KR20090124292A - Apparatus and method for transmitting and receiving resource allocation information in a communication system using an orthogonal frequency division multiple access scheme - Google Patents

Abstract

PURPOSE: A method and a device for transmitting and receiving resource allocation information are provided to reduce processing overhead by identifying values of pilot tones in the final sub channel in which the MAP message is allocated by an MS. CONSTITUTION: A discrambled signal is converted into a logic channel structure using a reverse sub-channelization pattern(804). An MS initializes a start point and a size of an individual MAP message(806). The MS determines whether the corresponding sub channel is the final sub channel of the individual MAP message(808). If the corresponding sub channel is not the final sub channel, the above process is performed again after increasing the size of the MAP message. If the corresponding sub channel is the final sub channel, the MCS level is initialized(812). The individual MAP message is demodulated by the reverse modulation, the deinterleaving, and decoding(816). If the CRC test is successful, the individual MAP message information is extracted(822).

Description

Device and method for transmitting and receiving resource allocation information in a communication system using orthogonal frequency division multiple access scheme {APPARATUS AND METHOD FOR TRANSMITTING AND RECEIVING RESOURCE ALLOCATION INFORMATION IN A COMMUNICATION SYSTEM USING AN ORTHOGONAL FREQUENCY DIVISION MULTIPLE ACCESS SCHEME}

The present invention relates to an apparatus for transmitting and receiving resource allocation information in a communication system (hereinafter referred to as an "OFDMA communication system") using an Orthogonal Frequency Division Multiple Access (OFDMA) scheme and It is about a method.

The next generation communication system is developing in the form of providing a variety of high-speed, high-capacity services to mobile terminals (MSs). Representative examples of next generation communication systems include the Institute of Electrical and Electronics Engineers (IEEE) 802.16e communication system and the IEEE 802.16m communication system.

Meanwhile, in the IEEE 802.16e communication system and the IEEE 802.16m communication system, resources are allocated to the MS for transmitting and receiving downlink and uplink data, and the resource allocation information is allocated to the MS using the resource allocation message. Notify Here, the resource allocation message may be a map (MAP, hereinafter referred to as 'MAP') message. Now, a method of transmitting a MAP message in the IEEE 802.16e communication system and the IEEE 802.16m communication system will be described.

First, in the IEEE 802.16e communication system, a base station (BS) (hereinafter referred to as a 'BS') generates resource allocation information for each MS into one MAP message, that is, an entire MAP message, The applied modulation and coding scheme (MCS) level may be informed to each MS through a frame control header (FCH). However, this method transmits the full MAP message using the most robust MCS level among the MCS levels supported by the BS so that all MSs can receive the full MAP message without considering the channel environment of each MS. Since the entire MAP message is transmitted using the transmission power considering the used MCS level, there is a problem that the efficiency of the resource is lowered. Therefore, in order to overcome the problem of resource efficiency degradation, the IEEE 802.16m communication system proposes a method of transmitting a MAP message for each MS.

Next, a process of transmitting a MAP message for each MS in the IEEE 802.16m communication system will be described with reference to FIG. 1.

1 is a diagram illustrating a process of transmitting a MAP message for each MS in a general IEEE 802.16m communication system. Referring to FIG. 1, in the IEEE 802.16m communication system, the BS performs scheduling in steps 111-1 to 111- (N-1) to map each MAP of each MS, that is, the 0th MS to the (N-1) th MS. Create a message. Hereinafter, for convenience of description, a MAP message generated for each MS will be referred to as an “individual MAP message”. The BS adds a Cyclic Redundancy Check (CRC) field for each MAP message in steps 113-1 to 113- (N-1) for error detection in each MS. In step 115-1 to 115- (N-1), the BS selects an MCS level to be used for an individual MAP message according to the channel environment between the BS and the corresponding MS, and steps 117-1 to 117- (N-1). In coding is performed for each MAP message using a coding scheme corresponding to the selected MCS level. When the coding is completed, the BS performs interleaving for each individual MAP message in steps 119-1 to 119- (N-1). The BS performs modulation using a modulation scheme corresponding to the selected MCS level for each individual MAP message in steps 121-1 to 121- (N-1), and performs 123-1 to 123- (N In step -1), a power boosting value to be used for each individual MAP message is determined according to the channel environment between the BS and the MS and the selected MCS level.

When all the processes for generating the individual MAP message are completed as described above, the BS schedules the allocation position of the individual MAP message generated in step 125 and logically allocates a subchannel of the individual MAP message to the downlink frame according to the result. do.

