RU2458483C2 - Radio communication base station device and control channel presentation method - Google Patents

Abstract

FIELD: information technology.

SUBSTANCE: device includes: an resource block allocation unit (101) which allocates uplink resource blocks continuous on the frequency axis for respective radio communication mobile stations by frequency scheduling and generates allocation information indicating which uplink resource block has been allocated to which radio communication mobile station device; and an presentation unit (109) which presents a response signal to the radio communication mobile station device in the downlink control channels distributed/presented on the frequency axis while being correlated to the continuous uplink resource blocks according to the allocation information.

EFFECT: maximising the frequency diversity effect on downlink control channels.

21 cl, 22 dwg

Description

Technical field

The present invention relates to a radio base station apparatus and a method for displaying control channels.

State of the art

In mobile communications, an automatic data retransmission request (ARQ) is applied to the uplink data transmitted from the mobile radio station device (hereinafter simply referred to as the “mobile station”) to the radio base station device (hereinafter simply referred to as the “base station”) upstream the communication line, and a response signal showing the result of detecting data errors on the uplink is returned to the mobile station on the downlink. The base station performs a cyclic redundancy check (CRC) check for uplink data, and a confirmation signal (ACK) is returned as a response for the mobile station if CRC = OK (no errors) and a negative acknowledgment signal (NACK) is returned if CRC = NG (error).

To efficiently use downlink communication resources, studies have recently been conducted regarding ARQ queries that link uplink resource blocks (RB) for transmitting uplink data to downlink control channels for transmitting response signals in a downlink (e.g., see non-patent document 1). This means that the mobile station can identify the control channels in which the response signal is transmitted to the mobile station based on the resource block allocation information reported from the base station, even when the control channel allocation information is not separately reported.

In addition, studies have recently been conducted for ARQ queries, according to which the response signal is expanded and the expanded response signal is duplicated in order to average the interference of the response signal from neighboring cells or sectors and to provide increased frequency diversity for the response signal (for example, see non-patent document 2) .

Non-Patent Document 1: 3GPP RAN WG1, R1-070932, “Assignment of Downlink ACK / NACK,” Panasonic, February 2007.

Non-Patent Document 2: 3GPP RAN WG1, R1-070734, “E-UTRA Technology Downlink ACK / NACK,” TI, February 2007.

SUMMARY OF THE INVENTION

The tasks to be solved by the invention

It is possible to use the aforementioned recently studied ARQ queries by combining them. Now, a specific example of mapping response signals to downlink control channels will be explained. In the following explanation, the base station receives uplink data transmitted from the mobile stations using the uplink resource blocks RB # 1 through RB # 8 shown in FIG. 1, and the base station displays response signals for the uplink data (signals ACK and NACK signals) to the downlink control channels CH # 1 to CH # 8, mapped to four frequency bands, subcarriers f ₁ - f ₄ , f ₉ - f ₁₂ , f ₁₇ - f ₂₀ and f ₂₅ - f ₂₈ , shown in figure 2, and transmits response signals to mobile stations. In addition, the base station expands the response signal with an extension code having an expansion coefficient of 4, and repeats the extended response signal with a repetition factor of 2. Therefore, as shown in FIG. 2, downlink control channels CH # 1 through CH # 4 are displayed. to identical ranges subcarriers f ₁ - f ₄ and f ₁₇ - f ₂₀ , concentrated in one place, and downlink control channels CH # 5 - CH # 8 are mapped to identical ranges subcarriers f ₉ - f ₁₂ and f ₂₅ - f ₂₈ , with concentration in one place.

In addition, as shown in FIG. 3, the uplink resource blocks shown in FIG. 1 and the downlink control channels shown in FIG. 2 are associated with each other in series. Therefore, as shown in FIG. 3, the response signal for the uplink data transmitted using the resource block RB # 1 shown in FIG. 1 is mapped to the downlink control channel CH # 1, that is, mapped to subcarriers f ₁ - f ₄ and f ₁₇ - f ₂₀ shown in figure 2. Similarly, as shown in FIG. 3, a response signal for uplink data transmitted using resource block RB # 2 shown in FIG. 1 is mapped to downlink control channel CH # 2, that is, mapped to subcarriers f ₁ - f ₄ and f ₁₇ - f ₂₀ shown in figure 2. The same applies to resource blocks RB # 3 - RB # 8.

In addition, when a coding block is formed by a plurality of consecutive resource blocks in a frequency domain and resource blocks are allocated in elements with one block, the base station transmits response signals to mobile stations by mapping response signals to a plurality of downlink control channels in connection with a plurality of uplink resource blocks communications included in one coding unit. For example, when one coding unit is generated using three consecutive uplink resource blocks RB # 1 through RB # 3 among the uplink resource blocks RB # 1 through RB # 8 shown in FIG. 1, the base station displays code multiplexed extended response signals to the downlink control channels CH # 1 through CH # 3, mapped with concentration in identical ranges, subcarriers f ₁ through f ₄ and f ₁₇ through f ₂₀ shown in FIG. 2.

Although in the above example, the downlink control channels CH # 1 through CH # 8 are thus mapped to sixteen subcarriers, the subcarriers f ₁ through f ₄ , f ₉ through f ₁₂ , f ₁₇ through f ₂₀ and f ₂₅ through f ₂₈ , respectively signals are mapped to only eight subcarriers, subcarriers f ₁ through f ₄ and f ₁₇ through f ₂₀ . Thus, in the above example, response signals are mapped to only half of all subcarriers onto which downlink control channels are mapped.

In the case where the downlink control channels displayed in the limited frequency domain are used in this way, a small frequency diversity effect can be obtained depending on the positions at which the downlink control channels are displayed.

Therefore, it is an object of the present invention to provide a base station and a method for displaying control channels that can maximize the effect of frequency diversity on downlink control channels.

Means for solving problems

The base station of the present invention applies a configuration including: an allocation section that allocates a first control channel formed by a plurality of consecutive resource blocks or a plurality of CCEs to a mobile radio communication station device; and a display section that displays control signals for the mobile radio station device to a plurality of second control channels mapped in a distributed manner on a frequency domain with reference to a plurality of resource blocks or to a plurality of CCE elements.

The technical result of the invention

According to the present invention, it is possible to maximize the effect of frequency diversity on the downlink control channels.

Brief List of Drawings

FIG. 1 illustrates an example of mapping uplink resource blocks;

2 illustrates an example of a mapping of downlink control channels;

3 shows bindings between uplink resource blocks and downlink control channels;

4 is a block diagram showing a configuration of a base station in accordance with Embodiment 1 of the present invention;

5 is a block diagram showing a configuration of a mobile station in accordance with Embodiment 1 of the present invention;

6 illustrates a mapping of a downlink control channel in accordance with Embodiment 1 of the present invention;

7 illustrates a mapping of a downlink control channel in accordance with Embodiment 2 of the present invention;

Fig. 8 illustrates a mapping of a downlink control channel in a cell 2 in accordance with Embodiment 3 of the present invention;

FIG. 9 shows the mappings between SCCHs and downlink CCEs in accordance with Embodiment 4 of the present invention;

10 illustrates an example of a mapping of downlink CCEs in accordance with Embodiment 4 of the present invention;

11 shows mappings between downlink CCEs and downlink control channels in accordance with Embodiment 4 of the present invention;

12 is a block diagram showing a configuration of a base station in accordance with Embodiment 4 of the present invention;

13 is a block diagram showing a configuration of a mobile station in accordance with Embodiment 4 of the present invention;

FIG. 14 shows the bindings (options) between SCCHs and downlink CCEs in accordance with Embodiment 4 of the present invention;

15 illustrates a mapping of a downlink control channel in accordance with Embodiment 4 of the present invention;

16 illustrates downlink CCE elements used in the number of OFDM symbols for multiplexing in accordance with Embodiment 5 of the present invention;

17 is a block diagram showing a configuration of a base station in accordance with Embodiment 5 of the present invention;

Fig. 18A illustrates physical resources (number of OFDM symbols for multiplexing: 1) in accordance with Embodiment 5 of the present invention;

Figv illustrates physical resources (the number of OFDM symbols for multiplexing: 2) in accordance with embodiment 5 of the present invention;

19 is a block diagram showing a configuration of a mobile station in accordance with Embodiment 5 of the present invention;

20 illustrates a mapping of a downlink control channel in accordance with Embodiment 5 of the present invention;

21 illustrates another mapping of a downlink control channel (Example 1);

Fig. 22 illustrates another mapping of a downlink control channel (Example 2).

Preferred Embodiment

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The base station in accordance with the present embodiment of the present invention transmits a response signal using an orthogonal frequency division multiplexing (OFDM) scheme. In addition, the mobile station in accordance with the present embodiment transmits uplink data using frequency division multiple access spreading technique using discrete Fourier transform (DFTs-FDMS). When the uplink data is transmitted using the DFTs-FDMS technology, as described above, the coding block is formed by a plurality of consecutive resource blocks on the frequency axis (in the frequency domain) and the base station allocates the resource blocks to the mobile stations in elements with one block.

(Embodiment 1)

FIG. 4 shows a configuration of a base station 100 in accordance with the present embodiment, and FIG. 5 shows a configuration of a mobile station 200 in accordance with the present embodiment.

