Source: https://patents.google.com/patent/JP2006211017A/en
Timestamp: 2020-01-21 21:43:04
Document Index: 308356851

Matched Legal Cases: ['art 105', 'art 106', 'art 107', 'art 108', 'art 151', 'art 152', 'art 153', 'art 154']

JP2006211017A - Base station apparatus, communication terminal, and resource allocation method - Google Patents
Base station apparatus, communication terminal, and resource allocation method Download PDF
JP2006211017A
JP2006211017A JP2005016874A JP2005016874A JP2006211017A JP 2006211017 A JP2006211017 A JP 2006211017A JP 2005016874 A JP2005016874 A JP 2005016874A JP 2005016874 A JP2005016874 A JP 2005016874A JP 2006211017 A JP2006211017 A JP 2006211017A
JP2005016874A
Hidenori Shikayama
2005-01-25 Application filed by Matsushita Electric Ind Co Ltd, 松下電器産業株式会社 filed Critical Matsushita Electric Ind Co Ltd
2005-01-25 Priority to JP2005016874A priority Critical patent/JP2006211017A/en
2006-08-10 Publication of JP2006211017A publication Critical patent/JP2006211017A/en
<P>PROBLEM TO BE SOLVED: To provide a base station apparatus, a communication terminal, and a resource allocation method capable of determining a modulation system and a coding rate by selecting an optimum MCS level. <P>SOLUTION: An ACK/NACK information detection section 106 detects ACK information or NACK information denoting an error detection processing result in communication terminals. A channel quality information detection section 107 detects channel quality information denoting an MCS level requested from the communication terminals. A decoding repetition detection section 108 detects repetition information denoting the number of repetitive times of error correction decoding processing carried out by the communication terminals. A scheduling section 151 allocates a communication terminal being a data transmission destination on the basis of the channel quality information and determines a modulation system and a coding rate of transmission data to be transmitted to the allocated communication terminal on the basis of the ACK/NACK information, the channel quality information, and the repetitive number information. <P>COPYRIGHT: (C)2006,JPO&NCIPI
The present invention relates to a base station apparatus, a communication terminal apparatus, and a resource allocation method used in a radio communication system.
In HSDPA (High Speed Downlink Packet Access) standardized by 3GPP, high throughput is realized by applying scheduling technology and adaptive modulation technology. The scheduling technique is a technique in which the base station apparatus allocates user lines based on channel quality (eg, SINR (desired wave to interference wave ratio)) measured by each communication terminal apparatus. The base station apparatus determines a combination of the transmission data modulation scheme and error correction coding rate (hereinafter referred to as “MCS level”) for each communication terminal apparatus based on the reception quality measured by each communication terminal apparatus. Technology.
Hereinafter, an example of a general MCS level selection method in conventional adaptive modulation will be described with reference to FIG. In FIG. 10, the horizontal axis represents SINR, and the vertical axis represents throughput. In FIG. 10, the throughput with respect to SINR is shown for a plurality of MCS levels (MCS1, MCS2, MCS3, MCS4). In FIG. 10, the SINR at which the throughput at the MCS level (n + 1) is equal to the throughput at the MCS level n is defined as a threshold value THn that is a boundary between the area to which the MCS level (n + 1) is allocated and the area to which the MCS level n is allocated. Is set.
Each communication terminal apparatus stores the SINR range to which each MCS level is assigned as a table, determines the MCS level required from the base station apparatus based on the measured SINR value, and provides channel quality information indicating this to the base station apparatus Send to. The base station apparatus compares the MCS levels transmitted from the respective communication terminal apparatuses, assigns a user line to the communication terminal apparatus having the highest MCS level, for example, modulates transmission data at the MCS level, and transmits the modulated transmission data.
3GPP TR25.848 V4.0.0 (2001-03) 3GPP TS25.214 V6.1.0 (2004-03)
However, in the above conventional method, the optimum MCS level can be selected in the communication terminal apparatus because the SINR varies depending on the propagation path condition, or there is also an SINR estimation error in the communication terminal apparatus. However, there is a possibility that waste of system throughput may occur due to the presence of a user who continues communication with excessive quality.