Next, a subchannel structure in a general IEEE 802.16m communication system will be described with reference to FIG. 2.

2 is a diagram illustrating a subchannel structure in a general IEEE 802.16m communication system. Referring to FIG. 2, each subchannel includes NumTile tiles (hereinafter, referred to as 'tiles'), and one tile includes n consecutive OFDM subcarriers and n OFDMAs in time in the frequency domain. Defined by the symbol. One tile includes NumPilotTone pilot tones and NumDataTone data tones. Here, the tone represents the minimum resource allocation unit defined by one subcarrier and one OFDMA symbol.

FIG. 2 shows a 7x2 tile subchannel with NumTile equal to 3, m equals 7, n equals 2, NumPilotTone equals 2, and NumDataTone equals 16. Pilot tones 200, 201, 202, 203, 204 and 205 are inserted for channel estimation purposes. do.

Meanwhile, if the subchannel of the individual MAP message is logically allocated to the subchannel, the BS proceeds to step 127 to allocate the logically allocated subchannel to the physical subchannel. In step 129, the BS scrambles the physical subchannel signal using a preset scrambling code, and in step 131, an inverse fast Fourier tramsform (IFFT) for the scrambled signal is performed. IFFT 'is called) and then transmitted to the corresponding MS.

Next, a process of receiving a MAP message for each MS in a general IEEE 802.16m communication system will be described with reference to FIG. 3.

3 is a diagram illustrating a process of receiving a MAP message for each MS in a general IEEE 802.16m communication system. Referring to FIG. 3, when a signal is received from the BS, the MS performs a Fast Fourier Transform (FFT) on the received signal in step 300 to convert it into a signal in a frequency domain. do. In step 302, the MS descrambles the FFT signal using a preset descrambling code. In step 304, the MS descrambles the descrambled signal using a desubchannelization pattern. To convert to a logical channel structure. As described above, in order to reduce the overhead of the physical layer, the BS does not transmit the location, MCS level and size of individual MAP messages to the MSs. Therefore, each MS should detect its own MAP message using a blind decoding scheme as follows.

In step 306, the MS initializes the start position (StartSubchannel) of the individual MAP message, the size of the MAP message (NumSubchannel), and the MCS level. Here, the size of the MAP message can be represented using the number of subchannels. The MS proceeds to step 308 to demodulate individual MAP messages. That is, the MS performs demodulation, deinterleaving and decoding corresponding to the start position, size and MCS level of the MAP message.

In step 310, the MS performs a CRC check on the decoded signal. If the CRC check is successful in step 312, the MS proceeds to step 314 to extract a MAP message. Otherwise, the MS proceeds to step 316 to use the currently used MCS level. Check if this is the maximum MCS level.

If the MCS level currently used in step 316 is not the maximum MCS level, the MS proceeds to step 318 to increase the MCS level and returns to step 308 again. If the MCS level is the maximum MCS level as a result of the check in step 316, the MS determines whether the size of the MAP message, that is, the number of subchannels, is the maximum in step 320. If the number of subchannels is not the maximum as a result of the determination, the MS initializes the MCS level in step 322, increases the number of subchannels, and returns to step 308 again. If the number of subchannels is the maximum in step 320, the MS proceeds to step 324 to initialize the MCS level and the number of subchannels, increases the start position of the MAP message, and returns to step 308.

As described above, in the conventional IEEE 802.16m communication system, resource allocation information is transmitted to each MS using an individual MAP message. In particular, in a general IEEE 802.16m communication system, channel utilization is increased by considering the channel environment of each MS in transmitting the individual MAP message. Meanwhile, in a typical IEEE 802.16m communication system, the BS does not transmit location, MCS level, and size information of individual MAP messages to each MS in order to reduce overhead of the physical layer. As a result, each MS finds its own MAP message start position in the entire subchannel region allocable by the BS to decode its MAP message because it cannot know the MS's own MAP message location, MCS level and size information. After finding the size of its own MAP message among the maximum subchannel sizes of, it is necessary to find the MCS level used for its MAP message among the maximum number of MCS levels. Therefore, in a typical IEEE 802.16m communication system, the decoding of the MAP message by the MS puts a heavy load on the throughput.