In order to avoid a complicated explanation, FIG. 4 shows components that are related to the reception of uplink data and downlink transmission of response signals for uplink data to which the present invention is closely related, and drawings and explanations of components are omitted. which are related to downlink data transmission. Similarly, FIG. 5 shows components that are related to uplink data transmission and downlink reception of response signals for uplink data to which the present invention is closely related, and drawings and explanations of components that are related are omitted. to receive data downlink.

In the base station 100 in FIG. 4, an allocation section 101 allocates uplink resource blocks to mobile stations by frequency scheduling and generates resource block allocation information showing which uplink resource blocks are allocated to which mobile stations (i.e., allocation information showing allocation results resource blocks), and provides generated information on the allocation of resource blocks of the encoding section 102 and the display section 109. In addition, the resource block allocation section 101 allocates resource blocks using a plurality of consecutive resource blocks included in one coding unit as one element. The resource block is formed by grouping into a block several subcarriers adjacent to each other at intervals of the coherence bandwidth.

The encoding section 102 encodes the resource block allocation information and provides encoded resource block allocation information of the modulation section 103.

The modulation section 103 modulates the encoded resource block allocation information to generate resource block allocation information symbols and provides resource block allocation information symbols of the serial-parallel (S / P) conversion section 104.

The S / P conversion section 104 converts the resource block allocation information symbols sequentially received as input from section 103 into parallel resource block allocation symbols and outputs parallel resource block allocation information symbols of the display section 109.

Modulation section 105 modulates a response signal received as input from CRC verification section 117 and provides a modulated response signal to extension section 106.

The extension section 106 expands the response signal received as input from the modulation section 105, and provides an extended response signal of the repetition section 107.

The repeat section 107 duplicates (repeats) the response signal received as input from the extension section 106, and provides a plurality of response signals including identical response signals, S / P transform sections 108.

The S / P conversion section 108 converts the response signals sequentially received as input from the repeat section 107 into parallel response signals and provides parallel response signals to the display section 109.

The mapping section 109 maps the resource block allocation information symbols and response signals to a plurality of subcarriers to form an OFDM symbol, and provides the displayed resource block allocation information symbols and response signals of the inverse fast Fourier transform (IFFT) section 110. Moreover, based on the resource block allocation information received as input from the resource block allocation section 101, the display section 109 displays response signals to the downlink control channels mapped to the frequency domain with reference to the uplink resource blocks. For example, when the display section 109 receives resource blocks RB # 1 through RB # 3 shown in FIG. 1 from the resource block allocation section 101 as resource block allocation information for the mobile station 200, as shown in FIG. 3, the display section 109 maps response signals for uplink data transmitted from mobile station 200 using resource blocks RB # 1 through RB # 3 to downlink control channels CH # 1 through CH # 3. The display process in the display section 109 will be described in detail later.

IFFT section 110 performs IFFT conversion on resource block allocation information symbols and on response signals mapped to a plurality of subcarriers to generate an OFDM symbol, and outputs the generated OFDM symbol of cyclic prefix (CP) adding section 111.

The cyclic prefix adding section 111 adds the same signal, which is the tail of the OFDM symbol, to the head of the OFDM symbol as a cyclic prefix.

The radio transmission section 112 performs transmission processing including digital-to-analog (D / A) conversion, amplification, and up-conversion above the cyclic prefix OFDM symbol and transmits the cyclic prefix OFDM symbol after processing the transmission from the antenna 113 to the mobile station 200.

Meanwhile, the radio reception section 114 receives the uplink data transmitted from the mobile station 200 through the antenna 113 and performs reception processing including down-conversion and analog-to-digital (A / D) conversion for this uplink data .

The demodulation section 115 demodulates the uplink data and provides demodulated uplink data to the decoding section 116.

The decoding section 116 decodes the demodulated uplink data and provides decoded uplink data to the CRC verification section 117.

CRC check section 117 performs error detection for uplink data after decoding using a CRC code to generate an ACK signal if CRC = OK (no errors) or a NACK signal if CRC = NG (error) as a response signal and outputs the generated a response signal from modulation section 105. In addition, CRC = OK (no errors), CRC verification section 117 provides uplink data after decoding as received data.

Meanwhile, in the mobile station 200 shown in FIG. 5, the radio receiving section 202 receives the OFDM symbol transmitted from the base station 100 through the antenna 201 and performs reception processing including down-conversion and analog-to-digital (A / D ) conversion, over this OFDM symbol.

The cyclic prefix deletion section 203 removes the cyclic prefix from the OFDM symbol after receiving processing.

Fast Fourier Transform (FFT) section 204 performs FFT conversion on the OFDM symbol after removing the cyclic prefix to obtain resource allocation and response signal allocation information symbols and provides them to the demultiplexing section 205.

The demultiplexing section 205 demultiplexes the input signals to resource block allocation information symbols and response signals and provides resource block allocation information symbols to the serial-parallel (P / S) conversion section 206 and the response signals of the P / S conversion section 210. Meanwhile, the demultiplexing section 205 demultiplexes the response signals from the input signal based on a specific result received as input from the display determination section 209.

The P / S transform section 206 converts a plurality of parallel resource block allocation information symbols, received as input from the demultiplexing section 205, into serial resource block allocation information symbols, and sequentially outputs resource block allocation information symbols of the demodulation section 207.

The demodulation section 207 demodulates the resource block allocation information symbols and provides demodulated resource block allocation information of the decoding section 208.

The decoding section 208 decodes the demodulated resource block allocation information and provides decoded resource block allocation information of the transmission control section 214 and the display determination section 209.

Based on the resource block allocation information received as input from the decoding section 208, the display determining section 209 determines downlink control channels to which response signals for uplink data transmitted from the mobile station are displayed. For example, when the resource block allocation information for the mobile station is the resource blocks RB # 1 through RB # 3 shown in FIG. 1, as shown in FIG. 3, the mapping determination section 209 determines that the channels CH # 1 through CH # 3 are downlink control channels for the mobile station to which response signals are mapped. Then, the display determination section 209 provides a predetermined result of the demultiplexing section 206. The determination process in display determination section 209 will be described in detail later.

The P / S transform section 210 converts the parallel response signals received as input from the demultiplexing section 205 into serial and sequentially outputs the response signals of the compression section 211.

The compression section 211 compresses the response signals and provides the compressed response signals of the combining section 212.

In the compressed response signals, the combining section 212 combines the initial response signal and the response signals generated by repeating the initial response signal and provides a response signal after combining the demodulation section 213.

The demodulation section 213 demodulates the response signal after combining and provides a demodulated response signal of the retransmission control section 216.

When the resource block allocation information received as input from the decoding section 208 indicates that the uplink resource blocks are allocated to the mobile station in question, the transmission control section 214 displays transmission data to the resource blocks indicated in the resource block allocation information and provides displayed data transmitting coding section 215.

Encoding section 215 encodes the transmission data and provides encoded transmission data of the retransmission control section 216.

Upon initial transmission, the retransmission control section 216 holds the encoded transmission data and provides them to the modulation section 217. The retransmission control section 216 holds the transmission data until the retransmission control section 216 receives an ACK signal from the demodulation section 213. In addition, when a NACK signal is received as input from the demodulation section 213, that is, upon retransmission, the retransmission control section 216 provides the held transmission data of the modulation section 217.

The modulation section 217 modulates the encoded transmission data received as input from the retransmission control section 216 and provides the modulated transmission data of the radio transmission section 218.

The radio transmission section 218 performs transmission processing, including digital-to-analog (D / A) conversion, amplification, and up-conversion, on the modulated transmission data, and transmits transmission data after transmission processing from the antenna 201 to the base station 100. Data transmitted in this way become uplink data.

Next, display processing in the display section 109 in the base station 100 and determination processing in the display determination section 209 in the mobile station 200 will be explained in detail.

In the present embodiment, the base station 100 receives uplink data transmitted from the mobile station 200 using the resource blocks RB # 1 through RB # 8 shown in FIG. 1, and the base station 100 displays response signals for the uplink data ( ACK signals and NACK signals) to channels CH # 1 to CH # 8 mapped in four frequency bands subcarriers f ₁ to f ₄ , f ₉ to f ₁₂ , f ₁₇ to f ₂₀ and f ₂₅ to f ₂₈ shown in FIG. .6, and transmits response signals to the mobile station 200. In addition, similarly to FIG. 2, the extension section 106 in the extension base station 100 yields a response signal with an extension code having an expansion coefficient of 4, and the repetition section 107 repeats the extended response signal with a repetition factor of 2. In addition, as shown in FIG. 3, the uplink resource blocks shown in FIG. 1 and the channels the downlink controls shown in FIG. 6 are tied in series with each other.

The display section 109 maps the response signals for the mobile station 200 to a plurality of downlink control channels that are associated with a plurality of resource blocks and which are distributed mapped to a frequency domain. The display section 109 stores binding information between the uplink resource blocks and the downlink control channels shown in FIG. 3 and the display information of the downlink control channels shown in FIG. 6, and based on them, displays response signals on subcarriers, onto which downlink control channels are mapped.

More specifically, when the resource block allocation information for the mobile station 200 assigns the RB # 1 to RB # 3 resource blocks, the display section 109 displays response signals to the CH # 1 channel associated with the RB # 1 resource block, as shown in FIG. 3, that is, it maps the response signals to the subcarriers f ₁ through f ₄ and f ₁₇ through f ₂₀ shown in FIG. Similarly, the display section 109 maps the response signals to channel CH # 2 associated with the resource block RB # 2, that is, maps the response signals to subcarriers f ₉ - f ₁₂ and subcarriers f ₂₅ - f ₂₈ , and maps the response signals to channel CH # 3, tied to resource block RB # 3, that is, it maps response signals to subcarriers f ₁ to f ₄ and subcarriers f ₁₇ to f ₂₀ .