For example, in FIG. 10, when the SINR measurement result becomes point 12 due to the SINR estimation error even though the original SINR is point 11, the communication terminal apparatus uses the MCS according to the conventional method. Despite being able to receive at level 3, MCS level 2 is requested from the base station apparatus with an excess margin with respect to the reception performance limit of the receiver.
The present invention has been made in view of the above points, and provides a base station apparatus, a communication terminal apparatus, and a resource allocation method capable of selecting an optimal MCS level and determining a modulation scheme and a coding rate. Objective.
In order to solve this problem, the base station apparatus of the present invention compares the MCS level requested from each communication terminal apparatus in communication, assigns a data transmission destination communication terminal apparatus, and requests from the assigned communication terminal apparatus. Scheduling means for determining a modulation scheme and a coding rate based on the assigned MCS level, the result of error detection processing in the assigned communication terminal device, and the number of repetitions of error correction decoding processing performed in the assigned communication terminal device; And a transmission means for transmitting transmission data addressed to the allocated communication terminal apparatus with the modulation scheme and coding rate determined by the scheduling means.
A communication terminal apparatus according to the present invention is a communication terminal apparatus that performs communication with a base station apparatus that assigns a communication terminal apparatus as a data transmission destination by comparing MCS levels requested from each communication terminal apparatus that is performing communication. Decoding repetition number counting means for counting the number of repetitions of error correction decoding processing for the received signal, line quality measuring means for measuring the line quality of the received signal, and MCS requested to the base station apparatus based on the measured line quality A channel quality information generating means for determining a level, correcting the MCS level based on the number of repetitions of the error correction decoding process, and generating channel quality information indicating the corrected MCS level; and a signal including the channel quality information And a transmitting means for transmitting to the base station apparatus.
The resource allocation method of the present invention includes a step of assigning a communication terminal device as a data transmission destination by comparing MCS levels requested from each communication terminal device in communication, an MCS level requested from the assigned communication terminal device, Modulation method and coding rate of data transmitted to the allocated communication terminal apparatus based on the error detection process result in the allocated communication terminal apparatus and the number of repetitions of the error correction decoding process performed in the allocated communication terminal apparatus And a step of determining the method.
According to the present invention, the MCS level requested from the communication terminal device assigned as the data transmission destination is corrected by considering the number of repetitions of the error correction decoding process performed in the communication terminal device. An appropriate MCS level can be selected, and a modulation scheme and a coding rate can be determined.
First, the configuration of the base station apparatus according to Embodiment 1 of the present invention will be described using the block diagram of FIG. The base station apparatus 100 of FIG. 1 performs wireless communication simultaneously with a plurality of communication terminal apparatuses. A signal transmitted from each communication terminal apparatus to the base station apparatus 100 includes channel quality information indicating a requested MCS level, ACK / NACK information indicating an error detection processing result, and repetition indicating the number of times of error correction decoding processing. Number information is included. The ACK information is information indicating that no error has been detected, and the NACK information is information indicating that an error has been detected.
The duplexer 102 outputs the signal received by the antenna 101 to the reception radio unit 103. The duplexer 102 wirelessly transmits the signal output from the transmission wireless unit 158 from the antenna 101.
Reception radio section 103 converts the radio frequency reception signal output from duplexer 102 into a baseband signal and outputs the baseband signal to demodulation section 104. The demodulator 104 is prepared for the number of communication terminal apparatuses that perform radio communication, performs demodulation processing such as despreading and RAKE combining on the received baseband signal, and outputs the demodulated signal to the error correction decoding unit 105. .
Error correction decoding sections 105 are prepared for the number of communication terminal apparatuses that perform wireless communication, perform error correction decoding processing on the demodulated signal, and obtain received data that is a decoding result. Then, error correction decoding section 105 outputs the received data to ACK / NACK information detection section 106, channel quality information detection section 107, decoding repetition number detection section 108, and a subsequent process (not shown).
