WO2004091117A1 - 基地局装置および適応変調方法 - Google Patents
基地局装置および適応変調方法 Download PDFInfo
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- WO2004091117A1 WO2004091117A1 PCT/JP2004/002956 JP2004002956W WO2004091117A1 WO 2004091117 A1 WO2004091117 A1 WO 2004091117A1 JP 2004002956 W JP2004002956 W JP 2004002956W WO 2004091117 A1 WO2004091117 A1 WO 2004091117A1
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- WIPO (PCT)
- Prior art keywords
- quality information
- line quality
- modulation
- base station
- received
- Prior art date
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Classifications
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
- H04L1/0015—Systems modifying transmission characteristics according to link quality, e.g. power backoff characterised by the adaptation strategy
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
- H04L1/0002—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the transmission rate
- H04L1/0003—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the transmission rate by switching between different modulation schemes
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
- H04L1/0009—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the channel coding
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0008—Modulated-carrier systems arrangements for allowing a transmitter or receiver to use more than one type of modulation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
- H04W88/08—Access point devices
Definitions
- the present invention relates to a base station apparatus and an adaptive modulation method used for a wireless communication system that performs downlink high-speed bucket transmission.
- an adaptive modulation scheme is used for bucket transmission from a base station apparatus in order to transmit a bucket at an optimum transmission rate according to a downlink propagation environment.
- a communication terminal apparatus measures downlink quality (line quality) and transmits line quality information indicating the measured line quality to a base station apparatus as a communication partner.
- the base station device achieves an optimal transmission rate by adaptively switching a modulation and coding scheme (MCS) according to the channel quality information transmitted from the communication terminal device (for example, See Japanese Patent Application Laid-Open No. 2002-44416).
- MCS modulation and coding scheme
- a delay time always occurs between the communication terminal device and the base station device.
- This delay time generally includes (1) terminal processing delay time, (2) propagation delay time, and (3) base station processing delay time.
- the terminal processing delay time is the time from when the communication terminal device measures the line quality to when it transmits the line quality information.
- the propagation delay time is the time from when the communication terminal device transmits the line quality information to when the base station device receives the line quality information.
- the base station processing delay time is defined as the bucket transmission using a modulation and coding method based on the channel quality information after the base station device receives the channel quality information. It is time to do.
- the control of the adaptive modulation scheme may react excessively to the fluctuation of the line quality. is there. That is, even when the channel quality changes are instantaneous, the modulation and coding method may be switched based on the channel quality information indicating the instantaneous channel quality. Therefore, there is a high possibility that an appropriate modulation and coding scheme will not be set for the line quality at the time of transmitting a packet, and there is a certain limit in improving the throughput of the wireless communication system. Disclosure of the invention
- An object of the present invention is to provide a base station apparatus and an adaptive modulation method that can always transmit a packet using a modulation and coding method that is appropriate for the line quality and can improve the throughput of a wireless communication system. It is to provide.
- a base station apparatus sets a receiving unit for receiving line quality information transmitted from a communication terminal apparatus, and a modulation and coding scheme based on a plurality of received line quality information. And setting means.
- an adaptive modulation method includes a receiving step of receiving line quality information transmitted from a communication terminal apparatus, and a setting for setting a modulation and coding scheme based on the received plurality of pieces of line quality information. And a step.
- FIG. 1 is a block diagram illustrating a configuration of a base station apparatus according to Embodiment 1 of the present invention.
- FIG. 2 is a block diagram of a communication terminal apparatus that communicates with the base station apparatus according to Embodiment 1 of the present invention. Block diagram showing an example,
- FIG. 3 is a diagram for explaining operations of the base station device and the communication terminal device according to Embodiment 1 of the present invention,
- FIG. 4 is a block diagram illustrating a configuration of a base station apparatus according to Embodiment 2 of the present invention.
- FIG. 5 is a diagram illustrating operations of a base station apparatus and a communication terminal apparatus according to Embodiment 2 of the present invention. The figure of the
- FIG. 6 is a diagram for explaining line quality information averaged in the base station apparatus according to Embodiment 2 of the present invention.
- FIG. 7 is a block diagram illustrating a configuration of a base station apparatus according to Embodiment 3 of the present invention
- FIG. 8 is a block diagram illustrating a configuration of a base station apparatus according to Embodiment 4 of the present invention
- FIG. 10 is a block diagram showing the configuration of the base station apparatus according to Embodiment 6 of the present invention.
- the gist of the present invention is to set a modulation and coding scheme based on a plurality of pieces of channel quality information transmitted from a communication terminal apparatus.
- FIG. 1 is a block diagram showing a configuration of a base station apparatus according to Embodiment 1 of the present invention.
