking from an initial ranking and a handover ranking is performed using a second ranking interval, and periodic ranking is performed using the first ranking interval. 10. The mobile station apparatus of claim 9, wherein the ranking channel allocation information includes a frequency of allocating a ranking subframe and location information in a time domain of a ranking subframe. 11. The mobile station device according to claim 9, in which the information separation code ranking includes information about the number of codes (N) in the group of codes for the initial ranking, the number of codes (O) in the group of codes for ranking the transmission of service and the number of codes (M ) in the code group for periodic ranking. 12. The mobile station device according to claim 11, further comprising a code generator having a sequence corresponding to an uplink permutation base as an initiating sequence, the processor generating codes corresponding to the number of codes (N), the number of codes (O) and the number of codes (M) from the initiation code (S) of the ranking channel in accordance with the initial ranking, handover ranking and periodic ranking, respectively, using a code generator.

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