In this case, when displaying the downlink control channels shown in FIG. 6, the downlink control channels (for example, channels CH # 1 and CH # 2) associated with two successive uplink resource blocks shown in FIG. 1 ( for example, to resource blocks RB # 1 and RB # 2), are mapped to different frequency ranges in a distributed manner. In other words, the downlink control channels displayed with concentration in identical ranges in FIG. 6 correspond to a plurality of non-sequential uplink resource blocks at intervals of two resource blocks shown in FIG. 1. More specifically, for example, downlink control channels mapped onto subcarriers f ₁ through f ₄ shown in FIG. 6, concentrated in one place, are control channels CH # 1, CH # 3, CH # 5 and CH # 7 downlink and uplink resource blocks associated with these downlink control channels are inconsistent resource blocks at intervals of two resource blocks, resource blocks RB # 1, RB # 3, RB # 5 and RB # 7, as shown in figure 3.

Therefore, when the base station 100 transmits response signals for uplink data transmitted from the mobile station 200 using a plurality of consecutive uplink resource blocks, it is possible to prevent the response signals from being concentrated in identical ranges. Thus, the base station 100 can display response signals over a plurality of frequency ranges in a distributed manner to transmit response signals subject to distributed display. For example, as described above, when the resource block allocation information for the mobile station 200 assigns the resource blocks RB # 1 to RB # 3, the display section 109 maps the response signals to the subcarriers f ₁ through f ₄ and f ₁₇ through f ₂₀ shown in FIG. 6, the response signals to the subcarriers f ₉ - f ₁₂ and f ₂₅ - f ₂₈ and the response signals to the subcarriers f ₁ - f ₄ and f ₁₇ - f ₂₀ . This means that the response signals are uniformly displayed in a distributed manner on all subcarriers f ₁ - f ₄ , f ₉ - f ₁₂ , f ₁₇ - f ₂₀ and f ₂₅ - f ₂₈ , on which the downlink control channels are mapped.

Thus, the display section 109 displays response signals to the downlink control channels based on the mappings between the uplink resource blocks and the downlink control channels shown in FIG. 3 and based on the mapping of the downlink control channels shown in FIG. .6, thus, the radio transmission section 112 in the base station 100 can transmit response signals to the mobile station 200 using downlink control channels that are associated with resource blocks uplink and which are displayed in a distributed manner on the frequency domain.

Similarly, the mapping determination section 209 in the mobile station 200 (FIG. 5) stores binding information between the uplink resource blocks and the downlink control channels shown in FIG. 3 and the mapping information of the downlink control channels shown in FIG. 6, and determines the downlink control channels to which response signals for the mobile station are mapped from the received resource block allocation information. More specifically, when the mapping determination section 209 receives resource block allocation information as input indicating that the resource blocks RB # 1 to RB # 3 shown in FIG. 1 are allocated to the mobile station from the decoding section 208 based on the bindings shown in FIG. .3, the mapping determination section 209 determines that the response signals for the mobile station are mapped to the subcarriers f ₁ through f ₄ and f ₁₇ through f ₂₀ onto which the downlink control channels CH # 1 and CH # 3 are mapped and to the subcarriers f ₉ - f ₁₂ and f ₂₅ - f ₂₈ , which are displayed downlink control channel CH # 2, as shown in FIG. 6.

Thus, in accordance with the present embodiment, it is less likely that response signals for uplink data that are transmitted using a plurality of consecutive uplink resource blocks are concentrated in identical frequency bands and multiplexed by a code, so it is possible to display the response signals in a distributed manner on the frequency domain. Therefore, in accordance with the present embodiment, it is possible to maximize the effect of frequency diversity on the downlink control channels.

(Embodiment 2)

By displaying extended blocks generated by expanding response signals on successive subcarriers (e.g., subcarriers f ₁ through f ₄ shown in FIG. 6) in Embodiment 1, the intersymbol interference (ISI) that occurs between adjacent subcarriers is reduced to such level that they can be ignored.

However, if the base station 100 controls the transmit power for each downlink control channel, it is no longer possible to ignore intersymbol interference, since the transmit power varies between the multiple downlink control channels displayed in identical frequency ranges and the intersymbol interference from the downlink control channel increases. communication with higher transmit power to the downlink control channel with lower transmit power. For example, when paying attention to the downlink control channels CH # 1 and CH # 3 shown in FIG. 6, if the transmit power for the downlink control channel CH # 1 is greater than the transmit power for the downlink control channel CH # 3 communications, the downlink control channels CH # 1 and CH # 3 are mapped to identical frequency bands subcarriers f ₁ through f ₄ and f ₁₇ through f ₂₀ , and therefore intersymbol interference from the downlink control channel CH # 1 to the CH # channel 3 downlink controls occur in both frequency ranges .

Then, the display section 109 in accordance with the present embodiment displays response signals to a plurality of downlink control channels with various display patterns in a distributed manner in the frequency domain.

Thus, in FIG. 6, downlink control channels CH # 1 and CH # 3 are mapped onto subcarriers f ₁ through f ₄ and f ₁₇ through f ₂₀ with identical display patterns. In contrast, in the present embodiment, as shown in FIG. 7, the display pattern of the downlink control channel CH # 1 and the display pattern of the downlink control channel CH # 3 are mapped, the downlink control channel CH # 1 is mapped to subcarriers f ₁ through f ₄ and f ₁₇ through f ₂₀ , and the downlink control channel CH # 3 is mapped onto subcarriers f ₁ through f ₄ and f ₉ through f ₁₂ . Thus, in the present embodiment, as shown in FIG. 7, downlink control channels CH # 1 and CH # 3 are mapped to identical subcarriers f ₁ through f ₄ , and meanwhile, the downlink control channel CH # 1 is mapped onto subcarriers f ₁₇ through f ₂₀ , and the downlink control channel CH # 3 is mapped onto subcarriers f ₉ through f ₁₂ . Thus, channels CH # 1 and CH # 3 are displayed in different display patterns in a distributed manner in the frequency domain.

Thus, similar to Embodiment 1, when the display section 109 displays response signals for uplink data transmitted using resource blocks RB # 1 through RB # 3 on downlink control channels CH # 1 through CH # 3, intersymbol interference do not occur in the frequency ranges of subcarriers f ₉ - f ₁₂ and subcarriers f ₁₇ - f ₂₀ , although intersymbol interference occurs in subcarriers f ₁ - f ₄ between the downlink control channel CH # 1 with higher transmit power and the downlink control channel CH # 3 communication lines with less power transmission.

Thus, in accordance with the present embodiment, it is possible to provide the same advantage as in Embodiment 1, and it is possible to reduce the intersymbol interference by randomly mixing the intersymbol interference caused by the transmission power control.

By randomly mapping the downlink control channels CH # 1 to CH # 8 to the frequency domain, it is possible to map the downlink control channels CH # 1 to CH # 8 with various display patterns in a distributed manner in the frequency domain.

(Embodiment 3)

In the present embodiment, response signals are mapped onto a plurality of downlink control channels using different display patterns between adjacent cells.

Here, the case where the cell adjacent to the cell 1 is one cell, the cell 2 will be explained. In addition, the cell 1 and the cell 2 are synchronized. In addition, when FIG. 6 shows a display pattern of a downlink control channel in a cell 1, FIG. 8 shows a display pattern of a downlink control channel in a cell 2. In addition, similarly to embodiment 1, the downlink control channels shown in FIG. .8 are displayed in a distributed manner on the frequency domain with reference to a plurality of consecutive uplink resource blocks.

The downlink control channels displayed in identical frequency ranges differ by a display pattern in cell 1 (FIG. 6) and a display pattern in cell 2 (FIG. 8). Thus, identical downlink control channels are mapped to different frequency ranges in a distributed manner in cell 1 and in cell 2.

More specifically, in cell 1, as shown in FIG. 6, downlink control channels CH # 1, CH # 3, CH # 5 and CH # 7 are mapped to subcarriers f ₁ through f ₄ and f ₁₇ through f ₂₀ and channels CH The downlink control # 2, CH # 4, CH # 6 and CH # 8 are mapped onto subcarriers f ₉ through f ₁₂ and f ₂₅ through f ₂₈ . In contrast, in cell 2, as shown in FIG. 8, downlink control channels CH # 2, CH # 4, CH # 6 and CH # 8 are mapped to subcarriers f ₁ through f ₄ and f ₁₇ through f ₂₀ and the downlink control channels CH # 1, CH # 3, CH # 5 and CH # 7 are mapped to subcarriers f ₉ through f ₁₂ and f ₂₅ through f ₂₈ .

Thus, in accordance with the present embodiment, the mapping patterns of the downlink control channels CH # 1 through CH # 8 in the frequency domain are made different between neighboring cells. Therefore, in accordance with the present embodiment, it is possible to provide the same advantage as in Embodiment 1 in the same cell, and when the response signals are transmitted at the same time in neighboring cells, it is possible to reduce mutual interference between cells by randomly mixing the mutual interference between cells from neighboring cells between downlink control channels.