The ACK / NACK information detection unit 106 detects ACK information or NACK information included in the received data, and outputs the detection result to the scheduling unit 151 and the data retransmission control unit 152. Channel quality information detection section 107 detects channel quality information included in the received data and outputs the detection result to scheduling section 151. Decoding repetition number detection section 108 detects repetition number information included in the received data and outputs the detection result to scheduling section 151.
Scheduling section 151 assigns a communication terminal device to be a data transmission destination based on channel quality information, and transmits to the communication terminal device assigned as a data transmission destination based on ACK / NACK information, channel quality information, and repetition rate information. A transmission data modulation scheme, coding rate, and physical resources to be used are determined (resource allocation). Details of the modulation scheme and coding rate determination method in scheduling section 151 will be described later.
After performing resource allocation, scheduling section 151 outputs information indicating the communication terminal apparatus allocated as the data transmission destination to data retransmission control section 152, and resource allocation information indicating the resource allocation result to error correction encoding section 156. Output. Further, the scheduling unit 151 instructs the coding rate to the error correction coding unit 154 and instructs the modulation method to the modulation unit 155.
Data retransmission control section 152 selects one transmitted from the communication terminal apparatus assigned as the data transmission destination, from the ACK / NACK information output from ACK / NACK information detection section 106. Then, if the selected information is ACK information, data retransmission control section 152 instructs transmission data buffer section 153 to transmit new data to the communication terminal apparatus assigned as the data transmission destination. On the other hand, if the selected information is NACK information, data retransmission control section 152 instructs transmission data buffer section 153 to transmit retransmission data to the communication terminal apparatus assigned as the data transmission destination.
The transmission data buffer unit 153 temporarily stores transmission data to be transmitted to each communication terminal apparatus, and outputs the transmission data instructed by the data retransmission control unit 152 to the error correction encoding unit 154.
Error correction coding section 154 performs error correction coding at the coding rate indicated by scheduling section 151 on the output data of transmission data buffer section 153 and outputs the data after error correction coding to modulation section 155. To do. The error correction coding process performed by the error correction coding unit 154 is a type of error correction process such as turbo coding in which decoding is repeatedly performed on the decoding side and the reliability of decoding is increased each time. .
Modulation section 155 modulates and spreads the output data of error correction coding section 154 using the modulation scheme instructed by scheduling section 151, and outputs the modulated signal to transmission radio section 158.
Error correction coding section 156 performs error correction coding on the resource allocation information, and outputs the data after error correction coding to modulation section 157. Modulation section 157 modulates and spreads the output data of error correction coding section 156 and outputs the modulated signal to transmission radio section 158.
The transmission radio unit 158 converts the output signal of the modulation unit 155 and the output signal of the modulation unit 157 into a radio frequency signal and outputs the signal to the duplexer 102.
Next, the configuration of the communication terminal apparatus according to the present embodiment will be described using the block diagram of FIG. 2 performs radio communication with the base station apparatus 100 shown in FIG.
Duplexer 202 outputs the signal received by antenna 201 to reception radio section 203. The duplexer 202 wirelessly transmits the signal output from the transmission wireless unit 253 from the antenna 201.
Reception radio section 203 converts the radio frequency reception signal output from duplexer 202 into a baseband signal and outputs the baseband signal to demodulation section 204. Demodulation section 204 performs demodulation processing such as despreading and RAKE combining on the received baseband signal, and outputs the demodulated signal to error correction decoding section 205. Demodulation section 204 outputs information necessary for line quality measurement, such as desired wave power and interference wave power, obtained in the course of demodulation processing, to line quality measurement section 208.
The error correction decoding unit 205 repeatedly performs error correction decoding processing and error detection processing on the demodulated signal until no error is detected, and when no error is detected in the decoded signal, the decoding result The received data is output to a subsequent process (not shown). In addition, the error correction decoding unit 205 outputs information indicating the detection result to the ACK / NACK information generation unit 206 and the decoding repetition number counting unit 207 every time error detection processing is performed. The error correction decoding unit 205 stops the further error correction decoding process and outputs the received data when an error remains in the decoded signal even after repeating the error correction decoding process for a predetermined number of times. do not do.
