Scheduling apparatus and scheduling method

Description

Technical field

[0001] The present invention relates to a scheduler and a planning method.

State of the art

In 3GPP LTE (3rd Generation Partnership Project Long Term Evolution), the data signal of each terminal is allocated to adjacent frequency bands to reduce Cubic Metric (CM) and Peak-to-Average Power Ratio (PAPR). PeakTo-Average Power Ratió). Transmission using these adjacent frequency bands may be referred to as "adjacent frequency transmission".

[0003] The terminal transmits data in accordance with the frequency resource allocation information reported by the base station. The allocation of frequency resources for transmissions on adjacent frequencies includes two pieces of information, a start position and a stop position (or bandwidth from the start position) in the transmission band. Therefore, when the system bandwidth is expressed in NRB [RB], the number of bits of signaling the frequency resource allocation information may be represented by Equation 1 below. That is, since the number of start position and end position candidates in the transmit band can be expressed as Nrb (the number of both ends and boundaries between adjacent two RBs in the frequency band) +1, signaling bits are required for the combination numbers to select the two candidates into the starting position and the ending position in the frequency band among the number of NRB candidates + 1, in Equation 1.

[1]

Number of signaling bits

[bits] (Equation 1) wherein the Resource Block (RB) is the unit for assigning frequencies to data. One RB is made up of 12 sub-carriers. When the equation NRB = 100 [RB] is satisfied, the number of signaling bits is 13 [bits],

In the case of the uplink channel in LTE-Advanced, which is an evolved version of 3GPP LTE (3rd Generation Partnership Project Long Term Evolution), it is contemplated to use "non-adjacent frequency transmission" in addition to transmitting on adjacent frequencies to improve sector capacity (see non-patent literature 1).

[0005] Non-adjacent frequency transmission is a method of transmitting a data signal and a reference signal by allocating such signals to non-adjacent frequency bands that are spread over a wide bandwidth. As shown in FIG. 1, in transmission at non-adjacent frequencies, it is therefore possible to allocate the data signal and the reference signal to discrete frequency bands. Accordingly, in transmission at non-adjacent frequencies as compared to transmission at adjacent frequencies, flexibility in assigning a data signal and a reference signal to the frequency bands at each terminal increases. In this way, it is possible to obtain better frequency planning effects.

Here, as a method for reporting frequency resource allocation information for transmissions on non-adjacent frequencies, there is a method for reporting whether or not to grant to each RB in a system band using a bitmap (see Non-Patent Literature 2) . As shown in FIG. 2, the base station reports whether to allocate or not to allocate resources to each predetermined frequency assignment unit [RB] (for every 4 [RB] in FIG. 2) using one bit. Thus, the base station reports to the frequency-assigned terminal the frequency assignment bit sequence that is obtained by assigning a bit value 1 to the first and assigning a bit value 0 to the second assignment subband, out of the band that is allocated to the terminal to which it is allocated. allocated frequency and subbands with no allocation that is not allocated among the multiple subbands, which are formed by dividing the system bandwidth into frequency assignment units [RB], in FIG. 2 the frequency assignment unit to which the "1" bit is allocated is the frequency area that is allocated to the terminal to be allocated, and the frequency assignment unit to which the "0" bit is allocated is the frequency area that is not allocated to the terminal to be allocated. Therefore, when the system bandwidth is shown as Nrb [RB] and the frequency assignment unit is shown as P [RB], the number of signaling bits required for the frequency resource allocation information of this method can be expressed as Equation 2 below.

[2]

Number of signaling bits ⁼ [bits] (Equation 2)

List of references

Non-patent literature

[0007]

NPL 1

3GPP R1-090257, Panasonic, System performance of uplink non-contiguous resource allocation NPL 2

3GPP TS36.212 V8.3.0.5.3.3.1.2 DCI format 1 type 0, E-UTRA Multiplexing and channel coding (Release 8)

NPL 3

3GPP R1-084583, Panasonic, Comparison between Clustered DFT-s-OFDM and OFDM for supporting non-contiguous RB allocation within a component carrier

[0008] Uplink multiple access schemes for LTE-A, LG Electronics, R1 -083658, 3GPP TSG RAN WG1 # 54bis, Prague, Czech Republic, September 29 to October 3, 2008, examines different options for the uplink multiple access method for LTE-A in terms of CM and decoding performance for both non-MIMO and MIMO. In one discussed option, in the case of a clustered DFT-sOFDMA, the DFT precoding output may be mapped to multiple RBs in clusters in the frequency domain. This option can provide more scheduling flexibility in the uplink for a UE with better geometry while allowing single carrier transmission for a UE with limited power, by scheduling only localized RBs.