Although the case in which the present invention is implemented between neighboring cells has been explained above in the present embodiment, the present invention can also be implemented between neighboring sectors in the same cell. Thus, in the above explanation, considering cell 1 as sector 1 and cell 2 as sector 2, it is also possible to implement the present invention in neighboring sectors. In addition, it is not necessary to consider synchronization between neighboring sectors, and the present invention can be implemented between neighboring sectors easier than between neighboring cells.

In addition, although the case has been explained above with an example in which the number of cells is two, the present invention can also be implemented when the number of cells is three or more.

(Embodiment 4)

In the present embodiment, a case will be explained in which control channel elements (CCE elements) and downlink control channels for transmitting response signals in a downlink are associated.

The control information that is required for transmitting uplink data from the mobile station to the base station (for example, the resource block allocation information described above) is transmitted from the base station to the mobile station using a different downlink control channel other than the downlink control channel communications for transmitting response signals (e.g., a shared control channel (SCCH)).

In addition, the base station allocates a plurality of SCCH channels to the mobile stations and transmits to the mobile stations SCCH channel allocation information showing which SCCH channels in the plurality of SCCH channels are assigned to which mobile stations (i.e., allocation information showing SCCH allocation results) before transmitting information allocation of resource blocks.

In addition, each SCCH is formed using one or more CCEs. For example, SCCH # 1 through SCCH # 8 apply the configurations shown in FIG. 9. Thus, SCCH # 1 is formed using CCE # 1 and CCE # 2, SCCH # 2 is formed using CCE # 3 and CCE # 4, SCCH # 3 is formed using CCE # 5 and CCE # 6 , channel SCCH # 4 is formed using elements CCE # 7 and CCE # 8, channel SCCH # 5 is formed using elements CCE # 1 - CCE # 4 and channel SCCH # 6 is formed using elements CCE # 5 - CCE # 8. Thus, when one SCCH is formed by a plurality of CCEs, one SCCH is formed by a plurality of consecutive CCEs.

Elements CCE # 1 - CCE # 8 and physical resources on the frequency axis (in the frequency domain) are tied to each other, as shown, for example, in FIG. 10. Thus, one CCE is mapped to a plurality of physical resources mapped to a frequency domain in a distributed manner.

Moreover, for the efficient use of downlink communication resources, one possibility is to link the CCE elements and downlink control channels for transmitting downlink response signals and identify control channels in which response signals are transmitted to the mobile station based on the information SCCH allocation, which the base station reports to the mobile station. For example, as shown in FIG. 11, the CCEs shown in FIG. 9 and the downlink control channels shown in FIG. 2 are associated with each other in series. Therefore, as shown in FIG. 11, the response signals for the uplink data from the mobile station allocated to the SCCH # 1 shown in FIG. 9 are mapped to the downlink control channels CH # 1 and CH # 2, i.e., mapped on the subcarriers f ₁ through f ₄ and f ₁₇ through f ₂₀ shown in FIG. Similarly, as shown in FIG. 11, the response signals for the uplink data from the mobile station allocated to the SCCH # 2 shown in FIG. 9 are mapped to the downlink control channels CH # 3 and CH # 4, i.e. on the subcarriers f ₁ through f ₄ and f ₁₇ through f ₂₀ shown in FIG. The same applies to SCCH # 3 - SCCH # 6.

Although in the above example, the downlink control channels CH # 1 through CH # 8 are mapped to sixteen subcarriers, the subcarriers f ₁ through f ₄ , f ₉ through f ₁₂ , f ₁₇ through f ₂₀ and f ₂₅ through f ₂₈ , the response signals are displayed only eight subcarriers, subcarriers f ₁ - f ₄ and f ₁₇ - f ₂₀ . Thus, in the above example, response signals are mapped to only half of all subcarriers onto which the downlink control channels are mapped.

Therefore, even when the downlink CCE # 1 to CCE # 8 and the downlink control channels CH # 1 to CH # 8 are sequentially mapped to each other, as shown in FIG. 11, similar to the case where the resource blocks RB # 1 - RB # 8 uplink and downlink control channels CH # 1 - CH # 8 are tied in series with each other, as shown in FIG. 3, a small frequency diversity effect can be obtained depending on the positions at which downlink control channels are displayed.

In the present embodiment, when the CCE # 1 to CCE # 8 and the downlink control channels CH # 1 to CH # 8 are linked to each other, the mapping of the downlink control channels CH # 1 to CH # 8 is shown in FIG. (embodiment 1).

FIG. 12 shows a configuration of a base station 300 in accordance with the present embodiment, and FIG. 13 shows a configuration of a mobile station 400 in accordance with the present embodiment. In Fig. 12, components similar to Fig. 4 (Embodiment 1) are assigned the same reference numbers and a description thereof will be omitted. In addition, in FIG. 13, components similar to FIG. 5 (Embodiment 1) are assigned the same reference numbers, and a description thereof will be omitted.

In the base station 300 shown in FIG. 12, the SCCH channel allocation section 301 allocates SCCH # 1 to SCCH # 8 to the mobile stations, generates SCCH channel allocation information, and provides SCCH channel allocation information of the encoding section 302 and the display section 305.

The encoding section 302 encodes the SCCH channel assignment information and provides encoded SCCH channel assignment information to the modulation section 303.

The modulation section 303 modulates the encoded SCCH allocation information to generate SCCH allocation information symbols and provides SCCH allocation information symbols of the S / P transform section 304.

The S / P transform section 304 converts SCCH allocation information symbols sequentially received as input from the modulation section 303 into parallel SCCH allocation information symbols and outputs parallel SCCH allocation information symbols of the display section 305.

The mapping section 305 displays SCCH channel allocation information symbols, resource block allocation information symbols and response signals to a plurality of subcarriers to form an OFDM symbol, and provides displayed SCCH channel allocation information symbols, resource block allocation information symbols and response signals of the IFFT transform section 306.

Meanwhile, based on the SCCH channel allocation information received as input from the SCCH channel allocation section 301, the display section 305 displays response signals to the downlink control channels mapped to the frequency domain in association with CCE elements. For example, when the display section 305 receives the SCCH # 1 channel shown in FIG. 9 from the SCCH channel allocation section 301 as SCCH channel allocation information for the mobile station 400, as shown in FIG. 9, the SCCH # 1 channel is generated using elements CCE # 1 and CCE # 2, as shown in FIG. 11. Therefore, the display section 305 maps the response signals for the uplink data transmitted from the mobile station 400 to the downlink control channels CH # 1 and CH # 2 associated with the elements CCE # 1 and CCE # 2. This mapping process will be described in detail later.

In addition, based on the SCCH channel allocation information received as input from the SCCH channel allocation section 301, the display section 305 maps resource block allocation information symbols to SCCH # 1 to SCCH # 8 mapped to the frequency domain. For example, when the display section 305 receives the SCCH # 1 from the SCCH channel allocation section 301 as SCCH channel allocation information for the mobile station 400, the display section 305 maps resource block allocation information symbols to the SCCH # 1.

The IFFT transform section 306 performs IFFT transform on the SCCH allocation information symbols, resource block allocation information symbols, and response signals mapped onto a plurality of subcarriers to generate an OFDM symbol and provides the generated OFDM symbol of the cyclic prefix (CP) adding section 111.

Meanwhile, in the mobile station 400 shown in FIG. 13, the FFT transform section 401 performs FFT conversion on the OFDM symbol after removing the cyclic prefix (CP) to obtain SCCH channel information symbols, resource block allocation information symbols and response signals and provides them demultiplexing section 402.

The demultiplexing section 402 demultiplexes the input signals into SCCH allocation information symbols, resource block allocation information symbols and response signals and provides SCCH allocation information symbols of a P / S transform section 40, resource block allocation information symbols of a P / S transform section 206 and section response signals 210 P / S conversions. Moreover, based on the specific result received as input from the display determination section 406, the demultiplexing section 402 demultiplexes the resource block allocation information symbols and response signals from the input signal.

The P / S transform section 403 converts a plurality of parallel SCCH channel allocation information symbols received as input from the demultiplexing section 402 into consecutive SCCH channel allocation information symbols and sequentially outputs SCCH channel allocation information symbols of the demodulation section 404.

The demodulation section 404 demodulates the SCCH channel allocation information symbols and provides demodulated SCCH channel allocation information of the decoding section 405.

The decoding section 405 decodes the demodulated SCCH channel assignment information and provides decoded SCCH channel assignment information to the mapping determination section 406.

Based on the SCCH channel allocation information received as input from the decoding section 405, the mapping determination section 406 determines downlink control channels to which response signals for uplink data transmitted from the mobile station are displayed. For example, when the SCCH channel allocation information for the mobile station is the SCCH # 1 channel shown in FIG. 9, the SCCH # 1 channel is generated using the CCE # 1 and CCE # 2 elements, as shown in FIG. 9, and therefore, as shown in FIG. 11, the mapping determination section 406 defines the CH # 1 and CH # 2 channels as downlink control channels for the mobile station to which response signals are mapped. Then, the mapping determination section 406 provides a specific result of the demultiplexing section 402. Definition processing will be described in detail later.