만큼의 디코딩 동작을 수행해야만 한다. 따라서 일반적인 IEEE 802.16m 통신 시스템에서는 MS에서의 MAP 메시지 디코딩에 따른 처리 부하가 크고, 채널 활용도가 저하된다는 문제가 있다.For example, if the maximum number of subchannels that can be allocated to one frame is MaxNumTotalSubchannel, the maximum number of MCS levels is MaxNumMCSlevel, and the maximum number of subchannels that can be allocated to individual MAP messages is MaxNumMAPsubchannel, the MS is the maximum.

You must perform as many decoding operations. Therefore, in the conventional IEEE 802.16m communication system, there is a problem in that the processing load due to MAP message decoding in the MS is large and channel utilization is reduced.

The present invention proposes an apparatus and method for transmitting and receiving resource allocation information in an OFDMA communication system.

In addition, the present invention proposes an apparatus and method for transmitting and receiving resource allocation information that reduces overhead of a physical layer and increases channel utilization in an OFDMA communication system.

The method proposed in the present invention; A method for transmitting resource allocation information of a transmitting apparatus in an orthogonal frequency division multiple access (OFDMA) communication system, the method comprising: generating resource allocation information for each of the m receiving apparatuses, and the m resource allocation information Assigning each of n subchannels to transmit corresponding resource allocation information, selecting a specific subchannel among the allocated n subchannels for each of the m resource allocation information, and m Setting, for each resource allocation information, p pilot tones included in the selected subchannel to a value having orthogonality with values of pilot tones included in each of the remaining subchannels except the selected subchannel. And for each of the m resource allocation information, the resource allocation information after the setting through the allocated n subchannels. And transmitting, wherein m, n, and p are integers greater than or equal to one.

In addition, the method proposed in the present invention; In a method for receiving resource allocation information of a receiving apparatus in an orthogonal frequency division multiple access (OFDMA) communication system, a first subchannel among a plurality of subchannels is set as a start subchannel of resource allocation information, Initializing a size of the resource allocation information to a preset value, setting a first subchannel located in the starting subchannel as a second subchannel in which the resource allocation information is received, and setting the second subchannel Determining whether the resource allocation information is the last subchannel to which the resource allocation information is allocated; and when the determination is the last subchannel, identifying all the subchannels to which the resource allocation information is allocated using the start subchannel and the last subchannel. And decoding the identified all subchannels.

And the device proposed in the present invention; A transmitting apparatus for transmitting resource allocation information in an orthogonal frequency division multiple access (OFDMA) communication system, comprising: a map generator for generating resource allocation information for each of m receiving apparatuses, and the m resources For each allocation information, a logical map generator for allocating n subchannels to transmit corresponding resource allocation information, and for each of the m resource allocation information, selects a specific subchannel among the allocated n subchannels. And, for each of the m resource allocation information, a value having p orthogonality with a value of p pilot tones included in the selected subchannel and a value of orthogonality to values of pilot tones included in each of the remaining subchannels except the selected subchannel. A pilot modulator for setting n and the resource allocation information after the setting for each of the m resource allocation information, And a transmitter for transmitting through two subchannels, wherein m, n, and p are integers greater than or equal to one.

Finally, the device proposed in the present invention; In an orthogonal frequency division multiple access (OFDMA) communication system, an apparatus for receiving resource allocation information, setting a first subchannel among a plurality of subchannels as a start subchannel of resource allocation information, and assigning the resource Initialize the size of the information to a preset value, and set the first subchannel located in the starting subchannel to the second subchannel where the resource allocation information is received, and the resource allocation information is allocated to the set second subchannel. A subchannel checker for determining whether the terminal is the last subchannel, and a map information extractor for identifying all subchannels to which the resource allocation information is allocated using the start subchannel and the last subchannel when the determination is the last subchannel. Include.

In the present invention, there is an advantage that the blind MAP decoding can be more effectively performed without the MS receiving the position and size information of the individual MAP. In addition, the present invention has the advantage of reducing the overhead of the physical layer, and the processing burden in the MS during blind MAP decoding. In addition, the present invention has the effect of reducing the loss of data allocation resources to increase the system capacity, and save the battery of the MS.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

The present invention provides an apparatus and method for transmitting and receiving resource allocation information in an OFDMA communication system. To this end, the present invention generates resource allocation information for each of the m receiving apparatuses, allocates n subchannels for transmitting corresponding resource allocation information to each of the m resource allocation information, and then the m resource allocation information. A specific subchannel is selected from among the n subchannels allocated for each, and the values of p pilot tones included in the selected subchannel for each of the m resource allocation information are the remaining subchannels except the selected subchannel. A value having orthogonality to the values of the pilot tones included in each of the two is set, and the resource allocation information is transmitted through the allocated n subchannels after the setting for each of the m resource allocation information.