- the base station apparatus 100 shown in FIG. 1 includes a reception antenna 102, a radio reception unit 104, a demodulation unit 106, a channel quality information storage unit 108, a determination unit 110, an MCS determination unit 1 It has 12 adaptive modulation sections 114 radio transmission sections 116 and transmission antennas 118.
- Radio reception section 104 receives a radio transmission signal including channel quality information via reception antenna 102. It also down-converts radio transmission signals from RF (Radio Frequency) signals to baseband signals and analyzes analog signals. A predetermined radio reception process including a digital-to-digital conversion is performed.
- RF Radio Frequency
- the line quality information is information (for example, CQI: Channel Quality Indicator) continuously transmitted from the communication terminal apparatus to the communicating base station apparatus 100, and the downlink quality ( This is information indicating the result of measuring the (line quality). More specifically, a modulation and coding scheme required for the base station apparatus 100 to keep the transmission rate on the downlink and the reception error rate at the communication terminal apparatus within a desired range (for example, the modulation scheme and coding Rate, etc.). The generation and transmission of the line quality information in the communication terminal will be described later.
- CQI Channel Quality Indicator
- the demodulation unit 106 demodulates the radio transmission signal subjected to the radio reception processing. Also, it extracts the line quality information from the radio transmission signal.
- the combination of the wireless reception unit 104 and the demodulation unit 106 has a role as a reception unit that receives the channel quality information transmitted from the communication terminal device.
- the line quality information storage unit 108 stores each line quality information from the demodulation unit 106.
- the determination unit 110 stores a prescribed number N (N is an integer of 2 or more) in advance. Further, it is determined whether or not the specified number N of continuously received line quality information among the plurality of line quality information stored by the line quality information storage unit 108 is the same.
- determining section 110 first determines which of the value indicated in the line quality information received at a certain point in time and the value indicated in the line quality information received after a certain point in time, Judge whether the line quality is good. For example, it is judged that the reception quality of the line quality information with the larger multi-level number of the modulation method corresponding to the indicated value is better, and the error correction capability is lower (the code redundancy is lower). It is determined that the reception quality of the line quality information indicating the value to be performed is good, and if the indicated value is the same, the line quality information is excluded from the target of the determination. Then, the determination unit 110 determines whether or not the determination result is the same for N consecutive times.
- MCS determination section 112 stores in advance a table indicating the correspondence between the value of the channel quality information and the modulation and coding scheme to be output. Also, the modulation and coding scheme is determined according to the result of the determination by determination section 110. More specifically, when the received line quality information is the same for N consecutive times, the modulation and coding scheme is determined. Then, the modulation coding method corresponding to the value of the channel quality information is output. On the other hand, if the received line quality information is not the same N times consecutively, no modulation coding scheme is determined. Then, it outputs the same modulation and coding scheme as the previously output modulation and coding scheme.
- the combination of the channel quality information storage unit 108, the determination unit 110, and the MCS determination unit 112 serves as a setting unit that sets the modulation and coding scheme based on the received multiple pieces of channel quality information. Having. For example, as a result of the determination by the determination unit 110, if the line quality information is the same for N consecutive times, the modulation and coding method is determined, so the setting of the modulation and coding method is changed. . On the other hand, if the result of the determination by the determination unit 110 is that N times does not indicate that the same channel quality information is the same, the modulation and coding scheme is not determined, so the modulation and coding scheme setting is changed Not done.
- Adaptive modulation section 114 performs predetermined adaptive modulation processing, including error correction coding and modulation, on transmission data to be transmitted to the communication terminal apparatus, using the set modulation and coding scheme.
- the radio transmission section 116 performs predetermined radio transmission including digital-to-analog conversion of transmission data (bucket) and pilot (PL) signals that have undergone adaptive modulation processing, and an upcoming from a baseband signal to an RF signal. Perform the processing.
- a signal subjected to wireless transmission processing (wireless transmission signal) is transmitted via the transmission antenna 118.
- FIG. 2 is a block diagram showing a configuration of a communication terminal device that communicates with base station device 100.
- Communication terminal apparatus 150 shown in FIG. 2 performs a predetermined radio reception process on a radio transmission signal from base station apparatus 100 received via reception antenna 152 and reception antenna 152 A radio receiving unit 154; an adaptive demodulation unit 156 for performing a predetermined adaptive demodulation process on transmission data in a radio transmission signal using the modulation and coding scheme determined in the base station apparatus 100; PL signal demodulation unit 158 that demodulates the pilot signal in the wireless transmission signal, and line quality measurement unit 16 that measures the line quality (for example, BER: Bit Error Rate) using the demodulation result of the pilot signal 0, a line quality information generation unit 162 that generates line quality information based on the measured line quality, a modulation unit 164 that modulates the line quality information, and A wireless transmission section 16 6 for performing predetermined wireless transmission processing; And a Na 1 6 8.