In addition, based on the SCCH channel allocation information received as input from the decoding section 405, the mapping determination section 406 determines the SCCH channel onto which the resource block allocation information symbols for the mobile station are mapped. For example, when the SCCH channel allocation information for the mobile station is SCCH # 1, the mapping determination section 406 defines the SCCH # 1 channel as the SCCH channel for the mobile station onto which the resource block allocation information symbols for the mobile station are mapped. Then, the mapping determination section 406 provides a specific result of the demultiplexing section 402.

The demodulation section 208 decodes the demodulated resource block allocation information and provides decoded resource block allocation information of the transmission control section 214.

Next, the display process in the display section 305 in the base station 300 and the determination process in the display determination section 406 in the mobile station 400 will be explained in detail.

In the present embodiment, the mobile station 400 receives resource block allocation information transmitted from the base station 300 using the SCCH # 1 - SCCH # 8 channels shown in FIG. 9. In addition, the base station 300 maps the response signals for the uplink data (ACK signals and NACK signals) to the downlink control channels CH # 1 through CH # 8 mapped in the four frequency bands onto subcarriers f ₁ through f ₄ , f ₉ - f ₁₂ , f ₁₇ - f ₂₀ and f ₂₅ - f ₂₈ shown in Fig.6, and transmits the response signals of the mobile station 400. In addition, similarly to Fig.2, the extension section 106 in the base station 300 expands the response signal with an extension code having an expansion coefficient of 4, and the repetition section 107 repeats the extended response signal with a repetition factor of 2. In addition, as shown in Figure 11, elements CCE, shown in Figure 9, channels and downlink control shown in Figure 6, linked with sequences correspond to each other.

The display section 305 maps the response signals for the mobile station 400 to a plurality of downlink control channels that are associated with a plurality of CCEs and which are distributed in a frequency domain. The mapping section 305 stores the binding information between the SCCHs and the CCEs shown in FIG. 9, the binding information between the CCEs and the downlink control channels shown in FIG. 11 and the mapping information of the downlink control channels shown in FIG. 6, and based on them, displays response signals to subcarriers onto which downlink control channels are mapped.

More specifically, when the SCCH channel allocation information for the mobile station 400 denotes the SCCH # 1 channel, the SCCH # 1 channel is generated using the elements CCE # 1 and CCE # 2, as shown in FIG. 9. Therefore, the display section 305 maps the response signals to the channel CH # 1 associated with the CCE # 1 element in FIG. 11, that is, maps the response signals to the subcarriers f ₁ through f ₄ and f ₁₇ through f ₂₀ shown in FIG. 6, and maps response signals to channel CH # 2 associated with CCE # 2, that is, maps response signals to subcarriers f ₉ through f ₁₂ and f ₂₅ through f ₂₈ .

Moreover, when displaying the downlink control channels shown in FIG. 6, the downlink control channels (for example, channels CH # 1 and CH # 2) associated with two consecutive downlink CCEs in FIG. 9 (for example, elements CCE # 1 and CCE # 2) are mapped to different frequency ranges in a distributed manner. In other words, the downlink control channels displayed concentrated in identical frequency ranges in FIG. 6 correspond to a plurality of inconsistent downlink CCEs at intervals of two CCEs in FIG. 9. More specifically, for example, downlink control channels mapped to subcarriers f ₁ through f ₄ shown in FIG. 6, concentrated in one place, are control channels CH # 1, CH # 3, CH # 5 and CH # 7 the downlink and downlink CCE elements associated with these downlink control channels are inconsistent CCE elements at intervals of two CCE elements, elements CCE # 1, CCE # 3, CCE # 5 and CCE # 7, as shown in 11.

Therefore, when the base station 300 transmits response signals for the uplink data transmitted from the mobile station 400 to which the resource block allocation information is transmitted using the SCCH generated by the plurality of consecutive CCEs, it is possible to prevent the response signals from being concentrated in identical frequency ranges. Thus, the base station 300 can display response signals over a plurality of frequency ranges in a distributed manner to transmit response signals subject to distributed display. For example, as described above, when the SCCH channel allocation information for the mobile station 400 denotes the SCCH # 1 channel, the display section 305 maps the response signals to the subcarriers f ₁ through f ₄ and f ₁₇ through f ₂₀ shown in FIG. 6 and the response signals on subcarriers f ₉ - f ₁₂ and f ₂₅ - f ₂₈ . Thus, the response signals are uniformly mapped onto all subcarriers f ₁ through f ₄ , f ₉ through f ₁₂ , f ₁₇ through f ₂₀ and f ₂₅ through f ₂₈ , onto which the downlink control channels are mapped in a distributed manner.

Thus, the display section 305 displays the response signals to the downlink control channels based on the mappings between the SCCH and the CCEs shown in FIG. 9, the mappings between the CCE elements and the downlink control channels shown in FIG. 11 and the display 6, the downlink control channel so that the radio section 112 in the base station 300 can transmit response signals to the mobile station 400 using the downlink control channels that are associated with downlink CCE elements and which are displayed in a distributed manner on the frequency domain.

Similarly, the mapping determination section 406 in the mobile station 400 (FIG. 13) stores the binding information between the SCCHs and the CCEs shown in FIG. 9, the binding information between the CCEs and the downlink control channels shown in FIG. 11, and the downlink control channel display information shown in FIG. 6 and determines the downlink control channels to which response signals for the mobile station are mapped from the received SCCH channel allocation information. More specifically, when the mapping determination section 406 receives, as input from the decoding section 495, SCCH channel allocation information indicating that the SCCH # 1 shown in FIG. 9 is allocated to the mobile station based on the binding shown in FIGS. 9 and 11 , the mapping determination section 406 determines that the response signals for the mobile station are mapped to the subcarriers f ₁ through f ₄ and f ₁₇ through f ₂₀ onto which the downlink control channel CH # 1 is mapped and mapped to the subcarriers f ₉ through f ₁₂ and f ₂₅ - f _28, are displayed on the channel CH # 2 control downlink, as shown in Figure 6.

Thus, in accordance with the present embodiment, when one SCCH is formed by a plurality of consecutive downlink CCEs, it is less likely that the response signals are concentrated in identical frequency bands and multiplexed by a code, so it is possible to display the response signals in a distributed manner in frequency domain. Therefore, according to the present embodiment, like in Embodiment 1, it is possible to maximize the frequency diversity effect on the downlink control channels.

Although the case in which the SCCH is an example of a control channel formed by a plurality of CCEs has been clarified in the present embodiment, the control channels applicable to the present invention are not limited to the SCCH. All control channels formed by a plurality of successive CCEs are applicable to the present invention.

In addition, similarly to embodiment 2, the display section 305 in the present embodiment can display response signals to a plurality of downlink control channels displayed in a distributed manner in the frequency domain in different patterns.

In addition, similarly to embodiment 3, the display section 305 in the present embodiment can display response signals to a plurality of downlink control channels using different display patterns between adjacent cells or sectors.

In addition, although a case has been clarified in the present embodiment in which SCCH channel allocation information is transmitted before resource block allocation information in the SCCH is transmitted, it is not necessary to transmit SCCH channel allocation information before transmitting resource block allocation information. For example, the base station includes identifiers of mobile stations that can identify mobile stations in SCCH channels and transmits them, and the mobile station decodes all received SCCH channels and performs blind detection if there is a SCCH channel for this mobile station, so it may be unnecessary transmitting SCCH allocation information before transmitting resource block allocation information.

In addition, with regard to the switching time of the downlink control channels associated with the CCEs to the newly allocated SCCH, a fixed time can be set in advance, or a time that changes adaptively can be reported from the base station of the mobile station, for example, using channel SCCH.

In addition, when SCCH # 1 through SCCH # 6 apply the configurations shown in FIG. 14, that is, when SCCH # 1 is generated using CCE # 1 and CCE # 3, SCCH # 2 is formed using CCE # 5 and CCE # 7, SCCH # 3 is formed using CCE # 2 and CCE # 4, SCCH # 4 is formed using CCE # 6 and CCE # 8, SCCH # 5 is formed using CCE # 1 , CCE # 3, CCE # 5 and CCE # 7 and channel SCCH # 6 is formed using elements CCE # 2, CCE # 4, CCE # 6 and CCE # 8, channels CH # 1 through CH # 8 of the downlink control may be displayed as shown in FIG. Downlink control channels (e.g., CH # 1 and CH # 3) associated with a plurality of downlink CCE elements forming SCCH channels (e.g., CCE # 1 and CCE # 3 elements forming SCCH # 1), 14 are displayed in different frequency ranges in a distributed manner. Therefore, when the base station 300 transmits response signals for the uplink data transmitted from the mobile station 400 to which the resource block allocation information is transmitted using the SCCH generated by the plurality of CCEs, it is possible to prevent the response signals from being displayed concentrated in identical frequency ranges . Thus, as described above, the base station 300 can transmit response signals by mapping response signals to a plurality of bands in a distributed manner.

(Embodiment 5)

In the present embodiment, a case in which the number of used CCEs is changed for each subframe will be explained.