The decoding repetition number counting unit 207 counts the number of repetitions of the error correction decoding process in the error correction decoding unit 205 and outputs the count value to the error correction coding unit 251 as repetition number information. The ACK / NACK information generation unit 206 generates ACK information when no error is detected in the decoded signal during the error correction decoding process, and the error correction decoding process may be repeated a predetermined number of times. If an error remains in the decoded signal, NACK information is generated, and the ACK information or the NACK information is output to the error correction coding unit 251.
The channel quality measurement unit 208 measures SINR (channel quality) based on the information output from the demodulation unit 204 and outputs information indicating the measured SINR to the channel quality information generation unit 209. The channel quality information generation unit 209 stores the SINR range to which each MCS level is assigned as a table, determines the MCS level required from the base station apparatus 100 based on the measured SINR value, and channel quality information indicating this Is output to the error correction encoding unit 251.
Error correction coding section 251 multiplexes channel quality information, ACK / NACK information, and repetition number information on transmission data, performs error correction coding on the multiplexed signal, and outputs the result to modulation section 252. Each piece of information may be individually subjected to error correction coding.
Modulation section 252 modulates and spreads the output signal of error correction coding section 251 and outputs the result to transmission radio section 253. Transmission radio section 253 converts the output signal of modulation section 252 into a radio frequency signal and outputs the signal to duplexer 202.
Next, the communication order between the base station apparatus and the communication terminal apparatus according to the present embodiment will be described using the sequence diagram of FIG.
First, the base station apparatus transmits data to the communication terminal apparatus (S301, S302).
The communication terminal apparatus performs error detection processing (S303), measures channel quality (S304), counts the number of repetitions of error correction decoding processing (S305), and obtains ACK / NACK information, channel quality information, and repetition number information. The included control information is transmitted to the base station apparatus (S306, S307).
The base station apparatus allocates a communication terminal apparatus as a data transmission destination based on the line quality information, and modulates and codes the transmission data to be transmitted to the communication terminal apparatus based on the ACK / NACK information, the line quality information, and the repetition number information. Resource allocation for determining the conversion rate is performed (S308). Then, the base station apparatus transmits control information including resource allocation information indicating the resource allocation result to the communication terminal apparatus (S309, S310), and then transmits data to the communication terminal apparatus (S311, S312).
Next, the modulation scheme and coding rate determination method in scheduling section 151 of base station apparatus 100 according to the present embodiment will be described in detail with reference to the flowchart of FIG.
First, scheduling section 151 is a case where ACK information has been received from a communication terminal apparatus assigned as a data transmission destination (S401: YES), and the number of repetitions of error correction decoding processing indicated in repetition number information is If it is less than the predetermined threshold (S402: YES), the MCS level indicated in the line quality information is corrected upward (S403). On the other hand, when the number of repetitions of the error correction decoding process indicated in the repetition number information in S402 is equal to or greater than a predetermined threshold (S402: NO), the scheduling unit 151 keeps the MCS level indicated in the line quality information. (S404). Then, the scheduling unit 151 determines the modulation scheme and coding rate according to the MCS level set in S403 or S404 (S405). The upward correction is to correct the MCS level so as to increase the transmission rate. In addition, when the NACK information is received from the communication terminal device assigned as the data transmission destination in S401 (S401: NO), the scheduling unit 151 performs a process after receiving the conventional NACK information (S406). As a process after receiving conventional NACK information, in the case of H-ARQ (Hybrid-Automatic Repeat Request) method, the same bit is transmitted at the same MCS level as in the previous transmission, or additional redundant bits are transmitted. It is done.
As described above, according to the present embodiment, the base station apparatus modifies the MCS level requested from the communication terminal apparatus based on the number of repetitions of the error correction decoding process, thereby selecting the optimum MCS level. The modulation scheme and coding rate can be determined.