- BER Bit Error Rate
- FIG. 3 is a diagram for explaining operations of base station apparatus 100 and communication terminal apparatus 150.
- communication terminal apparatus 150 demodulates a pilot signal in PL signal demodulation section 158.
- the line quality measuring section 160 measures the line quality using the demodulation result of the pilot signal.
- the line quality information generating section 162 generates line quality information based on the line quality measured by the line quality measuring section 160. More specifically, using the above channel quality, the error rate (reception error rate) and the downlink transmission rate in the adaptive demodulation section 156 of the communication terminal apparatus 150 are set within a desired range. Therefore, the modulation and coding scheme required for the base station apparatus 100 is selected. Then, a value corresponding to the selected modulation and coding scheme is selected as the channel quality information with reference to a table indicating the correspondence between the modulation and coding scheme and the value to be transmitted as the channel quality information. Outputs the encoding method. In this way, the setting of the modulation and coding scheme is performed by the above-described processing in determination section 110 and MCS determination section 112.
- adaptive modulation section 114 performs predetermined adaptive modulation processing on transmission data to be transmitted to communication terminal apparatus 150 using the set modulation and coding scheme.
- radio transmission section 116 performs predetermined radio transmission processing on transmission data (packets), pilot signals, and the like that have been adaptively modulated by adaptive modulation section 114.
- the radio-transmitted signal is transmitted via the transmission antenna 118.
- the radio transmission signal transmitted from base station apparatus 100 is received by communication terminal apparatus 150.
- the above operation is repeated as long as communication between base station apparatus 100 and communication terminal apparatus 150 continues.
- the modulation and coding method is determined according to the determination result. For example, if the N pieces of channel quality information are the same, the modulation and coding scheme is determined. If the N pieces of the channel quality information are not the same, the modulation and coding scheme is not determined. Therefore, it is possible to set the modulation and coding method after excluding instantaneous line quality fluctuations in a period shorter than the period in which N pieces of line quality information are received, and to set only the regular line quality fluctuations. It is possible to set a modulation and coding method according to the setting.
- FIG. 4 is a block diagram showing a configuration of a base station apparatus according to Embodiment 2 of the present invention.
- the base station apparatus according to Embodiment 2 has the same basic configuration as base station apparatus 100 described in Embodiment 1, and the same components are denoted by the same reference numerals. And description thereof is omitted.
- a feature of the present embodiment is that the base station apparatus averages a plurality of pieces of line quality information from the communication terminal apparatus for each position of the communication terminal apparatus at the time when each piece of the line quality information is transmitted, and obtains an averaged link. Determining the modulation and coding scheme according to the quality information 7 Then, a predetermined modulating process is performed on the channel quality information in the modulating section 164. Then, radio transmission section 166 performs predetermined radio transmission processing on the channel quality information modulated by modulation section 164, and transmits the radio quality-processed channel quality information via transmission antenna 168. I do.
- radio reception section 104 receives a radio transmission signal including channel quality information transmitted from communication terminal apparatus 150 via reception antenna 102. Then, predetermined radio reception processing is performed on the radio transmission signal. Then, the demodulation unit 106 performs a predetermined demodulation process on the radio transmission signal subjected to the radio reception process by the radio reception unit 104. Also, it extracts channel quality information from the demodulated radio transmission signal.
- the line quality information storage unit 108 stores the line quality information (current line quality information) extracted by the demodulation unit 106.
- determination section 110 determines whether or not the received line quality information is the same N times consecutively among a plurality of pieces of line quality information stored in line quality information storage section 108. Then, when these N pieces of line quality information are the same, one of the N pieces of line quality information is output as the current determination result. Out of the N pieces of line quality information, the output line quality information is, for example, the worst line quality among the N pieces of line quality information, or corresponds to the average value of the N pieces of line quality information. Line quality information. On the other hand, if the N pieces of line quality information are not the same, the previously output determination result is output as the current determination result. That is, if the line quality information is not the same continuously, the line quality indicated in the line quality information is regarded as instantaneous and used in the processing in the MCS determining unit 112. Exclude from the target.
- MCS determining section 112 determines the modulation and coding scheme according to the determination result output from determining section 110. More specifically, referring to a table indicating the correspondence between the value indicated in the line quality information and the modulation and coding method to be output, the judgment unit 110 outputs the line quality information output as a determination result. Modulation symbol corresponding to the value You.
- the base station apparatus 200 shown in FIG. 4 is different from the base station apparatus 100 shown in FIG. 1 in that the judgment unit 110 and the MCS determination unit 112 are deleted, and the information acquisition unit 202
- the configuration is such that a quality information averaging unit 204, a channel quality information search unit 206 and an MCS determination unit 208 are provided.