[0009] Uplink multiple access for LTE-Advanced, Nokia Siemens Networks, R1-082609, RAN WG1 Meeting # 53bis, Warsaw, Poland, June 30 to July 4, 2008 discusses the need to change uplink multiple access in LTE-Advanced, as also options for multiple access providing backward compatibility, such as for DFT-s-OFDMA with subcarrier mapping in clusters. [0010] The document EP 3 131 358 A1, which is covered by Art. 54 (3) EPC and not relevant to the inventive step relates to a method of communication between a user equipment, a UE, and a node B in a communication system. A method of communication including receiving a scheduling grant including resource allocation type, resource allocation, modulation and coding method, MCS ( Modulation and Coding Scheme), and a frequency hopping flag from node B; and data transmission based on the resource allocation to node B, the resource allocation type indicating whether the resource allocation is for the first set of at least one contiguous resource block or the second set of resource blocks, and the frequency hopping flag is used as part of the resource allocation for a resource allocation type database, and wherein each of the second files comprises one or more consecutive resource block groups.

Summary of the invention

Technical problem

[0011] However, transmission on non-adjacent frequencies has the problem that the number of signaling bits required to report frequency resource allocation information increases compared to transmission on adjacent frequencies. For example, when the equations NRB = 100 [RB] and P = 4 [RB] are satisfied, the number of signaling bits is 25 [bits]. Although it is possible to increase the RB (P) allocation unit to reduce the number of signaling bits, if the RB allocation unit is simply increased, the frequency allocation flexibility is decreased, thus negatively affecting system throughput.

[0012] Accordingly, it is an object of the present invention to provide a scheduler and a scheduling method to enable the maintenance of system capacity and reduce the amount of signaling for frequency resource allocation information.

Solution

[0013] The scheduler of the present invention uses a configuration including a frequency assignment setting section that sets a frequency assignment unit based on the number of clusters to be used for the terminal to which the frequency is assigned based on the set frequency assignment unit.

The scheduling method of the present invention uses a configuration for setting a frequency allocation unit based on the number of clusters to use for the terminal to which the frequency is allocated; and allocates frequency resources to the terminal to which the frequency is allocated based on the set frequency allocation unit.

Beneficial Effects of the Invention

[0015] According to the present invention, it is possible to provide a scheduler and a scheduling method to enable maintaining system capacity and reducing the amount of signaling for the frequency resource allocation information.

Brief description of the drawings

[0016]

FIG. 1 shows transmission on non-adjacent frequencies;

FIG. 2 shows a method of reporting frequency resource allocation information for transmission at non-adjacent frequencies;

FIG. 3 is a block diagram showing the configuration of the base station apparatus according to embodiment 1 of the present invention;

FIG. 4 is a block diagram of a configuration of an end device according to embodiment 1 of the present invention;

FIG. 5 is an example of a table showing the relationship between a plurality of cluster numbers and the frequency assignment units corresponding to each cluster number;

FIG. 6 shows the relationship between the maximum number of clusters that can be transmitted by the end device and the average sector throughput;

FIG. 7 shows a method of determining a frequency assignment unit corresponding to each number of clusters;

FIG. 8 is an example of a table showing the correspondence between a plurality of cluster numbers and the frequency assignment units corresponding to each cluster number;

FIG. 9 is a block diagram showing the configuration of the base station apparatus according to embodiment 2 of the present invention;

FIG. 10 is an example of a table showing the correspondence between a plurality of cluster numbers and the frequency assignment units corresponding to each cluster number;

FIG. 11 is a block diagram of a configuration of an end device according to embodiment 2 of the present invention;

FIG. 12 is a block diagram showing the configuration of the base station apparatus according to embodiment 3 of the present invention;

FIG. 13 shows offset information for fine-tuning the frequency assignment position;

FIG. 14 is an example of a table showing the correspondence between a plurality of cluster numbers and the frequency assignment units corresponding to each cluster number;

FIG. 15 is an example of a table showing the correspondence between a plurality of cluster numbers and the frequency assignment units corresponding to each cluster number;

FIG. 16 is an example of a table showing the correspondence between a plurality of cluster numbers and the frequency assignment units corresponding to each cluster number; and

FIG. 17 is an example of a table showing the correspondence between a plurality of cluster numbers and the frequency assignment units corresponding to each cluster number.