Information known to all receiving apparatuses without occupying additional resource elements in an OFDMA communication system includes a frame length, a size of an entire frequency allocation region, a position of a synchronization signal, a position of a pilot tone, and the like. The present invention proposes a method of allowing a receiving device to more easily detect the size of its own MAP message by using a pilot tone inserted for channel estimation in a tile among the information known to all receiving devices as described above. In the OFDMA communication system, all pilot tones in a subchannel through which individual MAP messages are transmitted have tones of a predetermined pattern as shown in FIG. 2 and are set to a value of 1 and transmitted. Every receiving device knows information about the occupancy pattern of the pilot tones. Accordingly, in the present invention, the values of the pilot tones in the last subchannel to which the individual MAP message is assigned are changed to be orthogonal to the values of the pilot tones in the remaining subchannels, so that all receiving apparatuses use the individual MAPs using the pilot tones in the subchannels. Make sure you know the end of the message.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the description of an embodiment of the present invention, for convenience, the transmitter and the receiver will be limited to 'BS' and 'MS', respectively. However, it will be apparent to those skilled in the art that the present invention is not applicable only to the BS and the MS.

4 is a block diagram of a BS for transmitting a MAP message for each MS in an OFDMA communication system according to an embodiment of the present invention.

Referring to FIG. 4, the BS according to the present invention includes an individual map generator 400, a CRC adder 402, a scheduler 404, an encoder 406, an interleaver 408, a modulator 410, and a logical map. The generator 412 includes a pilot modulator 414, a physical allocator 416, a scrambler 418, and an IFFT unit 420.

The individual map generator 400 generates an individual MAP message for each MS by performing scheduling. The individual MAP message generated by the individual map generator 400 is output to the CRC adder 402.

The CRC adding unit 402 attaches a CRC field for each MAP message to detect an error in the MS. The scheduler 404 selects an MCS level for each MAP message according to a channel environment between the BS and the MS. Then, according to the selected MCS level, the encoder 406, the interleaver 408, and the modulator 410 respectively perform coding, interleaving, and modulation for each MAP message. When this process is completed, the scheduler 404 determines the power boosting value of each individual MAP message in consideration of the channel environment between the BS and the MS and the selected MCS level. The scheduler 404 schedules an allocation position of the received individual MAP message and outputs the result to the logical map generator 412. The logical map generator 412 logically allocates a subchannel of an individual MAP message to a downlink frame according to the scheduling result.

Then, the pilot modulator 414 selects a specific subchannel among subchannels of the logically allocated individual MAP message according to an exemplary embodiment of the present invention, and selects pilot tones within the specific subchannel in the remaining subchannels. Control to be orthogonal to the values of the tones. The embodiment of the present invention will be described by limiting the specific subchannel to the last subchannel for better understanding. However, it will be apparent to those skilled in the art that the specific subchannel may be a subchannel other than the last subchannel.

In general, the values of the pilot tones in the subchannel are set to one. Accordingly, the pilot modulator 414 multiplies the values of the pilot tones of the last subchannel among the subchannels to which individual MAP messages are assigned by '1.-1, 1, -1.' In order. This may be represented as in Equation 1 below.

In Equation 1, k denotes an index of a pilot tone in a subchannel, p [k] denotes a value of pilot tones in the last subchannel, and C [k] multiplies a value of pilot tones in the last subchannel. Indicates a value. Here, C [k] is set to 1 when the pilot tone has an even index, and C [k] is set to 1 when the pilot tone has an odd index. Thus, if C [k] set to 1 or -1 is multiplied by p [k], which is the value of the kth pilot tone, the result is Ppeak [k]. Ppeak [k] calculated in this way is set to the value of the pilot tone in the last subchannel. According to an embodiment of the present invention, a subchannel in which a pilot tone value is set in the above manner is illustrated in FIG. 5.

 FIG. 5 illustrates that the number of tiles NumTile is 3, the number of subcarriers m is 7, the number of OFDMA symbols n is 2, the number of pilot tones NumPilotTone is 2, and data The number of tones (NumDataTone) shows an example of a logical allocation structure of subchannels having a 16 by 7x2 tile structure.