- the information acquisition unit 202 acquires position information indicating the position of the communication terminal device when the communication terminal device transmitted the channel quality information to the base station device 200. Further, the communication terminal device obtains date and time information indicating the time and date when the communication terminal device transmitted the line quality information to the base station device 200. Further, based on the statement indicated in the date and time information, day of the week information indicating the day of the week when the communication terminal apparatus transmitted the line quality information to the base station apparatus 200 may be acquired.
- the line quality information averaging unit 204 stores the plurality of line quality information stored by the line quality information storage unit 108 for each position indicated in the position information acquired by the information acquisition unit 202. Average. Also, it stores the line quality information averaged for each position.
- the line quality information averaging unit 204 converts the plurality of line quality information accumulated by the line quality information accumulation unit 108 into the position information acquired by the information acquisition unit 202. Averaging may be performed for each combination of the indicated position and the time indicated in the date and time information. In this case, the line quality information averaged for each combination of location and time is stored.
- the line quality information averaging unit 204 indicates the plurality of line quality information accumulated by the line quality information accumulation unit 108 in the position information acquired by the information acquisition unit 202. Averaging may be performed for each combination of the specified position and the date indicated in the date and time information. In this case, the line quality information averaged for each combination of position and date is stored.
- the line quality information averaging unit 204 is accumulated by the line quality information accumulating unit 108.
- a plurality of line quality information may be averaged for each combination of the position indicated by the position information and the day of the week indicated by the day of the week information. In this case, the line quality information averaged for each combination of location days is stored.
- the channel quality information averaging unit 204 may execute an operation that combines the above averaging operation. That is, the channel quality information averaging unit 204 executes an operation of averaging a plurality of pieces of channel quality information accumulated by the channel quality information accumulation unit 108 at least for each position.
- the channel quality information search unit 206 receives the current line quality information transmitted from the communication terminal device to the base station device 200 based on the position information from the information acquisition unit 202. Is retrieved from the line quality information averaged for each position by the line quality information averaging unit 204.
- the line quality information search unit 206 receives the time information transmitted from the communication terminal device to the base station device 200.
- the line quality information corresponding to the combination of the position and date when the line quality information was transmitted is averaged by the line quality information averaging unit 204 for each combination of position and date. You may search from.
- the line quality information search unit 206 determines the current time when the communication terminal device transmitted to the base station device 200.
- the line quality information corresponding to the combination of position and time when the line quality information was transmitted is averaged by the line quality information averaging unit 204 for each combination of position and time. You may search from.
- the line quality information retrieving unit 206 determines the current time when the communication terminal device transmitted to the base station device 200.
- the line quality information corresponding to the combination of the position and the day of the week when the line quality information was transmitted is averaged by the line quality information averaging unit 204 for each position / day combination. You may search from.
- the MCS determination unit 208 determines the value of the channel quality information and the modulation and coding scheme to be output. Are stored in advance.
- the modulation and coding method to be output is determined with reference to the line quality information retrieved in 206. That is, a modulation and coding method corresponding to the value of the channel quality information is output.
- the combination of the line quality information storage unit 108, the information acquisition unit 202, the line quality information averaging unit 204, the line quality information search unit 206, and the MCS determination unit 208 It has a role as a setting unit for setting the modulation and coding scheme based on the plurality of pieces of channel quality information thus set.
- FIG. 5 is a diagram for explaining operations of the base station apparatus 200 and the communication terminal apparatus 150.
- the operation of communication terminal apparatus 150 is the same as that described in the first embodiment. Therefore, the description is omitted.
- radio reception section 104 receives a radio transmission signal including channel quality information transmitted from communication terminal apparatus 150 via reception antenna 102. Then, predetermined radio reception processing is performed on the radio transmission signal.
- the demodulation unit 106 performs a predetermined demodulation process on the radio transmission signal subjected to the radio reception process by the radio reception unit 104. Also, it extracts channel quality information from the demodulated radio transmission signal.
- the line quality information storage unit 108 stores the line quality information (current line quality information) extracted by the demodulation unit 106.
- the information acquisition unit 202 acquires the position information and the date and time information.
- the acquisition of the position information and the date and time information by the information acquisition unit 202 may be performed simultaneously with the reception of the corresponding line quality information.
- the line quality information averaging unit 204 averages the plurality of pieces of line quality information accumulated by the line quality information storage unit 108 at least for each position indicated in the position information.
- FIG. 6 is a diagram for explaining the averaged line quality information.
- the base station apparatus 200 is installed at an intermediate position between the city area, the coast, and the station or the railway.