Description of the embodiments

[0017] Now, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the exemplary embodiments, the same parts will be designated with the same reference numbers and repeated descriptions will be omitted.

(Embodiment 1)

[0018] FIG. 3 is a block diagram showing the configuration of the base station apparatus 100 according to embodiment 1 of the present invention. In FIG. 3 the base station apparatus 100 is equipped with an RF receiving section 101, demultiplexing section 102, DFT sections 103 and 104, demapping sections 105 and 106, channel estimation section 107, frequency domain correction section 108, IDFT section 109, demodulation section 110, decoding section 11, frequency assignment parameter setting section 112, scheduling section 113, coding section 114, modulation section 115 and RF transmission section 116.

[0019] The RF receive section 101 performs reception processing such as down-conversion and A / D conversion on a signal received from the terminal 200 (described below) via the antenna, and outputs the signal after the reception processing to the demultiplexing section 102.

[0020] The demultiplexing section 102 demultiplexes the signal input from the RF receive section 101 into a pilot signal and a data signal. Then, the demultiplexing section 102 sends a pilot signal to the DFT section 103 and sends the data signal to the DFT 104 section.

[0021] The DFT section 103 performs DFT processing on a pilot signal received from the demultiplexing section 102 to convert the time-domain signal to a frequency-domain signal. Then, the DFT section 103 sends a pilot transformed into the frequency domain to the demapping section 105.

[0022] The demapping section 105 acquires a pilot corresponding to the transmission band of the terminal 200 (described below) from the frequency domain pilot received from the DFT section 103 and outputs the pilot to the channel estimation section 107.

The channel estimation section 107 estimates the frequency variation on the channel (i.e., the frequency response of the channel) and the reception quality for each frequency band by performing correlation calculations on the receive pilot received from the demapping section 105 and on the transmission pilot as known between the apparatus base station 100 and end device 200. Then, the channel estimation section 107 sends the estimation value resulting from the estimation to the frequency domain correction section 108 and the scheduling section 113.

[0024] The DFT section 104 performs DFT processing on the data signal received from the demultiplexing section 102 to convert the time-domain signal to a frequency-domain signal. Then, the DFT section 104 sends the data signal transformed into the frequency domain to the demapping section 106.

[0025] The demapping section 106 acquires the data signal portion corresponding to the transmission band of the terminal 200 from the signal received from the DFT section 104 and outputs the data signal to the frequency-domain correction section 108.

[0026] The frequency domain correction section 108 performs correcting processing on the data signal received from demapping section 106 using a channel estimation value (i.e., channel frequency response) received from channel estimation section 107. Next, the frequency domain correction section 108 outputs the signal obtained from the result of the correction processing it to IDFT 109.

[0027] The IDFT section 109 performs IDFT processing on the data signal input from the frequency-domain correction section 108. Then, the IDFT section 109 sends the signal derived from the IDFT processing to the demodulation section 110.

[0028] The demodulation section 110 performs the demodulation processing on a signal received from the IDFT section 109 and outputs the signal obtained from the demodulation processing to the decoding section 111.

[0029] The decoding section 111 performs decoding processing on a signal received from the demodulation section 110 and acquires the reception data.

[0030] The frequency assignment parameter setting section 112 maintains information about the relationship between the number of clusters and the frequency assignment unit that is applied to the terminal to which the frequency is assigned. The frequency assignment parameter setting section 112, for example, maintains a table showing the correspondence between a plurality of cluster numbers and the frequency assignment units corresponding to each cluster number. Next, the frequency assignment parameter setting section 112 sets a frequency assignment unit corresponding to the number of clusters indicated by the cluster number input information to the scheduling section 113. This set-up processing based on the frequency assignment unit is performed for each terminal to which the frequency is assigned. That is, the frequency assignment parameter setting section 112 matches the frequency assignment unit to be set in scheduling section 113 based on the number of clusters to use for the terminal to which the frequency is assigned.