In the above description, a case has been described in which the scheduling unit 151 first selects a communication terminal device as a data transmission destination and corrects the MCS level for the communication terminal device. However, in this embodiment, the scheduling unit 151 First, the MCS level of all the communication terminal devices can be corrected, and then the data transmission destination communication terminal device can be selected.
Hereinafter, the modulation scheme and coding rate determination method in scheduling section 151 of base station apparatus 100 in this case will be described in detail with reference to the flowchart of FIG.
In this case, the scheduling unit 151 performs the processing of S401 to S404 for all the communication terminal devices (S501 to S504).
Then, the scheduling unit 151 compares the corrected MCS levels, assigns, for example, a communication terminal apparatus having the highest MCS level as a data transmission destination (S505), and determines a modulation scheme and a coding rate according to the MCS level ( S405).
In the second embodiment, a case will be described in which an MCS level is selected in consideration of an allowable delay determined by a user service type. The configurations of the base station apparatus and communication terminal apparatus of the present embodiment are the same as those of base station apparatus 100 of FIG. 1 and communication terminal apparatus 200 of FIG. However, in addition to channel quality information, ACK / NACK information, and repetition count information, allowable delay information indicating the amount of delay allowed in each communication terminal apparatus is input to scheduling section 151 of base station apparatus 100. Different from the first embodiment.
First, the scheduling unit 151 receives ACK information from the communication terminal device when the allowable delay amount of the communication terminal device assigned as the data transmission destination is equal to or greater than a predetermined threshold (S601: NO). If (S602: YES) and the number of repetitions of the error correction decoding process indicated by the repetition number information is less than the predetermined threshold A (S603: YES), the MCS level indicated by the line quality information is corrected upward ( S604). In addition, the scheduling unit 151 is a case where the ACK information is received from the communication terminal device when the allowable delay amount of the communication terminal device assigned as the data transmission destination is smaller than a predetermined threshold (S601: YES). If (S605: YES) and the number of repetitions of the error correction decoding process indicated in the repetition number information is equal to or greater than a predetermined threshold B (S606: NO), the MCS level indicated in the line quality information is corrected downward. (S607). Further, the scheduling unit 151 performs the error correction decoding process indicated in the repetition number information indicated in S606 when the number of repetitions of the error correction decoding process indicated in the repetition number information in S603 is equal to or greater than a predetermined threshold A (S603: NO). If the number of repetitions is less than the predetermined threshold B (S606: YES), the MCS level indicated in the line quality information is maintained (S608). Then, the scheduling unit 151 determines a modulation scheme and a coding rate according to the MCS level set in S604, S607, or S608 (S609). Further, when receiving the NACK information from the communication terminal device assigned as the data transmission destination in S602 or S605 (S602: NO, S605: NO), the scheduling unit 151 performs the processing after receiving the conventional NACK information. This is performed (S610). In FIG. 6, the threshold A and the threshold B may be different values or the same.
As described above, according to the present embodiment, the MCS level requested by the base station apparatus from the communication terminal apparatus is corrected based on the number of repetitions of the error correction decoding process and the allowable delay amount, so that the optimum MCS level is obtained. And the modulation scheme and coding rate can be determined.
In Embodiment 3, a case will be described in which the communication terminal apparatus side modifies and transmits the MCS level requested of the base station apparatus based on the number of repetitions of the error correction decoding process. In this case, the configuration of the base station apparatus is a configuration in which the decoding repetition number detecting unit 108 is deleted from the base station apparatus 100 of FIG. 1 shown in the first embodiment, and the scheduling unit 151 performs ACK / Based on the NACK information and the channel quality information, a modulation method and a coding rate of transmission data to be transmitted to the communication terminal apparatus are determined.
FIG. 7 is a block diagram showing a configuration of the communication terminal apparatus according to the present embodiment. In the communication terminal device 700 of FIG. 7, the same reference numerals as those in FIG. 2 are assigned to the same components as those in the communication terminal device 200 shown in FIG. The communication terminal device 700 in FIG. 7 differs from the communication terminal device 200 shown in FIG. 2 in that the operation of the line quality information generation unit 701 is different from that of the line quality information generation unit 209.