Studies are underway to change the number of OFDM symbols, on the basis of which CCE elements are multiplexed, forming a downlink control channel (for example, SCCH) for reporting uplink or downlink allocation information (hereinafter referred to as “the number of OFDM symbols for multiplexing”), for each subframe. The number of OFDM symbols for multiplexing is reported from the base station to the mobile stations using the physical channel of the control format indicator (PCFICH). There are more physical resources for multiplexing CCEs after increasing the number of OFDM symbols for multiplexing, and therefore, the number of CCEs for further use is increasing. For example, when the number of OFDM symbols for multiplexing is one, among the CCE # 1 to CCE # 16 elements shown in FIG. 16, the CCE # 1 to CCE # 4 are multiplexed on one OFDM symbol, and when the number of OFDM symbols for multiplexing is two , CCE # 1 - CCE # 16 elements are multiplexed on two OFDM symbols. Thus, in the case where one SCCH is formed using one CCE or a plurality of CCEs, any of the CCE # 1 to CCE # 4 is used when the number of OFDM symbols for multiplexing is one, and any of the CCE # 1 to CCE # 16 is used when the number of OFDM symbols for multiplexing is two.

Moreover, among the elements CCE # 1 - CCE # 16 shown in Fig. 16, elements CCE # 1 - CCE # 4 are used with different numbers of OFDM symbols for multiplexing (one or two), and elements CCE # 5 - CCE # 16 are used only when the number of OFDM symbols for multiplexing is two. Thus, the elements of CCE # 1 - CCE # 16 are divided into CCE elements that are used with different numbers of OFDM symbols for multiplexing, and CCE elements that are not used. In addition, the CCEs are mapped to downlink control channels for transmitting response signals in the downlink, and the number of CCEs to use increases or decreases depending on the number of OFDM symbols for multiplexing, and accordingly, the number of control channels increases or decreases downlink used to transmit response signals. Thus, similarly to the CCE elements, the downlink control channels are divided into downlink control channels that are used with various numbers of OFDM symbols for multiplexing, and downlink control channels that are not used.

Moreover, if the number of OFDM symbols for multiplexing is equal to one, that is, if only the CCE # 1 - CCE # 4 elements shown in Fig. 16 are used, the downlink control channels CH # 1 - CH # 4 are displayed concentrated in identical frequency ranges, subcarriers f ₁ - f ₄ and subcarriers f ₁₇ - f ₂₀ , undergoing a mapping of control channels downlink, shown, for example, in figure 2. Therefore, the transmit power varies between the frequency ranges onto which the downlink control channels are mapped (i.e., between the four frequency ranges of the subcarriers f ₁ - f ₄ , f ₉ - f ₁₂ , f ₁₇ - f ₂₀ and f ₂₅ - f ₂₈ in FIG. 2). In particular, if the response signals are concentrated and multiplexed using a code in the frequency ranges onto which the downlink control channels CH # 1 to CH # 4 are mapped, the interference power against other cells increases. In addition, intersymbol interference increases in the frequency ranges in which the response signal is concentrated and multiplexed with a code.

In the present embodiment, downlink control channels for transmitting response signals associated with CCE elements that are used with different numbers of OFDM symbols for multiplexing are mapped in a distributed manner in the frequency domain.

FIG. 17 shows a configuration of a base station 500 in accordance with the present embodiment, and FIG. 19 shows a configuration of a mobile station 600 in accordance with the present embodiment. In FIG. 17, components similar to FIG. 12 (embodiment 4) are assigned the same reference numbers and a description thereof will be omitted. In addition, in FIG. 19, components similar to FIG. 13 (embodiment 4) are assigned the same reference numbers and a description thereof will be omitted.

In the base station 500 shown in FIG. 17, the multiplexing OFDM symbol number determining section 501 determines the number of OFDM symbols on which CCEs are multiplexed according to the number of SCCHs that should report control information for each subframe. More specifically, the multiplexing OFDM symbol number determining section 501 determines an increase in the number of OFDM symbols for multiplexing when the number of SCCH channels to report control information is larger. Then, the multiplexing OFDM symbol number determining section 501 generates multiplexing OFDM symbol number determining information showing the determined number of OFDM symbols for multiplexing, and provides generated generated multiplexing OFDM symbol information of the coding section 502 and the SCCH allocation section 505.

The encoding section 502 encodes the OFDM symbol number determination information of the multiplexing and provides encoded multiplexing OFDM symbol determination information of the modulation section 503.

The modulation section 503 modulates the encoded information for determining the number of OFDM symbols for multiplexing to generate information symbols for determining the number of OFDM symbols for multiplexing and provides information symbols for determining the number of OFDM symbols for the multiplexing of the S / P transform section 504.

The S / P conversion section 504 converts the multiplexing OFDM symbol information information symbols sequentially received as input from the modulation section 503 into parallel multiplexing OFDM symbol information symbols and outputs parallel information symbols of the display section 506.

Based on the information for determining the number of OFDM symbol multiplexing received as input from the number of OFDM symbol determining section 501, the SCCH channel allocating section 505 allocates SCCH channels to the mobile stations. For example, when the number of multiplexing OFDM symbols received as input from the multiplexing OFDM symbol determining section 501 is one, the SCCH channel allocating section 505 allocates to the mobile stations SCCH channels generated by one CCE or a plurality of CCEs among the CCE # 1 - CCE # 4 shown in FIG. 16 above. Meanwhile, when the number of OFDM symbols for multiplexing, received as input from the multiplexing OFDM symbol determination section 501, is two, the SCCH channel allocation section 505 allocates to the mobile stations SCCH channels generated by one CCE or a plurality of CCEs among the CCEs # 1 - CCE # 16 shown in FIG. 16 above.

The mapping section 506 displays the information symbols for determining the number of multiplexing OFDM symbols, the resource block allocation information symbols, and response signals to a plurality of subcarriers to form an OFDM symbol and provides them to the IFFT transform sections 507. In this case, the display section 506 displays the response signals to the downlink control channels CH # 1 to CH # 6, including the downlink control channels CH # 1 to CH # 4, which are displayed in a distributed manner on the frequency domain associated with CCE elements # 1 — CCE # 4, which are used with various numbers of OFDM symbols for multiplexing, among the CCE # 1 — CCE # 16 elements shown in FIG. 16 above. This mapping process will be described in detail later.

Then, the display section 506 maps the information symbols for determining the number of multiplexing OFDM symbols to the PCFICH channels mapped to the frequency domain.

The IFFT transform section 507 performs IFFT transform on the information symbols for determining the number of multiplex OFDM symbols, information symbols of the resource block allocation and response signals mapped onto the plurality of subcarriers to generate the OFDM symbol, and provides the generated OFDM symbol to the cyclic prefix (CP) adding section 111.

Downlink control channels for transmitting response signals (e.g., ACK / NACK channels), PCFICHs, and CCEs are multiplexed on physical resources defined in the frequency domain and time domain, for example, as shown in FIGS. 18A and 18B. When the number of OFDM symbols for multiplexing is one, as shown in FIG. 18A, the ACK / NACK channels, PCFICH channels, and CCE # 1 to CCE # 4 are multiplexed on one OFDM symbol, and when the number of OFDM symbols for multiplexing is two, as shown 18B, ACK / NACK channels, PCFICH channels, and CCE # 1 through CCE # 16 are multiplexed on two OFDM symbols.

Meanwhile, in the mobile station 600 shown in FIG. 19, the FFT transform section 601 performs FFT conversion on the OFDM symbol after removing the cyclic prefix (CP) to obtain information symbols for determining the number of multiplex OFDM symbols, information symbols for resource block allocation and response signals, and provides their demultiplexing sections 602.

The demultiplexing section 602 demultiplexes the input signals into the information symbols for determining the number of OFDM symbols of the multiplexing, information symbols for the allocation of resource blocks and response signals and provides information symbols for determining the number of symbols of the OFDM multiplexing in the P / S transform section 603, the information symbols for the allocation of resource blocks in the P / S transform section 206 and response signals of the P / S conversion section 210.

The P / S transform section 603 converts parallel multiplex OFDM symbol information information symbols received as input from the demultiplexing section 602 into serial multiplex OFDM symbol information information symbols and sequentially outputs the multiplex OFDM symbol information information symbols of the demodulation section 604.

The demodulation section 604 demodulates the information symbols for determining the number of OFDM symbols of the multiplexing and provides demodulated information for determining the number of OFDM symbols of the multiplexing of the decoding section 605.

The decoding section 605 decodes the demodulated multiplexing OFDM symbol number determination information and provides decoded multiplexing OFDM symbol determination information of the OFDM multiplexing section 606.

The multiplexing OFDM symbol number extraction section 606 extracts the number of OFDM symbols for multiplexing from the multiplexing OFDM symbol determination information received as input from the decoding section 605.

Based on the number of multiplexing OFDM symbols received as input from the multiplexing OFDM symbol extraction section 606, the mapping determination section 607 determines downlink control channels to which response signals are mapped and CCEs to use for SCCH allocation. Then, the display determination section 607 provides a specific result to the demultiplexing section 602. The determination process will be described in detail later.

Next, the display process in the display section 506 in the base station 500 and the determination process in the display determination section 607 in the mobile station 600 will be explained in detail.

In the present embodiment, as shown in FIG. 16, there are two possible values for the number of OFDM symbols for multiplexing, one or two. In addition, the mobile station 600 receives resource block allocation information transmitted from the base station 500 using SCCHs generated by one CCE or a plurality of CCEs among the CCEs # 1 to CCE # 16 shown in FIG. 16. Furthermore, in the same manner as in Embodiment 4, the extension section 106 in the base station 500 expands the response signal with an extension code having an expansion coefficient of 4, and the repetition section 107 repeats the extended response signal with a repetition factor of 2. However, for simplicity, explanation will be given only for CH channels # 1 - CH # 16 of downlink control # 1 mapped to four frequency bands, subcarriers f ₁ - f ₄ , f ₉ - f ₁₂ , f ₁₇ - f ₂₀ and f ₂₅ - f ₂₈ , to which response signals are mapped, as shown in FIG. 20, excluding repetition. In addition, the CCE # 1 to CCE # 16 elements shown in FIG. 16 and the downlink control channels CH # 1 to CH # 16 are associated with each other in series.