[0031] Here, the frequency assignment unit varies according to the number of clusters. In addition, an upper bound value is determined for the number of clusters to use for the terminal to which the frequency is allocated. In this regard, a relationship between the number of clusters and the frequency allocation unit that are applied to the terminal to which the frequency is allocated is determined in advance for each base station device 100 or the entire system. This relationship will be described in more detail below.

[0032] The scheduling section 113 allocates frequency resources to the terminal to which the frequency is allocated based on the frequency assignment unit set by the frequency assignment parameter setting section 112. Specifically, the scheduling section 113 performs frequency scheduling for any assigned terminal based on reception quality information on each subband of the predetermined transmission band with a signal transmitted in the predetermined transmission band from any terminal to which it is allocated the frequency, which is received from the channel estimation section 107, and the frequency assignment unit, which is received from the frequency assignment parameter setting section 112, and is used for any terminal to which the frequency is assigned. Reporting of frequency assignment information is performed, as described above, by a sequence of frequency assignment bits corresponding to the pattern of the assignment subband that is allocated to the terminal to which the frequency is allocated and the subbands with no assignment that is not allocated, across multiple subbands. which are formed by dividing the system bandwidth into frequency allocation units.

[0033] The coding section 114 codes the transmission data including frequency assignment information for the terminal to which the frequency is assigned, and outputs the coded data to modulation section 115.

[0034] The modulation section 115 modulates the coded data received from the coding section 114 and outputs the modulated signal to the RF transmission section 116.

[0035] The RF transmission section 116 performs transmission processing such as D / A conversion, up-conversion and gain on the modulated signal received from the modulation section 115 and transmits the acquired radio signal to terminal 200 via the antenna.

[0036] FIG. 4 is a block diagram showing the configuration of an end device 200 according to embodiment 1 of the present invention. In FIG. 4, the terminal 200 is equipped with an RF receiving section 201, demodulation section 202, decoding section 203, frequency assignment parameter setting section 204, scheduling information setting section 205, encoding section 206, modulation section 207, DFT section 208, mapping section 209, an IDFT section 210 and an RF transmission section 211.

[0037] The RF receive section 201 performs reception processing such as down-conversion and A / D conversion on the signal received via the antenna and outputs the signal after the reception processing to the demodulation section 202.

[0037] The demodulation section 202 performs correction processing and demodulation processing on the signal received from the RF reception section 201 and outputs the processed signal to the decoding section 203. The decoding section 203 performs decoding processing on the signal received from the demodulation section 202 and acquires control data including reception data and frequency assignment information.

[0040] The coding section 206 codes the transmission data and outputs the acquired coded data to the modulation section 207.

[0041] The modulation section 207 modulates the data received from the coding section 206 and outputs a modulated data signal to the DFT section 208.

[0042] The DFT section 208 performs DFT processing on the modulated data signal received from the modulation section 207 and outputs the acquired frequency-domain data signal to the mapping section 209.

[0043] The mapping section 209 maps the data signal received from the DFT section 208 to the frequency domain resources according to the frequency assignment information received from the setting information setting section 205, and outputs the acquired signal to IDFT section 210.

[0044] The frequency assignment parameter setting section 204 acquires information about the number of clusters included in the control data received from the decoding section 203. Further, the frequency assignment parameter setting section 204 maintains a table showing a correspondence which is similar to the table held in the frequency assignment parameter setting section 112 in the decoding section. the base station device 100. Then, the frequency assignment parameter setting section 204 sends the frequency assignment unit corresponding to the cluster number indicated by the acquired cluster number information to the scheduling information setting section 205.

[0045] The scheduling information setting section 205 acquires frequency assignment information contained in control data received from the decoding section 203. Then, the scheduling information setting section 205 determines frequency planning information for the terminal 200 based on the acquired frequency assignment information and the frequency assignment unit received. from the setting section of the frequency assignment parameter 204. Specifically, the scheduling information setting section 205 reads the frequency assignment information reported from the base station device 100 for each frequency assignment unit received from the frequency assignment parameter setting section 204, and determines whether or not the information is correct frequency assignment information to be used by end device 200. Then, the scheduling information setting section 205 sends the frequency assignment information for end device 200 to the mapping section 209.

[0046] The IDFT section 210 performs IDFT processing on the signal received from the mapping section 209. Then, the IDFT section 210 sends the signal obtained by the IDFT processing to the transmission section RF211.