- the urban area is a densely populated area with poor propagation environment all day. Therefore, the line quality information transmitted from the communication terminal apparatus 150a located in the city area to the base station apparatus 200 often indicates that the line quality is relatively low. Therefore, the channel quality information obtained by averaging has a value indicating a low channel quality.
- the coast is an area with good propagation environment. Therefore, the line quality information transmitted by the communication terminal device 150b located on the coast to the base station device 200 often indicates that the line quality is relatively high. Therefore, the line quality information obtained by averaging has a value indicating high line quality.
- the vicinity of a station or a track is an area where the propagation environment changes over time. Therefore, the line quality information transmitted by the communication terminal device 150c located near the station or the track to the base station device 200 indicates that the line quality is relatively high and that the line quality information is relatively low. Varies depending on the time of transmission. More specifically, in the rush hour period, the line quality information obtained by averaging has a value indicating a low line quality. On the other hand, outside the rush hour, the line quality information obtained by averaging has a value indicating high line quality.
- the line quality information search unit 206 the line quality information corresponding to at least the position at the time when the communication terminal apparatus 150 transmitted the current line quality information is sent to the line quality information averaging unit 204. Therefore, it searches from the line quality information averaged for each location. Then, the 1 ⁇ 3 determining unit 208 refers to the line quality information searched by the line quality information searching unit 206 to determine the modulation and coding scheme to be output. As described above, the information coding unit 202, the channel quality information averaging unit 204, the channel quality information searching unit 206, and the MCS determining unit 208 set the modulation and coding scheme by the above-described processing. I do.
- adaptive modulation section 114 performs predetermined adaptive modulation processing on transmission data to be transmitted to communication terminal apparatus 150 using the set modulation and coding scheme.
- radio transmission section 116 performs predetermined radio transmission processing on transmission data (packets), pilot signals, and the like that have been adaptively modulated by adaptive modulation section 114.
- the radio-transmitted signal is transmitted via the transmission antenna 118.
- the radio transmission signal transmitted from base station apparatus 200 is received by communication terminal apparatus 150.
- the above operation is repeated as long as communication between the base station apparatus 200 and the communication terminal apparatus 150 continues.
- a plurality of line quality information is averaged for each position of the communication terminal device when each of the plurality of received line quality information is transmitted, and the averaged line quality A modulation coding scheme is determined according to the information. That is, the modulation and coding method is determined according to the channel quality information derived by the statistical method. Therefore, it is possible to set the modulation and coding method after excluding the instantaneous line quality indicated in each of the received line quality information, and to obtain a statistically optimum modulation for the position of the communication terminal.
- the encoding method can be set, and the transmission rate can be stabilized at a statistically optimum level.
- FIG. 7 is a block diagram showing a configuration of a base station apparatus according to Embodiment 3 of the present invention.
- the base station apparatus according to Embodiment 3 has the same basic configuration as base station apparatus 100 described in Embodiment 1, and the same constituent elements are denoted by the same reference numerals. The description is omitted.
- the feature of this embodiment is that the base station apparatus determines whether or not a predetermined number of pieces of line quality information continuously received among a plurality of pieces of line quality information from One of the line quality information averaged for each position of the communication terminal device when the information was transmitted is selected according to the result of comparing the accumulated amount of the line quality information with a predetermined threshold value, and is selected. The other is to determine the modulation and coding method according to the other method.
- the base station apparatus 300 shown in FIG. 7 is different from the base station apparatus 100 shown in FIG. 1 in that the information acquisition unit 202 of the base station apparatus 200 shown in FIG. 4 (Embodiment 2)
- a circuit quality information averaging unit 204 and a circuit quality information search unit 206 are provided, a storage amount comparison unit 302 and a selection unit 304 are added, and instead of the MCS determination unit 112
- the MCS deciding unit 306 is provided in the configuration.
- the accumulation amount comparison unit 302 detects the accumulation amount of the line quality information accumulated by the line quality information accumulation unit 108. Then, the accumulated amount is compared with a predetermined threshold value stored in advance. Then, the result of the comparison is output.
- the selection unit 304 obtains the judgment result of the judgment unit 110 and the line quality information averaged by the line quality information averaging unit 204 according to the result of the comparison by the accumulation amount comparison unit 302. One of the line quality information searched by the line quality information search unit 206 is selected.
- the determination result is selected.
- the searched line quality information is selected from the averaged line quality information.
- the MCS determining unit 303 stores in advance a table indicating the correspondence between the value of the channel quality information and the modulation and coding scheme to be output. Also, one of the line quality information output by the determination unit 110 as the determination result and the line quality information searched by the line quality information search unit 206 selected by the selection unit 304. , Determine the modulation and coding scheme to be output. That is, a modulation and coding method corresponding to the value of the channel quality information is output.