The display section 506 maps the response signals for the mobile station 600 to the downlink control channels CH # 1 through CH # 16, including the channels CH # 1 through CH # 4, which are distributed across the frequency domain and associated with CCE # 1 - CCE # 4 used with various numbers of OFDM symbols for multiplexing, among the CCE # 1 to CCE # 16 elements shown in FIG. 16 above.

Thus, as shown in FIG. 20, the downlink control channel CH # 1 is mapped to subcarriers f ₁ to f ₄ , the downlink control channel CH # 2 is mapped to subcarriers f ₉ to f ₁₂ , the downlink control channel CH # 3 the link is mapped to subcarriers f ₁₇ through f ₂₀ , and the downlink control channel CH # 4 is mapped to subcarriers f ₂₅ through f ₂₈ .

In addition, as shown in FIG. 20, downlink control channels CH # 5 through CH # 16, other than downlink control channels CH # 1 through CH # 4, are mapped to four frequency bands subcarriers f ₁ through f ₄ , f ₉ - f ₁₂ , f ₁₇ - f ₂₀ and f ₂₅ - f ₂₈ .

Moreover, in the mapping of the downlink control channels shown in FIG. 20, the downlink control channels CH # 1 to CH # 4, which are associated with CCE # 1 to CCE # 4 elements used with different numbers of OFDM symbols for multiplexing ( one or two) in FIG. 16 are displayed in a distributed manner in different ranges. In other words, the downlink control channels displayed concentrated in identical frequency ranges in FIG. 20 are one channel of the downlink control channels CH # 1 through CH # 4 associated with the CCE # 1 through CCE # 4. used with different numbers of OFDM symbols for multiplexing in FIG. 16, and three channels from downlink control channels CH # 5 - CH # 16 associated with CCE # 5 - CCE # 16 elements used only when the number of OFDM symbols for multiplexing equal to two in FIG. More specifically, for example, downlink control channels mapped to subcarriers f ₁ through f ₄ shown in FIG. 20, concentrated in one place, are channels CH # 1, CH # 5, CH # 9 and CH # 13 downlink control. As shown in FIG. 16, downlink CCEs associated with these downlink control channels are CCE # 1 used with various number of OFDM symbols for multiplexing (one or two), and CCE # 5, CCE # 9 and CCE # 13, used only when the number of OFDM symbols for multiplexing is two.

Therefore, when the base station 500 transmits response signals for the uplink data transmitted from the mobile station 600, the transmitted resource block allocation information using SCCHs generated by CCEs that are used with different numbers of OFDM symbols for multiplexing, it is possible to prevent so that the response signals are displayed concentrated in identical frequency ranges. Thus, the base station 500 can display the response signals over a plurality of frequency bands in a distributed manner, transmit response signals subject to a distributed display, even when the number of OFDM symbols for multiplexing is one. Thus, the number of response signals for multiplexing using the code is the same in the frequency ranges.

Thus, the transmission power in the frequency ranges onto which the downlink control channels for transmitting the response signals are mapped varies little, and therefore, the effect of averaging the transmission power is improved. Thus, it is possible to suppress a partial increase in transmit power in the frequency ranges onto which the downlink control channels are displayed in a concentrated manner, and therefore it is possible to reduce interference between neighboring cells. In addition, it is possible to prevent the response signals from being concentrated in identical frequency ranges, since the response signals are distributed in a distributed manner in the frequency domain, and therefore it is also possible to reduce intersymbol interference between downlink control channels displayed in identical frequency ranges.

Thus, based on the information on the number of OFDM symbols for multiplexing shown in FIG. 16 and the mapping of the downlink control channels shown in FIG. 20, the display section 506 displays response signals to the downlink control channels. Thus, the radio transmission section 112 in the base station 500 can transmit response signals to the mobile station 600 using downlink control channels mapped in a distributed manner in the frequency domain associated with downlink CCE elements used with different numbers of OFDM symbols for multiplexing.

Similarly, the mapping determination section 607 in the mobile station 600 (FIG. 19) stores the OFDM symbol number information for multiplexing shown in FIG. 16 and the downlink control channel mapping information shown in FIG. 20 and determines control channels the downlink to which the response signals for the mobile station are mapped from the received information of determining the number of OFDM symbol multiplexing. For example, when the number of multiplex OFDM symbols received as input from the multiplex OFDM symbol extraction section 606 is one, the display determining section 607 determines downlink control channels to which response signals for the mobile station are mapped from channels CH # 1 - The downlink control CH # 4 shown in FIG. 20 tied to the CCE # 1 to CCE # 4 elements shown in FIG. 16.

Thus, in accordance with the present embodiment, downlink control channels associated with CCEs for use with various numbers of OFDM symbols for multiplexing are mapped in a distributed manner in the frequency domain. Thus, it is less likely that the response signals are concentrated in identical frequency ranges and multiplexed by a code. Thus, the present embodiment provides the same advantage as the embodiment 4. In addition, according to the present embodiment, even when the number of OFDM symbols for multiplexing is changed for each subframe, the transmission power of the downlink control channels is averaged between frequency ranges, and therefore it is possible to reduce interference between neighboring cells. In addition, in accordance with the present embodiment, it is possible to reduce intersymbol interference between downlink control channels displayed in the same frequency range.

Although the present embodiment has clarified a case in which there are two possible values, one or two, for the number of OFDM symbols for multiplexing, the present invention can also be implemented when there are three or more possible values for the number of OFDM symbols for multiplexing.

In addition, although in the present embodiment, a case has been clarified in which a plurality of CCEs are divided into CCEs that are used with several different numbers of OFDM symbols for multiplexing and CCEs that are not used, a plurality of CCEs can be divided based on how often they are used. For example, if the number of OFDM symbols for multiplexing is between one and three, the CCE element that is used when the number of OFDM symbols for multiplexing is between one and three has a "high" frequency of use, the CCE element that is used when the number of OFDM symbols for the multiplexing is two or three, has an “average” frequency of use, and the CCE element, which is used when the number of OFDM symbols for multiplexing is only three, has a “low” frequency of use. Then the base station can display the response signals to the control channels downlink in a distributed manner in the frequency domain, tied to the CCE elements with a "high" frequency of use.

In the present embodiment, a case has been clarified in which the numbers of CCE elements (i.e., CCE # 1 to CCE # 4 elements shown in FIG. 16) that are used with different numbers of OFDM symbols for multiplexing are consecutive. However, there is no limitation that the CCE element numbers that are used with different numbers of OFDM symbols for multiplexing are consecutive. The present invention may also be practiced when CCE element numbers that are used with different numbers of OFDM symbols for multiplexing are inconsistent.

In addition, although in the present embodiment, a case has been clarified in which CCE element numbers and downlink control channels for transmitting response signals are linked to each other, the present invention can also be implemented in a case in which the downlink control channels formed a plurality of CCEs, for example, SCCH and downlink control channel numbers for transmitting response signals are tied to each other.

In addition, although in the present embodiment, a case has been clarified in which response signals are multiplexed on a plurality of downlink control channels displayed in different frequency ranges in connection with a plurality of CCE elements that are used with different numbers of OFDM symbols for multiplexing, multiplexing response signals on a plurality of downlink control channels displayed in different ranges, and multiplexing response signals on different coding units extension are equivalent.

In addition, although in the present embodiment, a case has been clarified in which the number of OFDM symbols for multiplexing is determined in accordance with the number of SCCH channels to report control information, in the present invention, the number of OFDM symbols for multiplexing can be determined in accordance with other control information without limiting the number of SCCH channels. For example, the number of OFDM symbols for multiplexing may be determined in accordance with the number of multiplexing of ACK / NACK channels that multiplex response signals.

Embodiments of the present invention have been explained.

The present invention can be applied to mobile stations located near the edge of a cell. In general, channel quality is poorer near the edge of the cell than in the center of the cell, and the mobile station near the edge of the cell transmits uplink data using a low level modulation and coding (MCS) scheme. Thus, the mobile station near the edge of the cell transmits uplink data using a lower code rate and a modulation scheme with a lower modulation order than the mobile station near the center of the cell, and therefore longer uplink data lengths are required, i.e. more sequential resource blocks. Then, by applying the present invention to a mobile station near the edge of a cell, it is possible to obtain a greater frequency diversity effect.

In addition, although in the above embodiments, cases have been clarified as an example of fully sequential resource blocks, the present invention can also be implemented by resource blocks with a high degree of sequence, even when the resource blocks partially have non-sequential parts.

In addition, although the cases in which the number of uplink resource blocks and the number of downlink CCEs are eight are explained in the above embodiments, the number of uplink resource blocks and the number of downlink CCEs are not limited to eight.

In addition, although in the above embodiments, cases have been explained as an example in which eight downlink control channels CH # 1 through CH # 8 are mapped to sixteen subcarriers, subcarriers f ₁ through f ₄ , f ₉ through f ₁₂ , f ₁₇ through f ₂₀ and f ₂₅ through f ₂₈ , the number of subcarriers and the number of downlink control channels are not limited to these numbers. For example, as shown in FIG. 21, sixteen downlink control channels CH # 1 through CH # 16 are mapped to thirty-two subcarriers, as shown in FIG.