[0047] The RF transmission section 211 performs the transmission processing such as D / A conversion, up-conversion and gain on the signal received from IDFT section 210 and transmits the acquired radio signal to the base station apparatus 100 via the antenna.

[0048] Next, information about the relationship between the number of clusters and the frequency allocation unit applied to the terminal to which the frequency is allocated, which is held in the frequency allocation parameter setting section 112, will be described below.

[0049] FIG. 5 is an example of a table showing the correspondence between a plurality of cluster numbers and the frequency assignment units corresponding to each cluster number. In FIG. The upper limit of the number of clusters is 4. Moreover, the number of clusters 1 is excluded as this number indicates transmission on adjacent frequencies. In addition, the number of bits of frequency assignment information (i.e. the number of bits making up the frequency assignment bit sequence is constant regardless of the number of clusters.

[0050] Here, the cluster number upper limit is set based on a relationship between the number of clusters and the system capacity. FIG. 6 shows the relationship between the maximum number of clusters that can be transmitted by an end device and the average sector throughput (see Non-Patent Literature 3). FIG. 6 shows that the system throughput does not deteriorate even when the number of clusters is limited to 3 to 4. This is because the probability that the number of terminal clusters will be 4 or greater is low. As described above, since the impact on the system throughput is small, it is possible to set an upper limit for the number of clusters.

[0051] Furthermore, the frequency assignment unit corresponding to each number of clusters is determined as described below. First, a reference number of clusters is determined, which is the standard. For example, the number of clusters that is used most often is selected as the reference number of clusters. Then, when the reference number of clusters is selected, the number of signaling bits that is required to report frequency resource allocation information is set as the reference number of bits. Then, a frequency allocation unit having a number of signaling bits closest to the reference number of bits, number of signaling bits required to report frequency resource allocation information using that number of clusters is selected as the number of clusters in addition to the reference number of clusters.

[0052] FIG. 7 shows a method of determining a frequency assignment unit corresponding to each number of clusters. Each point in FIG. 7 is plotted based on Equation 3 below.

[3]

Number of signaling bits ⁼ flog 2 ([nrb i ^c2Ncltaler)] [bits]

... (Equation 3) where the system bandwidth is expressed as Nrb [RB], the number of clusters is expressed as Nciuster and the frequency assignment unit is expressed as P [RB],

[0053] FIG. 7 shows a plot of the number of clusters and the number of signaling bits when the equation Nrb = 100 [RB] is satisfied, Assuming that the number of 18 [bits] signaling bits for the number of clusters 2 and P = 2 [RB] is set as the reference number of bits a frequency assignment unit of 4, having a number of signaling bits closest to the reference number of bits 18, is selected when the number of clusters is 3, and similarly, a frequency assignment unit 5 is selected, when the number of clusters is 4.

[0054] FIG. 7 shows the number of signaling bits when the above-described conventional technique is used in which the number of signaling bits is constant (number of signaling bits is 25 bits when P = 4) regardless of the number of clusters. As can be seen from FIG. 7, by limiting the maximum number of clusters to 4 in accordance with the present embodiment, it is possible to reduce the number of signaling bits compared to the conventional technique.

[0055] Furthermore, by providing the same number of signaling bits for each number of clusters, it is possible to use one signaling format regardless of the number of clusters. In this way, the end device 200 can reduce the number of attempts of blind decoding processes to detect the signaling format.

[0056] As described above, according to the present embodiment, in the base station apparatus 100, the scheduling section 113 allocates frequency resources to the terminal to which the frequency is allocated based on the set frequency assignment unit, and the frequency assignment parameter setting section 112 matches the unit. allocation of frequencies to be set in scheduling section 113 based on the number of clusters to be used for the terminal, to which the frequency is assigned.

[0057] In this way, it is possible to perform an allocation of frequency resources based on a frequency allocation unit optimized with the number of signaling bits for each number of clusters. As a result, it is possible to reduce the amount of signaling for the frequency resource allocation information. In addition, by setting the number of clusters, which is a parameter having little effect on system bandwidth, as the frequency allocation unit setting parameter, it is possible to maintain system bandwidth.

[0058] Moreover, the number of bits making up the bit sequence of the frequency allocation is constant regardless of the number of clusters.

[0059] In this way, it is possible to report the frequency resource allocation information using a common signaling format independent of the number of clusters. In this way, it is possible to reduce the amount of blind decoding processing to detect the signaling format at the side receiving the scheduling information.