- the line quality information storage unit 108, the determination unit 110, the information acquisition unit 202, the line quality information averaging unit 204, the line quality information search unit 206, and the storage amount comparison unit 302 The combination of the selection unit 304 and the MCS determination unit 303 has a role as a setting unit that sets a modulation and coding scheme based on the received plurality of channel quality information.
- the present embodiment it is determined whether or not the specified number N of continuously received line quality information among the plurality of received line quality information of the plurality of line quality is the same. Either the result or the line quality information averaged for each location of the communication terminal device when each of the multiple pieces of line quality information was transmitted, and the result of comparing the accumulated amount of line quality information with the threshold.
- the modulation and coding scheme is determined according to the selected one.
- the modulation and coding method can be determined according to the result of the determination, and when the accumulated amount is equal to or more than the threshold value, according to the averaged line quality information, Even when the amount of stored circuit quality information is insufficient, packets can always be transmitted using the modulation and coding method appropriate for the circuit quality, and the throughput of the wireless communication system can be improved.
- FIG. 8 is a block diagram showing a configuration of a base station apparatus according to Embodiment 4 of the present invention.
- the base station apparatus according to Embodiment 4 has the same basic configuration as base station apparatus 100 described in Embodiment 1, and the same constituent elements are denoted by the same reference numerals. The description is omitted.
- the feature of this embodiment is that the base station apparatus determines whether or not a predetermined number of pieces of line quality information continuously received among a plurality of pieces of line quality information from One of the line quality information averaged for each position of the communication terminal device when the information was transmitted is selected according to the result of comparing the reception error rate of the line quality information with a predetermined threshold, It is to determine the modulation and coding method according to the selected one.
- the base station apparatus 400 shown in FIG. 8 is different from the base station apparatus 100 shown in FIG. 1 in that the information acquisition unit 202 of the base station apparatus 200 shown in FIG.
- a channel quality information averaging unit 204 and a channel quality information search unit 206 are provided, an error rate comparison unit 402 and a selection unit 404 are added, and instead of the MCS determination unit 112 In this configuration, the MCS determination section 303 of the base station apparatus 300 shown in FIG.
- Error rate comparing section 402 detects the reception error rate (eg, B ER) of the channel quality information demodulated by demodulating section 106. Then, the detected reception error rate is compared with a predetermined threshold value stored in advance. Then, the result of the comparison is output.
- the reception error rate eg, B ER
- the selection unit 404 determines the judgment unit according to the result of the comparison by the error rate comparison unit 402.
- One of the line quality information searched for by the line quality information search unit 206 is selected from among the determination results obtained by 110 and the line quality information averaged by the line quality information averaging unit 204. .
- the searched line quality information is selected from the averaged line quality information.
- the judgment result is selected.
- Line quality information storage unit 108 judgment unit 110, information acquisition unit 202, line quality information averaging unit 204, line quality information search unit 206, error rate comparison unit 402, selection
- the combination of the selector 404 and the MCS determiner 306 has a role as a setting unit that sets the modulation and coding scheme based on the received plurality of pieces of circuit quality information.
- the modulation and coding scheme can be determined according to the determination result when the reception error rate is less than the threshold, and according to the averaged line quality information when the reception error rate is equal to or more than the threshold. Also, even when the reliability of the received line quality information is low, packets can always be transmitted using a modulation and coding method appropriate for the line quality, and the throughput of the wireless communication system can be improved.
- FIG. 9 is a block diagram showing a configuration of a base station apparatus according to Embodiment 5 of the present invention.
- the base station apparatus according to Embodiment 5 has the same basic configuration as base station apparatus 100 described in Embodiment 1, and the same components are denoted by the same reference numerals. The description is omitted.
- a feature of the present embodiment is that the base station apparatus compares the line quality information received after a predetermined time among the plurality of pieces of line quality information from the communication terminal apparatus with the line quality information received at the predetermined time. According to the result of the comparison, the predetermined number in the determination as to whether or not the predetermined number of continuously received line quality information is the same is changed.
- the base station apparatus 500 shown in FIG. 9 is different from the base station apparatus 100 shown in FIG. 1 in that a determining section 502 is provided instead of the determining section 110, and a channel quality information comparing section 50 4 and a specified number changing unit 506 are added.
- the determination unit 502 stores in advance a specified number N a (N a is an integer of 2 or more) and a specified number N b (N b is an integer of 3 or more, N b> N a) in advance. Also, of the plurality of line quality information stored by the line quality information storage unit 108, the same number of line quality information of the specified number Na or the specified number Nb continuously transmitted from the communication terminal device is the same. Is determined.