Decoding repetition number counting section 207 counts the number of repetitions of error correction decoding processing in error correction decoding section 205 and outputs the count value to channel quality information generation section 701 as repetition number information. The channel quality measurement unit 208 measures SINR (channel quality) based on the information output from the demodulation unit 204 and outputs information indicating the measured SINR to the channel quality information generation unit 701.
Channel quality information generation section 701 stores the SINR range to which each MCS level is assigned as a table, determines the MCS level required from base station apparatus 100 based on the measured SINR value, and performs error correction decoding processing The MCS level is corrected based on the number of repetitions of. Specifically, the line quality information generation unit 701 corrects the MCS level upward when the number of repetitions of the error correction decoding process is less than a predetermined threshold, and the number of repetitions of the error correction decoding process is equal to or greater than the predetermined threshold. In this case, the MCS level is maintained. Then, channel quality information generation section 701 outputs channel quality information indicating the corrected MCS level to error correction encoding section 251.
Error correction coding section 251 multiplexes channel quality information and ACK / NACK information with transmission data, performs error correction coding on the multiplexed signal, and outputs the result to modulation section 252.
As described above, according to the present embodiment, the base station apparatus sets the optimum MCS level by correcting the MCS level requested by the communication terminal apparatus from the base station apparatus based on the number of repetitions of the error correction decoding process. A modulation scheme and a coding rate can be determined.
In the third embodiment, the MCS level requested of the base station apparatus can be corrected based on the number of repetitions of error correction decoding processing and the allowable delay amount so as to correspond to the second embodiment.
In the fourth embodiment, a case will be described in which the communication terminal apparatus side includes a plurality of tables used when determining the MCS level required for the base station apparatus, and appropriately selects the table based on the number of repetitions of the error correction decoding process. .
The configuration of the communication terminal apparatus according to the present embodiment is the same as that of communication terminal apparatus 700 shown in FIG. However, the line quality information generation unit 701 of the communication terminal device 700 stores a plurality of MCS tables as shown in FIG. Each MCS table shown in FIG. 8 indicates a SINR range to which each MCS level is assigned, and the ranges are different from each other. For example, the SINR range to which MCS2 is assigned in the MCS table 1 is a range that is greater than or equal to TH11 and smaller than TH12. The SINR range that is assigned to the MCS2 in the MCS table 2 is greater than TH21 and less than TH22, also delta 11 dB less than TH11, TH22 also delta 12 dB less than TH12.
The channel quality information generation unit 701 selects an MCS table based on the number of repetitions of the error correction decoding process, and determines the MCS level requested to the base station apparatus 100 based on the selected MCS table based on the measured SINR value. To do. For example, the line quality information generation unit 701 selects the MCS table 3 if the number of repetitions is 1 to 3, selects the MCS table 2 if it is 4 to 6, and selects the MCS table 1 if it is 7 or more. To do.
As described above, according to the present embodiment, the base station apparatus selects the table for determining the MCS level required by the communication terminal apparatus from the base station apparatus based on the number of repetitions of the error correction decoding process. Can select the optimal MCS level and determine the modulation scheme and coding rate.
In the fourth embodiment, the MCS level required for the base station apparatus can be corrected based on the number of repetitions of error correction decoding processing and the allowable delay amount so as to correspond to the second embodiment.
In the fifth embodiment, a case will be described in which a communication terminal apparatus serving as a data transmission destination is assigned in consideration of repetition number information in addition to line quality information. The configurations of the base station apparatus and communication terminal apparatus of the present embodiment are the same as those of base station apparatus 100 of FIG. 1 and communication terminal apparatus 200 of FIG.
Next, a method for allocating communication terminal apparatuses serving as data transmission destinations in scheduling section 151 of base station apparatus 100 according to the present embodiment will be described in detail with reference to the flowchart of FIG.