In addition, although in the above embodiments, the cases have been clarified to show in the figures only those subcarriers onto which the downlink control channels are mapped, other control channels or data channels can be mapped to frequencies other than the frequencies to which the control channels are mapped downlink.

In addition, although the cases in which the response signal is expanded are explained in the above embodiments, the response signal can be mapped to a downlink control channel mapped to frequencies without expanding the response signal and transmitted. For example, as shown in FIG. 22, the response signal may be mapped onto the downlink control channels CH # 1 through CH # 8 in a frequency domain without spreading the response signal, that is, without multiplexing with a code at the same frequencies.

In addition, although in the above embodiments, examples have been clarified in which the spreading factor SF is 4 in the spreading section 106 and the repeat coefficient RF is 2 in the repeat section 107, the SF and RF coefficients are not limited to these values.

In addition, although the above embodiments have clarified cases of a method for displaying downlink control channels, the present invention can be applied to uplink control channels. For example, the mobile station performs the same process as the base station 100 or 300, and the base station performs the same process as the mobile station 200 or 400, and therefore, the present invention can be applied to the uplink.

In addition, although cases in which DFTs-FDMA access is used as the uplink access scheme have been explained in the above embodiments, the present invention is not limited to DFTs-FDMA access, and the same advantage described above can be achieved in the communication scheme in which a plurality of consecutive resource blocks are allocated to one mobile station, and in a communication scheme in which one control channel is formed from a plurality of consecutive CCE elements.

Furthermore, although in the above embodiments, cases have been explained as an example in which the downlink communication scheme is an OFDM scheme, the downlink communication scheme is not limited in the present invention, and the same advantage described above can be provided in the scheme communication performing transmission using different frequencies.

In addition, the downlink control channels for transmitting response signals used in the explanation of the above embodiments are channels for reverse transmission of ACK signals or NACK signals for mobile stations. Therefore, downlink control channels for transmitting response signals may be referred to as dedicated control channels (DCCH), ACK / NACK channels, response channels, and a hybrid Automatic Repeat Request (HICH) indicator channel.

In addition, although the cases of the downlink control channels for displaying the response signals have been clarified in the above embodiments, the signals mapped to the downlink control channels are not limited to the response signals. For example, control signals for reporting a modulation scheme or code rate for retransmission, control signals for reporting transmit power during retransmission, control signals for reporting the time at which a transmission is being performed, for retransmission, or control signals for resource block allocation messages upon retransmission.

In addition, the resource block used in the explanation of the above embodiments may be other data transmission units in the frequency domain, for example, a subcarrier block and a subband.

The base station, mobile station, and subcarrier may be referred to as Node B, user equipment (UE), and tone, respectively. The cyclic prefix (CP) may be called the guard interval (GI).

In addition, the error detection method is not limited to cyclic redundancy check (CRC).

In addition, the conversion method between the frequency domain and the time domain is not limited to IFFT and FFT transforms.

In addition, although the cases in which the present invention is implemented by means of hardware have been described in the above embodiments, the present invention can be implemented by software.

Each function block used in the above description of an embodiment may typically be implemented as a large integrated circuit (LSI) consisting of integrated circuits. They can be separate microcircuits or partially or completely contained in one microcircuit. The name "large integrated circuit" is used here, but it can also be referred to as an integrated circuit (IC), a system large integrated circuit, an ultra-large integrated circuit or an ultra-large integrated circuit depending on various degrees of integration.

In addition, the method of integrating the circuit is not limited to a large integrated circuit, and an implementation using dedicated circuitry or general-purpose processors is also possible. After manufacturing the large integrated circuit, it is also possible to use a programmable gate array (FGPA) or reconfigurable processor in which the connections and settings of the circuit cells within the large integrated circuit can be reconfigured.

In addition, if the integrated circuit technology extends beyond the large integrated circuit as a result of advancing a semiconductor technology or is a derivative of another technology, it is also naturally possible to integrate a function block using this technology. It is also possible to use biotechnology.

Disclosures of Japanese Patent Application No. 2007-077502, filed March 23, 2007, Japanese Patent Application No. 2007-120853, filed May 1, 2007, and Japanese Patent Application No. 2007-211104, filed August 13, 2007, including specifications, drawings, and abstracts are incorporated herein by reference in their entirety.

Industrial applicability

The present invention is applicable, for example, to mobile communication systems.

Claims (21)

1. A base station device comprising:
an allocation module, configured to allocate to the mobile station one or a plurality of uplink resource blocks that are sequential in the frequency domain;
a display module, configured to map the response signal to the downlink resource, this resource being determined based on the index of the allocated resource block, and
a transmission module, configured to transmit the displayed response signal to the mobile station;
wherein the indices of the plurality of consecutive resource blocks are associated with a plurality of resources that are different in the frequency domain, respectively; a plurality of resources consists of a plurality of subcarrier groups that are inconsistent in the frequency domain, respectively; and said display module maps a response signal to a group of subcarriers. 2. The base station apparatus of claim 1, wherein said transmission unit transmits allocation information indicating a allocated resource block to a mobile station. 3. The base station device according to claim 1, wherein said display module maps the response signal to a resource, determined based on the index of the resource block, which is used for transmission on the uplink. 4. The base station apparatus of claim 1, wherein said display module displays a response signal to a plurality of resources distributed in a frequency domain. 5. The base station device according to claim 1, further comprising an expansion module configured to expand the response signal, said display module displaying the extended response signal to the resource. 6. The base station device according to claim 1, further comprising a repetition module configured to generate a plurality of identical response signals using repetition, said display module mapping a plurality of identical response signals to a plurality of resources distributed in a frequency domain, respectively. 7. The base station apparatus of claim 1, wherein the response signal is transmitted over the hybrid ARQ indicator channel (HICH) and said display module maps the response signal to the hybrid ARQ indicator channel resource. 8. The base station apparatus of claim 1, wherein said display module maps a plurality of response signals to a resource by code-multiplexing the response signals. 9. The base station apparatus of claim 1, wherein the response signal is transmitted over the hybrid ARQ indicator channel (HICH) and said display module maps the plurality of response signals to a resource to which the plurality of hybrid ARQ indicator channels are mapped by code multiplexing the response signals. 10. The base station device according to claim 1, in which the resource block index is associated with a resource depending on the cell. 11. A mobile station device, comprising:
a receiving module, configured to receive allocation information from the base station indicating one or more allocated uplink resource blocks that are consecutive in the frequency domain; and a determining module, configured to determine the downlink resource to which a response signal transmitted from the base station is displayed based on the index of the allocated resource block based on the allocation information;
wherein the indices of the plurality of consecutive resource blocks are associated with a plurality of resources that are different in the frequency domain, respectively; the plurality of resources consists of a plurality of subcarrier groups that are inconsistent in the frequency domain, respectively, and the response signal is mapped to the subcarrier group. 12. The mobile station apparatus of claim 11, further comprising a transmission module configured to transmit data using the uplink resource block (s) based on the allocation information, said determining module determining a resource to which a response signal is mapped based on index of the resource block used for data transmission. 13. The mobile station apparatus of claim 11, wherein the response signal is mapped to a plurality of resources allocated in the frequency domain. 14. The mobile station apparatus of claim 11, wherein the response signal is expanded at the base station and the enhanced response signal is mapped to a resource. 15. The mobile station apparatus of claim 11, wherein a plurality of identical response signals are generated by repetition in a base station and a plurality of identical response signals are mapped to a plurality of resources allocated in the frequency domain, respectively. 16. The mobile station apparatus of claim 11, wherein the response signal is transmitted via the hybrid ARQ indicator channel (HICH) to the base station and the response signal is mapped to the hybrid ARQ indicator channel resource (HICH). 17. The mobile station apparatus of claim 11, wherein the plurality of response signals are mapped to a resource by code multiplexing. 18. The mobile station apparatus of claim 11, wherein the response signal is transmitted via the hybrid ARQ indicator channel (HICH) to the base station and the plurality of response signals are mapped to a resource to which the plurality of hybrid ARQ indicator channels are mapped by code multiplexing. 19. The mobile station apparatus of claim 11, wherein the resource block index is associated with a cell-dependent resource. 20. A method for displaying a response signal, comprising the steps of:
displaying the response signal in the downlink resource, which is determined based on the index of the allocated uplink resource block, and one or a plurality of resource blocks that are sequential in the frequency domain are allocated;
wherein the indices of the plurality of consecutive resource blocks are associated with a plurality of resources that are different in the frequency domain, respectively; a plurality of resources consists of a plurality of subcarrier groups that are inconsistent in the frequency domain, respectively; and the response signal is mapped to the subcarrier group. 21. A method for determining the resource of the response signal, comprising stages in which:
receiving allocation information indicating one or a plurality of allocated uplink resource blocks that are consecutive in the frequency domain; and determining the downlink resource to which the response signal is mapped based on the index of the allocated resource block based on the allocation information;
wherein the indices of the plurality of consecutive resource blocks are associated with a plurality of resources that are different in the frequency domain, respectively; the plurality of resources consists of a plurality of subcarrier groups that are inconsistent in the frequency domain, respectively, and the response signal is mapped to the subcarrier group.

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