First, referring to FIG. 5 (a), pilot tones 500, 501, 502, 503, 504, and 505 in a subchannel other than the last subchannel according to an embodiment of the present invention. Is set to 1 without modification. In contrast, the values of the pilot tones in the last subchannel are pilot tones 510, 512, and 514 with even indices, as shown in FIG. Is set to 1, and pilot tones 511, 513, and 515 having odd indices are set to -1.

Meanwhile, in the exemplary embodiment of the present invention, the pilot tones having the even index are multiplied by 1 and the pilot tones having the odd index are multiplied by -1 to set the pilot tones of the last subchannel. The value of the pilot tones of the last subchannel may be set by multiplying the value of the pilot tone having a by 1 and the value of the pilot tone having an even index.

When the pilot tones of the subchannels to which the individual MAP message is allocated are set in the pilot modulator 414 as described above, the physical allocator 416 converts the resources logically allocated to the subchannels into physical allocation signals. Then, the scrambler 418 scrambles the physical allocation signal for each OFDMA symbol, and the IFFT unit 420 IFFTs the scrambled signal and transmits the IFFT signal to the terminal.

As such, in the embodiment of the present invention, the BS provides the MS with the convenience of identifying the last subchannel by setting the values of the pilot tones of the subchannel to which the individual MAP message is allocated as described above.

Hereinafter, a block diagram of an MS for receiving an individual MAP message in an OFDMA communication system according to an embodiment of the present invention will be described with reference to FIG. 6.

Referring to FIG. 6, the MS according to an embodiment of the present invention includes an FFT unit 600, a descrambler 602, a desubchannelerizer 604, a scheduler 606, and a logical map degenerator. ) 608, subchannel checker 610, demodulator 612, deinterleaver 614, decoder 616, CRC checker 618, and map information extractor 620).

When the signal is received from the BS, the FFT unit 600 converts the received signal into a signal in the frequency domain by FFT. The descrambler 602 receives a signal output from the FFT unit 600 and descrambles the received signal. The desubchannelizer 604 then desubchannels the descrambled signal using a desubchannelization pattern and the MCS level set in the scheduler 606, the size of the MAP message, and the like. Output to the logical map inverse generation unit 608. Then, the logical map inverse generation unit 608 inversely generates the output inverse subchannelized signal into a logical MAP message and outputs the inverse subchannel check unit 610.

The subchannel checker 610 initializes the start position and size of the MAP message to check the subchannel according to the output signal. The subchannel checker 610 determines whether the corresponding subchannel is the last subchannel allocated to the individual MAP message according to the size of the set MAP message. If the subchannel test unit 610 is not the last subchannel, the subchannel tester 610 increases the number of subchannels and checks whether the subchannel is the last subchannel. The subchannel tester 610 initializes the MCS level in the case of the last subchannel and outputs the MCS level to the inverse modulator 612. The inverse modulator 612 inversely modulates the output signal and outputs the de-interleaver 614. Then, the deinterleaver 614 deinterleaves the output signal, and the decoder 616 decodes the deinterleaved signal and outputs the deinterleaved signal to the CRC checker 618.

The CRC checker 618 checks the CRC of the decoded signal and outputs the result to the MAP information extractor 620. Then, the MAP information extracting unit 620 extracts MAP message information when the CRC check is successful and checks the MCS level when an error occurs. If the MCS level is not the highest level, the MAP information extractor 620 increases the MCS level and outputs the MCS level to the inverse modulator 610.

When the MCS level is the highest level, the MAP information extracting unit 620 sets the start position of a new individual MAP message by adding the size of the current MAP message to the start position of the current MAP message, and sets the size of the MAP message. Initializes and checks whether or not it is the last subchannel through the subchannel checker 606 again.

Hereinafter, a process of transmitting a MAP message for each MS in a BS according to an embodiment of the present invention will be described with reference to FIG. 7.

In FIG. 7, the processes from steps 711 to 711- (N-1) to steps 723-1 to 723- (N-1) are described in steps 111-1 to 111- (N-1) of FIG. 1 as described above. Since the process is the same as the steps 1 to 123- (N-1), detailed description thereof will be omitted.

Referring to the process below step 725 to which the present invention is applied, according to an embodiment of the present invention, when the BS completes all processes for generating the individual MAP message in the above-described step, the process proceeds to step 725 and generates the individual MAP message. And allocates logical sub-channels of individual MAPs to the downlink frame according to the result. In step 727, the BS sets the values of the pilot tones of the logically allocated subchannel. According to an embodiment of the present invention, the BS identifies the values of the pilot tones of the last subchannel among the logically allocated subchannels, and sets the identified pilot tones to have orthogonality with the values of the pilot tones of the remaining subchannels. do. This will be described in detail as follows.