[0060] In the above description, a case has been described where the number of bits constituting the sequence of frequency allocation bits is constant regardless of the number of clusters. However, the number of bits making up the sequence of frequency allocation bits may vary with the number of clusters. In such a case, the encoding section 114 makes the total number of bits constant regardless of the number of clusters by adding the padding bits (e.g., bit value 0) before encoding the frequency assignment bit sequence. For example, as shown in FIG. 8, when determining the frequency assignment units and the number of signaling bits for the cluster numbers 3 and 4 by setting the number of signaling bits (= 22 [bits]) for the number of clusters 2 as the reference number of bits, the number of signaling bits required to report frequency allocation information does not are the same. In this case, since the coding section 114 adds padding bits to align the numbers of signaling bits, it is possible to share the signaling format, allowing to reduce the amount of blind decoding processing to detect the signaling format at the side receiving the scheduling information.

(Execution example 2)

[0061] The case of embodiment 2 will be described here, in which "system bandwidth" is taken as the parameter for determining the frequency assignment unit in addition to the number of clusters.

[0062] FIG. 9 is a block diagram showing the configuration of the base station apparatus 300 according to embodiment 2 of the present invention. In FIG. 9, the base station apparatus 300 is provided with a frequency assignment parameter setting section 301.

[0063] The frequency assignment parameter setting section 301 maintains information about the relationship between the number of clusters and the frequency assignment unit that is applied to the terminal to which the frequency is assigned over the system bandwidth. The frequency assignment parameter setting section 301 includes, for example, a second table showing the correspondence shown in FIG. 10 in addition to the first correspondence table shown in FIG. 5. The system bandwidths to be used for the first suitability table and the second suitability table are different. In this case, the term "system bandwidth" refers to the entire bandwidth that can be received by the base station device 300, i.e. the entire bandwidth that can be allocated to a terminal in a cell covered by the base station device 300.

[0064] Next, in the table showing the correspondence corresponding to the system bandwidth to be entered, the frequency assignment parameter setting section 301 sets the frequency assignment unit according to the number of clusters indicated by the cluster number information to be entered into the scheduling section 113. Setting section 113. frequency assignment parameter 301, for example, uses the first table showing the correspondence shown in FIG. 5, when the system bandwidth is 100 [RB], and uses a second table showing the correspondence shown in FIG. 10, when the system bandwidth is 200 [RB], That is, the frequency assignment parameter setting section 301 switches between the tables showing the suitability for the application depending on the system bandwidth.

[0065] Here, when the system bandwidth varies, the utilization rate changes to the number of endpoint clusters in the system. For example, since the amount of frequency resources that can be used by an end device varies as the system bandwidth increases, it is necessary to allocate more clusters to the end device to improve throughput.

[0066] Accordingly, the frequency assignment parameter setting section 301 switches the tables showing the suitability to use depending on the system bandwidth, so that it is possible to use the optimal table showing the suitability according to the system bandwidth.

[0067] FIG. 11 is a block diagram showing the configuration of an end device 400 according to embodiment 2 of the present invention. In FIG. 11, end device 400 is provided with a frequency assignment parameter setting section 401.

[0068] The frequency assignment parameter setting section 401 acquires the cluster number information and the system bandwidth information which is included in the control data received from the decoding section 203. Further, the frequency assignment parameter setting section 401 maintains a table showing the correspondence which is similar to the table. held in the frequency assignment parameter setting section 301 of the base station apparatus 300. Then, the frequency assignment parameter setting section 401 sends a frequency assignment unit corresponding to the system bandwidth indicated by the cluster number information to the setting section of scheduling information 205.

[0069] As described above, according to the present embodiment, at the base station apparatus 300, the frequency assignment parameter setting section 301 adjusts the frequency assignment unit to be set based on the system bandwidth in addition to the number of clusters.

[0070] In this way, it is possible to apply an optimal correspondence between the number of clusters and the frequency allocation unit corresponding to the system bandwidth, allowing the system throughput to be improved.

(Embodiment 3)

[0071] With Embodiment 3, a case will be described here where, when the number of bits constituting the sequence of frequency allocation bits changes depending on the number of clusters, offset information is added to fine-tune the position of the frequency allocation without being padded with "0" bits.