First, the scheduling unit 151 receives ACK information for each communication terminal apparatus (S901: YES), and the number of repetitions of the error correction decoding process indicated in the repetition number information is greater than a predetermined threshold. When the number is low (S902: YES), the priority of resource allocation is lowered (S903). On the other hand, if the scheduling unit 151 has received NACK information in S901 (S901: NO), or if the number of repetitions of the error correction decoding process indicated in the repetition number information in S902 is greater than or equal to a predetermined threshold value (S902: NO), the priority of resource allocation is maintained (S904).
Then, the scheduling unit 151 performs the processing of S901 to S904 for all the communication terminal devices (S905 to S908), compares the MCS levels among the communication terminal devices in which the priority is maintained, for example, the most MCS A communication terminal device having a high level is assigned as a data transmission destination (S909).
Thus, according to the present embodiment, a communication terminal device with a high margin is assigned as a data transmission destination by lowering the priority of a communication terminal device in which the number of repetitions of error correction decoding processing is less than a predetermined threshold. Can be prevented.
In each of the above embodiments, the case where the communication terminal apparatus transmits information indicating the number of repetitions of the error correction decoding process to the base station apparatus has been described. However, the present invention is not limited to this, and the error correction decoding process is performed. Information indicating the value obtained by normalizing the number of repetitions with the maximum number of repetitions of the decoder of the communication terminal device or information indicating the likelihood when no error is detected may be transmitted to the base station device. .
In each of the above embodiments, downlink resource allocation has been described. However, the present invention is not limited to this, and can also be applied to uplink resource allocation.
The present invention is suitable for use in a base station apparatus and a communication terminal apparatus that perform wireless communication.
The block diagram which shows the structure of the base station apparatus which concerns on Embodiment 1 of this invention. The block diagram which shows the structure of the communication terminal device which concerns on the said embodiment. The sequence diagram which shows the communication order between the base station apparatus and communication terminal device which concern on the said embodiment Flow chart showing a modulation method and coding rate determination method according to the above embodiment Flow chart showing a modulation method and coding rate determination method according to the above embodiment FIG. 7 is a flowchart showing a modulation method and coding rate determination method according to Embodiment 2 of the present invention; The block diagram which shows the structure of the communication terminal device which concerns on Embodiment 3 of this invention. The figure which shows the MCS table memorize | stored in the communication terminal device which concerns on Embodiment 4 of this invention. The flowchart which shows the allocation method of the communication terminal device used as the data transmission destination which concerns on Embodiment 5 of this invention. The figure for demonstrating an example of the selection method of a MCS level
DESCRIPTION OF SYMBOLS 100 Base station apparatus 104 Demodulation part 105 Error correction decoding part 106 ACK / NACK information detection part 107 Channel quality information detection part 108 Decoding repetition number detection part 151 Scheduling part 152 Data retransmission control part 153 Transmission data buffer part 154, 156 Error correction code Conversion unit 155, 157 Modulation unit 200, 700 Communication terminal device 204 Demodulation unit 205 Error correction decoding unit 206 ACK / NACK information generation unit 207 Decoding repetition number counting unit 208 Channel quality measurement unit 209, 701 Channel quality information generation unit 251 Error correction Encoder 252 Modulator
The MCS level requested from each communication terminal device in communication is compared to assign a communication terminal device as a data transmission destination, the MCS level requested from the assigned communication terminal device, and the error detection process in the assigned communication terminal device Scheduling means for determining a modulation scheme and a coding rate based on a result and the number of repetitions of error correction decoding processing performed in the assigned communication terminal device;
A base station apparatus comprising: transmission means for transmitting transmission data addressed to the assigned communication terminal apparatus at a modulation scheme and coding rate determined by the scheduling means.
The scheduling means, when no error is detected in the received signal in the communication terminal apparatus assigned as the data transmission destination and the number of repetitions of the error correction decoding process is less than a predetermined threshold, the MCS requested from the communication terminal apparatus The base station apparatus according to claim 1, wherein the level is corrected upward, and a modulation scheme and a coding rate corresponding to the corrected MCS level are set.