In general, the values of the pilot tones of the subchannel are all set to one. Accordingly, the BS multiplies the values of the pilot tones of the last subchannel by 1, -1, 1, -1 in index order, and multiplies the values of the pilot tones of the last subchannel by the values of the pilot tones of the remaining subchannels. To distinguish it from In an embodiment of the present invention, the values of the pilot tones of the last subchannel are multiplied by 1, -1, 1, -1 in order, but -1,1, -1, 1., or 1,1, -1, It will be apparent to those skilled in the art that various permutations can be multiplied, such as

When the BS sets the values of the pilot tones of the subchannels in the same manner as above, the BS proceeds to step 729 to allocate the logically allocated subchannels to the physical subchannels. The BS scrambles the physical subchannel signal using a scrambling code preset in step 731, and IFFTs the scrambled signal in step 733.

Next, a process of receiving a MAP message for each MS according to an embodiment of the present invention will now be described with reference to FIG. 8.

Referring to FIG. 8, when a signal is received from the BS, the MS performs an FFT on the received signal and converts the received signal into a signal in a frequency domain. The MS descrambles using a descrambling code preset in step 802, and converts the descrambled signal into a logical channel structure using an inverse subchannelization pattern in step 804.

In step 806, the MS initializes the start position (StartSubchannel) and the size (NumSubchannel) of the individual MAP message. In step 808, the MS determines whether the corresponding subchannel is the last subchannel of the individual MAP message. If the MS determines that the last subchannel is determined in step 810, the MS proceeds to step 812. Otherwise, the MS proceeds to step 814 to increase the size of the MAP message, that is, increases the number of subchannels and returns to step 808. Determine if it is a channel.

If the MS is determined to be the last subchannel, the MS initializes the MCS level in step 812 and proceeds to step 816 to inversely modulate, deinterleave, and decode the individual MAP message. In step 818, the MS examines the CRC. If the MS succeeds in step 820, the MS proceeds to step 822 to extract individual MAP message information. Otherwise, the MS proceeds to step 824 to determine whether the MCS level is maximum. Here, if the MCS level is not maximum, the MS increases the MCS level in step 826 and returns to step 816. If the MCS level is maximum, the MS proceeds to step 828 to change the start position, initializes the size of the MAP message, and returns to step 808.

Meanwhile, the process of the MS determining whether the corresponding subchannel is the last subchannel in step 808 will be described in detail with reference to FIG. 9.

9 is a diagram illustrating a process of checking whether a MS has a last subchannel according to an embodiment of the present invention. Referring to FIG. 9, the MS determines whether a pilot signal is received in step 900. According to an embodiment of the present invention, the pilot signal of the currently received subchannel may be expressed as Equation 2 below.

In Equation 2, k denotes a pilot index in a corresponding subchannel, y [k] denotes a received pilot signal, h [k] denotes a channel used by the pilot, and n [k] denotes noise including thermal noise and interference. Indicates.

및

를 산출한다. 본 발명의 실시 예에 따라

및

는 다음 수학식 3을 통해 산출될 수 있다.The MS is a channel of tile from the received pilot signal

And

Calculate According to an embodiment of the present invention

And

May be calculated through Equation 3 below.

는 i번째 tile의 제1방식으로 산출된 채널,

는 i번째 tile의 제2방식으로 산출된 채널을 나타낸다. In Equation 3, i is a tile index in the subchannel,

Is a channel calculated by the first method of the i-th tile,

Denotes a channel calculated by the second scheme of the i-th tile.

과

가 산출되면, 상기 산출된

및

채널 각각의 전력 P1 및 P2를 계산한다. 상기 P1 및 P2는 다음 수학식 4에 나타난 바와 같이 상기 파일럿 수신 신호 y[k]와 상기 산출된

및

를 통해 산출된다. 하기 수학식 4에서 j는 tile 내의 파일럿 인덱스를 나타낸다.The MS is as above

and

Is calculated, the calculated

And

Calculate the power P1 and P2 of each channel. P1 and P2 are calculated with the pilot received signal y [k] as shown in Equation 4 below.

And

Calculated by In Equation 4, j represents a pilot index in a tile.