- determining section 502 first determines which of the value indicated in the line quality information received at a certain point in time and the value indicated in the line quality information received after a certain point in time, Judge whether the line quality is good. For example, if the value shown It is judged that the reception quality of the line quality information with the larger multi-level number of the corresponding modulation method is good, and the error correction capability is low (the code redundancy is low). The line quality that indicates the coding rate and the value corresponding to the code rate If the reception quality of the information is judged to be good and the indicated values are the same, the line quality information is excluded from the judgment. Then, the determination unit 502 determines whether or not the result of the determination is the same for Na times or Nb times.
- the prescribed number Na and the prescribed number Nb used in the judgment are switched.
- Channel quality information comparing section 504 compares the channel quality information transmitted after the predetermined time with the channel quality information transmitted at the predetermined time. Then, the result is output.
- the specified number changing unit 506 changes the specified number Na and the specified number Nb used in the determination unit 502 based on the result of the comparison by the line quality information comparing unit 504. More specifically, a comparison is made that the line quality indicated in the line quality information transmitted after the predetermined time is better than the line quality indicated in the line quality information transmitted at the predetermined time. If the result indicates, the determination unit 502 outputs an instruction to use the specified number Nb. On the other hand, the comparison result indicates that the line quality indicated in the line quality information transmitted after the predetermined time is worse than the line quality indicated in the line quality information transmitted at the predetermined time. If so, an instruction to make the determination unit 502 use the specified number Na is output.
- the combination of the line quality information storage unit 108, the judgment unit 502, the line quality information comparison unit 504, the specified number change unit 506, and the MCS determination unit 112 It has a role as a setting unit that sets the modulation and coding scheme based on the.
- the line quality information received after a predetermined time is compared with the line quality information received at the predetermined time.
- the prescribed number Na and the prescribed number Change the number N b.
- the specified number Nb is used, and the line quality information indicated in the line quality information after the predetermined point in time is used.
- a specified number N a smaller than the specified number N b can be used. Therefore, it is possible to quickly follow a change in the line quality when the line quality is deteriorated as compared with a case where the line quality is improved, and it is possible to perform so-called fail-safe control.
- FIG. 10 is a block diagram showing a configuration of a base station apparatus according to Embodiment 6 of the present invention.
- the base station apparatus according to Embodiment 6 has the same basic configuration as base station apparatus 100 described in Embodiment 1, and the same components are denoted by the same reference numerals. And the description is omitted.
- the feature of the present embodiment is that the base station apparatus compares a variation amount of two pieces of line quality information continuously received among a plurality of pieces of line quality information from the communication terminal apparatus with a predetermined threshold value, and according to the comparison result, This is to determine the modulation and coding method.
- the base station apparatus 600 shown in FIG. 10 is different from the base station apparatus 100 shown in FIG.
- the configuration is such that an MCS determination unit 604 is provided in place of the determination unit 112.
- the fluctuation amount comparison unit 602 is configured to calculate the difference between the previous line quality information received from the communication terminal device and the current line quality information among the line quality information stored by the line quality information storage unit 108. That is, the variation is compared with a predetermined threshold value stored in advance. Then, the result of the comparison is output.
- MCS determining section 604 stores in advance a table indicating the correspondence between the value of the channel quality information and the modulation and coding scheme to be output. Further, the modulation and coding method is determined according to the result of the comparison by the variation amount comparing section 602. More specifically, if the amount of fluctuation is equal to or greater than the threshold value, the modulation coding method is not determined based on the current channel quality information. And the same modulation as the modulation coding method output last time Outputs the encoding method. On the other hand, if the variation is less than the threshold, the modulation and coding method is determined based on the current line quality information. Then, it outputs the modulation and coding method corresponding to the value of the current line quality information.
- the combination of the line quality information storage unit 108, the fluctuation amount comparison unit 602, and the MCS determination unit 604 serves as a setting unit that sets the modulation and coding method based on the received plurality of line quality information. Has a role.