The scheduling means, when no error is detected in the received signal for each communication terminal apparatus in communication and the number of repetitions of the error correction decoding process is less than a predetermined threshold, the MCS level requested from the communication terminal apparatus The base station apparatus according to claim 1 or 2, wherein a communication terminal apparatus as a data transmission destination is assigned by comparing the corrected MCS level with the corrected MCS level.
The scheduling means has an allowable delay amount of a communication terminal apparatus assigned as a data transmission destination equal to or greater than a predetermined threshold, wherein no error is detected in a received signal in the communication terminal apparatus, and the number of repetitions of error correction decoding processing The base station apparatus according to claim 1, wherein when M is less than a predetermined threshold, the MCS level requested from the communication terminal apparatus is upwardly corrected, and a modulation scheme and a coding rate corresponding to the corrected MCS level are set.
The scheduling means is a case where an allowable delay amount of a communication terminal apparatus assigned as a data transmission destination is smaller than a predetermined threshold, and an error is detected in a received signal in the communication terminal apparatus, and error correction decoding processing is repeated. The base station according to claim 1, wherein when the number of times is equal to or greater than a predetermined threshold, the MCS level requested from the communication terminal apparatus is corrected downward, and a modulation scheme and a coding rate corresponding to the corrected MCS level are set. apparatus.
A communication terminal apparatus that communicates with a base station apparatus that allocates a communication terminal apparatus as a data transmission destination by comparing MCS levels requested from each communication terminal apparatus in communication,
Decoding repetition number counting means for counting the number of repetitions of error correction decoding processing on the received signal;
Channel quality measuring means for measuring channel quality of the received signal;
Based on the measured channel quality, the MCS level required for the base station apparatus is determined, the MCS level is corrected based on the number of repetitions of the error correction decoding process, and the channel quality information indicating the corrected MCS level Line quality information generating means for generating
A communication terminal apparatus comprising: transmission means for transmitting a signal including the channel quality information to the base station apparatus.
7. The communication terminal apparatus according to claim 6, wherein the channel quality information generating unit corrects the MCS level upward when no error is detected in the received signal and the number of repetitions of the error correction decoding process is less than a predetermined threshold value. .
The channel quality information generating means stores a plurality of MCS tables indicating a range of channel quality to which each MCS level is assigned, and uses the MCS table used when determining the MCS level based on the number of repetitions of the error correction decoding process. The communication terminal device according to claim 6 to be selected.
Comparing the MCS level requested from each communication terminal device in communication and assigning a communication terminal device as a data transmission destination;
The allocated communication based on the MCS level requested from the allocated communication terminal apparatus, the error detection processing result in the allocated communication terminal apparatus, and the number of repetitions of the error correction decoding process performed in the allocated communication terminal apparatus. Determining a modulation scheme and a coding rate of data to be transmitted to the terminal device.
A resource allocation method in a system in which one base station apparatus and a plurality of communication terminal apparatuses perform wireless communication,
The communication terminal apparatus determines the MCS level required from the base station apparatus based on the channel quality of the received signal, corrects the MCS level based on the number of times of error correction decoding processing for the received signal, and Transmits line quality information indicating a later MCS level to the base station apparatus,
The base station device compares the MCS level indicated in the channel quality information transmitted from each communication terminal device in communication, assigns a data transmission destination communication terminal device, and sets the MCS level of the assigned communication terminal device. A resource allocation method for determining a modulation scheme and a coding rate based on the method.
JP2005016874A 2005-01-25 2005-01-25 Base station apparatus, communication terminal, and resource allocation method Pending JP2006211017A (en)
JP2005016874A JP2006211017A (en) 2005-01-25 2005-01-25 Base station apparatus, communication terminal, and resource allocation method
JP2006211017A true JP2006211017A (en) 2006-08-10
ID=36967417
JP2005016874A Pending JP2006211017A (en) 2005-01-25 2005-01-25 Base station apparatus, communication terminal, and resource allocation method
JP (1) JP2006211017A (en)
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