[0072] FIG. 12 is a block diagram showing the configuration of the base station apparatus 500 according to embodiment 3 of the present invention. In FIG. 12, the base station apparatus 500 is provided with a frequency assignment parameter setting section 501 and a scheduling section 502.

The setting section of frequency assignment parameter 501 determines whether to shift or not shift the frequency resources allocated in the scheduling section 502 towards the frequency based on a channel estimation value received from the channel estimation section 107. A standard for deciding whether to implement an offset or not, it is based on the quality of the channel in the RB to be allocated. For example, the RB to be allocated having the higher average SINR is selected by calculating the average SINR of the RB to be allocated in the cases where a shift is performed and not performed. In this way, since it is possible to allocate to the RB terminal having a higher channel quality, the throughput of the system can be improved.

[0074] The scheduling section 502 forms a sequence of frequency assignment bits as does the scheduling section 113. Also, the scheduling section 502 adds offset information to the frequency assignment bit sequence according to the result of the determination in the frequency assignment parameter setting section 501. For example, as shown in FIG. 13, bit value 0 is set as offset information when a decision not to execute an offset is made, and a value of 1 bit is set as offset information when a shift is performed. An example of a table showing the correspondence in such a case is shown in FIG. 14.

[0075] As described above, in accordance with the present invention, in the base station apparatus 500, the frequency assignment parameter setting section 501 determines whether to shift or not shift the frequency resources allocated in the scheduling section 502 towards the frequency based on the channel estimation value. and the scheduling section 502 adds offset information to the frequency assignment bit sequence corresponding to the determination result in the setting section of frequency assignment parameter 501.

[0076] Thereby, the flexibility for frequency planning is increased, so that it is possible to accurately allocate frequency resources having a good channel quality, which enables the system throughput to be improved.

(Another embodiment)

[0077] (1) In the above embodiments, it is possible to switch the frequency assignment information reporting methods according to the cluster number between the methods of embodiments 1 to 3 and the conventional method (i.e., the reporting method in bitmap format). For example, as shown in FIG. 15, it is possible to use any method of embodiments 1 to 3 when the number of clusters is 4 or less, and use the conventional method when the number of clusters is 5 or more.

(2) In the above embodiments, when the number of clusters to be reported is not a power of 2, it is possible to report the identification information using a pattern combining the number of clusters and the frequency assignment information. For example, as shown in FIG. 16, by reporting the identification information using a combining pattern of cluster number and frequency assignment information, it is possible to reduce the total number of signaling bits for the cluster number and frequency assignment information. A comparison of FIG. 16 with FIG. 8 shows that for the number of clusters 3, it is possible to reduce the total number of signaling bits for the number of clusters and frequency assignment information by one bit. By allocating this reduced number of bits to the offset information, it is possible to increase the frequency planning flexibility, which enables the system throughput to be improved.

(3) Although the above embodiments have described the cases where the case of the number of clusters 1 is excluded, it is possible to allow the number of clusters 1 (adjacent frequency allocation). For example, as shown in FIG. 17, by sharing a common signaling format in both the adjacent frequency assignment and the non-adjacent frequency assignment, it is possible to reduce the amount of blind decoding processing to detect the signaling format at the side receiving the scheduling information.

(4) Moreover, while the above embodiments are described as examples where the present invention is hardware-configured, the present invention may also be implemented in software.

[0078] Each functional block used in describing each of the aforementioned embodiments typically may be embodied in an LSI constituted by an integrated circuit. They can be separate integrated circuits or circuits partially or completely contained in one integrated circuit. The term "LSI" is adopted here, but may also be called "IC", "system LSI", "super LSI" or "ultra LSI" depending on the different degrees of integration.

[0079] In addition, the method of circuit integration is not limited to LSI circuits, and an implementation using dedicated circuitry or general purpose processors is also possible. After production of the LSI, a user-programmable Field Programmable Gate Array (FPGA) that can be programmed may be used, or a processor that can be reconfigured that allows reconfiguration of chip connections and settings in the LSI.

[0080] Moreover, if circuit integration technology replacing LSI appears as a result of advances in semiconductor technology or other derivative technologies, it is naturally also possible to implement the integration of functional blocks using this technology.

Industrial applications

[0081] The scheduler and scheduling method of the present invention is useful for maintaining system capacity and reducing the amount of signaling for frequency resource allocation information.

Sun Patent Trust

Proxy:

PL-PAT-2012-1526

EP 2 400 807 B1