When P1 and P2 are calculated as described above, the MS proceeds to step 906 to determine whether P2 / P1 is greater than a threshold. If the P2 / P1 is larger than the threshold, the MS proceeds to step 908 to determine the last subchannel. If not, the MS determines the remaining subchannel in step 910.

만큼 감소시킬 수 있는 이점이 있다.As such, in the embodiment of the present invention, since the MS can easily identify the values of the pilot tones in the last subchannel to which the individual MAP message is allocated, the processing overhead caused by the unreceived position and size of the individual MAP message is eliminated. It has the advantage of being able to detect its own MAP message while reducing it. Specifically, when the maximum number of individual MAP messages that can be allocated to one frame is called MaxNumIndividualMAP, and the maximum number of MCS levels is called MaxNumMCSlevel, the MS according to the present invention performs decoding by the maximum MaxNumIndividualMAP * MaxNumMCSlevel. Thus, the present invention is directed to the processing burden at the MS for MAP detection.

There is an advantage that can be reduced as much.

1 is a diagram illustrating a process of transmitting a MAP message for each MS in a general IEEE 802.16m communication system;

2 is a diagram illustrating a logical allocation structure of subchannels in a general IEEE 802.16m communication system;

3 is a diagram illustrating a process of receiving a MAP message for each MS in a general IEEE 802.16m communication system;

4 is a block diagram of a BS for transmitting a MAP message for each MS in an OFDMA communication system according to an embodiment of the present invention;

5 is an exemplary diagram of a logical allocation structure of subchannels in an OFDMA communication system according to an embodiment of the present invention;

6 is a block diagram of an MS for receiving an individual MAP message in an OFDMA communication system according to an embodiment of the present invention;

7 is a diagram illustrating a process of transmitting a MAP message for each MS in a BS according to an embodiment of the present invention;

8 is a diagram illustrating a process of receiving a MAP message for each MS according to an embodiment of the present invention;

9 is a diagram illustrating a process of checking whether a MS has a last subchannel according to an embodiment of the present invention.

Claims (21)

A method of transmitting resource allocation information of a transmitting device in an orthogonal frequency division multiple access (OFDMA) communication system, generating resource allocation information for each of the m receiving devices; Allocating n subchannels to transmit corresponding resource allocation information for each of the m resource allocation information; Selecting a specific subchannel among the allocated n subchannels for each of the m resource allocation information; For each of the m resource allocation information, a value of p pilot tones included in the selected subchannel is set to a value having orthogonality with values of pilot tones included in each of the remaining subchannels except the selected subchannel. Process, And for each of the m resource allocation information, transmitting the resource allocation information through the allocated n subchannels after the setting, wherein m, n, and p are integers of 1 or more. How to send allocation information. The method of claim 1, And the specific subchannel is a last subchannel.  The method of claim 1, The value of the p pilot tones is set using Equation 5 below.

In Equation 5, k denotes an index of pilot tones included in the allocated n subchannels, p [k] denotes values of pilot tones included in the specific subchannel, and C [k] denotes the Represents a signal value that is multiplied by the values of pilot tones included in a particular subchannel, wherein pend [k] represents a value having the orthogonality.  A method for receiving resource allocation information of a receiving apparatus in an orthogonal frequency division multiple access (OFDMA) communication system, Setting a first subchannel among a plurality of subchannels as a start subchannel of resource allocation information, and initializing a size of the resource allocation information to a preset value; Setting a first subchannel located in the starting subchannel as a second subchannel in which the resource allocation information is received; Determining whether the set second subchannel is the last subchannel to which the resource allocation information is allocated; If the determination result is the last subchannel, resource allocation comprising identifying all subchannels to which the resource allocation information is allocated using the start subchannel and the last subchannel, and decoding the identified subchannels. How to receive information. The method of claim 4, wherein And determining that the resource is allocated to the last subchannel after increasing the size of the resource allocation information, if it is not the last subchannel. The method of claim 4, wherein The determining of the last subchannel may include receiving a pilot signal included in the second subchannel; Calculating a first channel and a second channel corresponding to the corresponding tile in the second subchannel using the first and second methods, respectively, by using the received pilot signal; Calculating a first power according to the calculated first channel and a second power according to the calculated second channel; Comparing the calculated ratio of the first power and the second power with a threshold; And determining whether the terminal is the last subchannel according to the comparison result. The method of claim 6, The first method and the second method is a method of receiving resource allocation information, characterized in that the following equation (6).