- the base station apparatus and the adaptive modulation method of the present invention have the effect of improving the throughput of a radio communication system by transmitting a bucket using a modulation and coding method that is always appropriate for the channel quality. This is useful in wireless communication systems that perform
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- Engineering & Computer Science (AREA)
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- Computer Networks & Wireless Communication (AREA)
- Quality & Reliability (AREA)
- Mobile Radio Communication Systems (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/517,006 US20050255807A1 (en) | 2003-04-08 | 2004-03-08 | Base station device and adaptive modulation method |
EP04718422A EP1515460A1 (en) | 2003-04-08 | 2004-03-08 | Base station device and adaptive modulation method |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP2003-104405 | 2003-04-08 | ||
JP2003104405A JP2004312458A (ja) | 2003-04-08 | 2003-04-08 | 基地局装置および適応変調方法 |
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WO2004091117A1 true WO2004091117A1 (ja) | 2004-10-21 |
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PCT/JP2004/002956 WO2004091117A1 (ja) | 2003-04-08 | 2004-03-08 | 基地局装置および適応変調方法 |
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US (1) | US20050255807A1 (ja) |
EP (1) | EP1515460A1 (ja) |
JP (1) | JP2004312458A (ja) |
CN (1) | CN1698292A (ja) |
WO (1) | WO2004091117A1 (ja) |
Cited By (1)
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CN101651515B (zh) * | 2008-08-15 | 2012-12-12 | 电信科学技术研究院 | 自适应调制和编码方法、***及装置 |
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JP4069034B2 (ja) * | 2003-07-31 | 2008-03-26 | 松下電器産業株式会社 | 無線送信装置、無線受信装置、無線通信システム、無線送信方法及び無線受信方法 |
JP4552732B2 (ja) * | 2005-03-30 | 2010-09-29 | 日本電気株式会社 | 無線受信装置及び送受信モードの決定方法 |
US20090061767A1 (en) * | 2005-03-30 | 2009-03-05 | Matsushita Electric Industrial Co., Ltd. | Wireless communication apparatus and wireless communication method |
JP4615353B2 (ja) * | 2005-04-14 | 2011-01-19 | 三菱電機株式会社 | 基地局装置 |
KR20080045134A (ko) | 2005-08-18 | 2008-05-22 | 마츠시타 덴끼 산교 가부시키가이샤 | 무선 통신 단말 장치 및 cqi 선택 방법 |
KR101365751B1 (ko) * | 2005-12-08 | 2014-02-20 | 한국전자통신연구원 | 이동 통신 시스템에서 채널 품질 정보 관리 방법, 상기채널 품질 정보 전송을 위한 채널 할당 방법 그리고 그장치 |
CN100417242C (zh) * | 2006-01-13 | 2008-09-03 | 华为技术有限公司 | 一种确定调制编码方式的方法 |
JP4732935B2 (ja) * | 2006-03-20 | 2011-07-27 | 株式会社エヌ・ティ・ティ・ドコモ | 基地局、移動局及び方法 |
EP2103025B1 (en) * | 2006-12-14 | 2013-03-27 | Thomson Licensing | Arq with adaptive modulation for communication systems |
KR20090099553A (ko) | 2006-12-14 | 2009-09-22 | 톰슨 라이센싱 | 통신 시스템에서의 레이트리스 인코딩 |
EP2103024B1 (en) * | 2006-12-14 | 2018-04-25 | Thomson Licensing | Modulation indication method for communication systems |
WO2008073102A1 (en) * | 2006-12-14 | 2008-06-19 | Thomson Licensing | Concatenated coding/decoding in communication systems |
EP2103023B1 (en) * | 2006-12-14 | 2015-04-15 | Thomson Licensing | Rateless codes decoding method for communication systems |
US8098601B2 (en) * | 2007-03-23 | 2012-01-17 | Research In Motion Limited | Slow adaptation of modulation and coding for packet transmission |
CN101615974B (zh) * | 2008-06-27 | 2012-11-14 | 富士通株式会社 | 用于通信***的调制编码集合的设计方法和装置 |
JP2010056734A (ja) * | 2008-08-27 | 2010-03-11 | Pioneer Electronic Corp | コンテンツ再生装置及びコンテンツ再生方法 |
US8787177B2 (en) * | 2008-11-03 | 2014-07-22 | Apple Inc. | Techniques for radio link problem and recovery detection in a wireless communication system |
JP5195920B2 (ja) * | 2008-12-17 | 2013-05-15 | 日本電気株式会社 | 無線通信システムおよび無線装置 |
US20170026976A1 (en) * | 2015-07-20 | 2017-01-26 | Qualcomm Incorporated | Flexible coding schemes |
CN106358313A (zh) * | 2016-08-30 | 2017-01-25 | 中兴长天信息技术(南昌)有限公司 | 一种用于物联网的lora无线通信网络信道接入控制方法 |
CN113574927B (zh) * | 2019-03-29 | 2024-04-09 | 本田技研工业株式会社 | 控制装置、控制方法、以及存储介质 |
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- 2004-03-08 EP EP04718422A patent/EP1515460A1/en not_active Withdrawn
- 2004-03-08 US US10/517,006 patent/US20050255807A1/en not_active Abandoned
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Also Published As
Publication number | Publication date |
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US20050255807A1 (en) | 2005-11-17 |
CN1698292A (zh) | 2005-11-16 |
JP2004312458A (ja) | 2004-11-04 |
EP1515460A1 (en) | 2005-03-16 |
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