In Equation 6, j is an index of a pilot signal included in the second subchannel, y [j] represents a received pilot signal, i is a tile index included in the second subchannel,

Represents the first channel calculated by the first scheme of the i-th tile,

Represents the second channel calculated in the second manner of the i < th > tile. The method of claim 7, wherein And the first power and the second power are calculated according to Equation 7 below.

In Equation 7, P1 represents the first power, and P2 represents the second power. The method of claim 4, wherein Initializing a modulation and coding scheme (MCS) level after identifying the entire subchannel; Performing a CRC check after decoding the entire subchannel; Detecting individual resource allocation information when an error does not occur as a result of the CRC check; And adjusting the MCS level and performing the CRC check when an error occurs as a result of the CRC check. The method of claim 9, After adjusting the MCS level, determining whether the MCS level is maximum; And changing the start subchannel when the MCS level is maximum, and determining the last subchannel by initializing the size of the resource allocation information. A transmitting apparatus for transmitting resource allocation information in an orthogonal frequency division multiple access (OFDMA) communication system, a map generator for generating resource allocation information for each of the m receiving devices; A logical map generator for allocating each of the m resource allocation information, n subchannels to transmit corresponding resource allocation information; For each of the m resource allocation information, a specific subchannel is selected among the allocated n subchannels, and for each of the m resource allocation information, values of p pilot tones included in the selected subchannel are selected. A pilot modulator configured to set a value having orthogonality to values of pilot tones included in each of the remaining subchannels except the selected subchannel; A transmission unit configured to transmit the resource allocation information through the allocated n subchannels after the setting, for each of the m resource allocation information, And m, n, and p are integers of 1 or more. The method of claim 11, And the specific subchannel is a last subchannel.  The method of claim 11, And the value of the p pilot tones is set using Equation (8).

 In Equation 8, k denotes an index of pilot tones included in the allocated n subchannels, p [k] denotes values of pilot tones included in the specific subchannel, and C [k] denotes the Represents a signal value that is multiplied by the values of pilot tones included in a particular subchannel, wherein pend [k] represents a value having the orthogonality.  An apparatus for receiving resource allocation information in an orthogonal frequency division multiple access (OFDMA) communication system, A first subchannel among a plurality of subchannels is set as a start subchannel of resource allocation information, the size of the resource allocation information is initialized to a preset value, and the first subchannel located in the start subchannel is allocated to the resource allocation information. A subchannel checking unit for setting a second subchannel to be received and determining whether the set second subchannel is the last subchannel to which the resource allocation information is allocated; And a map information extracting unit for identifying all subchannels to which the resource allocation information has been allocated using the start subchannel and the last subchannel when the result is the last subchannel. The method of claim 14, And if the subchannel checker determines that the last subchannel is increased after increasing the size of the resource allocation information when the subchannel checker is not the last subchannel. The method of claim 14, The subchannel inspecting unit receives a pilot signal included in the second subchannel when determining whether the terminal is the last subchannel, and uses the received pilot signal to correspond to a corresponding tile in the second subchannel. After calculating the channel and the second channel using the first method and the second method, respectively, the first power according to the calculated first channel and the second power according to the calculated second channel are calculated and calculated. And comparing the ratio of the first power to the second power to a threshold, and determining whether the terminal is the last subchannel according to a result of the comparison. The method of claim 16, The apparatus of claim 1, wherein the first scheme and the second scheme are as shown in Equation (9).

In Equation 9, j is an index of a pilot signal included in the second subchannel, y [j] represents a received pilot signal, i is a tile index included in the second subchannel,

Represents the first channel calculated by the first scheme of the i-th tile,

Represents the second channel calculated in the second manner of the i < th > tile. The method of claim 17, And the first power and the second power are calculated according to Equation 10 below.

In Equation 10, P1 represents the first power, and P2 represents the second power. The method of claim 14, And the map information extracting unit initializes a modulation and coding scheme (MCS) level after identifying the entire subchannel. The method of claim 19, A decoder for decoding the entire subchannels after the MCS level is initialized; The CRC check is performed on all of the decoded subchannels to detect individual resource allocation information when no error occurs as a result of the CRC check, and the MCS level adjusted by the map information extractor when an error occurs as a result of the CRC check. And a CRC checker configured to perform the CRC check on all subchannels having the at least one subchannel. The method of claim 20, The map information extracting unit determines whether the MCS level is the maximum after adjusting the MCS level, and if the MCS level is the maximum, changes the start subchannel, and initializes the size of the resource allocation information to the last. And determining whether it is a subchannel.

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